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Gene Difference May Explain SARS Epidemic
HONG KONG (Reuters) - Scientists in Hong Kong have discovered people
with a certain pattern of genes have a much higher risk of getting SARS, a finding that could help diagnose and prevent the spread of the deadly disease. A study of SARS patients in Hong Kong showed individuals with a pattern known as HLA-B*0703 were four times as likely to contract the respiratory disease, said Paul Chan, an associate professor in microbiology at the Chinese University of Hong Kong. Those with a pattern labeled HLA-DRBI*0301 had a much lower risk, indicating genetic make-up may play a key role in determining if some people are more susceptible to the virus than others. "Our findings from this study will help us more accurately diagnose the disease and design effective prevention programs," Chan said on Thursday. "For example, we could test an unproven vaccine or prevention method on the high-risk group. Hospitals may also consider sending only low-risk health workers to take care of SARS patients," he said. The Hong Kong researchers examined the blood samples of 90 SARS patients and studied the patterns of their human leucocyte antigen (HLA) genes, which influence the activity of cells that are responsible for the immune system's response during infections. The results were then compared with samples from people who did not have Severe Acute Respiratory Syndrome. More than 1,700 people in Hong Kong contracted SARS last year after it spread from southern China and nearly 300 of them died. Worldwide, more than 8,000 people were infected and more than 800 died. China recently announced its first confirmed SARS case in months and two suspected SARS cases in the southern city of Guangzhou. The government is still awaiting definitive test results on the suspected cases. Another Hong Kong scientist said on Wednesday it was a new variety of the SARS virus that had emerged in China and it appeared to be less contagious than the strain last year. Both are believed to be from the same family of coronaviruses, which also cause the common cold. By Maggie Fox, Health and Science Correspondent WASHINGTON (Reuters) - A genetic susceptibility may explain why SARS raged last year in southeast Asia and nowhere else in the world outside of Toronto, Taiwanese researchers reported this week. They found a certain variant in an immune system gene called human leukocyte antigen, or HLA, made patients in Taiwan much more likely to develop life-threatening symptoms of SARS. The gene variant is common in people of southern Chinese descent, the team at Mackay Memorial Hospital in Taipei reported. Their finding, published in an online journal, BMC Medical Genetics, must be confirmed by independent researchers. But the Taiwanese team said the genetics could explain the puzzling distribution of SARS last year. "After the outbreak of SARS coronavirus infection in the Guangdong Province of China, it was surprising to observe that the spreading of the disease was mostly confined among southern Asian populations (the Hong Kong people, Vietnamese, Singaporeans and Taiwanese)," they wrote. Severe Acute Respiratory Syndrome first arose in Guangdong last November. It spread to Hong Kong, Vietnam, Beijing and Singapore, and was transported around the world by airliner. SARS eventually was suspected of affecting 8,098 people and killing 774, according to the World Health Organization's latest figures. The flu-like disease is caused by a virus from a family known as coronaviruses. They cause diseases in livestock and some cases of the common cold in people. The SARS coronavirus is unique genetically but similar versions have been found in animals sold in Chinese food markets. Marie Lin, Chun-Hsiung Huang and colleagues examined the HLA gene in 37 cases of probable SARS, 28 fever patients excluded later as probable SARS, and 101 non-infected health care workers who were exposed or possibly exposed to SARS coronavirus. "An additional control set of 190 normal healthy unrelated Taiwanese was also used in the analysis," they wrote in their report. They found that patients with severe cases of SARS were likely to have a version of the HLA gene called HLA-B 4601. They noted that no indigenous Taiwanese, who make up about 1.5 percent of the population, ever developed SARS. HLA-B 4601 is not seen among indigenous Taiwanese, they noted. "Interestingly, (HLA-B 4601) is also seldom seen in European populations," they added. |
#2
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Experts: Chinese Flu Could Become Epidemic Gene Difference May Explain SARS Epidemic
Key quote:
"The first time an avian flu virus was found to have infected people was in Hong Kong in 1997. At least 18 people fell severely ill and six died. Experts believe a pandemic may have been averted that time by the rapid slaughter of Hong Kong's entire poultry supply — an estimated 1.5 million birds killed in three days. That flu virus was the H5N1 variety, one of 15 known subtypes of avian flu. The WHO calls it worrisome for several reason: It mutates rapidly and tends to acquire genes from flu viruses in other animal species; it is clearly dangerous to people; and it spreads quickly. Infected birds give off the virus for at least 10 days in their feces and oral secretions. H5N1 appeared again last February, when two members of a family returning to Hong Kong from China became ill. One died and the other recovered." By DANIEL Q. HANEY, AP Medical Editor With luck, the world will escape the latest outbreak of bird flu with no more than the six human deaths already blamed on it and the loss of millions of chickens. But public health experts worry of a much greater disaster: A catastrophe they say is among the worst imaginable, a global outbreak of an entirely new form of human flu. There is no clear sign that will happen. Nevertheless, avian influenza's sudden sweep through Asia, along with its tendency for wholesale mutation, leave many wondering about the bug's potential for rampant spread among humans. It is a possibility the medical journal The Lancet calls "massively frightening." "The question everybody is asking is, 'Is this the progenitor to a pandemic?'" says Dr. Gregory Poland, chief of vaccine research at the Mayo Clinic. Influenza pandemics typically strike three or four times a century. The worst in the past 100 years, the 1918-19 Spanish flu, caused an estimated 40 million to 50 million deaths. Another is considered inevitable and perhaps overdue, but when it will happen and how bad it will be are almost totally unpredictable. The nightmare this time would be a flu virus leaping from birds to people and spreading, introducing a disease for which humans have no natural defense. The potential source is the strain of bird flu that has moved rapidly through parts of Asia since December, infecting chickens in at least six countries. Millions of birds have died of the flu or were destroyed by workers trying to contain the outbreak. The World Health Organization says eliminating this "animal reservoir" is urgent. Avian flu is naturally carried by wild ducks, and it ordinarily does not attack creatures other than birds or pigs, so experts are especially concerned that this bird flu is occasionally infecting people. Human cases have been reported in Vietnam and Thailand, including six deaths as of Saturday in Vietnam, the WHO said, and one suspected death in Thailand. Experts believe all caught the virus from chickens, not other people. "We know there are two possible ways a new pandemic strain can emerge," said Dr. Steve Ostroff, deputy director of the National Center for Infectious Diseases at the Centers for Disease Control and Prevention (news - web sites). One is a human flu virus that resurfaces after years of dormancy, so people have no defense built up from earlier bouts. The other is a non-human variety acquiring the ability to infect people and spread. The latter may happen if somebody already infected with a human flu virus also catches the bird virus. Inside the body, these two may recombine into a new mutant, part-human virus, part-bird. The more people are around infected chickens and other birds, experts say, the more chances there are for such a disaster to occur. "If the virus continues to spread in chickens, it may adapt itself so it can grow in humans," says Dr. Arnold Monto, a University of Michigan epidemiologist. "If it is transmitted human to human, then we are concerned this is the start of the great pandemic." The first time an avian flu virus was found to have infected people was in Hong Kong in 1997. At least 18 people fell severely ill and six died. Experts believe a pandemic may have been averted that time by the rapid slaughter of Hong Kong's entire poultry supply — an estimated 1.5 million birds killed in three days. That flu virus was the H5N1 variety, one of 15 known subtypes of avian flu. The WHO calls it worrisome for several reason: It mutates rapidly and tends to acquire genes from flu viruses in other animal species; it is clearly dangerous to people; and it spreads quickly. Infected birds give off the virus for at least 10 days in their feces and oral secretions. H5N1 appeared again last February, when two members of a family returning to Hong Kong from China became ill. One died and the other recovered. How and where they got infected was never learned. The disease now circulating in Asia is the same H5N1, but it is so widespread that a quick purging, like Hong Kong accomplished seven years ago, is unlikely. Testing shows it has mutated but has not yet picked up any genes from human flu viruses. If a bird flu pandemic occurs, could it be stopped? Many experts fear not. Flu is so contagious that quarantining victims, a method that eventually contained SARS last year, is unlikely to work. Studies suggest that prescription drugs used to treat human flu strains could also keep people from catching the bird flu. However, spot shortages were reported during this winter's U.S. flu outbreak, and supplies would quickly run out during a pandemic. No country has stockpiled the drugs, Tamiflu, Relenza and the older amantadine and rimantadine. The WHO is already working on a prototype vaccine against the bird flu. But even the standard annual flu shot takes six months to manufacture, and experts doubt a new vaccine could be ready in time. If there is evidence the bird flu is producing significant illness in humans, "there would be a full-bore effort to produce a vaccine," says the CDC's Ostroff. "It's hard to predict the timeliness of it and how widely it could be put into people's arms." ___ EDITOR'S NOTE: Medical Editor Daniel Q. Haney is a special correspondent for The Associated Press. HONG KONG (Reuters) - Scientists in Hong Kong have discovered people with a certain pattern of genes have a much higher risk of getting SARS, a finding that could help diagnose and prevent the spread of the deadly disease. A study of SARS patients in Hong Kong showed individuals with a pattern known as HLA-B*0703 were four times as likely to contract the respiratory disease, said Paul Chan, an associate professor in microbiology at the Chinese University of Hong Kong. Those with a pattern labeled HLA-DRBI*0301 had a much lower risk, indicating genetic make-up may play a key role in determining if some people are more susceptible to the virus than others. "Our findings from this study will help us more accurately diagnose the disease and design effective prevention programs," Chan said on Thursday. "For example, we could test an unproven vaccine or prevention method on the high-risk group. Hospitals may also consider sending only low-risk health workers to take care of SARS patients," he said. The Hong Kong researchers examined the blood samples of 90 SARS patients and studied the patterns of their human leucocyte antigen (HLA) genes, which influence the activity of cells that are responsible for the immune system's response during infections. The results were then compared with samples from people who did not have Severe Acute Respiratory Syndrome. More than 1,700 people in Hong Kong contracted SARS last year after it spread from southern China and nearly 300 of them died. Worldwide, more than 8,000 people were infected and more than 800 died. China recently announced its first confirmed SARS case in months and two suspected SARS cases in the southern city of Guangzhou. The government is still awaiting definitive test results on the suspected cases. Another Hong Kong scientist said on Wednesday it was a new variety of the SARS virus that had emerged in China and it appeared to be less contagious than the strain last year. Both are believed to be from the same family of coronaviruses, which also cause the common cold. By Maggie Fox, Health and Science Correspondent WASHINGTON (Reuters) - A genetic susceptibility may explain why SARS raged last year in southeast Asia and nowhere else in the world outside of Toronto, Taiwanese researchers reported this week. They found a certain variant in an immune system gene called human leukocyte antigen, or HLA, made patients in Taiwan much more likely to develop life-threatening symptoms of SARS. The gene variant is common in people of southern Chinese descent, the team at Mackay Memorial Hospital in Taipei reported. Their finding, published in an online journal, BMC Medical Genetics, must be confirmed by independent researchers. But the Taiwanese team said the genetics could explain the puzzling distribution of SARS last year. "After the outbreak of SARS coronavirus infection in the Guangdong Province of China, it was surprising to observe that the spreading of the disease was mostly confined among southern Asian populations (the Hong Kong people, Vietnamese, Singaporeans and Taiwanese)," they wrote. Severe Acute Respiratory Syndrome first arose in Guangdong last November. It spread to Hong Kong, Vietnam, Beijing and Singapore, and was transported around the world by airliner. SARS eventually was suspected of affecting 8,098 people and killing 774, according to the World Health Organization's latest figures. The flu-like disease is caused by a virus from a family known as coronaviruses. They cause diseases in livestock and some cases of the common cold in people. The SARS coronavirus is unique genetically but similar versions have been found in animals sold in Chinese food markets. Marie Lin, Chun-Hsiung Huang and colleagues examined the HLA gene in 37 cases of probable SARS, 28 fever patients excluded later as probable SARS, and 101 non-infected health care workers who were exposed or possibly exposed to SARS coronavirus. "An additional control set of 190 normal healthy unrelated Taiwanese was also used in the analysis," they wrote in their report. They found that patients with severe cases of SARS were likely to have a version of the HLA gene called HLA-B 4601. They noted that no indigenous Taiwanese, who make up about 1.5 percent of the population, ever developed SARS. HLA-B 4601 is not seen among indigenous Taiwanese, they noted. "Interestingly, (HLA-B 4601) is also seldom seen in European populations," they added. |
