Information on H3N2 Variant Influenza A Viruses

Since July 12, 2012, 145 human cases of H3N2v (originally identified in swine) infections have been reported in the US. Of these, 113 were identified in Indiana, 30 were reported in Ohio, one was reported in Hawaii and one was reported in Illinois (Cole County). Most cases have had exposures to swine or state/county fairs where pigs were present. While there is no evidence at this time that sustained person to person spread is occurring, all influenza viruses have the capacity to change and it's possible that this virus may become widespread. So far, the severity of illnesses associated with this virus in people has been similar to the severity of illnesses associated with seasonal flu virus infections.  

Click here to read more about H3N2v.

Take Action to Prevent Influenza Virus Spread Between People.

The risk of infection and spread of influenza viruses between people, including H3N2v, can be reduced by taking a combination of actions.  CDC recommends you:

Take everyday preventive actions, including:

• Cover your nose and mouth with a tissue when you cough or sneeze. (Throw the tissue in the trash after you use it.)
• Wash your hands often with soap and water, especially after you cough or sneeze. If soap and water are not available, an alcohol-based hand rub may be used.
• Avoid touching your eyes, nose or mouth. Germs spread that way.
• Try to avoid close contact with sick people.
• If you are sick, stay home from work or school until your illness is over.

If you Get Sick.

At this time, CDC recommends the following:

If you go to a doctor for flu symptoms (see below) following direct or close contact with swine, tell your doctor about this exposure.

If you have flu symptoms, follow CDC’s regular recommendations for seeking treatment for influenza.

• If you have symptoms of flu and are very sick or worried about your illness contact your health care provider.
• Certain people are at greater risk of serious flu-related complications (including young children, elderly persons, pregnant women and people with certain long-term medical conditions) and this is true both for seasonal flu and novel flu virus infections. (A full list of people at higher risk of flu related complications is available at People at High Risk of Developing Flu-Related Complications.)
• If these people develop ILI, it’s best for them to contact their doctor as soon as possible. (The majority of recent H3N2v cases have been in children.)
• Your doctor may prescribe antiviral drugs that can treat the flu, including H3N2v. These drugs work better for treatment the sooner they are started. If you are prescribed antiviral drugs by your doctor, you should finish all of the medication, according to your doctor’s instructions.
• Also, whenever you have flu symptoms and are seeing a health care provider, always remember to tell them if you have asthma, diabetes, heart disease, neurological and neurodevelopmental conditions, are pregnant, or are older than 65 or younger than 5 years. These conditions and age factors put you at high risk of serious complications if you have the flu.
• Flu signs and symptoms usually include fever and respiratory symptoms, such as cough and runny nose, and possibly other symptoms, such as body aches, nausea, vomiting, or diarrhea.
• Health care providers will determine whether influenza testing and possible treatment are needed.
• There are influenza antiviral drugs that can be used to treat infection with H3N2v viruses as well as seasonal influenza viruses. More information about influenza antiviral drugs is available at Treatment (Antiviral Drugs).