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The human race has evolved into such a strong species that its only threat are people themselves – and microbes.

An expert in health geography mechanisms, Professor Markku Löytönen says that the risk of a pandemic, a global epidemic, has increased for two reasons.

“ Faster means of travel made possible by technological development along with the accelerating growth of population have made conditions favourable for microbes,” Löytönen says.

Despite the few dozen deaths, the notorious bird flu in itself is still not a threat to people. But if the virus mutates and acquires the ability to be transmitted from human to human, it will become a serious threat.

“ So far there is no evidence of a clear human-to-human transmission,” Löytönen says.

In order to become a human-to-human virus, it has to learn at least two things.

“ The virus has to be able to use the sialic acid receptors in human cells and multiply efficiently in the low temperature of the human upper respiratory tract,” says Professor Olli Vapalahti from the Department of Basic Veterinary Sciences.

Yet it is only a matter of time until a pandemic of some degree erupts. When enough time has passed since the latest influenza epidemics, a greater number of people will become more susceptible to new viruses. Of the pandemics in the past century, the Spanish flu raging in 1918 killed, depending on various estimates, some 20 to 50 million people, while the Asian flu of 1957 and the Hong Kong flu of 1968 left many of the older, more immune generation untouched.

During the past decade, bird flu has been kept in check, particularly with the mass slaughtering of poultry in Hong Kong in 1997 and the Netherlands in 2003. To stop the virus now in the news, some 150 million birds have been destroyed mainly in Southeast Asia.

“ Wild waterfowl are natural hosts for A viruses and transmit them to farm birds, which in turn infect people,” Vapalahti says.

Text: Kai Maksimainen
Picture: Finfood
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Translation: Valtasana Oy