With many county and state fairs underway, human and animal health officials are closely monitoring the prospects of H3N2 influenza virus exposure between swine and humans.

Cases started surfacing in July in Ohio, Indiana and Hawaii, mostly related to county fairs. As of the Aug. 3, 29 people had been identified with the virus since July 2011, with 12 of those coming in the last two weeks. The cases break out like this: Ohio (10), Indiana (7), Iowa (3), Pennsylvania (3), Maine (2), West Virginia (2), Utah (1) and Hawaii (1), according to the Centers for Disease Control and Prevention (CDC). Twenty-three of the individuals reported swine contact prior to the onset of illness, 19 cases were associated with fairs.

CDC officials indicate that “it is not a widespread concern, but it’s something to watch.”

The H3N2 virus is not uncommon in swine, and people and pigs are known to exchange certain strains of the virus. The key to further exposure and concern is when a virus moves between species and it is then continues to spread through the human population. That has not occurred, so far, with the H3N2 virus.

The H3N2 virus in question contains the M gene from the 2009 H1N1 virus, CDC reports.  

The reported symptoms in humans included a cough, fevers, muscle aches and sore throat. Certainly July and August are unusual times for influenza virus to surface. CDC reports that three hospitalizations have occurred, but all of those people had “high-risk” conditions.

Most recently, the Ohio Department of Agriculture stepped up swine testing procedures at the Ohio State Fair, which concluded on Sunday, and found a few pigs that were positive for the H3N2 virus.

The Indiana State Fair got underway last Friday (Aug. 3) and animal and human health officials are monitoring developments there.

The Indiana Board of Animal Health and the Indiana State Department of Health identified the H3N2 influenza virus in swine and people attending the La Porte County Fair in mid-July.  

"All the people who were diagnosed in this situation had direct contact with the swine," said Janelle Thompson, public information officer for the Indiana Board of Animal Health. "They were all in the barn working with the animals. At this time we have not heard of any fairgoers becoming ill.”

All recovered and no person-to-person spread was reported. Thompson indicated that the virus sampling occurred following reports of respiratory illness in both pigs and children. She added that “pork is still completely safe to eat" as influenza viruses are respiratory viruses and are not transmitted via meat.

Flu symptoms in pigs includes fever, depression, coughing/barking, discharge from nose and eyes, sneezing, panting and going off feed. However, infected swine also can exhibit no significant symptoms.

The CDC advises people in contact with swine—especially fairgoers—to remember some basic precautions:

  • Wash hands frequently with soap and hot water before and after exposure to animals
  • Do not eat or drink in animal areas, or put things in your mouth.
  • Watch animals for signs of illness and call in a veterinarian if you suspect health issues.
  • Avoid contact with swine if you have flu-like symptoms.
  • Avoid contact with swine that exhibit signs of illness
  • Young children, pregnant women, people with weakened immune systems and people 65 and older should be extra careful around animals.   

More information from CDC is available here.