Human Human bird flue cases

Doctors fear latest human-to-human bird-flu cases

Published on Dec 01 , 2005

The two latest confirmed cases of human bird flu in Thailand might be
human-to-human transmissions, a senior health official said yesterday.

Dr Charoen Chuchottaworn, a bird-flu expert at the Public Health
Ministry's Department of Medical Services, said doctors concluded after
reviewing the history of the past two cases that both victims presented
very mild symptoms of avian influenza and neither had any physical
contact with chickens or birds.

One of the victims was a boy in Bangkok and the other was an
18-year-old man from Nonthaburi province.

This left doctors no clues as to where the patients became infected
with the H5N1 virus and showed that the avian influenza had moved from
causing severe human infection to milder cases.

Charoen, who is also a member of the national committee issuing
guidelines for the treatment of avian influenza, was speaking at the
Joint International Tropical Medicine Meeting 2005 in Bangkok.

Dr Kamnuan Ungchusak, director of the Epidemiology Bureau, challenged
Charoen's assertion about human-to-human transmissions.

He told The Nation that while neither of the patients had direct
contact with chickens, they lived in an environment where the virus was
prevalent.

"Chickens were dying near their homes and chicken droppings were
everywhere around their neighbourhood," he said.

"They might have contracted the virus through contaminated soil."

Dr Charoen said that the milder the symptoms, the harder it is for
doctors to diagnose. This means that a lot more advanced laboratory
facilities are needed with a testing technique called RT-PCR to confirm
cases and decide if patients should be treated with antiviral Tamiflu
(oseltamivir phosphate).

He said this meant that avian influenza could become asymptomatic now.

The only tool available in Thailand to fight H5N1 infections at the
moment is insufficient, he said. At present, Thailand has about a
million capsules (for 100,000 treatments) of Tamiflu, but it is
estimated that about 120 million capsules of the drug will be needed.

In the past, only severe cases of human bird flu have been detected in
Thailand simply because patients went to hospital for treatment. But
doctors believe that there have been many cases with mild symptoms of
the disease.

"We believe that this is the tip of the iceberg," he said.

Signs of possible human-to-human transmission were closely observed in
Vietnam, where 10 clusters of probable human transmissions were
detected in which the victims had no contact with infected poultry,
Charoen said.

Thailand and Indonesia had one official cluster, he said, but the
Indonesian cluster showed clear-cut evidence because a child contracted
H5N1 without going to an infected area, as her father had.

Arthit Khwankhom

The Nation