H5N1 Bird Flu Case in Downtown Bangkok
Recombinomics Commentary
August 7, 2006
A man was admitted into a hospital in downtown Bangkok on Monday on suspicion of deadly bird flu virus, the Bangkok Metropolitan government officials told Xinhua.
The man who lives in Sathorn District, a main commercial zone of Bangkok, was isolated by the hospital after suffering a few days of flu symptoms, the official said.
It was very likely that the patient has been infected with the deadly H5N1 bird flu virus.
The above comments support recent media reports that the patient has tested positive for H5N1 in initial tests. Reports also indicate that he has touched a pigeon. This is the fourth patient to have tested positive. Two have been confirmed in local testing and have died. A third person was not confirmed. The sudden increase in lab confirmed H5N1 in three separate provinces of Thailand is cause for concern.
In addition, a number of suspect cases are teasing positive for seasonal flu. Many if not most of the seasonal flu patients are H1 positive. However, a number are influenza A positive, H5 negative, but have not been sero-typed.
The number of influenza positive fatalities has increased and the number cited for this year is equal to a 5% case fatality rate, which is extraordinarily high for seasonal flu. I recent fatality of a 19 year old in a district that has had both human and bird H5N1 was said to have died from complications of pneumonia. This year there have already been 300 flu deaths.
These numbers raise concerns that H5N1 fatalities are being misdiagnosed as seasonal flu. Requests were made for further testing of the second H5N1 fatality because the live chickens were H5N1 negative. The tight linkage expectations are cause for concern.
In Indonesia, the number of fatal cases has now reached 43, the highest in the world. However, the H5N1 in human cases in Indonesia does not match the avian sequences in Indonesia. Instead, these patients have mammalian polymorphisms, including those found in H1N1. In addition, there are polymorphisms commonly found in H5N1 from Vietnam.
The sequence data raises concerns over an evolving H5N1 that is acquiring mammalian polymorphisms and becoming better adopted to humans. Reassortment experiments failed to find H3N2/H5N1combinations that produce more growth or transmission. However, H5N1 has been evolving via recombination. The acquisitions of new polymorphisms has produce an ever increasing variety of H5N1 strains capable of producing fatal infections in humans.
The Fujian strain, which causes fatal human infections in China has been detected in Laos and Malaysia. Qinghai sequences, which are readily transported and transmitted by migratory waterfowl, have also been found in Indonesia cases.
More information of sequences of H5N1 in poultry and people in Thailand, as well as sequences of the H1 seasonal flu would be useful.
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