As the current version of Avian influenza is gaining traction countries around the globe are announcing new biosafety measures aimed at curbing the swiftly spreading illness. There are now reports of dozens of infected penguins in South Africa, there are many cases no win South Korea, and here in the US more than +49 million birds in 46 states have either died as a result of bird flu virus infection or have been culled (killed) due to exposure to infected birds. The disease is also the highest on record in Europe with +3,000 outbreaks in poultry, and over +59 million birds culled in the affected establishments.
In early September, scientists at the University of Florida confirmed that a bottlenose dolphin, found dead in a canal on the Gulf Coast in March, carried a highly pathogenic kind of avian influenza. Its brain was inflamed. True to its label, this virus is skilled at infecting birds, but it sometimes goes farther afield. A few months after the dolphin’s death, another mammal, a porpoise, was found stranded and weak on the west coast of Sweden. It subsequently died, bearing the same virus. Between these events, there was another concerning case in Colorado, when a man tested positive for bird flu. He was a state prison inmate, at work in a prerelease job that involved culling birds on a poultry farm where the infection had struck. Bottom line, experts around the globe are wondering what exactly is happening.
Currently, the bird flu that is running amok in Europe and North America is predominantly caused by a strain called H5N1. It’s worth noting that Europe, Asia, and Africa have had many flare-ups of bird flu viruses since the late nineteenth century, but the outbreaks were limited mainly to poultry with the culling of affected flocks usually keeping the disease from spreading to wild birds. But since the early 2000s, researchers have begun to notice a sustained spread of avian flu among wild birds, and over the past year, this transmission has increased drastically.
According to Rebecca Poulson, a wildlife-disease researcher at the University of Georgia in Athens, the disease also seems to be spreading to mammals more frequently, meaning that these unprecedented patterns of transmission reveal that something is quite different about the current virus that is circulating.
From what I understand, these viruses usually approach North America from the west, but this time around it appeared in the east, and since then the disease has been circulating uncontrollably in wild birds rather than remaining mostly contained to poultry farms. Unfortunately, the high number of infected wild birds seems to be making it easier for the virus to spill over into domestic flocks.
What’s most puzzling to scientists is why this outbreak isn’t fizzling out as it has in the past. Theories now include possibilities such as genetic mutations having increased the virus’s ability to replicate. Also, mutations may have allowed the virus to infect a broader range of bird species than previous strains were capable of. Unfortunately, as researchers do more testing and collect more data they seem to be coming up with more questions than answers.
It’s expected that we’ll see many more cases in the coming weeks as birds are congregating to migrate together. The hope is as the migratory season will eventually wind down the number of infections will as well. If you see a wild bird that appears sick, call your local wildlife hospital before approaching it.
Keep in mind, bird flu is considered low risk for humans, at least in its current form. According to the World Health Organization, about 450 people have died from bird flu since 2003. But as with any contagious virus, there’s always the possibility of a jump to humans. The Centers for Disease Control and Prevention says bird flu infections in humans remain rare, but the agency acknowledges that a “shift” could occur, in which the virus jumps to humans.
You can go to the CDCs page HERE to get up-to-date details as well as the locations most affected. (Source: nature.com, cdc.gov)
