A(H3N2)v Influenza: What you Should Know

Submitted By:  Mike Yoder and Brent Jennings of NC State University

Recently, a number of cases of infection with a variant  influenza A(H3N2) virus A(H3N2)v have been reported in the USA.  The A(H3N2)v virus is different from the seasonal viruses currently affecting humans.  Seven genes from the A(H3N2) viruses that have been circulating in North American swine and the M gene from an A(H1N1)pdm09 virus, a virus that has been circulating in the human population, make up the A(H3N2)v virus.  This may make it easier for the disease to pass from pigs to humans and from humans to pigs.

Most of the 153 human cases of A(H3N2)v have been found in Indiana and Ohio, with all of those infected having had direct or indirect contact with infected swine.  County and state fairs in Indiana and Ohio and surrounding states are taking precautions to minimize the risk of human exposure to the disease.  Swine exhibitors, children under 5 years of age, the elderly, pregnant women and anyone with a compromised immune system are at highest risk of contracting this virus.

Dr. Tom Ray, Director of Large Animal Health Programs for the North Carolina Department of Agriculture & Consumer Services reported Tuesday, August 14, 2012, that the disease has not been identified in North Carolina.  As a result, both NCDA&CS and NIFA are encouraging exhibitors to be completely aware and remain up to date with best management and husbandry practices that are in place, and help both us and our animals stay healthy.  Livestock show managers and swine owners should however, be vigilant and prepared to take immediate action should a pig or human presenting symptoms of the disease be identified.  Symptoms include an elevated temperature, lethargy, decreased appetite, and possible respiratory distress.

In addition to good biosecurity practices already recommended by both NCDA&CS and NIFA, we strongly encourage any individuals that happen to travel to areas where the A(H3N2)v virus has been identified to minimize contact with swine, swine shows, and people who have worked at, or been spectators at, swine shows in those states.   We suggest that anyone who has made contact with a suspected case of influenza or contact with swine in areas where this novel virus has been identified, avoid contact with swine for a period of at least 14 days (two incubation periods).

If you suspect influenza in pigs, call a veterinarian immediately.  If you are exhibiting any influenza-like symptoms, avoid all contact with animals and contact your physician right away.    It should be remembered that most of the human cases identified so far have only exhibited mild cases of the flu, with only 2 of the 152 infected humans hospitalized as a result of this disease.  No deaths have been reported.

Our hope is that you will help in dispersing this information out to youth, parents, exhibitors etc.. that have direct contact with swine.  The National Pork Board and the NC Pork Council have put together a useful website and materials with lots of information regarding prevention.  Please take some time to look through the information posted at the link below.