4 May 2009
By Kounteya Sinha
New Delhi, India
Flu Has Affected 872 People In 18 Countries
Ironically, a virus believed to have originated from pigs is now being found to be jumping from humans to swines. On a day when the World Health Organisation announced a surge of confirmed H1N1 flu cases among humans – nearly 872 in 18 countries – Canada reported the globe’s first reverse transmission of H1N1 from humans to pigs.
Canadian health officials believe the infection that was found in 220 hogs – about 10% of the farm’s pig population – spread from a farm worker Who became ill during a recent trip to Mexico. Another worker on the farm is being tested for symptoms.
Interestingly, the same H1N1 strain that is presently infecting humans was found to have caused the infection in pigs. “This is the first detection of the virus in pigs that up until now was being seen to be jumping from human to human,” said the Who. The global health body, however, was quick to reiterate that at present there was no recommendation to cull pigs, which is normally the job of the OIE or FAO.
Experts in Geneva say influenza viruses are known to reassert all the time in nature. However, this case of reverse transmission has led to fears of the H1N1 virus mixing with another highly pathogenic influenza strain – the H5N1 avian influenza virus – and becoming a more dangerous strain.
“With hogs and poultry sometimes being part of the same farm, it’s a concern that H1N1 may mix with H5N1. Better surveillance will ensure the virus does not spread geographically picking up new viruses,” Who said.
Indian Council of Medical Research director general Dr V M Katoch told TOI, “The virus now jumping from humans to pigs should not worry India too much as controlled pig farms are rare in the country.”
In the light of the virus’s new traits, Who’s scientific committee is meeting in Geneva on Monday to discuss what they now know of the virus – its incubation period, its severity, maybe its origin and which groups may be most vulnerable.
Who also said it was unclear when the latest outbreak would be termed as a pandemic at phase 6 level as at present, epidemeological data suggests that the virus had not spread in a sustained way outside of the Americas, a condition necessary to declare a full global pandemic.
Cautioning against Mexico’s view that the epidemic was easing having peaked between April 23–27 in the country, and that the virus’s genetic makeup lacked traits seen in the deadly 1918 flu pandemic strain, the Who said the only wise course was to prepare for the worst.
“In 1918, the Spanish flu surged during spring, disappeared in summer only to reappear with a vengeance during autumn and ultimately take over 40 million lives. Such increase and decrease of virus activity should not make us lower our guard. There is a high possibility the virus will come back in colder months,” an official said.
Michael Ryan, Who’s director for global alert and response, added, “This is the time for us to prepare, and be ready.”
Although human cases have been confirmed in Europe and Asia, there is still no evidence suggesting that sustained community outbreaks have occurred in the two regions.
Meanwhile on Sunday, Ireland and Colombia became the latest countries to report H1N1 infection.
Who is sending 2 million treatment courses of antiviral drugs to 72 developing countries to help them prepare for a possible pandemic.