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H3N2v

H3N2v is a variant of H3N2 influenza virus that infected 321 people in the United States in 2011 and 2012. In 2013, 19 cases of H3N2v were reported in the United States across five states. In 2014 there have been two reported cases, both in Ohio. Since 2012 there have been 18 total hospitalizations due to H3N2v and one death among these patients.

When this virus occurs in pigs, it is called “swine influenza.” The virus does not usually infect people or spread among people. It is very different from human seasonal H3N2 viruses.

  • 340 cases of H3N2v have occurred from 2011-2013.
  • Symptoms of H3N2v are similar to seasonal flu symptoms.
  • There has been limited person-to-person transmission and one death.

Is H3N2v a threat?

Most cases of H3N2v virus infection result in symptoms similar to seasonal flu: fever, cough, runny nose, sore throat, and muscle aches.

In 2012, 309 cases of H3N2v were detected, resulting in 16 hospitalizations. Most of the people who were hospitalized had health factors that put them at high risk of flu-related complications. There has been one death reported of an older adult with multiple underlying health conditions. This occurred in Ohio in August 2012. The individual had direct exposure to pigs in a fair setting. In 2013, 19 cases of H3N2v were reported in the United States, including 14 in Indiana, 2 in Michigan, 1 in Illinois, 1 in Ohio, and 1 in Iowa.  In 2014 there have been two reported cases, both in Ohio.

Most cases occurred after direct or close contact to pigs and many of these exposures have been at county agricultural fairs. CDC continues to closely monitor human infections with H3N2v viruses.

What are the symptoms of H3N2v flu?

So far, symptoms and severity of H3N2v are similar to the seasonal flu symptoms and can include fever, cough, and runny nose.

How does H3N2v spread?

H3N2v can spread to humans from infected pigs, and usually infections have occurred after contact with pigs at county fairs. In some cases, H3N2v also has spread between people. This happens in the same way that seasonal flu viruses spread—through close contact with sick people who may spread their infections through coughs or sneezes. Since there has been limited virus transmission from person-to-person, it is considered less contagious among people than the seasonal flu.

How can I avoid H3N2v flu?

You should follow everyday steps to keep yourself healthy this flu season. In addition, avoid close contact with animals, especially with pigs, that are known or suspected to be sick. If you must come in contact with sick animals, you should take appropriate precautions such as wearing gloves and a mask.

A precautionary vaccine against H3N2v is in development but not yet available.

Does seasonal flu vaccine protect against H3N2v?

The seasonal flu vaccine is not designed to protect against H3N2v.

Is there an H3N2v vaccine?

Not at this time, but early steps to make an H3N2v vaccine have taken place. A pilot H3N2v vaccine was produced and preliminary clinical studies show positive results.

What should I do if I think I have H3N2v?

If you live in an area where H3N2v cases have been identified recently and develop flu symptoms, contact your health care provider (doctor, physician’s assistant, etc…). Tell them if you have had contact with pigs or with other sick people. Your health care provider will determine whether influenza testing and possibly treatment are needed. Influenza antiviral drugs can treat H3N2v infection, just as they can treat seasonal flu infection. Antivirals work better for treatment the sooner they are started.

Who monitors H3N2v in the United States?

The Centers for Disease Control and Prevention (CDC) tracks cases of H3N2v in humans and reports them on its website. The CDC also reports human cases of H3N2v to the World Health Organization (WHO). The USDA is responsible for tracking flu in pigs.

Can people get swine influenza from eating pork?

Swine influenza has not been shown to be transmissible to people through eating properly handled and prepared pork (pig meat) or other products derived from pigs. For more information about the proper handling and preparation of pork, visit the USDA website fact sheet Fresh Pork from Farm to Table.

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