In 1983 a low-grade bird flu virus, perhaps left by ducks, spread into chicken warehouses in Pennsylvania. There, it mutated from a minor infection to become what Robert Webster, the virologist at the scene, called "Ebola for chickens."
This outbreak took two years and the destruction of 17 million birds to control. Webster links some of its spread to New York City's live bird markets, where chickens are packed into cages in close quarters with ducks and geese, natural carriers of bird flu.
Webster believes these markets pose a greater risk than CAFOs in the developed world where so-called "biosecurity" procedures to keep diseases out have been tightened since the emergence of H5N1. "Live bird markets are the breeding place for all pandemic strains in my opinion," he says, and, despite attempts to purge it, avian influenza continues to show up in American live bird markets.
But for those whose daily animal interaction doesn't extend beyond shooing squirrels or feeding the dog, the prospect of zoonotic disease shouldn't keep them awake at night. "Most people should be more afraid to walk into a doctor's office during flu season," says Pennsylvania State University avian pathologist Patty Dunn.
As for pigeons: research has shown that even those infected with bird flu actually transmit very little. And they carry so little West Nile virus in their bloodstreams that they are unlikely to infect mosquitoes who could then infect humans, Kilpatrick says, making the birds more likely to slow an epidemic than spread one.
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3 Comments
Add CommentPigeons are not as responsible for transmittion of infectious diseases as we thought.
Reply | Report Abuse | Link to thisEven so, Aspergillus and other agents are dangerous for immune-compromised hosts.
That is one of the reasons why it is essentially important to avoid feeding pigeons near a hospital.
Seems to me that we are our worst vectors.
Reply | Report Abuse | Link to thisHumans over the last _100-150 years have become hysterical about
Reply | Report Abuse | Link to thishygiene. The truth is that we live in a world dominated by microbes
most of which are not pathogenic. This obsession about diseases
carried by other animal species is just another variation on this nonsensical theme. In fact, most of the epidemic diseases that are real threats to humans are carried and spread by humans and can be supressed and controlled by appropriate vaccination programs.