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Declan Butler, who began writing about the H5N1 virus long before most people were paying attention, has been on a roll the past couple of weeks with a number of terrific articles in the journal Nature about the H1N1 virus.
Today he explores the idea that the largely ignored equatorial regions of the earth may be a likely birthplace of flu mutations.
Swine flu attention turns to the tropics
New flu strains are more likely to arise in equatorial countries, where influenza is present the year round and surveillance is poor.
Influenza outside the developed countries of the Northern Hemisphere is often overlooked.
A. BIRAJ/REUTERS
With the influenza season over in the temperate Northern Hemisphere, and just getting under way on the other side of the world, scientists are watching the A(H1N1) swine flu virus to see where it goes next and whether it will reassort with other flu viruses, or mutate, to cause more severe disease or acquire resistance to antiviral drugs.
Some researchers are warning, however, that such changes might be more likely to occur not in the northern or southern temperate zones where flu is seasonal, but in the narrow, often-overlooked belt of tropical countries where flu circulates all year round.
"We should be getting the message across that it is probably in the tropical countries, more than in the Southern Hemisphere, that this virus will be going through some reassortment contortions in the coming months," says Ken Shortridge, a veteran of flu research in China and southeast Asia, now retired in New Zealand.
Outbreaks of the new virus have so far been largely confined to the Northern Hemisphere, and public-health officials are crossing their fingers that as summer approaches outbreaks may wane — although that is far from a given. That would buy time for a new vaccine to become available just before the expected wave of new cases next winter.
An intriguing article. Highly recommended.
