Bird Hit

But it’s not a new phenomenon. So why the to-do now?
According to the WHO, the current outbreak of avian influenza—caused by the H5N1 virus, which was first detected in southeast Asia in mid 2003—is the largest and most severe on record. Never before has the disease killed so many birds and affected so many countries, including Indonesia, Vietnam, Cambodia, China and Thailand.

‘‘Despite the death or culling of an estimated 150 million birds, the virus is spreading,’’ says Dr CM Gulati, former WHO drug expert and editor, Monthly Index of Medical Sciences. The WHO says it will take years to control the disease among poultry.

How does it affect people?
The highly pathogenic H5N1 virus is known to have crossed the bird-human divide. About 200 cases of bird flu have been reported among humans so far across the world; 70 people have died.

What’s the scene in India?
Though no bird flu cases have been reported here so far, migratory birds do pose a threat to the country. About 6,000 bar-headed geese died in the wetlands of China in spring because of avian flu—these birds migrate to India in the winter.

While the WHO maintains that the role of migratory birds in the spread of the disease is not fully understood, they are suspected to have directly spread the H5N1 virus.

What are the symptoms of bird flu in people?
Unlike normal seasonal influenza, where infection causes only mild respiratory symptoms, the disease caused by H5N1 follows an unusually aggressive clinical course, with rapid deterioration and fatality. It starts with viral pneumonia and often ends in multiple organ failure. And that’s not all the bad news.

It gets worse?
What has the WHO really worried are the chances of mutation in the virus. Influenza viruses have a tendency to mutate. If it mixes with other viruses and changes into a form that is highly infectious for humans, it could mark the beginning of a global outbreak, a pandemic.

That’s quite dark. Any silver lining?
Well, no human-to-human transmission of bird flu has been reported so far. But if it does, a pandemic is virtually inevitable, since the virus can spread very rapidly through coughing or sneezing. ‘‘The fact that infected people can spread the virus even before they show any symptoms adds to the international risk via asymptomatic air travellers,’’ says Dr Gulati.

Who’s most at risk?
According to WHO, the following increases the risk of human infection:
• Coming in direct contact with infected poultry
• Contact with surfaces and objects contaminated by the faeces of infected birds
• Exposure to infected birds during slaughter, de-feathering, butchering and dressing (as in pre-cooking prep)

Is it safe to eat chicken?
‘‘You have to be in really close contact with the birds to run the risk,’’ emphasises

Dr Gulati, ‘‘bird flu doesn’t spread by eating thoroughly cooked meat or eggs’’. In other words, it’s quite safe to pick up dressed chicken from the neighbourhood meat shop.

What about travelling to countries that have reported outbreaks?
That’s quite all right too, as long as you stay away from bird-slaughter scenes.

Are there vaccines or treatments available?
Though a vaccine against the H5N1 virus is being developed in several countries, none is ready for commercial production or expected to be available several months into a pandemic. But two drugs can reduce the severity and duration of illnesses caused by avian influenza: Oseltamivir (aka Tamiflu) and Zanamivir (aka Relenza). Neither of these, however, are very readily available.