#3
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China accused of starting bird flu outbreak Experts: Chinese Flu Could Become Epidemic Gene Difference May Explain SARS Epidemic
JAN 29, 2004
BEIJING (AFP) - China was on Thursday facing allegations that it was the source of the Asia-wide bird flu outbreak as the World Health Organisation asked for an explanation of the deaths of two Hong Kong tourists a year ago. The respected British weekly New Scientist said it believed the outbreak began in southern China in early 2003 after a poultry vaccination scheme went wrong and that it had since been covered up. The report has put the spotlight back on the two dead tourists who visited southern China in February last year. The WHO has asked the Chinese government for more information as part of efforts to establish the history of the bird flu outbreak which has been detected in 10 Asian nations. 'It's definitely worth getting a final conclusion on the case,' Beijing-based WHO spokesman Roy Wadia said on Thursday. An eight-year-old Hong Kong girl fell ill and died in south-east China's Fujian province in February last year while visiting her family. Her father died 12 days later after returning to Hong Kong, and post-mortem specimens showed he had come down with the H5N1 strain of the bird flu virus which has claimed 10 lives in Vietnam and Thailand. The WHO last week asked the Chinese health authorities for more details about this case, although it has warned about making any premature link between the two deaths and the current bird flu outbreak. 'There could have been several emerging sources,' said Mr Wadia, adding that so far the UN health body had received no response. The New Scientist, quoting unidentified health experts, said the outbreak 'probably' began in China. 'A combination of official cover-up and questionable farming practices allowed it to turn into the epidemic now under way,' said the magazine. China on Thursday denied the allegations. Foreign ministry spokesman Zhang Qiyue rejected the charges saying: 'We believe that such an allegation is totally inaccurate, groundless and doesn't respect science.' China earlier this week confirmed bird flu had been discovered at a duck farm near its border with Vietnam. Suspected cases of bird flu have also been detected in central China's Hubei and Hunan provinces. Local officials said on Wednesday that those cases have been provisionally confirmed as bird flu. Indonesia agrees to cull Meanwhile, Indonesia on Thursday caved in to international pressure and ordered the immediate killing of all poultry infected with bird flu, but it was unclear whether the cull would extend to healthy poultry as it has in other nations. 'We will do it. We will destroy those infected. The good ones will be saved,' Welfare Minister Yusuf Kalla said. Indonesia has said millions of birds across much of the vast archipelago have been infected. India bans all poultry imports The Indian government said on Thursday it has banned all poultry imports from all countries. 'India has completely banned the import of poultry (products) from any country following the outbreak of the deadly bird flu,' Health Minister Sushma Swaraj told reporters. She added that no case of a bird death due to the flu had been reported from any part of the country. Key quote: "The first time an avian flu virus was found to have infected people was in Hong Kong in 1997. At least 18 people fell severely ill and six died. Experts believe a pandemic may have been averted that time by the rapid slaughter of Hong Kong's entire poultry supply ? an estimated 1.5 million birds killed in three days. That flu virus was the H5N1 variety, one of 15 known subtypes of avian flu. The WHO calls it worrisome for several reason: It mutates rapidly and tends to acquire genes from flu viruses in other animal species; it is clearly dangerous to people; and it spreads quickly. Infected birds give off the virus for at least 10 days in their feces and oral secretions. H5N1 appeared again last February, when two members of a family returning to Hong Kong from China became ill. One died and the other recovered." By DANIEL Q. HANEY, AP Medical Editor With luck, the world will escape the latest outbreak of bird flu with no more than the six human deaths already blamed on it and the loss of millions of chickens. But public health experts worry of a much greater disaster: A catastrophe they say is among the worst imaginable, a global outbreak of an entirely new form of human flu. There is no clear sign that will happen. Nevertheless, avian influenza's sudden sweep through Asia, along with its tendency for wholesale mutation, leave many wondering about the bug's potential for rampant spread among humans. It is a possibility the medical journal The Lancet calls "massively frightening." "The question everybody is asking is, 'Is this the progenitor to a pandemic?'" says Dr. Gregory Poland, chief of vaccine research at the Mayo Clinic. Influenza pandemics typically strike three or four times a century. The worst in the past 100 years, the 1918-19 Spanish flu, caused an estimated 40 million to 50 million deaths. Another is considered inevitable and perhaps overdue, but when it will happen and how bad it will be are almost totally unpredictable. The nightmare this time would be a flu virus leaping from birds to people and spreading, introducing a disease for which humans have no natural defense. The potential source is the strain of bird flu that has moved rapidly through parts of Asia since December, infecting chickens in at least six countries. Millions of birds have died of the flu or were destroyed by workers trying to contain the outbreak. The World Health Organization says eliminating this "animal reservoir" is urgent. Avian flu is naturally carried by wild ducks, and it ordinarily does not attack creatures other than birds or pigs, so experts are especially concerned that this bird flu is occasionally infecting people. Human cases have been reported in Vietnam and Thailand, including six deaths as of Saturday in Vietnam, the WHO said, and one suspected death in Thailand. Experts believe all caught the virus from chickens, not other people. "We know there are two possible ways a new pandemic strain can emerge," said Dr. Steve Ostroff, deputy director of the National Center for Infectious Diseases at the Centers for Disease Control and Prevention (news - web sites). One is a human flu virus that resurfaces after years of dormancy, so people have no defense built up from earlier bouts. The other is a non-human variety acquiring the ability to infect people and spread. The latter may happen if somebody already infected with a human flu virus also catches the bird virus. Inside the body, these two may recombine into a new mutant, part-human virus, part-bird. The more people are around infected chickens and other birds, experts say, the more chances there are for such a disaster to occur. "If the virus continues to spread in chickens, it may adapt itself so it can grow in humans," says Dr. Arnold Monto, a University of Michigan epidemiologist. "If it is transmitted human to human, then we are concerned this is the start of the great pandemic." The first time an avian flu virus was found to have infected people was in Hong Kong in 1997. At least 18 people fell severely ill and six died. Experts believe a pandemic may have been averted that time by the rapid slaughter of Hong Kong's entire poultry supply ? an estimated 1.5 million birds killed in three days. That flu virus was the H5N1 variety, one of 15 known subtypes of avian flu. The WHO calls it worrisome for several reason: It mutates rapidly and tends to acquire genes from flu viruses in other animal species; it is clearly dangerous to people; and it spreads quickly. Infected birds give off the virus for at least 10 days in their feces and oral secretions. H5N1 appeared again last February, when two members of a family returning to Hong Kong from China became ill. One died and the other recovered. How and where they got infected was never learned. The disease now circulating in Asia is the same H5N1, but it is so widespread that a quick purging, like Hong Kong accomplished seven years ago, is unlikely. Testing shows it has mutated but has not yet picked up any genes from human flu viruses. If a bird flu pandemic occurs, could it be stopped? Many experts fear not. Flu is so contagious that quarantining victims, a method that eventually contained SARS last year, is unlikely to work. Studies suggest that prescription drugs used to treat human flu strains could also keep people from catching the bird flu. However, spot shortages were reported during this winter's U.S. flu outbreak, and supplies would quickly run out during a pandemic. No country has stockpiled the drugs, Tamiflu, Relenza and the older amantadine and rimantadine. The WHO is already working on a prototype vaccine against the bird flu. But even the standard annual flu shot takes six months to manufacture, and experts doubt a new vaccine could be ready in time. If there is evidence the bird flu is producing significant illness in humans, "there would be a full-bore effort to produce a vaccine," says the CDC's Ostroff. "It's hard to predict the timeliness of it and how widely it could be put into people's arms." ___ EDITOR'S NOTE: Medical Editor Daniel Q. Haney is a special correspondent for The Associated Press. HONG KONG (Reuters) - Scientists in Hong Kong have discovered people with a certain pattern of genes have a much higher risk of getting SARS, a finding that could help diagnose and prevent the spread of the deadly disease. A study of SARS patients in Hong Kong showed individuals with a pattern known as HLA-B*0703 were four times as likely to contract the respiratory disease, said Paul Chan, an associate professor in microbiology at the Chinese University of Hong Kong. Those with a pattern labeled HLA-DRBI*0301 had a much lower risk, indicating genetic make-up may play a key role in determining if some people are more susceptible to the virus than others. "Our findings from this study will help us more accurately diagnose the disease and design effective prevention programs," Chan said on Thursday. "For example, we could test an unproven vaccine or prevention method on the high-risk group. Hospitals may also consider sending only low-risk health workers to take care of SARS patients," he said. The Hong Kong researchers examined the blood samples of 90 SARS patients and studied the patterns of their human leucocyte antigen (HLA) genes, which influence the activity of cells that are responsible for the immune system's response during infections. The results were then compared with samples from people who did not have Severe Acute Respiratory Syndrome. More than 1,700 people in Hong Kong contracted SARS last year after it spread from southern China and nearly 300 of them died. Worldwide, more than 8,000 people were infected and more than 800 died. China recently announced its first confirmed SARS case in months and two suspected SARS cases in the southern city of Guangzhou. The government is still awaiting definitive test results on the suspected cases. Another Hong Kong scientist said on Wednesday it was a new variety of the SARS virus that had emerged in China and it appeared to be less contagious than the strain last year. Both are believed to be from the same family of coronaviruses, which also cause the common cold. By Maggie Fox, Health and Science Correspondent WASHINGTON (Reuters) - A