Influenza is and has always been a serious disease. On average, each year in the U.S. there are an estimated 36,000 deaths due to influenza related causes. Because this is a new influenza virus, people will not have immunity to it.

To date, most people who have become ill with the novel H1N1 influenza A virus have recovered without requiring medical treatment.

How will I know if what I have is H1N1 flu (swine flu) or regular seasonal influenza?

Since at this time the H1N1 virus appears to cause similar symptoms as regular seasonal influenza, there is no way to know just from a person’s signs and symptoms.

Current data shows that most influenza A strains that have been tested are novel H1N1 influenza A.

General

What is H1N1 influenza?

H1N1 influenza viruses usually cause respiratory disease in pigs; these are in the type A influenza virus group. While outbreaks of this type of flu are most common in pigs, human cases of swine influenza do happen. While typically uncommon, pigs may spread disease to humans, and humans may spread disease to pigs.

The novel H1N1 flu (swine flu) virus causing disease in humans in the U.S. is different from the H1N1 influenza viruses typically found in pigs; see “why is the new H1N1 influenza virus being called “swine flu?” question below for more information.

Why is the new H1N1 Influenza virus being called “swine flu”?

The virus was originally called “swine flu” because lab tests showed that many of the genes in this new virus were very similar to influenza viruses that normally occur in pigs in North America. However, after further study, this new virus is very different from what normally circulates in North America in pigs.

The H1N1 flu (swine flu) virus associated with this recent outbreak has two genes from influenza viruses that normally circulate in pigs in Europe and Asia, as well as avian genes and human genes. Scientists call this a “quadruple reassortant” virus since it contains genes from four influenza virus types.

Do pigs carry this virus and can I catch this virus from a pig?

At this time, there is no evidence that swine (pigs) in the United States are infected with this new virus. However, there are flu viruses that commonly cause outbreaks of illness in pigs. Most of the time, these viruses do not infect people, but influenza viruses can spread back and forth between pigs and people.

Why should I be concerned about this new H1N1 flu (swine flu) that appears to respond well to antiviral medications?

Because this is a new influenza virus, most people will not have immunity to it. This means that the virus has the potential to cause widespread illness this upcoming flu season.

It is important for people to be informed about the current situation and the key measures that help limit the spread of influenza illness. Sign up for H1N1 Email Alerts.

How long can influenza germs survive on surfaces after someone has coughed or sneezed on them?

In most cases, germs will only survive a couple of hours on surfaces such as handrails, door handles, etc. However, if the circumstances are just right (e.g. warm moist conditions as may be found in soiled linens or clothing) influenza germs can survive on surfaces for much longer periods of time. Studies have shown that typically, influenza viruses may survive for 2-8 hours on environmental surfaces.

Who is most at risk for infection of H1N1 flu (swine flu)?

All people are at risk for becoming infected with H1N1 flu (swine flu) because it is a new virus, and currently appears to be easily spread from person-to-person as with typical seasonal influenza.

High risk from complications from H1N1:

Babies under 2 years old
Seniors
Pregnant women
People with asthma, diabetes or other chronic conditions affecting the heart, lungs, blood, liver or kidneys.
People with weakened immune systems (ex. w/HIV)
People under 18 on long-term aspirin therapy.

Is the current H1N1 flu (swine flu) virus the same as the virus seen in the 1918 Influenza Pandemic?

All influenza A pandemics since the 1918 pandemic, and indeed almost all cases of influenza A worldwide (except human infections from avian viruses such as H5N1 and H7N7), have been caused by descendants of the 1918 virus, including "drifted" H1N1 viruses.

At this time, however, scientists are finding that this novel H1N1 flu virus does not have the same characteristics that made the 1918 influenza virus so severe. Studies are continuing to monitor and learn about this virus in order to understand its severity and ability to spread.

Transmission

How is novel H1N1 flu (swine flu) virus spread?

Like any other influenza virus, this novel H1N1 influenza (swine flu) appears to spread easily by person-to-person transmission. Person-to-person transmission mainly occurs when an infected person coughs or sneezes and another person is exposed to droplets from the infected person which contain the virus. People may also become infected by touching something that has influenza viruses on it, and then touching their mouth, nose, or eyes.

It is important to note that the Centers for Disease Control and Prevention (CDC) say that this novel H1N1 flu (swine flu), and other swine influenza viruses, are not transmitted by food or by eating pork.

How long can infected people spread H1N1 flu (swine flu) to others?

As with other seasonal influenza viruses, it is thought that a person can spread this novel H1N1 flu (swine flu) virus before symptoms begin. It is presumed that as with seasonal influenza virus, a person may infect another person one day before symptoms start, and up to seven or more days after becoming sick.

People with H1N1 flu (swine flu) virus infection should be considered contagious for as long as they show symptoms. Children, especially younger children, may be contagious for longer periods of time; for example, with seasonal influenza, children may be contagious for approximately 10 days after becoming symptomatic.

What do I do if I have been around someone who has been exposed to a known case of H1N1 flu?

While it is possible you may get the flu from a person who has been exposed to someone with H1N1 flu, it is unlikely. Individuals are considered contagious 1 day before their symptoms until 24 hours after their symptoms resolve.

The time it takes from being exposed to showing symptoms (the incubation period) is 1-4 days in adults. The best thing to do is to watch your own symptoms and take appropriate precautions to keep yourself and your family healthy.

I have heard the terms, “incubation period” and “period of communicability” used many times with the novel H1N1 flu (swine flu) outbreak. What is the difference?

The “incubation period” refers to the time between when a person is first exposed to the virus (becomes infected) and when the person begins to show signs and symptoms of illness. For influenza, the estimated incubation period is 1-4 days.

