MOSCOW. (Yevgeny Kuznetsov for RIA Novosti) - In the first month of 2008, avian flu caused by the H5N1 strain was registered at least in 12 countries - Israel, Vietnam, Britain, India, Iran, China, Egypt, Germany, Thailand, Turkey, Ukraine, and Bulgaria.
Surprisingly, there have been no cases of avian flu in Russia, but there is a high risk of an outbreak in Russia's European South - the Krasnodar and Stavropol Territories.
This forecast is based on the fact that all cases of avian flu mentioned above were registered in places where birds spend their winters. There are such places in Russia's South as well. Almost all wild birds fly there from Siberia, a home to the majority of the waterfowl. The H5N1 strain has revealed itself in Russia quite often (most recently last December), but this does not mean that it is being spread by wild birds from this hotbed. Wild birds rarely get sick, whereas poultry die in large numbers. Hence, the virus does not come from Russia.
Reports about causes of the flu outbreaks sound like a squabble of exhausted people - veterinarians blame wild birds for spreading the virus, whereas ornithologists deny this. Many officials from international organizations are siding with the latter.
More than 350,000 wild birds have been tested in Europe, and very few had traces of the dangerous virus. In the meantime, poultry is regularly killed by avian flu throughout the year. Migration is seasonal - in spring, birds fly to the North, and in the fall to the South. If wild birds carried the dangerous virus and infected poultry, both would be dying along migration routes. But this is not the case.
Moreover, the highly pathogenic virus or its antibodies were revealed in 748 wild birds in 2006 (February-May), while the relevant figure for 2007 (late June-early August) was 308. These are completely different pictures, and so far no one has come up with any explanations. But one conclusion suggests itself - the virus keeps changing, and its mutations are not linked with wild birds because nothing is happening in their populations.
The most logical conclusion stems from the location of the flu outbreaks - it is disseminated by poultry. Even if wild birds are spreading the virus, they are doing so at short distances. There is no limit to the distance for trade in poultry, products of poultry farming, or wild birds.
The main task is to improve the upkeep of poultry in small and large farms. When recent cases of avian flu were registered in Russia's Rostov Region, the local vets blamed them on wild birds. But it transpired during the inquiry that few farms kept poultry in isolated premises, or observed sanitary standards. Even if we assume that the virus was brought in by wild birds, the responsibility for the massive death of chickens at the poultry farms rests with those who failed to abide by sanitary and technical standards.
Instead of repairing chicken coops to isolate poultry from contact with wild birds, some poultry farms hire hunters to ward off the latter. Hunters are supposed to fire into the air from time to time to scare off unwanted guests, but hunters are much less effective than major poultry farm overhaul. Strict isolation and sanitary norms have made American poultry farming completely immune to avian flu.
There is a hypothesis that for the most part explains why wild birds die of avian flu at winter nesting areas. If the virus has already emerged in the environment, it persists there for a long time. Its pathogenic qualities become more pronounced during winter, when wilds birds have a hard time (in Europe and southern Russia). Stress, low temperatures, and lack of food reduce their immunity, and they are more likely to catch different diseases, including avian flu.
The dangerous H5N1 strain has been circulating for five years. This is an unprecedentedly long period, but the strain is still as active as before. It was revealed in domestic geese in China in 1996 for the first time. A year later, it killed poultry at farms and wholesale markets of Hong Kong. Since 2003, people started dying from it. All in all, 357 people have been infected with this strain in 14 countries ( Azerbaijan, Cambodia, China, Djibouti, Egypt, Indonesia, Iraq, Laos, Myanmar, Nigeria, Pakistan, Thailand, Turkey and Vietnam), and 255 died from it.
Will this highly stable and active strain become a killer of humans? This would be a sad turn of events because millions could die from it.
For the time being, this strain cannot easily penetrate human cells, and we do not know if it will develop this ability in the future. Hopefully, it will remain an avian rather than human virus.
Yevgeny Kuznetsov is a leading scientist at the Wild Animal Protection Center.
The opinions expressed in this article are the author's and do not necessarily represent those of Trend.-0-