Recent news has been full of reports of the dreaded “bird flu” propagating through commercial flocks in the United States. Before giving up on eating chicken or turkey, however, some information about the latest outbreak of bird flu is in order. Bird flu has been around as long as human flu, and probably longer. Influenza A, in one of its many variations, infects birds and mammals, including human beings. Fortunately, all strains of Influenza A do not infect all animals and, on the contrary, are often highly specific to one species or another.
Bird flu, like human strains, undergoes constant antigenic shift and drift, changing its genetic material as it circles the globe. Wild birds can be, and often are, infected and transmit the disease to other birds as they migrate. Wild ducks and geese, as well other avian species can pass the infection on to domestic flocks all over the globe.
There have been periodic epidemics of bird flu in Southeast Asia for decades, but since bird flu does not readily infect human beings, only a few hundred deaths occur in the worst years. These fatalities are almost always among people with a very close contact with poultry, often raising ducks or chickens in their homes. Although bird flu can be fatal when contracted by humans, it is difficult to become infected, and the human host does not easily transmit it to others humans (unlike with human strains of influenza).
The latest bird flu epidemic in the United States has struck domestic flocks of chickens and turkeys in the past few months. As in humans, influenza spreads quickly and easily through a domestic flock, which often numbers in the thousands. Since there is not treatment for the birds, flocks—whether they be turkeys or chickens—must be euthanized to stop the danger of infection to other commercial flocks. The unsavory details of the process include smothering the entire flock in foam and then burying the carcasses in a pit, which is covered with dirt.
As unpleasant as this process sounds, exterminating the entire flock remains the only method of stopping accidental transmission. Workers, infected manure and contaminated equipment may also spread the virus, although the most likely source remains accidental contact with migratory birds. Mass slaughtering events have affected millions of turkeys and chickens in a number of poultry producing states across the United States.
All this being said, you cannot get bird flu from eating poultry. If you happen to have an infected backyard flock, the risk of getting bird flu is almost zero unless you have unusually close contact with the birds (something much more common in Southeast Asia). Hopefully a vaccine can be developed for commercial flocks, although the same challenges exist as with human influenza: constantly shifting virus genetics and the necessity of mass vaccination annually. The logistics of such a process and its cost could prove prohibitive.
Meanwhile, enjoy your chicken or turkey dinner and remember to get your flu shot in October or whenever it becomes available. Even though the flu shot for humans does not necessarily offer complete protection, it still reduces the morbidity and mortality associated with seasonal influenza.