The H3N2v virus contains the M gene from the human influenza A(H1N1)pdm09 (2009 H1N1) virus, as have the previous 17 cases detected since July 2011. All of this week’s reported cases occurred in people who had direct or indirect contact with swine prior to their illness. The 10 cases in Ohio were associated with attendance at a fair where reportedly ill swine were present. The H3N2v case reported by Indiana also occurred in a person who attended a fair where swine were present. CDC continues to recommend preventive actions people can take to make their fair experience a safe and healthy one.Most human illness with H3N2v virus infection has resulted in signs and symptoms of influenza (fever, cough, runny nose, sore throat, muscle aches); 3 hospitalizations have occurred. All of the people hospitalized had high risk conditions. All H3N2v virus cases have recovered fully.
According to USDA, swine influenza surveillance, this swine H3N2 virus with the pandemic M gene has been detected in swine in a number of U.S. states. This virus may be circulating widely in U.S. swine at this time. It should be noted, however, that influenza viruses have not been shown to be transmissible to people through eating properly handled and prepared pork (pig meat) or other products derived from pigs.
It is possible that acquisition of the M gene from the 2009 H1N1 virus may allow H3N2v viruses to be more transmissible from pigs to people and from person-to-person.
Late summer is typically fair season across the United States, and fairs are a setting that can provide many opportunities for exposures to occur between pigs and people. CDC continues to advise people to take recommended precautions when interacting with pigs or their environments, including frequent hand washing and avoiding contact with pigs that appear ill. This includes:
- Wash your hands frequently with soap and running water before and after exposure to animals.
- Never eat, drink or put things in your mouth while in animal areas and don’t take food or drink into animal areas.
- Young children, pregnant women, people 65 and older and people with weakened immune systems should be extra careful around animals.
- If you have animals – including swine – watch them for signs of illness and call a veterinarian if you suspect they might be sick.
- Avoid close contact with animals that look or act ill, when possible.
- Avoid contact with pigs if you are experiencing flu-like symptoms.
- If you must come in contact with pigs while you are sick, or if you must come in contact with pigs known or suspected to be infected, or their environment, you should use appropriate protective measures (for example, wear protective clothing, gloves, masks that cover your mouth and nose, and other personal protective equipment) and practice good respiratory and hand hygiene.