1st case of bird flu in pigs reported in US: What to know

The first case of H5N1 virus in a pig in the U.S. was detected, raising concerns for scientists and public health officials, The Washington Post reported Oct. 30.

Here are six things to know:

1. The first swine case was located on a backyard farm in Oregon, the U.S. Agriculture Department said Oct. 30. The bird flu was initially detected in poultry on the noncommercial farm. Seventy birds were euthanized to prevent the virus from spreading, and out of an abundance of caution, other farm animals were tested. The USDA's National Veterinary Services Laboratories confirmed the virus in one of the farm's five pigs. Two other pigs tested negative, with results pending for the remaining two. The infected pig did not show signs of illness and was euthanized to facilitate further diagnostic analysis, according to the agency.
   
   
2. Genetic analysis of the virus in the pig is underway. Preliminary sequencing of the virus found in poultry on the farm indicated it is not the same H5N1 strain that spread to dairy cows and infected at least 31 people this year. However, no changes were found that would suggest increased transmissibility to humans, the CDC and USDA said.
   
   
3. The agency did not specify how the livestock was infected. The animals share water sources, housing and equipment, making it possible that transmission could have occurred through these shared resources, or one of the pigs could have consumed an infected bird, the USDA reported.
   
   
4. Pigs were the source of the H1N1 flu pandemic in 2009 and 2010 and are one of the few animals in which avian viruses can adapt to become more like human viruses.
   
   "Pigs are very concerning because the virus can adapt," Katelyn Jetelina, PhD, an infectious disease specialist following the outbreak, told the Post. "They're mixing vessels. That's why we're nervous, but we have a lot of questions."
   
   
5. Other animals on the farm are under surveillance and have been quarantined to prevent further spread. The farm is not part of the commercial food supply, so the discovery has no impact on pork safety. The farm's small size also limits the potential for the virus to spread to humans, according to the agency.
   
   
6. The risk to the public remains low, but concerns over the virus continue to grow.