Pandemic Flu

H3N2v: The New Swine-Origin Flu

Understanding the nature of flu (influenza) viruses and how to prevent infection are the best ways to lower your chance of getting sick as a result of the current outbreak of a new influenza virus.

What is H3N2v?

H3N2 is a swine-origin flu virus that has been found in U.S. pigs and has also infected people. This new virus – called H3N2v when it infects humans - may spread more easily from pigs to humans than is usual for swine flu viruses. In some cases, the H3N2v virus seems to have spread from person-to-person.

Who is being infected with H3N2v?

So far, the majority of H3N2v infections have involved people who had direct contact with pigs carrying the virus – mainly at state or county fairs – or by workers in the swine industry. Most of these cases have been reported in children.

How does H3N2 spread from pigs to people?

Spread of H3N2 to people is thought to happen mainly when an infected pig coughs or sneezes. Droplets with influenza virus in them spread through the air. It is possible for you to become infected if:

these droplets land in your nose or mouth, or if you inhale them;
you touch something that has virus on it and then touch your own mouth or nose;
you inhale dust containing influenza virus.

Scientists are not really sure which of these ways is the most common.

How can risk of H3N2 infection be reduced?

A combination of actions can reduce the risk of infection and spread of influenza viruses. CDC recommends you take everyday preventive actions, including the following:

Avoid pigs and swine barns at the fair this year if you are at high risk of serious flu complications and are planning to attend a fair where pigs will be present.

Those who are at high risk of serious flu complications include:

children younger than 5 years
people 65 years and older
pregnant women
people with certain chronic medical conditions (like asthma, diabetes, heart disease, weakened immune systems, and neurological or neurodevelopmental conditions).

Take action to prevent influenza virus spread between people:

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, use an alcohol-based hand rub.
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.

Take action to prevent the spread of flu viruses between people and pigs:

Do not take food or drink into pig areas. Also, do not eat, drink or put anything in your mouth in pig areas.
Do not take toys, pacifiers, cups, baby bottles, strollers, or similar items into pig areas.
Wash your hands often with soap and running water before and after exposure to pigs. If soap and water are not available, use an alcohol-based hand rub.
Avoid close contact with pigs that look or act ill.
Take protective measures if you must come in contact with pigs that are known or suspected to be sick. This includes minimizing contact with pigs and wearing personal protective equipment like protective clothing, gloves and masks that cover your mouth and nose, when contact is required.
To further reduce the risk of infection, minimize contact with pigs and swine barns.
Watch your pig (if you have one) for signs of illness and call a veterinarian if you suspect it might be sick.
- Avoid contact with pigs if you have flu-like symptoms.
- Wait 7 days after your illness started or until you have been without fever for 24 hours without the use of fever-reducing medications, whichever is longer.
- If you must have contact with pigs while you are sick, take the protective actions listed above.

What should I do if I 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 pigs (swine), tell your doctor about this exposure. Flu signs and symptoms usually include:
fever
cough
runny nose
body aches
vomiting
diarrhea.

If you have flu symptoms, follow CDC’s regular recommendations for seeking treatment for influenza:
Contact your health care provider if you have symptoms of flu and are very sick or worried about your illness.
Contact your doctor as soon as possible if you or someone in your care is at greater risk of serious flu-related complications. This is true both for seasonal flu and novel flu virus infections like N3N2v. Always remember to tell the doctor if the patient:
- has asthma
- has diabetes
- has heart disease
- has neurological and neurodevelopmental conditions
- is pregnant
- older than younger than 5 years.

These conditions and age factors increase the chance of serious complications from flu.

If you are prescribed antiviral drugs by your doctor to treat the flu, including H3N2, finish all of the medication, according to your doctor’s instructions. These drugs work better for treatment the sooner they are started.

Your health care providers will determine whether influenza testing and treatment are needed.

Will my yearly flu shot protect me from H3N2v?

A seasonal flu vaccine will not protect you against H3N2v. But there are influenza antiviral drugs that can treat human H3N2v illness as well as seasonal influenza. A doctor must prescribe these antiviral drugs. Getting antiviral treatment early is most effective for treating influenza, so see a doctor as soon as you become ill.

So far, illness associated with this virus has been mostly mild with symptoms similar to seasonal flu, but like seasonal flu, serious illness with H3N2v infection is possible. A number of hospitalizations have occurred. One person with multiple underlying medical conditions has died from infection.

Can I get H3N2 flu by eating pork products?

No. Eating pork products is safe. H3N2 has not been shown to spread to people through eating properly handled and prepared pork (pig meat) or other products from pigs.

Where can I find the most current information about H3N2v?

For up-to-date information about H3N2v, please visit the following sites from the Centers for Disease Control (CDC):

For more information:

Go to the Pandemic Flu health topic, where you can:

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Last Reviewed: Sep 04, 2012

Y Mohamed Saif, DVM, PhD
Professor of Food Animal Health
Assistant Dean of Veterinary Medicine Administration
Professor of Animal Sciences
Professor of Veterinary Preventive Medicine
College of Veterinary Medicine
The Ohio State University

Chang Lee, PhD
Associate Professor
College of Food, Agricultural, & Environmental Science
The Ohio State University