genetic susceptibility may explain why SARS raged last year in southeast Asia and nowhere else in the world outside of Toronto, Taiwanese researchers reported this week. They found a certain variant in an immune system gene called human leukocyte antigen, or HLA, made patients in Taiwan much more likely to develop life-threatening symptoms of SARS. The gene variant is common in people of southern Chinese descent, the team at Mackay Memorial Hospital in Taipei reported. Their finding, published in an online journal, BMC Medical Genetics, must be confirmed by independent researchers. But the Taiwanese team said the genetics could explain the puzzling distribution of SARS last year. "After the outbreak of SARS coronavirus infection in the Guangdong Province of China, it was surprising to observe that the spreading of the disease was mostly confined among southern Asian populations (the Hong Kong people, Vietnamese, Singaporeans and Taiwanese)," they wrote. Severe Acute Respiratory Syndrome first arose in Guangdong last November. It spread to Hong Kong, Vietnam, Beijing and Singapore, and was transported around the world by airliner. SARS eventually was suspected of affecting 8,098 people and killing 774, according to the World Health Organization's latest figures. The flu-like disease is caused by a virus from a family known as coronaviruses. They cause diseases in livestock and some cases of the common cold in people. The SARS coronavirus is unique genetically but similar versions have been found in animals sold in Chinese food markets. Marie Lin, Chun-Hsiung Huang and colleagues examined the HLA gene in 37 cases of probable SARS, 28 fever patients excluded later as probable SARS, and 101 non-infected health care workers who were exposed or possibly exposed to SARS coronavirus. "An additional control set of 190 normal healthy unrelated Taiwanese was also used in the analysis," they wrote in their report. They found that patients with severe cases of SARS were likely to have a version of the HLA gene called HLA-B 4601. They noted that no indigenous Taiwanese, who make up about 1.5 percent of the population, ever developed SARS. HLA-B 4601 is not seen among indigenous Taiwanese, they noted. "Interestingly, (HLA-B 4601) is also seldom seen in European populations," they added. |
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SARS Virus Mutated Into More Infectious Form-Study China accused of starting bird flu outbreak Experts: Chinese Flu Could Become Epidemic Gene Difference May Explain SARS Epidemic
By Maggie Fox, Health and Science Correspondent
WASHINGTON (Reuters) - The SARS virus fine-tuned itself to become more infectious as last year's epidemic spread across China, researchers reported on Thursday. Early patients with Severe Acute Respiratory Syndrome had a form genetically very similar to that seen in civets, while the last patients in the epidemic had a slightly mutated form, the researchers said. "What we see is the virus fine-tuning itself to enhance its access to a new host -- humans," Chung-I Wu, a professor and chairman of ecology and evolution at the University of Chicago, said in a statement. "This is a disturbing process to watch, as the virus improves itself under selective pressure, learning to spread from person to person, then sticking with the version that is most effective." This may explain why the virus became more infectious with time, Wu said. The finding, published in the journal Science, supports the idea the virus leapt to people from animals and also should allow experts to understand the virus better. SARS infected more than 8,000 people last winter and killed nearly 800. This year, two people have been confirmed to have been infected with SARS and a third is considered a probable case -- all in China. The virus that causes the disease, marked by severe pneumonia, is a never-before-seen type of coronavirus. Coronaviruses cause the common cold in people and a range of infections in animals. Wu, Guoping Zhao of the Chinese National Human Genome Center, and colleagues in China including at the Guangdong Center for Disease Control and Prevention studied the spike protein on the virus -- known to give the microbe its ability to infect. In the first people infected it was virtually identical to viruses taken from civets, weasel-like animals valued for their meat and sold in markets in southern China. As the virus spread more freely from person to person, it mutated slightly, apparently adapting itself better to live in humans. That was when the "super-spreading" occurred that made the virus so frightening -- including the case of a doctor who infected several people at a Hong Kong hotel. The virus then gradually evolved into a more stable genetic form toward the end of the outbreak, Wu's team reported. They said the study should help researchers find a vaccine against SARS based on the spike protein. JAN 29, 2004 BEIJING (AFP) - China was on Thursday facing allegations that it was the source of the Asia-wide bird flu outbreak as the World Health Organisation asked for an explanation of the deaths of two Hong Kong tourists a year ago. The respected British weekly New Scientist said it believed the outbreak began in southern China in early 2003 after a poultry vaccination scheme went wrong and that it had since been covered up. The report has put the spotlight back on the two dead tourists who visited southern China in February last year. The WHO has asked the Chinese government for more information as part of efforts to establish the history of the bird flu outbreak which has been detected in 10 Asian nations. 'It's definitely worth getting a final conclusion on the case,' Beijing-based WHO spokesman Roy Wadia said on Thursday. An eight-year-old Hong Kong girl fell ill and died in south-east China's Fujian province in February last year while visiting her family. Her father died 12 days later after returning to Hong Kong, and post-mortem specimens showed he had come down with the H5N1 strain of the bird flu virus which has claimed 10 lives in Vietnam and Thailand. The WHO last week asked the Chinese health authorities for more details about this case, although it has warned about making any premature link between the two deaths and the current bird flu outbreak. 'There could have been several emerging sources,' said Mr Wadia, adding that so far the UN health body had received no response. The New Scientist, quoting unidentified health experts, said the outbreak 'probably' began in China. 'A combination of official cover-up and questionable farming practices allowed it to turn into the epidemic now under way,' said the magazine. China on Thursday denied the allegations. Foreign ministry spokesman Zhang Qiyue rejected the charges saying: 'We believe that such an allegation is totally inaccurate, groundless and doesn't respect science.' China earlier this week confirmed bird flu had been discovered at a duck farm near its border with Vietnam. Suspected cases of bird flu have also been detected in central China's Hubei and Hunan provinces. Local officials said on Wednesday that those cases have been provisionally confirmed as bird flu. Indonesia agrees to cull Meanwhile, Indonesia on Thursday caved in to international pressure and ordered the immediate killing of all poultry infected with bird flu, but it was unclear whether the cull would extend to healthy poultry as it has in other nations. 'We will do it. We will destroy those infected. The good ones will be saved,' Welfare Minister Yusuf Kalla said. Indonesia has said millions of birds across much of the vast archipelago have been infected. India bans all poultry imports The Indian government said on Thursday it has banned all poultry imports from all countries. 'India has completely banned the import of poultry (products) from any country following the outbreak of the deadly bird flu,' Health Minister Sushma Swaraj told reporters. She added that no case of a bird death due to the flu had been reported from any part of the country. Key quote: "The first time an avian flu virus was found to have infected people was in Hong Kong in 1997. At least 18 people fell severely ill and six died. Experts believe a pandemic may have been averted that time by the rapid slaughter of Hong Kong's entire poultry supply ? an estimated 1.5 million birds killed in three days. That flu virus was the H5N1 variety, one of 15 known subtypes of avian flu. The WHO calls it worrisome for several reason: It mutates rapidly and tends to acquire genes from flu viruses in other animal species; it is clearly dangerous to people; and it spreads quickly. Infected birds give off the virus for at least 10 days in their feces and oral secretions. H5N1 appeared again last February, when two members of a family returning to Hong Kong from China became ill. One died and the other recovered." By DANIEL Q. HANEY, AP Medical Editor With luck, the world will escape the latest outbreak of bird flu with no more than the six human deaths already blamed on it and the loss of millions of chickens. But public health experts worry of a much greater disaster: A catastrophe they say is among the worst imaginable, a global outbreak of an entirely new form of human flu. There is no clear sign that will happen. Nevertheless, avian influenza's sudden sweep through Asia, along with its tendency for wholesale mutation, leave many wondering about the bug's potential for rampant spread among humans. It is a possibility the medical journal The Lancet calls "massively frightening." "The question everybody is asking is, 'Is this the progenitor to a pandemic?'" says Dr. Gregory Poland, chief of vaccine research at the Mayo Clinic. Influenza pandemics typically strike three or four times a century. The worst in the past 100 years, the 1918-19 Spanish flu, caused an estimated 40 million to 50 million deaths. Another is considered inevitable and perhaps overdue, but when it will happen and how bad it will be are almost totally unpredictable. The nightmare this time would be a flu virus leaping from birds to people and spreading, introducing a disease for which humans have no natural defense. The potential source is the strain of bird flu that has moved rapidly through parts of Asia since December, infecting chickens in at least six countries. Millions of birds have died of the flu or were destroyed by workers trying to contain the outbreak. The World Health Organization says eliminating this "animal reservoir" is urgent. Avian flu is naturally carried by wild ducks, and it ordinarily does not attack creatures other than birds or pigs, so experts are especially concerned that this bird flu is occasionally infecting people. Human cases have been reported in Vietnam and Thailand, including six deaths as of Saturday in Vietnam, the WHO said, and one suspected death in Thailand. Experts believe all caught the virus from chickens, not other people. "We know there are two possible ways a new pandemic strain can emerge," said Dr. Steve Ostroff, deputy director of the National Center for Infectious Diseases at the Centers for Disease Control and Prevention (news - web sites). One is a human flu virus that resurfaces after years of dormancy, so people have no defense built up from earlier bouts. The other is a non-human variety acquiring the ability to infect people and spread. The latter may happen if somebody already infected with a human flu virus also catches the bird virus. Inside the body, these two may recombine into a new mutant, part-human virus, part-bird. The more people are around infected chickens and other birds, experts say, the more chances there are for such a disaster to occur. "If the virus continues to spread in chickens, it may adapt itself so it can grow in humans," says Dr. Arnold Monto, a University of Michigan epidemiologist. "If it is transmitted human to human, then we are concerned this is the start of the great pandemic." The first time an avian flu virus was found to have infected people was in Hong Kong in 1997. At least 18 people fell severely ill and six died. Experts believe a pandemic may have been averted that time by the rapid slaughter of Hong Kong's entire poultry supply ? an estimated 1.5 million birds killed in three days. That flu virus was the H5N1 variety, one of 15 known subtypes of avian flu. The WHO calls it worrisome for several reason: It mutates rapidly and tends to acquire genes from flu viruses in other animal species; it is clearly dangerous to people; and it spreads quickly. Infected birds give off the virus for at least 10 days in their feces and oral secretions. H5N1 appeared again last February, when two members of a family returning to Hong Kong from China became ill. One died and the other recovered. How and where they got infected was never learned. The disease now circulating in Asia is the same H5N1, but it is so widespread that a quick purging, like Hong Kong accomplished seven years ago, is unlikely. Testing shows it has mutated but has not yet picked up any genes from human flu viruses. If a bird flu pandemic occurs, could it be stopped? Many experts fear not. Flu is so contagious that quarantining victims, a method that eventually contained SARS last year, is unlikely to work. Studies suggest that prescription drugs used to treat human flu strains could also keep people from catching the bird flu. However, spot