June 15, 2015, Avian Influenza Update

chicksBy Anne Lichtenwalner, DVM, PhD, University of Maine Cooperative Extension

In the news this weekend was the story that highly pathogenic avian influenza (HPAI) is now in Arizona … or is it? Apparently a source in Iowa sold gamebird products that were contaminated with HPAI, and these were “traced” to destinations that include Arizona, a state that is not on the USDA list for having HPAI. However, as of right now, there are no poultry operations apparently affected by HPAI in Arizona.

What does this mean, though? Someone purchased this disease, bringing it into the state. Normal movements of chicks across state lines should not be sources of disease; this is why NPIP has a program to keep hatcheries “on their toes” about important poultry diseases, including several forms of salmonella and mycoplasma, besides AI. This doesn’t mean that imported chicks are guaranteed to be disease-free, but just makes it much less likely you’ll be importing a problem with your new birds. Of course, if you don’t inquire about NPIP status when you purchase your new birds, you might be in for an unpleasant surprise if the birds arrive with a problem. States also require a certificate of health for shipments of chicks. This form indicates that the birds were healthy when shipped.

For now, Maine has NOT restricted movements of domestic birds (shows, sales, or import/export). As ever, it’s very important that the “buyer beware” when purchasing birds. Perhaps if our poultry-owning public is very actively spreading the word about biosecurity, and practicing what they preach, we won’t have an AI problem in our region. Perhaps this checklist for those purchasing birds would be helpful:

  • When choosing a hatchery, choose only those with NPIP salmonella/SE/AI/Mycoplasma free status.
  • Inquire to be sure the birds will be sent with a health certificate.
  • All new birds should be quarantined (kept separate from other birds) and carefully observed for at least 2 weeks after entry.
  • Consider testing meconium papers for salmonella when importing layers or broilers (this testing can be done at the University of Maine Animal Health Lab).
  • Consider necropsy if the mortalities exceed 5% of the flock within the first week (this testing can be done at the University of Maine Animal Health Lab).

HPAI Epidemiology Report: USDA APHIS

A new report from APHIS has summarized the ongoing HPAI outbreak’s origins. In general, there are no surprises; wild birds brought HPAI into the country, then poor biosecurity, along with the ability of the virus to either bind to dust, or to become directly windborne, contributed to rapid spread of HPAI within and between commercial operations. After high winds, they found more spread of HPAI up to 5 days later. It’s not just one factor, though; as they state, “genetic analyses of the HPAI viruses suggest that independent introductions as well as transmission between farms were occurring in several States concurrently.”

The examples of poor biosecurity are instructive: “For example, APHIS has observed the following:

  • sharing of equipment between an infected and noninfected farm;
  • employees moving between infected and noninfected farms;
  • lack of cleaning and disinfection of vehicles moving between farms;
  • reports of rodents or small wild birds inside the poultry houses.”

For those used to dealing with salmonella control, these are expected means of spread. These observations suggest that, despite there being a lot of guidance about using biosecurity, people at commercial farms are having trouble “getting it.” Good biosecurity is pretty basic (and pretty demanding, too). If backyard farmers take these kinds of things seriously, it may help all of us avoid this (and other) poultry diseases.

The Official Numbers from APHIS Veterinary Services as of June 15

As of June 15, there were 21 states that have had HPAI cases in any kinds of birds (wild or domestic) (AR, CA, IA, ID, IN, KS, KY, MI, MN, MO, MT, NE, ND, NM, NV, OR, SD, UT, WA, WI, WY). Of the 230 total farms with HPAI, 209 are commercial flocks and 21 are backyard flocks. By far the greatest number of commercial flocks were in Minnesota (108), with Iowa a close second (70), then South Dakota (10), Wisconsin (9), Nebraska (5), California (2), Missouri (2), North Dakota (2), and a single farm in Arkansas.

The impact on commercial poultry industry includes the loss of approximately 7.5 million turkeys and about 41 million layers and pullets. This represents about 3% of U.S. turkey inventory, almost 10% of U.S. layer inventory, and about 6% of U.S. pullet inventory. The broiler industry is relatively unaffected.