Swine flu (H1N1) is a type of viral infection. It’s called swine flu because it resembles a respiratory infection that pigs can get. In 2009, an H1N1 pandemic infected millions of people worldwide. Today, you can prevent H1N1 with an annual flu shot. You can treat it with rest, fluids and antiviral medications.
Swine flu (H1N1) is an infection that a type of flu (influenza) virus causes. It’s called swine flu because it’s similar to a flu virus that affects pigs (swine). The virus leads to a lung (respiratory) disease in pigs. Swine flu (H1N1) is a respiratory infection in humans.
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In 1918, a flu pandemic from a strain of H1N1 infected 500 million people around the world. It was known as the Spanish flu. At least 50 million people worldwide died.
In April 2009, researchers discovered a new strain of H1N1. They detected it in the United States first. The virus spread quickly across the U.S. and around the world. It spread quickly because it was a new type of flu virus.
Young people weren’t immune to the new virus yet. Older people appeared to have some immunity to the virus. They may have had exposure to an older strain of H1N1 that helped protect them.
The new strain infected millions of people worldwide. At least 150,000 people worldwide died. Eighty percent of those who died were younger than 65.
The World Health Organization (WHO) said the pandemic was over in August 2010. However, people can still get and spread H1N1. H1N1 is one of the seasonal flu viruses. It can cause illness, hospitalization and death.
A virus causes swine flu (H1N1). It spreads from person to person. When a person coughs or sneezes, droplets go into the air. You can get the infection when you breathe in (inhale) the virus. You can also get the infection when you touch a contaminated surface and then touch your mouth, nose or eyes.
You can’t get H1N1 by eating pork.
Yes. Swine flu (H1N1) is contagious. It can spread from person to person.
The symptoms of swine flu (H1N1) are similar to the symptoms of regular flu. The symptoms may start three to five days after exposure to the virus. Symptoms may include:
Symptoms in babies and children may be different. If your baby or child has any of the following symptoms, call their healthcare provider right away:
Your healthcare provider can diagnose swine flu (H1N1). They may perform a physical exam and ask you about your symptoms. Your provider may order a rapid flu test. A rapid flu test checks for several different flu viruses. It may take a few days to get the H1N1 test results back.
Most people with swine flu (H1N1) who are otherwise healthy don’t need special drugs or treatments. If you have swine flu, you should:
If you’re very ill, your healthcare provider may prescribe an antiviral medicine. Antiviral drugs such as oseltamivir (Tamiflu®) or zanamivir (Relenza®) can kill the virus. These drugs can shorten the time you’re sick and help ease your symptoms. Antiviral drugs work best if you start taking them when your symptoms begin.
The best way to prevent swine flu (H1N1) is to get your annual flu vaccine. The flu vaccine has helped protect against swine flu since 2010.
Other ways to prevent getting and spreading swine flu (H1N1) include:
Most people can fight off swine flu (H1N1) on their own. The symptoms of H1N1 are similar to those of regular flu. On average, symptoms last about eight days. Call your healthcare provider if your symptoms last longer or worsen. They’ll let you know if you should come in to the office. They may have you take a rapid flu test to see if you have H1N1.
A note from Cleveland Clinic
Swine flu (H1N1) once caused a serious worldwide pandemic. Today, the virus is under control, but people can and do still get very sick from H1N1. It’s important to get your yearly flu shot, which can protect you from H1N1 and other strains of the flu. If you do get sick, make sure to get plenty of rest, drink fluids and call your healthcare provider if symptoms worsen.
Last reviewed by a Cleveland Clinic medical professional on 08/05/2022.
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