shortages were reported during this winter's U.S. flu outbreak, and supplies would quickly run out during a pandemic. No country has stockpiled the drugs, Tamiflu, Relenza and the older amantadine and rimantadine. The WHO is already working on a prototype vaccine against the bird flu. But even the standard annual flu shot takes six months to manufacture, and experts doubt a new vaccine could be ready in time. If there is evidence the bird flu is producing significant illness in humans, "there would be a full-bore effort to produce a vaccine," says the CDC's Ostroff. "It's hard to predict the timeliness of it and how widely it could be put into people's arms." ___ EDITOR'S NOTE: Medical Editor Daniel Q. Haney is a special correspondent for The Associated Press. HONG KONG (Reuters) - Scientists in Hong Kong have discovered people with a certain pattern of genes have a much higher risk of getting SARS, a finding that could help diagnose and prevent the spread of the deadly disease. A study of SARS patients in Hong Kong showed individuals with a pattern known as HLA-B*0703 were four times as likely to contract the respiratory disease, said Paul Chan, an associate professor in microbiology at the Chinese University of Hong Kong. Those with a pattern labeled HLA-DRBI*0301 had a much lower risk, indicating genetic make-up may play a key role in determining if some people are more susceptible to the virus than others. "Our findings from this study will help us more accurately diagnose the disease and design effective prevention programs," Chan said on Thursday. "For example, we could test an unproven vaccine or prevention method on the high-risk group. Hospitals may also consider sending only low-risk health workers to take care of SARS patients," he said. The Hong Kong researchers examined the blood samples of 90 SARS patients and studied the patterns of their human leucocyte antigen (HLA) genes, which influence the activity of cells that are responsible for the immune system's response during infections. The results were then compared with samples from people who did not have Severe Acute Respiratory Syndrome. More than 1,700 people in Hong Kong contracted SARS last year after it spread from southern China and nearly 300 of them died. Worldwide, more than 8,000 people were infected and more than 800 died. China recently announced its first confirmed SARS case in months and two suspected SARS cases in the southern city of Guangzhou. The government is still awaiting definitive test results on the suspected cases. Another Hong Kong scientist said on Wednesday it was a new variety of the SARS virus that had emerged in China and it appeared to be less contagious than the strain last year. Both are believed to be from the same family of coronaviruses, which also cause the common cold. By Maggie Fox, Health and Science Correspondent WASHINGTON (Reuters) - A genetic susceptibility may explain why SARS raged last year in southeast Asia and nowhere else in the world outside of Toronto, Taiwanese researchers reported this week. They found a certain variant in an immune system gene called human leukocyte antigen, or HLA, made patients in Taiwan much more likely to develop life-threatening symptoms of SARS. The gene variant is common in people of southern Chinese descent, the team at Mackay Memorial Hospital in Taipei reported. Their finding, published in an online journal, BMC Medical Genetics, must be confirmed by independent researchers. But the Taiwanese team said the genetics could explain the puzzling distribution of SARS last year. "After the outbreak of SARS coronavirus infection in the Guangdong Province of China, it was surprising to observe that the spreading of the disease was mostly confined among southern Asian populations (the Hong Kong people, Vietnamese, Singaporeans and Taiwanese)," they wrote. Severe Acute Respiratory Syndrome first arose in Guangdong last November. It spread to Hong Kong, Vietnam, Beijing and Singapore, and was transported around the world by airliner. SARS eventually was suspected of affecting 8,098 people and killing 774, according to the World Health Organization's latest figures. The flu-like disease is caused by a virus from a family known as coronaviruses. They cause diseases in livestock and some cases of the common cold in people. The SARS coronavirus is unique genetically but similar versions have been found in animals sold in Chinese food markets. Marie Lin, Chun-Hsiung Huang and colleagues examined the HLA gene in 37 cases of probable SARS, 28 fever patients excluded later as probable SARS, and 101 non-infected health care workers who were exposed or possibly exposed to SARS coronavirus. "An additional control set of 190 normal healthy unrelated Taiwanese was also used in the analysis," they wrote in their report. They found that patients with severe cases of SARS were likely to have a version of the HLA gene called HLA-B 4601. They noted that no indigenous Taiwanese, who make up about 1.5 percent of the population, ever developed SARS. HLA-B 4601 is not seen among indigenous Taiwanese, they noted. "Interestingly, (HLA-B 4601) is also seldom seen in European populations," they added. |
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WHO chides China over latest SARS SARS Virus Mutated Into More Infectious Form-Study China accused of starting bird flu outbreak Experts: Chinese Flu Could Become Epidemic Gene Difference May Explain SARS Epidemic
Sunday, February 1, 2004 Posted: 12:33 AM EST (0533 GMT)
BEIJING, China -- The World Health Organization has chided China over its handling of the reappearance of SARS after Beijing announced a fourth confirmed case of the deadly virus. The latest case -- a 40-year-old doctor -- has emerged in Guangdong, the southern Chinese province believed to be the epicenter of last year's outbreak which killed nearly 800 people and sickened around 8,000. The WHO on Saturday issued a strongly worded statement calling for China to undertake an urgent investigation into the sources of infection for the recent Guangdong cases. "The case raises a number of concerns about the manner in which the man's infection was detected, treated and reported," the WHO said. "WHO was not informed about this case until January 30," the agency said. "Early detection, swift isolation and prompt reporting of cases are vital in the control of any infectious disease." China came in for sharp criticism last year for apparently covering up the extent of the SARS problem and not acting swiftly enough to counter its spread. Beijing subsequently promised to be more open and timely in its communications concerning the SARS situation. In the most recent case, the doctor -- a director of a hospital in Guandong's main cirty, Guangzhou, -- fell ill on January 7 with a high fever, sore throat and fatigue. The man -- identified only by his family name, Liu -- checked himself into a hospital on January 13, the official Xinhua news agency reports. Within five days, "his body temperature dropped to normal and his condition stabilized." Liu "was already discharged from hospital several days ago upon total recovery," Xinhua said. The WHO said it was only informed about the case on January 31. The doctor has denied having any contact with animals or SARS patients, according to Xinhua. Health officials have been monitoring 48 people who had contact with him, but none has showed any symptoms, it said. WHO said it was important for health authorities to trace how the patients became sick as soon as possible. "Now we have four cases without a concrete source of infection," Roy Wadia, a WHO spokesman in Beijing, said, accordinfg to The Associated Press. "It's something we're very concerned about." http://www.cnn.com/2004/WORLD/asiapc...ars/index.html By Maggie Fox, Health and Science Correspondent WASHINGTON (Reuters) - The SARS virus fine-tuned itself to become more infectious as last year's epidemic spread across China, researchers reported on Thursday. Early patients with Severe Acute Respiratory Syndrome had a form genetically very similar to that seen in civets, while the last patients in the epidemic had a slightly mutated form, the researchers said. "What we see is the virus fine-tuning itself to enhance its access to a new host -- humans," Chung-I Wu, a professor and chairman of ecology and evolution at the University of Chicago, said in a statement. "This is a disturbing process to watch, as the virus improves itself under selective pressure, learning to spread from person to person, then sticking with the version that is most effective." This may explain why the virus became more infectious with time, Wu said. The finding, published in the journal Science, supports the idea the virus leapt to people from animals and also should allow experts to understand the virus better. SARS infected more than 8,000 people last winter and killed nearly 800. This year, two people have been confirmed to have been infected with SARS and a third is considered a probable case -- all in China. The virus that causes the disease, marked by severe pneumonia, is a never-before-seen type of coronavirus. Coronaviruses cause the common cold in people and a range of infections in animals. Wu, Guoping Zhao of the Chinese National Human Genome Center, and colleagues in China including at the Guangdong Center for Disease Control and Prevention studied the spike protein on the virus -- known to give the microbe its ability to infect. In the first people infected it was virtually identical to viruses taken from civets, weasel-like animals valued for their meat and sold in markets in southern China. As the virus spread more freely from person to person, it mutated slightly, apparently adapting itself better to live in humans. That was when the "super-spreading" occurred that made the virus so frightening -- including the case of a doctor who infected several people at a Hong Kong hotel. The virus then gradually evolved into a more stable genetic form toward the end of the outbreak, Wu's team reported. They said the study should help researchers find a vaccine against SARS based on the spike protein. JAN 29, 2004 BEIJING (AFP) - China was on Thursday facing allegations that it was the source of the Asia-wide bird flu outbreak as the World Health Organisation asked for an explanation of the deaths of two Hong Kong tourists a year ago. The respected British weekly New Scientist said it believed the outbreak began in southern China in early 2003 after a poultry vaccination scheme went wrong and that it had since been covered up. The report has put the spotlight back on the two dead tourists who visited southern China in February last year. The WHO has asked the Chinese government for more information as part of efforts to establish the history of the bird flu outbreak which has been detected in 10 Asian nations. 'It's definitely worth getting a final conclusion on the case,' Beijing-based WHO spokesman Roy Wadia said on Thursday. An eight-year-old Hong Kong girl fell ill and died in south-east China's Fujian province in February last year while visiting her family. Her father died 12 days later after returning to Hong Kong, and post-mortem specimens showed he had come down with the H5N1 strain of the bird flu virus which has claimed 10 lives in Vietnam and Thailand. The WHO last week asked the Chinese health authorities for more details about this case, although it has warned about making any premature link between the two deaths and the current bird flu outbreak. 'There could have been several emerging sources,' said Mr Wadia, adding that so far the UN health body had received no response. The New Scientist, quoting unidentified health experts, said the outbreak 'probably' began in China. 'A combination of official cover-up and questionable farming practices allowed it to turn into the epidemic now under way,' said the magazine. China on Thursday denied the allegations. Foreign ministry spokesman Zhang Qiyue rejected the charges saying: 'We believe that such an allegation is totally inaccurate, groundless and doesn't respect science.' China earlier this week confirmed bird flu had been discovered at a duck farm near its border with Vietnam. Suspected cases of bird flu have also been detected in central China's Hubei and Hunan provinces. Local officials said on Wednesday that those cases have been provisionally confirmed as bird flu. Indonesia agrees to cull Meanwhile, Indonesia on Thursday caved in to international pressure and ordered the immediate killing of all poultry infected with bird flu, but it was unclear whether the cull would extend to healthy poultry as it has in other nations. 'We will do it. We will destroy those infected. The good ones will be saved,' Welfare Minister Yusuf Kalla said. Indonesia has said millions of birds across much of the vast archipelago have been infected. India bans all poultry imports The Indian government said on Thursday it has banned all poultry imports from all countries. 