Editorial: Another global outbreak of bird flu

Published in The Hindu on February 12, 2007

With the recent outbreak of bird flu in a farm in Suffolk, Britain, after similar episodes in Hungary, Russia, and Nigeria and some Southeast Asian countries, the threat of another wave of the epidemic sweeping the globe is becoming real. While the new global outbreak was not totally unexpected given the high prevalence of the virus in birds, both poultry and wild, the short interval between the end of the previous global outbreak last year and the onset of the latest one is worrying. It is a reminder that despite prompt responses to contain the spread of avian flu in the countries affected by it last time, the threat persists even in the immediate term and the measures taken to tackle the problem have not been adequate. No outbreak has been reported in China so far but Vietnam and Indonesia appear to be the worst hit. While Southeast Asian countries are considered the hotbeds for the avian flu virus, the latest outbreak underlines the role of poultry and migratory birds in spreading the virus to countries across the globe. Compulsory vaccination of all poultry, in the absence of other biosecurity measures, appears to have had little effect in keeping the infections under check. In fact, and somewhat ironically, this is suspected to be a direct cause for fresh outbreaks and emergence of new strains, the two happenings that make disease control really challenging.

A new bird flu strain Fujian-like in poultry, first identified in March 2005 in a duck in Fujian, China, is now noticed in Hong Kong, Laos, Malaysia, and Thailand. It has been found to infect humans as well. The prospects of a complete elimination of the H5N1 virus appear bleak as birds continue to harbour the virus and act as carriers. The virus has also acquired the ability to infect cats and other mammals. Large-scale infection in mammals may result in the virus adapting itself to mammals and also help it acquire the ability to spread to humans and from one human to another. According to the World Health Organisation, 271 humans have been infected by H5N1 virus since 2003 and 165 have died. Human-to-human transmission of the virus has been confirmed with the death of seven members of an Indonesian family in May last year. Backyard rearing of poultry, common in many African and Asian countries, and close intermingling of humans with backyard poultry further provide an ideal environment for the virus to jump species. It is imperative for India, which is right now free of bird flu, to maintain a high level of hygiene, keep a constant vigil and, in the event of an outbreak, resort to immediate culling of birds and ring vaccination.