Around the world, in the last dozen years more than 800 people have been infected with a kind of flu carried by birds called “H5N1,” according to the World Health Organization, and about half of them have died. That makes any news about “bird flu” sound scary. Don't panic.
Remember that new kinds of flu crop up regularly among birds, and their viruses do not normally infect us. Here’s what has happened this year: two new strains have showed up in the United States among some wild birds, and some backyard and commercial poultry flocks. Turkey farmers in Minnesota have been hit the hardest; the governor has declared a state of emergency. However, there have been no cases of humans infected with these strains in the United States or elsewhere. Also, so far these strains do not contain the genetic markers that made H5N1 dangerous, the Centers for Disease Control and Prevention (CDC) said on April 22, 2015.
As the weather warms, fewer birds will be infected because the ultraviolet light in sunshine kills this kind of virus, although it’s too soon to say when the current outbreak will end; winter temperatures stubbornly persist in some parts of the country.
Past human infections with bird flus arose in people who had direct or close contact with infected poultry. Your best protection is to observe wild birds only from a distance and stay away from any poultry that appear ill or have died. Also, steer clear of areas that appear to be contaminated with feces from wild or domestic birds. If you do suspect you may have been near a contaminated bird, wash your hands and watch out for conjunctivitis, or flu-like symptoms; you might also see a doctor about taking influenza antiviral drugs preventatively.
It’s possible that the latest strains will mutate to become transmissible from one person to another. One way that could happen is if the bird virus infects a human via a bird and that human harbors a contagious human virus simultaneously. The two viruses could, in effect, combine forces.
The CDC will be monitoring anyone in the United States who has been exposed to the flu-carrying birds and, as of late April 2015, was monitoring some 100 people. As more people are exposed to the virus through birds, it will be easier to see how the virus might potentially cause human illness.
In addition, the first step has been taken towards a vaccine: researchers have developed a "seed strain," which must be tested to see if it will grow well in cells that could deliver a vaccine.
So far, bird flu has appeared in 16 U.S. states and on farms in Ontario, Canada.
April 24, 2015
Christopher Nystuen, MD, MBA