These days, the newspapers seem to have at least one story every day on avian or bird flu. Not just people but countries are frightened, and thousands of chickens all over the world have been slaughtered. What is bird flu, and why is it so troublesome? After all, the flu, or influenza to give it its full name, is a mild disease that nearly everyone gets and nearly everyone recovers from. At the most it’s a very bad cold, fever, body ache and a few days of bed rest and horrible medicines.
The flu is a common enough disease that’s caused by various types of related viruses. Usually it causes nothing more than an annoyingly painful short-term illness. But the flu is especially dangerous because it seems to be able to change or ‘mutate’ very rapidly. So the normal resistance that people have to the flu, the resistance that allows them to fight it and get better after a few days, may not work with mutated varieties of the flu, even though the parent virus itself may be very common. It is usually the very young or the old who are most at risk since their resistance is lower. Sometimes the mutated strains are so severe that they can turn into international disasters: between 1917 and 1918 a variety of the flu, known as the Spanish flu, killed nearly 50 million people as it spread all over the world. Incidentally, an international flu epidemic seems to happen three or four times every century.
Bird flu, as you would expect, is found in birds, which, like humans, are very susceptible to the flu. In fact, there are 15 types of bird flu of which the most contagious are H5 and H7. The type that is worrying doctors right now is the H5N1 strain. Migratory wild birds, such as ducks, are natural carriers of the virus, but are unlikely to actually develop an infection. But they can pass it on to domestic chickens that, because of the way they are reared in close proximity to each other, are much more susceptible to the virus than are wild birds. Because the virus is carried by wild birds, which obviously do not recognise national borders as they migrate, there is no way of preventing its spread.
It was thought that bird flu only infected birds until the first human cases were discovered in Hong Kong in 1997. In humans it can be fatal. Humans catch the disease through close contact with live infected birds. The usual infection route is by inhaling the virus from dry airborne bird faeces. The symptoms are the same as other types of flu: fever, tiredness, body ache, a sore throat and cough. This similarity could mean that many illnesses, even deaths, thought to have been caused by something else may have been due to the bird flu virus.
As of January 9, 2006, the World Health Organisation confirmed 146 cases of H5N1 in people in Indonesia, Vietnam, Thailand, Cambodia, China and Turkey. Of these infections 76 were fatal. In countries that have recorded large numbers of infected birds, most of which are in South East Asia, all the infected birds are being killed to try and prevent the spread of the disease to other birds.
Yet, the number of cases seems to be increasing and one explanation for this increase is that H5N1 has mutated into a form that can jump more easily between chickens and humans. If true, this also means that it could genetically mix with human influenza viruses, making its spread quicker. This is what experts fear the most. If the double infection happens it could create a new virus that can pass from person to person. Once the virus gains the ability to pass easily between humans the results could be catastrophic. Right now the only people who have got the bird flu are those who have been in close contact with sick birds. In fact, some researchers believe that the virus that caused the 1918 international epidemic was an avian flu virus that changed in precisely this way.
There is no vaccine yet that prevents people from catching the virus. Anti-viral drugs, especially one called Tamiflu, are being made and stocked by countries. Though Tamiflu helps limit the symptoms and slow the spread of the virus, it does not actually cure it. In fact, if there is a universal epidemic (called a pandemic) it will be of a mutated strain of the H5N1 virus, so scientists don’t actually know if Tamiflu will actually work.
One positive sign is the way countries of the world came together to fight the SARS epidemic a few years ago. That could have been a very bad pandemic, killing thousands if not millions of people, but proper identification of the infected and their isolation in hospitals was enough to halt the SARS epidemic. The bad news is that SARS patients were not infectious during the early stages of their illness; flu patients tend to be very infectious even before they actually begin to feel sick. So, diagnosing and identifying infected people will not be easy; people can have and spread the flu before showing any symptoms.
But there are people who think that bird flu is not a serious worry; that it’s a money-making scare made up by the rich developed countries, especially the USA, and the huge pharmaceutical companies based in them.
Tamiflu (Oseltamivir phosphate) was developed and patented in 1996 by a US company called Gilead Sciences, which then sold it to the Swiss-US pharmaceutical giant Roche. This is one of the world’s largest and most powerful corporations, and they are making a lot of money from the fear of avian flu as people and governments rush to buy and stock the drug. Roche does not allow other drug manufacturers to produce Tamiflu.
Gilead Sciences still also makes money from every dose of the drug sold. US Defence Secretary Donald H Rumsfeld not only used to work for Gilead Sciences he is also a major stockholder in the company. Other people in the US government or close to it also own shares in the company. All these people stand to make a lot of money from bird flu, and the scare surrounding the virus. Many development workers think this is more than just a coincidence.
-- Manoj Nadkarni
Kids For Change, February 2006