Bird flu is back in the U.S.

Backyard chickens, Long Island, NY. Credit: Erica Cirino

Backyard chickens, Long Island, NY. Credit: Erica Cirino

Just this week I finally published my reporting on the 2014-2015 U.S. avian influenza epidemic here on my website. If you’ve already checked it out, it’s probably clear to you I find the science and mechanisms of avian influenza transmission pretty interesting.

So you can imagine my reaction when this happened: Just an hour ago I opened an email from a USDA biologist I had interviewed earlier this year which informed me that highly pathogenic avian influenza—the type that’s lethal to chickens, turkeys and other domestic fowl—is back in the U.S.

This latest case was confirmed today by U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (USDA-APHIS), in a commercial turkey flock located in Dubois County, Indiana. The viral strain found in this flock, H7N8, is different from those at the root of the 2014-2015 epidemic.

Avian influenza viruses, like all flu viruses, are named for the two proteins found on their surface: hemagglutinin (the H) and neuraminidase (the N). The numbers next to each letter in a virus’s name indicate its subtype.

Some avian influenza viruses are transmissible to humans and other animals. Yet H7N8, like the three avian influenza viruses at the root of the 2014-2015 epidemic, is not known to cause infections in humans.

However, as I explain in my coverage of the 2014-2015 epidemic, avian influenzas, like all flu viruses, mutate readily. So there is no sure way to tell whether or not this strain will mutate into something that can infect humans or other animals.

Avian influenza monitoring is ongoing in wildlife and on poultry farms across the nation. With this new case, USDA will respond in the same way they responded to previous cases of highly pathogenic avian influenza: with rapid depopulation of infected flocks and decontamination of infected barns.

I will keep close tabs on this outbreak and will report back frequently with updates. 

Learn more about avian influenza on the USDA-APHIS website.