'India has completely banned the import of poultry (products) from any country following the outbreak of the deadly bird flu,' Health Minister Sushma Swaraj told reporters. She added that no case of a bird death due to the flu had been reported from any part of the country. Key quote: "The first time an avian flu virus was found to have infected people was in Hong Kong in 1997. At least 18 people fell severely ill and six died. Experts believe a pandemic may have been averted that time by the rapid slaughter of Hong Kong's entire poultry supply ? an estimated 1.5 million birds killed in three days. That flu virus was the H5N1 variety, one of 15 known subtypes of avian flu. The WHO calls it worrisome for several reason: It mutates rapidly and tends to acquire genes from flu viruses in other animal species; it is clearly dangerous to people; and it spreads quickly. Infected birds give off the virus for at least 10 days in their feces and oral secretions. H5N1 appeared again last February, when two members of a family returning to Hong Kong from China became ill. One died and the other recovered." By DANIEL Q. HANEY, AP Medical Editor With luck, the world will escape the latest outbreak of bird flu with no more than the six human deaths already blamed on it and the loss of millions of chickens. But public health experts worry of a much greater disaster: A catastrophe they say is among the worst imaginable, a global outbreak of an entirely new form of human flu. There is no clear sign that will happen. Nevertheless, avian influenza's sudden sweep through Asia, along with its tendency for wholesale mutation, leave many wondering about the bug's potential for rampant spread among humans. It is a possibility the medical journal The Lancet calls "massively frightening." "The question everybody is asking is, 'Is this the progenitor to a pandemic?'" says Dr. Gregory Poland, chief of vaccine research at the Mayo Clinic. Influenza pandemics typically strike three or four times a century. The worst in the past 100 years, the 1918-19 Spanish flu, caused an estimated 40 million to 50 million deaths. Another is considered inevitable and perhaps overdue, but when it will happen and how bad it will be are almost totally unpredictable. The nightmare this time would be a flu virus leaping from birds to people and spreading, introducing a disease for which humans have no natural defense. The potential source is the strain of bird flu that has moved rapidly through parts of Asia since December, infecting chickens in at least six countries. Millions of birds have died of the flu or were destroyed by workers trying to contain the outbreak. The World Health Organization says eliminating this "animal reservoir" is urgent. Avian flu is naturally carried by wild ducks, and it ordinarily does not attack creatures other than birds or pigs, so experts are especially concerned that this bird flu is occasionally infecting people. Human cases have been reported in Vietnam and Thailand, including six deaths as of Saturday in Vietnam, the WHO said, and one suspected death in Thailand. Experts believe all caught the virus from chickens, not other people. "We know there are two possible ways a new pandemic strain can emerge," said Dr. Steve Ostroff, deputy director of the National Center for Infectious Diseases at the Centers for Disease Control and Prevention (news - web sites). One is a human flu virus that resurfaces after years of dormancy, so people have no defense built up from earlier bouts. The other is a non-human variety acquiring the ability to infect people and spread. The latter may happen if somebody already infected with a human flu virus also catches the bird virus. Inside the body, these two may recombine into a new mutant, part-human virus, part-bird. The more people are around infected chickens and other birds, experts say, the more chances there are for such a disaster to occur. "If the virus continues to spread in chickens, it may adapt itself so it can grow in humans," says Dr. Arnold Monto, a University of Michigan epidemiologist. "If it is transmitted human to human, then we are concerned this is the start of the great pandemic." The first time an avian flu virus was found to have infected people was in Hong Kong in 1997. At least 18 people fell severely ill and six died. Experts believe a pandemic may have been averted that time by the rapid slaughter of Hong Kong's entire poultry supply ? an estimated 1.5 million birds killed in three days. That flu virus was the H5N1 variety, one of 15 known subtypes of avian flu. The WHO calls it worrisome for several reason: It mutates rapidly and tends to acquire genes from flu viruses in other animal species; it is clearly dangerous to people; and it spreads quickly. Infected birds give off the virus for at least 10 days in their feces and oral secretions. H5N1 appeared again last February, when two members of a family returning to Hong Kong from China became ill. One died and the other recovered. How and where they got infected was never learned. The disease now circulating in Asia is the same H5N1, but it is so widespread that a quick purging, like Hong Kong accomplished seven years ago, is unlikely. Testing shows it has mutated but has not yet picked up any genes from human flu viruses. If a bird flu pandemic occurs, could it be stopped? Many experts fear not. Flu is so contagious that quarantining victims, a method that eventually contained SARS last year, is unlikely to work. Studies suggest that prescription drugs used to treat human flu strains could also keep people from catching the bird flu. However, spot shortages were reported during this winter's U.S. flu outbreak, and supplies would quickly run out during a pandemic. No country has stockpiled the drugs, Tamiflu, Relenza and the older amantadine and rimantadine. The WHO is already working on a prototype vaccine against the bird flu. But even the standard annual flu shot takes six months to manufacture, and experts doubt a new vaccine could be ready in time. If there is evidence the bird flu is producing significant illness in humans, "there would be a full-bore effort to produce a vaccine," says the CDC's Ostroff. "It's hard to predict the timeliness of it and how widely it could be put into people's arms." ___ EDITOR'S NOTE: Medical Editor Daniel Q. Haney is a special correspondent for The Associated Press. HONG KONG (Reuters) - Scientists in Hong Kong have discovered people with a certain pattern of genes have a much higher risk of getting SARS, a finding that could help diagnose and prevent the spread of the deadly disease. A study of SARS patients in Hong Kong showed individuals with a pattern known as HLA-B*0703 were four times as likely to contract the respiratory disease, said Paul Chan, an associate professor in microbiology at the Chinese University of Hong Kong. Those with a pattern labeled HLA-DRBI*0301 had a much lower risk, indicating genetic make-up may play a key role in determining if some people are more susceptible to the virus than others. "Our findings from this study will help us more accurately diagnose the disease and design effective prevention programs," Chan said on Thursday. "For example, we could test an unproven vaccine or prevention method on the high-risk group. Hospitals may also consider sending only low-risk health workers to take care of SARS patients," he said. The Hong Kong researchers examined the blood samples of 90 SARS patients and studied the patterns of their human leucocyte antigen (HLA) genes, which influence the activity of cells that are responsible for the immune system's response during infections. The results were then compared with samples from people who did not have Severe Acute Respiratory Syndrome. More than 1,700 people in Hong Kong contracted SARS last year after it spread from southern China and nearly 300 of them died. Worldwide, more than 8,000 people were infected and more than 800 died. China recently announced its first confirmed SARS case in months and two suspected SARS cases in the southern city of Guangzhou. The government is still awaiting definitive test results on the suspected cases. Another Hong Kong scientist said on Wednesday it was a new variety of the SARS virus that had emerged in China and it appeared to be less contagious than the strain last year. Both are believed to be from the same family of coronaviruses, which also cause the common cold. By Maggie Fox, Health and Science Correspondent WASHINGTON (Reuters) - A genetic susceptibility may explain why SARS raged last year in southeast Asia and nowhere else in the world outside of Toronto, Taiwanese researchers reported this week. They found a certain variant in an immune system gene called human leukocyte antigen, or HLA, made patients in Taiwan much more likely to develop life-threatening symptoms of SARS. The gene variant is common in people of southern Chinese descent, the team at Mackay Memorial Hospital in Taipei reported. Their finding, published in an online journal, BMC Medical Genetics, must be confirmed by independent researchers. But the Taiwanese team said the genetics could explain the puzzling distribution of SARS last year. "After the outbreak of SARS coronavirus infection in the Guangdong Province of China, it was surprising to observe that the spreading of the disease was mostly confined among southern Asian populations (the Hong Kong people, Vietnamese, Singaporeans and Taiwanese)," they wrote. Severe Acute Respiratory Syndrome first arose in Guangdong last November. It spread to Hong Kong, Vietnam, Beijing and Singapore, and was transported around the world by airliner. SARS eventually was suspected of affecting 8,098 people and killing 774, according to the World Health Organization's latest figures. The flu-like disease is caused by a virus from a family known as coronaviruses. They cause diseases in livestock and some cases of the common cold in people. The SARS coronavirus is unique genetically but similar versions have been found in animals sold in Chinese food markets. Marie Lin, Chun-Hsiung Huang and colleagues examined the HLA gene in 37 cases of probable SARS, 28 fever patients excluded later as probable SARS, and 101 non-infected health care workers who were exposed or possibly exposed to SARS coronavirus. "An additional control set of 190 normal healthy unrelated Taiwanese was also used in the analysis," they wrote in their report. They found that patients with severe cases of SARS were likely to have a version of the HLA gene called HLA-B 4601. They noted that no indigenous Taiwanese, who make up about 1.5 percent of the population, ever developed SARS. HLA-B 4601 is not seen among indigenous Taiwanese, they noted. "Interestingly, (HLA-B 4601) is also seldom seen in European populations," they added. |
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Secrets of Sars virus's lethal mutation unlocked by scientists WHO chides China over latest SARS SARS Virus Mutated Into More Infectious Form-Study China accused of starting bird flu outbreak Experts: Chinese Flu Could Become Epidemic
By Steve Connor, Science Editor
30 January 2004 Scientists have identified thestages in the evolution of the Sars virus that turned it from a simple animal infection into a lethal human disease. A study of the genes of more than 60 Sars viruses has found that it took just three major changes to the virus's genetic material to transform it into a highly effective killer of people. During the earliest phase of the epidemic the Sars virus infected about 3 per cent of those who came into direct contact with it, according to the study. Within a few months the proportion was 70 per cent. Chinese scientists, working with a team at the University of Chicago, analysed the Sars virus from the early, middle and later phases of the 2002-03 epidemic. The researchers found that the first phase of the epidemic involved a virus virtually identical to that found in wild animals but it mutated to cause a second phase, during which the virus spread from human to human. A final, third phase involved a further set of mutations that allowed the virus to stabilise and get accustomed to spreading still further within its new host species, said Chung-I Wu, professor of ecology and evolution at the University of Chicago. "What we see is the virus fine-tuning itself to enhance its access to a new host - humans. The virus improves itself under selective pressure, learning to spread from person to person, then sticking with the version that is most effective," Professor Wu said. The findings, published in the journal Science, confirmed that Sars was an animal disease that had jumped the "species barrier" into man. But the study did not determine which animal was the natural "reservoir" for the virus. In the early stages of the epidemic, in November 2002, there were about 11 seemingly independent cases of human Sars in the Pearl river delta area of Guangdong province in China. The scientists found that the rapid economic development of the area had led to "culinary habits involving exotic animals". Six of the 11 outbreaks involved people who had contact with wild animals. During the middle phase of the epidemic the scientists discovered that there were changes to the Sars virus that enabled it to spread rapidly from person to person, accelerated by a "super-spreader" patient in a hospital in Guangzhou. This phase, in January 2003, resulted in an outbreak of about 130 cases, including 106 patients who acquired the virus in hospital. A doctor at the hospital carried the virus to the Metropole Hotel in Hong Kong where the guests became infected and spread the virus across the world. http://news.independent.co.uk/world/...p?story=486003 Sunday, February 