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Thailand Confirms H5N1 Fatality
Recombinomics Commentary
October 20, 2005
Health officials said the victim was a 48-year-old man in Kanchanaburi province, which has recently reported fresh outbreaks of the deadly avian influenza strain in poultry around 100 km (60 miles) west of the capital, Bangkok.
"The first lab results came out negative but we tested it several times and it confirmed it was positive," Thawat Suntrajarn, director general at the Department of Disease Control told Reuters.
Thawat said the victim's son, who had a history of contact with chickens, had so far not tested positive for the disease.
The above description of the first reported H5N1case in Thailand raises serious questions regarding false negatives in Thailand. Both Thailand and Vietnam reported human cases in 2004 and the case fatality rate in both countries was around 70%
This year there were cases in Vietnam, although the cases in the north were milder. In the south, the cases in Vietnam and neighboring Cambodia were approximately 100%. However, until now Thailand reported no human cases.
The lack of human cases in Thailand was curious. There had been H5N1 outbreaks in birds including wild birds, and the H5N1 isolated from the birds was virtually identical to the sequences from 2004, including the most famous cluster in people as well as tigers. In the human cluster in 2004, samples were not collected from the index case or mother ands the aunt initially tested negative. Like this current cluster, it seems that the H5N1 positive results were linked to the fact that the case was a cluster and high profile. It is not clear that any of the cluster cases would have been reported had they not been in clusters.
The sequence homology between 2004 and 2005 isolates in Thailand with H5N1 from its neighbors strongly suggested that the H5N1 in birds should result in H5N1 in people.
Like H5N1 in Vietnam, Cambodia, Laos, and Malaysia, the H5N1 isolates in Thailand were amantadine resistant and the eight genes contained a number of mammalian polymorphisms.
The latest H5N1 in positives suggests earlier cases were either no tested or were reported as negatives. A similar lack of reporting of lab confirmed cases in 2004 has also been reported, providing further evidence for a gross underestimate of the number of H5N1 cases and deaths in Thailand.
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