A global public health concern is rising over the recent spread of bird flu, with experts saying that it’s only a matter of time before the virus makes the jump from birds to humans.
Over the past three months, outbreaks of the influenza virus have been reported in poultry farms and wild birds across Europe, Africa and Asia, where at least half a dozen strains have been identified, including H5N1, H5N2, H5N8 AND H7N8. Since November, almost 40 countries have reported new outbreaks of bird flu, according to the World Health Organization, which has warned that the world “cannot afford to miss the early signals” of a possible human pandemic arising from the phenomenon.
“The rapidly expanding geographical distribution of these outbreaks and the number of virus strains currently co-circulating have put WHO on high alert,” director-general Margaret Chan told the start of the U.N. agency’s executive board in Geneva on Monday, Reuters reported.
Normally at a low risk for making the transition to humans, the rapid expansion of so many strains at once increases the chances for mutation of avian influenza and a possible jump to humans.
“This is a fundamental change in the natural history of influenza viruses,” Michael Osterholm, an infectious disease specialist at University of Minnesota, said of the proliferation of bird flu in terms of geography and strains – a situation he described as “unprecedented”.
In the UK, a strain of H5N8 has been confirmed in a flock of 19,500 turkeys at a farm in Boston, Lincolnshire, the third such confirmation in the area over the past month. The British Department for Environment, Food and Rural Affairs reports that a three km protection zone has been erected around the property where some of the birds have already died of the flu while the rest are due to be slaughtered.
Experts have tracked avian flu for over 100 years and while it has led to the deaths of millions of birds worldwide, very few known cases have been observed in humans so far. But the rapid expansion of poultry farming over the past few decades – one study estimates that poultry production increased by 76 per cent in developing countries during the 1990s and 23 per cent in developing countries – has made it much easier for avian flu strains to proliferate. The first documented cases of avian flu in humans were observed in Hong Kong in 1997 when 18 people were infected by the H5N1 virus, with six of them dying from the illness. Scientists say that a spread of “humanized” bird flu could become a worldwide pandemic.
The Canadian Food Inspection Agency tracks outbreaks of avian influenza in Canada, last year reporting on an outbreak on a commercial firm in St. Catherine’s, Ontario, where 14,000 ducks were killed to prevent further spread of the virus. The CFIA stated at the time that their main concern in terms of prevention is to keep external contact of livestock at a minimum and assured that the public is not at risk. “Avian influenza does not pose a risk to food safety when poultry and poultry products are properly handled and cooked and rarely affects humans,” said Dr. Harpeet Kochhar, Chief Veterinary Officer of Operations at CFIA, to the CBC.