1, 2004 Posted: 12:33 AM EST (0533 GMT) BEIJING, China -- The World Health Organization has chided China over its handling of the reappearance of SARS after Beijing announced a fourth confirmed case of the deadly virus. The latest case -- a 40-year-old doctor -- has emerged in Guangdong, the southern Chinese province believed to be the epicenter of last year's outbreak which killed nearly 800 people and sickened around 8,000. The WHO on Saturday issued a strongly worded statement calling for China to undertake an urgent investigation into the sources of infection for the recent Guangdong cases. "The case raises a number of concerns about the manner in which the man's infection was detected, treated and reported," the WHO said. "WHO was not informed about this case until January 30," the agency said. "Early detection, swift isolation and prompt reporting of cases are vital in the control of any infectious disease." China came in for sharp criticism last year for apparently covering up the extent of the SARS problem and not acting swiftly enough to counter its spread. Beijing subsequently promised to be more open and timely in its communications concerning the SARS situation. In the most recent case, the doctor -- a director of a hospital in Guandong's main cirty, Guangzhou, -- fell ill on January 7 with a high fever, sore throat and fatigue. The man -- identified only by his family name, Liu -- checked himself into a hospital on January 13, the official Xinhua news agency reports. Within five days, "his body temperature dropped to normal and his condition stabilized." Liu "was already discharged from hospital several days ago upon total recovery," Xinhua said. The WHO said it was only informed about the case on January 31. The doctor has denied having any contact with animals or SARS patients, according to Xinhua. Health officials have been monitoring 48 people who had contact with him, but none has showed any symptoms, it said. WHO said it was important for health authorities to trace how the patients became sick as soon as possible. "Now we have four cases without a concrete source of infection," Roy Wadia, a WHO spokesman in Beijing, said, accordinfg to The Associated Press. "It's something we're very concerned about." http://www.cnn.com/2004/WORLD/asiapc...ars/index.html By Maggie Fox, Health and Science Correspondent WASHINGTON (Reuters) - The SARS virus fine-tuned itself to become more infectious as last year's epidemic spread across China, researchers reported on Thursday. Early patients with Severe Acute Respiratory Syndrome had a form genetically very similar to that seen in civets, while the last patients in the epidemic had a slightly mutated form, the researchers said. "What we see is the virus fine-tuning itself to enhance its access to a new host -- humans," Chung-I Wu, a professor and chairman of ecology and evolution at the University of Chicago, said in a statement. "This is a disturbing process to watch, as the virus improves itself under selective pressure, learning to spread from person to person, then sticking with the version that is most effective." This may explain why the virus became more infectious with time, Wu said. The finding, published in the journal Science, supports the idea the virus leapt to people from animals and also should allow experts to understand the virus better. SARS infected more than 8,000 people last winter and killed nearly 800. This year, two people have been confirmed to have been infected with SARS and a third is considered a probable case -- all in China. The virus that causes the disease, marked by severe pneumonia, is a never-before-seen type of coronavirus. Coronaviruses cause the common cold in people and a range of infections in animals. Wu, Guoping Zhao of the Chinese National Human Genome Center, and colleagues in China including at the Guangdong Center for Disease Control and Prevention studied the spike protein on the virus -- known to give the microbe its ability to infect. In the first people infected it was virtually identical to viruses taken from civets, weasel-like animals valued for their meat and sold in markets in southern China. As the virus spread more freely from person to person, it mutated slightly, apparently adapting itself better to live in humans. That was when the "super-spreading" occurred that made the virus so frightening -- including the case of a doctor who infected several people at a Hong Kong hotel. The virus then gradually evolved into a more stable genetic form toward the end of the outbreak, Wu's team reported. They said the study should help researchers find a vaccine against SARS based on the spike protein. JAN 29, 2004 BEIJING (AFP) - China was on Thursday facing allegations that it was the source of the Asia-wide bird flu outbreak as the World Health Organisation asked for an explanation of the deaths of two Hong Kong tourists a year ago. The respected British weekly New Scientist said it believed the outbreak began in southern China in early 2003 after a poultry vaccination scheme went wrong and that it had since been covered up. The report has put the spotlight back on the two dead tourists who visited southern China in February last year. The WHO has asked the Chinese government for more information as part of efforts to establish the history of the bird flu outbreak which has been detected in 10 Asian nations. 'It's definitely worth getting a final conclusion on the case,' Beijing-based WHO spokesman Roy Wadia said on Thursday. An eight-year-old Hong Kong girl fell ill and died in south-east China's Fujian province in February last year while visiting her family. Her father died 12 days later after returning to Hong Kong, and post-mortem specimens showed he had come down with the H5N1 strain of the bird flu virus which has claimed 10 lives in Vietnam and Thailand. The WHO last week asked the Chinese health authorities for more details about this case, although it has warned about making any premature link between the two deaths and the current bird flu outbreak. 'There could have been several emerging sources,' said Mr Wadia, adding that so far the UN health body had received no response. The New Scientist, quoting unidentified health experts, said the outbreak 'probably' began in China. 'A combination of official cover-up and questionable farming practices allowed it to turn into the epidemic now under way,' said the magazine. China on Thursday denied the allegations. Foreign ministry spokesman Zhang Qiyue rejected the charges saying: 'We believe that such an allegation is totally inaccurate, groundless and doesn't respect science.' China earlier this week confirmed bird flu had been discovered at a duck farm near its border with Vietnam. Suspected cases of bird flu have also been detected in central China's Hubei and Hunan provinces. Local officials said on Wednesday that those cases have been provisionally confirmed as bird flu. Indonesia agrees to cull Meanwhile, Indonesia on Thursday caved in to international pressure and ordered the immediate killing of all poultry infected with bird flu, but it was unclear whether the cull would extend to healthy poultry as it has in other nations. 'We will do it. We will destroy those infected. The good ones will be saved,' Welfare Minister Yusuf Kalla said. Indonesia has said millions of birds across much of the vast archipelago have been infected. India bans all poultry imports The Indian government said on Thursday it has banned all poultry imports from all countries. 'India has completely banned the import of poultry (products) from any country following the outbreak of the deadly bird flu,' Health Minister Sushma Swaraj told reporters. She added that no case of a bird death due to the flu had been reported from any part of the country. Key quote: "The first time an avian flu virus was found to have infected people was in Hong Kong in 1997. At least 18 people fell severely ill and six died. Experts believe a pandemic may have been averted that time by the rapid slaughter of Hong Kong's entire poultry supply ? an estimated 1.5 million birds killed in three days. That flu virus was the H5N1 variety, one of 15 known subtypes of avian flu. The WHO calls it worrisome for several reason: It mutates rapidly and tends to acquire genes from flu viruses in other animal species; it is clearly dangerous to people; and it spreads quickly. Infected birds give off the virus for at least 10 days in their feces and oral secretions. H5N1 appeared again last February, when two members of a family returning to Hong Kong from China became ill. One died and the other recovered." By DANIEL Q. HANEY, AP Medical Editor With luck, the world will escape the latest outbreak of bird flu with no more than the six human deaths already blamed on it and the loss of millions of chickens. But public health experts worry of a much greater disaster: A catastrophe they say is among the worst imaginable, a global outbreak of an entirely new form of human flu. There is no clear sign that will happen. Nevertheless, avian influenza's sudden sweep through Asia, along with its tendency for wholesale mutation, leave many wondering about the bug's potential for rampant spread among humans. It is a possibility the medical journal The Lancet calls "massively frightening." "The question everybody is asking is, 'Is this the progenitor to a pandemic?'" says Dr. Gregory Poland, chief of vaccine research at the Mayo Clinic. Influenza pandemics typically strike three or four times a century. The worst in the past 100 years, the 1918-19 Spanish flu, caused an estimated 40 million to 50 million deaths. Another is considered inevitable and perhaps overdue, but when it will happen and how bad it will be are almost totally unpredictable. The nightmare this time would be a flu virus leaping from birds to people and spreading, introducing a disease for which humans have no natural defense. The potential source is the strain of bird flu that has moved rapidly through parts of Asia since December, infecting chickens in at least six countries. Millions of birds have died of the flu or were destroyed by workers trying to contain the outbreak. The World Health Organization says eliminating this "animal reservoir" is urgent. Avian flu is naturally carried by wild ducks, and it ordinarily does not attack creatures other than birds or pigs, so experts are especially concerned that this bird flu is occasionally infecting people. Human cases have been reported in Vietnam and Thailand, including six deaths as of Saturday in Vietnam, the WHO said, and one suspected death in Thailand. Experts believe all caught the virus from chickens, not other people. "We know there are two possible ways a new pandemic strain can emerge," said Dr. Steve Ostroff, deputy director of the National Center for Infectious Diseases at the Centers for Disease Control and Prevention (news - web sites). One is a human flu virus that resurfaces after years of dormancy, so people have no defense built up from earlier bouts. The other is a non-human variety acquiring the ability to infect people and spread. The latter may happen if somebody already infected with a human flu virus also catches the bird virus. Inside the body, these two may recombine into a new mutant, part-human virus, part-bird. The more people are around infected chickens and other birds, experts say, the more chances there are for such a disaster to occur. "If the virus continues to spread in chickens, it may adapt itself so it can grow in humans," says Dr. Arnold Monto, a University of Michigan epidemiologist. "If it is transmitted human to human, then we are concerned this is the start of the great pandemic." The first time an avian flu virus was found to have infected people was in Hong Kong in 1997. At least 18 people fell severely ill and six died. Experts believe a pandemic may have been averted that time by the rapid slaughter of Hong Kong's entire poultry supply ? an estimated 1.5 million birds killed in three days. That flu virus was the H5N1 variety, one of 15 known subtypes of avian flu. The WHO calls it worrisome for several reason: It mutates rapidly and tends to acquire genes from flu viruses in other animal species; it is clearly dangerous to people; and it spreads quickly. Infected birds give off the virus for at least 10 days in their feces and oral secretions. H5N1 appeared again last February, when two members of a family returning to Hong Kong from China became ill. One died and the other recovered. How and where they got infected was never learned. The disease now circulating in Asia is the same H5N1, but it is so widespread that a quick purging, like Hong Kong accomplished seven years ago, is unlikely. Testing shows it has mutated but has not yet picked up any genes from human flu viruses. If a bird flu pandemic occurs, could it be stopped? Many experts fear not. Flu is so contagious that quarantining victims, a method that eventually contained SARS last year, is unlikely to work. Studies suggest that prescription drugs used to treat human flu strains could also keep people from catching the bird flu. However, spot shortages were reported during this winter's U.S. flu outbreak, and supplies would quickly run out during a pandemic. No country has stockpiled the drugs, Tamiflu, Relenza and the older amantadine and rimantadine. The WHO