Scientists studying the H7N9 bird flu virus say they’ve discovered a new strain of bird flu lurking in the chickens at the poultry markets of China.
In their experiments on nonhuman animals, they’ve found that H7N7, as the virus is known, can pass directly from chickens to mammals, and “may pose threats beyond the current outbreak.”
In the journal Nature they report:
The continuing prevalence of H7 viruses in poultry could lead to the generation of highly pathogenic variants and further sporadic human infections, with a continued risk of the virus acquiring human-to-human transmissibility.
H7N9 created a considerable scare earlier this year, with 135 confirmed cases in humans, all of them in China and Taiwan, and only one of them a confirmed case of human-to-human transmission – at least so far.
The people researching H7N7 are already nervous about it.
“If (we) let this H7N7 continue circulating in chickens, I am sure that human infection cases will occur,” study co-author Yi Guan wrote in an email. “This virus could cause more severe infection than… H7N9, based on our animal experiment.” Does the fact that we haven’t seen catastrophic pandemics from recent bird flus mean that it’s all just a series of false alarms?
An earlier strain of H7N7 that broke out in the Netherlands in 2003 caused one human death among 80 cases reported.
Among 50 chickens taken at random from the poultry markets, 36 tested positive for H7N7, and several carried H7N9 as well.
Does the fact that we haven’t seen catastrophic pandemics from recent bird flus like H7N9, H5N1 and the H1N1 “swine flu” mean that it’s all just a series of false alarms?
Not so. The World Health Organization, the Centers for Disease Control and others are constantly monitoring these viruses, studying how they mutate and developing vaccines. In the poultry markets of China and other Asian countries, health officials are watching for any signs of new diseases in birds and any reports of sickness at the markets. Potentially dangerous infections among the birds lead to mass exterminations.
In order for a virus to set off a deadly pandemic, two things have to happen: It has to be able to transmit from human to human, and it has to be not so deadly (at least not in its early stages) that the infected humans can still walk around and keep transmitting it to others before they get really sick and die.
That hasn’t happened in recent decades. But with more and more humans crowding the planet, and more and more chickens and other animals crowding the filthy, inhumane markets and factory farms, scientists and governments know it’s only a matter of time before the two conditions are met.