Questions about H1N1 (swine flu)? Get the answers to common swine flu questions.
What is 2009 H1N1 (swine flu)?
2009 H1N1 (referred to as “swine flu” early on) is a new influenza virus causing illness in people. This new virus was first detected in people in the United States in April 2009. This virus is spreading from person-to-person worldwide, probably in much the same way that regular seasonal influenza viruses spread. On June 11, 2009, the World Health Organization (WHO) signaled that a pandemic of 2009 H1N1 flu was underway.
Why is 2009 H1N1 virus sometimes called “swine flu”?
This virus was originally referred to as “swine flu” because laboratory testing showed that many of the genes in this new virus were very similar to influenza viruses that normally occur in pigs (swine) in North America. But further study has shown that this new virus is very different from what normally circulates in North American pigs. It has two genes from flu viruses that normally circulate in pigs in Europe and Asia and bird (avian) genes and human genes. Scientists call this a “quadruple reassortant” virus.
How does 2009 H1N1 virus spread?
Spread of 2009 H1N1 virus is thought to occur in the same way that seasonal flu spreads. Flu viruses are spread mainly from person to person through coughing or sneezing by people with influenza. Sometimes people may become infected by touching something — such as a surface or object — with flu viruses on it and then touching their mouth or nose.
What are the signs and symptoms of this virus in people?
The symptoms of 2009 H1N1 flu virus in people include fever, cough, sore throat, runny or stuffy nose, body aches, headache, chills and fatigue. A significant number of people who have been infected with this virus also have reported diarrhea and vomiting. Severe illnesses and death has occurred as a result of illness associated with this virus.
How severe is illness associated with 2009 H1N1 flu virus?
Illness with the new H1N1 virus has ranged from mild to severe. While most people who have been sick have recovered without needing medical treatment, hospitalizations and deaths from infection with this virus have occurred.
How does 2009 H1N1 flu compare to seasonal flu in terms of its severity and infection rates?
With seasonal flu, seasons vary in terms of timing, duration and severity. Seasonal influenza can cause mild to severe illness, and at times can lead to death. Each year in the United States, an average of 36,000 people die from flu-related complications and more than 200,000 people are hospitalized from flu-related causes. Of those hospitalized, 20,000 are children younger than 5 years old. Over 90 percent of deaths and about 60 percent of hospitalization occur in people older than 65.
When the 2009 H1N1 outbreak was first detected in mid-April 2009, CDC began working with states to collect, compile and analyze information regarding the 2009 H1N1 flu outbreak, including the numbers of confirmed and probable cases and the ages of these people. The information analyzed by CDC supports the conclusion that 2009 H1N1 flu has caused greater disease burden in people younger than 25 years of age than older people. At this time, there are few cases and few deaths reported in people older than 64 years old, which is unusual when compared with seasonal flu.
However, pregnancy and other previously recognized high-risk medical conditions from seasonal influenza appear to be associated with increased risk of complications from this 2009 H1N1. These underlying conditions include asthma, diabetes, suppressed immune systems, heart disease, kidney disease, neurocognitive and neuromuscular disorders and pregnancy.
How long can an infected person spread this virus to others?
People infected with seasonal and 2009 H1N1 flu shed virus and may be able to infect others from 1 day before getting sick to 5 to 7 days after. This can be longer in some people, especially children and people with weakened immune systems and in people infected with the new H1N1 virus.
What can I do to protect myself from getting sick?
There is no vaccine available right now to protect against 2009 H1N1 virus. However, a 2009 H1N1 vaccine is currently in production and may be ready for the public in the fall. As always, a vaccine will be available to protect against seasonal influenza.
There are everyday actions that can help prevent the spread of germs that cause respiratory illnesses like influenza.
If you live in areas where people have been identified with 2009 H1N1 flu and become ill with influenza-like symptoms including fever, body aches, runny or stuffy nose, sore throat, nausea, or vomiting or diarrhea, you should stay home and avoid contact with other people. CDC recommends that you stay home for at least 24 hours after your fever is gone except to get medical care or for other necessities. (Your fever should be gone without the use of a fever-reducing medicine.) Stay away from others as much as possible to keep from making others sick. Staying at home means that you should not leave your home except to seek medical care. This means avoiding normal activities, including work, school, travel, shopping, social events and public gatherings.
How long can influenza virus remain viable on objects (such as books and doorknobs)?
Studies have shown that influenza virus can survive on environmental surfaces and can infect a person for 2 to 8 hours after being deposited on the surface.
What kills influenza virus?
Influenza virus is destroyed by heat (167–212°F [75–100°C]). In addition, several chemical germicides, including chlorine, hydrogen peroxide, detergents (soap), iodophors (iodine-based antiseptics) and alcohols are effective against human influenza viruses if used in proper concentration for a sufficient length of time. For example, wipes or gels with alcohol in them can be used to clean hands. The gels should be rubbed into hands until they are dry.
What surfaces are most likely to be sources of contamination?
Germs can be spread when a person touches something that is contaminated with germs and then touches his or her eyes, nose or mouth. Droplets from a cough or sneeze of an infected person move through the air. Germs can be spread when a person touches respiratory droplets from another person on a surface like a desk, for example, and then touches their own eyes, mouth or nose before washing their hands.
Can I get infected with 2009 H1N1 virus from eating or preparing pork?
No. 2009 H1N1 viruses are not spread by food. You cannot get infected with novel HIN1 virus from eating pork or pork products. Eating properly handled and cooked pork products is safe.
Is there a risk from drinking water?
Tap water that has been treated by conventional disinfection processes does not likely pose a risk for transmission of influenza viruses. Current drinking-water treatment regulations provide a high degree of protection from viruses. No research has been completed on the susceptibility of 2009 H1N1 flu virus to conventional drinking-water treatment processes. However, recent studies have demonstrated that free chlorine levels typically used in drinking-water treatment are adequate to inactivate highly pathogenic H5N1 avian influenza. It is likely that other influenza viruses such as 2009 H1N1 would also be similarly inactivated by chlorination. To date, there have been no documented human cases of influenza caused by exposure to influenza-contaminated drinking water.