is already working on a prototype vaccine against the bird flu. But even the standard annual flu shot takes six months to manufacture, and experts doubt a new vaccine could be ready in time. If there is evidence the bird flu is producing significant illness in humans, "there would be a full-bore effort to produce a vaccine," says the CDC's Ostroff. "It's hard to predict the timeliness of it and how widely it could be put into people's arms." ___ EDITOR'S NOTE: Medical Editor Daniel Q. Haney is a special correspondent for The Associated Press. HONG KONG (Reuters) - Scientists in Hong Kong have discovered people with a certain pattern of genes have a much higher risk of getting SARS, a finding that could help diagnose and prevent the spread of the deadly disease. A study of SARS patients in Hong Kong showed individuals with a pattern known as HLA-B*0703 were four times as likely to contract the respiratory disease, said Paul Chan, an associate professor in microbiology at the Chinese University of Hong Kong. Those with a pattern labeled HLA-DRBI*0301 had a much lower risk, indicating genetic make-up may play a key role in determining if some people are more susceptible to the virus than others. "Our findings from this study will help us more accurately diagnose the disease and design effective prevention programs," Chan said on Thursday. "For example, we could test an unproven vaccine or prevention method on the high-risk group. Hospitals may also consider sending only low-risk health workers to take care of SARS patients," he said. The Hong Kong researchers examined the blood samples of 90 SARS patients and studied the patterns of their human leucocyte antigen (HLA) genes, which influence the activity of cells that are responsible for the immune system's response during infections. The results were then compared with samples from people who did not have Severe Acute Respiratory Syndrome. More than 1,700 people in Hong Kong contracted SARS last year after it spread from southern China and nearly 300 of them died. Worldwide, more than 8,000 people were infected and more than 800 died. China recently announced its first confirmed SARS case in months and two suspected SARS cases in the southern city of Guangzhou. The government is still awaiting definitive test results on the suspected cases. Another Hong Kong scientist said on Wednesday it was a new variety of the SARS virus that had emerged in China and it appeared to be less contagious than the strain last year. Both are believed to be from the same family of coronaviruses, which also cause the common cold. By Maggie Fox, Health and Science Correspondent WASHINGTON (Reuters) - A genetic susceptibility may explain why SARS raged last year in southeast Asia and nowhere else in the world outside of Toronto, Taiwanese researchers reported this week. They found a certain variant in an immune system gene called human leukocyte antigen, or HLA, made patients in Taiwan much more likely to develop life-threatening symptoms of SARS. The gene variant is common in people of southern Chinese descent, the team at Mackay Memorial Hospital in Taipei reported. Their finding, published in an online journal, BMC Medical Genetics, must be confirmed by independent researchers. But the Taiwanese team said the genetics could explain the puzzling distribution of SARS last year. "After the outbreak of SARS coronavirus infection in the Guangdong Province of China, it was surprising to observe that the spreading of the disease was mostly confined among southern Asian populations (the Hong Kong people, Vietnamese, Singaporeans and Taiwanese)," they wrote. Severe Acute Respiratory Syndrome first arose in Guangdong last November. It spread to Hong Kong, Vietnam, Beijing and Singapore, and was transported around the world by airliner. SARS eventually was suspected of affecting 8,098 people and killing 774, according to the World Health Organization's latest figures. The flu-like disease is caused by a virus from a family known as coronaviruses. They cause diseases in livestock and some cases of the common cold in people. The SARS coronavirus is unique genetically but similar versions have been found in animals sold in Chinese food markets. Marie Lin, Chun-Hsiung Huang and colleagues examined the HLA gene in 37 cases of probable SARS, 28 fever patients excluded later as probable SARS, and 101 non-infected health care workers who were exposed or possibly exposed to SARS coronavirus. "An additional control set of 190 normal healthy unrelated Taiwanese was also used in the analysis," they wrote in their report. They found that patients with severe cases of SARS were likely to have a version of the HLA gene called HLA-B 4601. They noted that no indigenous Taiwanese, who make up about 1.5 percent of the population, ever developed SARS. HLA-B 4601 is not seen among indigenous Taiwanese, they noted. "Interestingly, (HLA-B 4601) is also seldom seen in European populations," they added. |
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Dual Outbreaks Force China to Reflect WHO chides China over latest SARS SARS Virus Mutated Into More Infectious Form-Study China accused of starting bird flu outbreak Experts: Chinese Flu Could Become Epidemic Gene Difference May
Tue Feb 10, 2:16 AM ET
By AUDRA ANG, Associated Press Writer BEIJING - The lessons: Be prepared. Be aggressive. And above all, be open. Faced with back-to-back outbreaks of SARS (news - web sites) and avian flu in the past year, China has been forced to examine and reshape its shaky health-care system and the way it handles — and appears to handle — public health emergencies. The lessons have been bitter, tinged with criticism and mistrust of the Beijing leadership by the international community. As it copes with avian influenza, the government seems to be edging away from secrecy and sluggishness and inching toward transparency. Where once state-run media were silent on cases of infection, newspapers and broadcasters now offer blanket coverage, including disease-fighting and prevention efforts. The official Xinhua News Agency sends urgent dispatches; the Health Ministry provides daily SARS updates. "We have learned from fighting SARS that prevention work must be carried out in early stage, and it must be transparent," said Xu Ruiheng, deputy director of the Center for Disease Control and Prevention (news - web sites) in Guangdong. The province was home to SARS' earliest cases and, now, has confirmed avian flu in birds. Chinese leaders have promised a good fight, beefed up with intense surveillance and accurate reporting. But the changes are only slowly navigating through the onion layers of officialdom, where bottom-up communication remains spotty and cover-ups are still a fear. When telephoned, many local officials still dismiss journalists by saying they are "not clear" about the situation or refuse to provide any details without going through "proper channels" — many of which take days. "It's far from ideal," said Henry Niman, a Harvard University Medical School instructor and frequent critic of SARS responses who moderates e-mail lists about both SARS and bird flu. "In some senses, they're a little more forthcoming" with bird flu, Niman said Tuesday. "But in some senses it's the same. ... There's no human cases? It just doesn't quite add up." Last month, the World Health Organization issued a sternly worded statement when China's fourth SARS case of the season was announced only after the patient had left the hospital in Guangdong. "Early detection, swift isolation and prompt reporting of cases are vital in the control of any infectious disease," it said, urging quick investigation. The Health Ministry said officials in Guangdong, where SARS emerged in November 2002, did not inform them until weeks after the man became sick. Asia's biggest health crisis this year is bird flu, which has infected millions of chickens and jumped to humans in two countries, killing at least 19. Health experts say the more people are infected, the greater the chances for a killer hybrid flu that could be easily transmitted among people — something that hasn't been detected yet. China has reported no human cases of avian influenza so far. But on Monday, WHO expressed concern that human cases might already exist in China given the wide reports of poultry cases here. Sunday, February 1, 2004 Posted: 12:33 AM EST (0533 GMT) BEIJING, China -- The World Health Organization has chided China over its handling of the reappearance of SARS after Beijing announced a fourth confirmed case of the deadly virus. The latest case -- a 40-year-old doctor -- has emerged in Guangdong, the southern Chinese province believed to be the epicenter of last year's outbreak which killed nearly 800 people and sickened around 8,000. The WHO on Saturday issued a strongly worded statement calling for China to undertake an urgent investigation into the sources of infection for the recent Guangdong cases. "The case raises a number of concerns about the manner in which the man's infection was detected, treated and reported," the WHO said. "WHO was not informed about this case until January 30," the agency said. "Early detection, swift isolation and prompt reporting of cases are vital in the control of any infectious disease." China came in for sharp criticism last year for apparently covering up the extent of the SARS problem and not acting swiftly enough to counter its spread. Beijing subsequently promised to be more open and timely in its communications concerning the SARS situation. In the most recent case, the doctor -- a director of a hospital in Guandong's main cirty, Guangzhou, -- fell ill on January 7 with a high fever, sore throat and fatigue. The man -- identified only by his family name, Liu -- checked himself into a hospital on January 13, the official Xinhua news agency reports. Within five days, "his body temperature dropped to normal and his condition stabilized." Liu "was already discharged from hospital several days ago upon total recovery," Xinhua said. The WHO said it was only informed about the case on January 31. The doctor has denied having any contact with animals or SARS patients, according to Xinhua. Health officials have been monitoring 48 people who had contact with him, but none has showed any symptoms, it said. WHO said it was important for health authorities to trace how the patients became sick as soon as possible. "Now we have four cases without a concrete source of infection," Roy Wadia, a WHO spokesman in Beijing, said, accordinfg to The Associated Press. "It's something we're very concerned about." http://www.cnn.com/2004/WORLD/asiapc...ars/index.html By Maggie Fox, Health and Science Correspondent WASHINGTON (Reuters) - The SARS virus fine-tuned itself to become more infectious as last year's epidemic spread across China, researchers reported on Thursday. Early patients with Severe Acute Respiratory Syndrome had a form genetically very similar to that seen in civets, while the last patients in the epidemic had a slightly mutated form, the researchers said. "What we see is the virus fine-tuning itself to enhance its access to a new host -- humans," Chung-I Wu, a professor and chairman of ecology and evolution at the University of Chicago, said in a statement. "This is a disturbing process to watch, as the virus improves itself under selective pressure, learning to spread from person to person, then sticking with the version that is most effective." This may explain why the virus became more infectious with time, Wu said. The finding, published in the journal Science, supports the idea the virus leapt to people from animals and also should allow experts to understand the virus better. SARS infected more than 8,000 people last winter and killed nearly 800. This year, two people have been confirmed to have been infected with SARS and a third is considered a probable case -- all in China. The virus that causes the disease, marked by severe pneumonia, is a never-before-seen type of coronavirus. Coronaviruses cause the common cold in people and a range of infections in animals. Wu, Guoping Zhao of the Chinese National Human Genome Center, and colleagues in China including at the Guangdong Center for Disease Control and Prevention studied the spike protein on the virus -- known to give the microbe its ability to infect. In the first people infected it was virtually identical to viruses taken from civets, weasel-like animals valued for their meat and sold in markets in southern China. As the virus spread more freely from person to person, it mutated slightly, apparently adapting itself better to live in humans. That was when the "super-spreading" occurred that made the virus so frightening -- including the case of a doctor who infected several people at a Hong Kong hotel. The virus then gradually evolved into a more stable genetic form toward the end of the outbreak, Wu's team reported. They said the study should help researchers find a vaccine against SARS based on the spike protein. JAN 29, 2004 BEIJING (AFP) - China was on Thursday facing allegations that it was the source of the Asia-wide bird flu outbreak as the World Health Organisation asked for an explanation of the deaths of two Hong Kong tourists a year ago. The respected British weekly New Scientist said it believed the outbreak began in southern China in early 2003 after a poultry vaccination scheme went wrong and that it had since been covered up. The report has put the spotlight back on the two dead tourists who visited southern China in February last year. The WHO has asked the Chinese government for more information as part of efforts to establish the history of the bird flu outbreak which has been detected in 10 Asian nations. 