Infectious Diseases 2006

Infectious Diseases 2006

Resurgence of avian influenza in Asian countries

17 August, 2006

(Continuing outbreaks in China, recurrence in Cambodia, Laos and Thailand, and the steady march of the disease in Indonesia)
Both endemic and new virus strains to blame for avian influenza recurrence in Asia’s poultry
Laboratory confirmation points to both old and new isolates of the avian influenza virus as sources of recent HPAI outbreaks in Southeast Asia, FAO said today.
Concerned about the recurrence of avian influenza in Asia, close monitoring of diagnostic results by FAO has revealed that avian influenza is endemic in some areas while new strains have emerged in other places.
“Last month’s HPAI outbreak in Thailand’s Pichit province was caused by the same virus strain circulating in the area since 2003/4. The H5N1 virus thus remained alive in central Thailand in a reservoir of birds and poultry, most probably a mix of backyard chicken, ducks and fighting cocks,” said Laurence Gleeson, regional manager of FAO’s avian influenza centre in Bangkok today.
H5N1 endemic in Thailand's Pichit province
This indicates that the H5N1 virus is endemic in the area. While the number and size of outbreaks has been reduced, past control efforts were only partly successful.
On the other hand, the outbreaks in Nakhon Phanom and Vientiane were caused by a H5N1 virus strain previously not detected in Thailand and Laos. Instead, the virus is similar to recent isolates from southern China, suggesting that the virus spread from China to Thailand and Laos.
Risky cross-border trade continues
FAO recognizes that poultry trade across borders is continuing in Southeast and East Asia despite well-known risks to the governments and people in the region (FAO).