Bird flu is back in the U.S. - PART II

Avian influenza samples awaiting testing: A photo from my visit to the USGS National Wildlife Health Center in Madison, WI, in September 2015. Continued monitoring of wildlife and poultry is important now more than ever in light of the news of this recent outbreak.  Credit: Erica Cirino

Avian influenza samples awaiting testing: A photo from my visit to the USGS National Wildlife Health Center in Madison, WI, in September 2015. Continued monitoring of wildlife and poultry is important now more than ever in light of the news of this recent outbreak.

Credit: Erica Cirino

Since Friday, which is when I broke the news that a new case of lethal avian influenza had hit the U.S. in the first time in about seven months, nine new cases of the low-pathogenic version of that virus have been confirmed.

All 10 of these new cases are (for now) isolated to farms in Dubois County, Indiana, the state’s most productive turkey- and egg-producing region.

According to the Indiana Board of Animal Health, the state agency in charge of monitoring the outbreak, birds on nine commercial turkey farms and in one egg-laying facility have tested positive for the H7 strain of avian influenza--which was found to be highly pathogenic on that first farm. So, in accordance with federal and state animal health regulations, all of these birds will all have to be euthanized. An 11th farm, a commercial egg-laying facility, hasn’t tested positive for avian influenza, but is located in close proximity to an infected farm. So its birds will be euthanized as a precaution.

In all, on these 11 farms more than 400,000 egg-laying hens and turkeys will be euthanized to prevent the spread of avian influenza to other farms in the region. Euthanasia also prevents avian influenza from spreading into the environment, where wild migratory birds can pick up the virus and carry it elsewhere.

In addition, a quarantine area has been set up around Dubois and surrounding counties, which restricts the movement of animals, equipment, workers and vehicles between farms. Besides euthanasia of birds on infected and possibly infected farms, quarantine is another measure that can help prevent the spread of disease.

Currently, H7N8 is not known to infect humans or other animals. However, like all flu viruses, H7N8 can mutate readily, meaning human infection is not out of the question. That the first case was highly pathogenic suggests that the low pathogenic strains found on the other nine farms likely already underwent mutation. Strains belonging to the same H7 group as the H7N8 avian influenza strain that’s now in the U.S. has been known to sicken people in other countries.

The 2014-2015 outbreak led to the combined death and euthanasia of more than 48 million chickens, turkeys and other fowl, increasing egg prices, causing egg shortages and hurting U.S. poultry farmers’ bottom lines. While no one got sick, in order to prevent similar economic devastation and possible human infection, federal farm and health officials continue to research the virus and conduct routine sampling of both poultry and wild birds across the country.

The federal government is also working to stockpile up to 500 million doses of avian influenza vaccines that would be distributed to U.S. farmers if a major outbreak were to grow out of these 10 confirmed cases.

That first farm diagnosed in this most recent outbreak belongs to Farbest Foods, Inc. Earlier this month, Farbest Farms had reported an unusual amount of turkey deaths to the Indiana Board of Animal Health. Tests done by the Indiana Animal Disease Diagnostic Laboratory at Purdue University and USDA-APHIS National Veterinary Laboratory in Ames, Iowa, subsequently confirmed that the deceased turkeys had contracted the lethal virus.

Avian influenza is a disease I learned quite a lot about over the past six months. Consequently my interest in avian influenza has led me to closely monitor the news and social media for new cases.

It’s a borderline addiction at this point, I’d say. Which is good for you in the sense that you can rely on me to deliver you the most up-to-date info on any new developments. For me it means staying connected to my sources—wildlife experts, farmers and public health officials—and keeping a vigilant eye on my news and Twitter feeds.

It's hard to predict what will happen next. Stay tuned!

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.