'It's definitely worth getting a final conclusion on the case,' Beijing-based WHO spokesman Roy Wadia said on Thursday. An eight-year-old Hong Kong girl fell ill and died in south-east China's Fujian province in February last year while visiting her family. Her father died 12 days later after returning to Hong Kong, and post-mortem specimens showed he had come down with the H5N1 strain of the bird flu virus which has claimed 10 lives in Vietnam and Thailand. The WHO last week asked the Chinese health authorities for more details about this case, although it has warned about making any premature link between the two deaths and the current bird flu outbreak. 'There could have been several emerging sources,' said Mr Wadia, adding that so far the UN health body had received no response. The New Scientist, quoting unidentified health experts, said the outbreak 'probably' began in China. 'A combination of official cover-up and questionable farming practices allowed it to turn into the epidemic now under way,' said the magazine. China on Thursday denied the allegations. Foreign ministry spokesman Zhang Qiyue rejected the charges saying: 'We believe that such an allegation is totally inaccurate, groundless and doesn't respect science.' China earlier this week confirmed bird flu had been discovered at a duck farm near its border with Vietnam. Suspected cases of bird flu have also been detected in central China's Hubei and Hunan provinces. Local officials said on Wednesday that those cases have been provisionally confirmed as bird flu. Indonesia agrees to cull Meanwhile, Indonesia on Thursday caved in to international pressure and ordered the immediate killing of all poultry infected with bird flu, but it was unclear whether the cull would extend to healthy poultry as it has in other nations. 'We will do it. We will destroy those infected. The good ones will be saved,' Welfare Minister Yusuf Kalla said. Indonesia has said millions of birds across much of the vast archipelago have been infected. India bans all poultry imports The Indian government said on Thursday it has banned all poultry imports from all countries. 'India has completely banned the import of poultry (products) from any country following the outbreak of the deadly bird flu,' Health Minister Sushma Swaraj told reporters. She added that no case of a bird death due to the flu had been reported from any part of the country. Key quote: "The first time an avian flu virus was found to have infected people was in Hong Kong in 1997. At least 18 people fell severely ill and six died. Experts believe a pandemic may have been averted that time by the rapid slaughter of Hong Kong's entire poultry supply ? an estimated 1.5 million birds killed in three days. That flu virus was the H5N1 variety, one of 15 known subtypes of avian flu. The WHO calls it worrisome for several reason: It mutates rapidly and tends to acquire genes from flu viruses in other animal species; it is clearly dangerous to people; and it spreads quickly. Infected birds give off the virus for at least 10 days in their feces and oral secretions. H5N1 appeared again last February, when two members of a family returning to Hong Kong from China became ill. One died and the other recovered." By DANIEL Q. HANEY, AP Medical Editor With luck, the world will escape the latest outbreak of bird flu with no more than the six human deaths already blamed on it and the loss of millions of chickens. But public health experts worry of a much greater disaster: A catastrophe they say is among the worst imaginable, a global outbreak of an entirely new form of human flu. There is no clear sign that will happen. Nevertheless, avian influenza's sudden sweep through Asia, along with its tendency for wholesale mutation, leave many wondering about the bug's potential for rampant spread among humans. It is a possibility the medical journal The Lancet calls "massively frightening." "The question everybody is asking is, 'Is this the progenitor to a pandemic?'" says Dr. Gregory Poland, chief of vaccine research at the Mayo Clinic. Influenza pandemics typically strike three or four times a century. The worst in the past 100 years, the 1918-19 Spanish flu, caused an estimated 40 million to 50 million deaths. Another is considered inevitable and perhaps overdue, but when it will happen and how bad it will be are almost totally unpredictable. The nightmare this time would be a flu virus leaping from birds to people and spreading, introducing a disease for which humans have no natural defense. The potential source is the strain of bird flu that has moved rapidly through parts of Asia since December, infecting chickens in at least six countries. Millions of birds have died of the flu or were destroyed by workers trying to contain the outbreak. The World Health Organization says eliminating this "animal reservoir" is urgent. Avian flu is naturally carried by wild ducks, and it ordinarily does not attack creatures other than birds or pigs, so experts are especially concerned that this bird flu is occasionally infecting people. Human cases have been reported in Vietnam and Thailand, including six deaths as of Saturday in Vietnam, the WHO said, and one suspected death in Thailand. Experts believe all caught the virus from chickens, not other people. "We know there are two possible ways a new pandemic strain can emerge," said Dr. Steve Ostroff, deputy director of the National Center for Infectious Diseases at the Centers for Disease Control and Prevention (news - web sites). One is a human flu virus that resurfaces after years of dormancy, so people have no defense built up from earlier bouts. The other is a non-human variety acquiring the ability to infect people and spread. The latter may happen if somebody already infected with a human flu virus also catches the bird virus. Inside the body, these two may recombine into a new mutant, part-human virus, part-bird. The more people are around infected chickens and other birds, experts say, the more chances there are for such a disaster to occur. "If the virus continues to spread in chickens, it may adapt itself so it can grow in humans," says Dr. Arnold Monto, a University of Michigan epidemiologist. "If it is transmitted human to human, then we are concerned this is the start of the great pandemic." The first time an avian flu virus was found to have infected people was in Hong Kong in 1997. At least 18 people fell severely ill and six died. Experts believe a pandemic may have been averted that time by the rapid slaughter of Hong Kong's entire poultry supply ? an estimated 1.5 million birds killed in three days. That flu virus was the H5N1 variety, one of 15 known subtypes of avian flu. The WHO calls it worrisome for several reason: It mutates rapidly and tends to acquire genes from flu viruses in other animal species; it is clearly dangerous to people; and it spreads quickly. Infected birds give off the virus for at least 10 days in their feces and oral secretions. H5N1 appeared again last February, when two members of a family returning to Hong Kong from China became ill. One died and the other recovered. How and where they got infected was never learned. The disease now circulating in Asia is the same H5N1, but it is so widespread that a quick purging, like Hong Kong accomplished seven years ago, is unlikely. Testing shows it has mutated but has not yet picked up any genes from human flu viruses. If a bird flu pandemic occurs, could it be stopped? Many experts fear not. Flu is so contagious that quarantining victims, a method that eventually contained SARS last year, is unlikely to work. Studies suggest that prescription drugs used to treat human flu strains could also keep people from catching the bird flu. However, spot shortages were reported during this winter's U.S. flu outbreak, and supplies would quickly run out during a pandemic. No country has stockpiled the drugs, Tamiflu, Relenza and the older amantadine and rimantadine. The WHO is already working on a prototype vaccine against the bird flu. But even the standard annual flu shot takes six months to manufacture, and experts doubt a new vaccine could be ready in time. If there is evidence the bird flu is producing significant illness in humans, "there would be a full-bore effort to produce a vaccine," says the CDC's Ostroff. "It's hard to predict the timeliness of it and how widely it could be put into people's arms." ___ EDITOR'S NOTE: Medical Editor Daniel Q. Haney is a special correspondent for The Associated Press. HONG KONG (Reuters) - Scientists in Hong Kong have discovered people with a certain pattern of genes have a much higher risk of getting SARS, a finding that could help diagnose and prevent the spread of the deadly disease. A study of SARS patients in Hong Kong showed individuals with a pattern known as HLA-B*0703 were four times as likely to contract the respiratory disease, said Paul Chan, an associate professor in microbiology at the Chinese University of Hong Kong. Those with a pattern labeled HLA-DRBI*0301 had a much lower risk, indicating genetic make-up may play a key role in determining if some people are more susceptible to the virus than others. "Our findings from this study will help us more accurately diagnose the disease and design effective prevention programs," Chan said on Thursday. "For example, we could test an unproven vaccine or prevention method on the high-risk group. Hospitals may also consider sending only low-risk health workers to take care of SARS patients," he said. The Hong Kong researchers examined the blood samples of 90 SARS patients and studied the patterns of their human leucocyte antigen (HLA) genes, which influence the activity of cells that are responsible for the immune system's response during infections. The results were then compared with samples from people who did not have Severe Acute Respiratory Syndrome. More than 1,700 people in Hong Kong contracted SARS last year after it spread from southern China and nearly 300 of them died. Worldwide, more than 8,000 people were infected and more than 800 died. China recently announced its first confirmed SARS case in months and two suspected SARS cases in the southern city of Guangzhou. The government is still awaiting definitive test results on the suspected cases. Another Hong Kong scientist said on Wednesday it was a new variety of the SARS virus that had emerged in China and it appeared to be less contagious than the strain last year. Both are believed to be from the same family of coronaviruses, which also cause the common cold. By Maggie Fox, Health and Science Correspondent WASHINGTON (Reuters) - A genetic susceptibility may explain why SARS raged last year in southeast Asia and nowhere else in the world outside of Toronto, Taiwanese researchers reported this week. They found a certain variant in an immune system gene called human leukocyte antigen, or HLA, made patients in Taiwan much more likely to develop life-threatening symptoms of SARS. The gene variant is common in people of southern Chinese descent, the team at Mackay Memorial Hospital in Taipei reported. Their finding, published in an online journal, BMC Medical Genetics, must be confirmed by independent researchers. But the Taiwanese team said the genetics could explain the puzzling distribution of SARS last year. "After the outbreak of SARS coronavirus infection in the Guangdong Province of China, it was surprising to observe that the spreading of the disease was mostly confined among southern Asian populations (the Hong Kong people, Vietnamese, Singaporeans and Taiwanese)," they wrote. Severe Acute Respiratory Syndrome first arose in Guangdong last November. It spread to Hong Kong, Vietnam, Beijing and Singapore, and was transported around the world by airliner. SARS eventually was suspected of affecting 8,098 people and killing 774, according to the World Health Organization's latest figures. The flu-like disease is caused by a virus from a family known as coronaviruses. They cause diseases in livestock and some cases of the common cold in people. The SARS coronavirus is unique genetically but similar versions have been found in animals sold in Chinese food markets. Marie Lin, Chun-Hsiung Huang and colleagues examined the HLA gene in 37 cases of probable SARS, 28 fever patients excluded later as probable SARS, and 101 non-infected health care workers who were exposed or possibly exposed to SARS coronavirus. "An additional control set of 190 normal healthy unrelated Taiwanese was also used in the analysis," they wrote in their report. They found that patients with severe cases of SARS were likely to have a version of the HLA gene called HLA-B 4601. They noted that no indigenous Taiwanese, who make up about 1.5 percent of the population, ever developed SARS. HLA-B 4601 is not seen among indigenous Taiwanese, they noted. "Interestingly, (HLA-B 4601) is also seldom seen in European populations," they added. |
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