The “period of communicability” refers to the time that a person is able to spread illness to others. For influenza, the period of communicability ranges from 1 day before symptoms begin, to up to 7 days after onset of symptoms in most people.

With seasonal influenza, children and immunocompromised persons have been documented to shed virus for longer periods of time; it is presumed that this novel H1N1 flu (swine flu) virus may similarly be shed for longer periods of time in children.

Can influenza viruses remain alive on objects such as books, countertops, door handles, etc., and if so, for how long?

Studies have shown that influenza viruses can survive on such surfaces with the ability to infect a person for up to 2-8 hours after being deposited there.

Can pets or other animals get novel H1N1 flu?

Many different animals, along with humans, can be infected by influenza viruses, but the viruses generally affect one species or another. Sometimes influenza viruses jump from one species to another, and sometimes viruses from different species can infect the same host and result in a new combination of virus genes.

At this point, it is unknown how the novel H1N1 flu virus may impact animals. Federal, state, and local public health agencies are continuing to collect information to better understand the virus and its impact.

Travel

Visit http://wwwn.cdc.gov/travel for the latest information on travel.

What do I do if I am planning travel in and out of the U.S.?

If you decide to travel, there are certain everyday actions that can be taken to help to prevent the spread of germs that cause respiratory illnesses such as influenza; these actions include:

Frequent hand washing with soap and water (especially after a cough or sneeze)
or use an alcohol-based hand sanitizer frequently when hand washing is not
possible.
Cover your nose and mouth with a tissue when coughing or sneezing. Throw the
tissue away after using it.
If you don’t have a tissue and need to cough or sneeze, do so into your elbow.
Wash your hands after you cough or sneeze.
Avoid touching your eyes, nose, or mouth.
Avoid close contact (e.g. within 6 feet) with sick people.
Do not go to work or school (this includes children in daycare) if you are sick.
If you are sick, limit contact with other people as much as possible.

Prevention

Do I need to wear a facemask?

When in areas or crowded settings where there is confirmed H1N1 flu (swine flu) virus, your risk of infection can be reduced through a combination of actions.

If used correctly, facemasks and respirators may help reduce the risk of getting influenza, but they should be used along with other preventive measures such as: social distancing (keeping 6 feet away from other individuals), frequent hand washing, covering you mouth and nose when coughing or sneezing, and limiting contact with ill people.

As with many other respiratory illnesses, to prevent illness from spreading, time spent with ill people should be as short as possible.

How can I prevent novel H1N1 flu (swine influenza)?

It is most important to use the same precautions that you would take to prevent regular seasonal influenza:

Avoid close contact with people who are sick.
Stay home when you are sick and stay home until 24 hours after symptoms go away.
Avoid school, work, and large crowds when you are sick if possible.
Cover your mouth and nose with a tissue when you cough or sneeze and discard the
tissue.
If you don’t have a tissue and need to cough or sneeze, do so into your elbow. Wash
your hands after you cough or sneeze.
Wash your hands often with soap and water, or use an alcohol-based hand sanitizer
when hand washing is not possible.
Avoid touching your eyes, nose or mouth, as germs can more easily gain entrance
into your body through those areas.

If I am sick, what can I do to prevent from spreading my illness to others?

If you are sick, you may be ill for a week or longer. If you develop influenza-like symptoms, you should stay home and avoid contact with others as much as possible until 24 hours after your fever subsides.

If you leave the house to seek medical care, wear a mask, or cover your coughs and sneezes with a tissue, and then dispose of that tissue once it is used. CDC believes that the novel H1N1 flu virus is spread much the same way as regular seasonal influenza; it is presumed that people may be contagious (able to spread influenza germs to others) from one day before the development of symptoms to up 24 hours after symptoms go away.

Children, especially younger children, might be contagious for longer periods of time.

What cleaning should be done in the household to prevent the spread of the influenza virus?

Keep surfaces (especially bedside tables, surfaces in the bathroom, kitchen counters, and toys for children) clean by wiping them down with a household disinfectant according to directions on the product label.

Household disinfectants are sufficient to clean surfaces that have been contaminated with the flu virus.

How should linens, eating utensils, and dishes of persons infected with influenza virus be handled?

Linens, eating utensils, and dishes belonging to those who are sick do not need to be cleaned separately. But these items should not be reused by another person until they have been washed thoroughly.

Linens (such as bed sheets and towels) should be washed by using household laundry soap and tumbled dry on a hot setting. Individuals should avoid “hugging” laundry prior to washing it to prevent contaminating themselves.

Individuals should wash their hands with soap and water or alcohol-based hand rub immediately after handling dirty laundry. Eating utensils should be washed either in a dishwasher, or by hand with water and soap.

Signs and Symptoms

What are the symptoms of novel H1N1 flu (swine flu)?

Symptoms of H1N1 flu (swine flu) appear to be similar to those of the common flu, including:

Fever and chills
Sore throat
Cough
Runny nose
Headache, body aches, and fatigue (general tiredness)
Diarrhea and vomiting may also be present

Watch for these symptoms in children. Seek emergency medical care if your child
experiences any of the following warning signs:

Fever with a rash
Dehydration
Fast breathing
Bluish skin coloration
Slow to wake or sluggish interaction
Flu-like symptoms improve, but then return and cough worsens
Severe irritability

For adults, emergency medical care is needed if you experience these warning signs:

Difficulty breathing
Dizziness
Confusion
Severe or persistent vomiting
Pain/pressure in the chest or stomach

What should I do if I have symptoms or think I have been exposed to the H1N1 flu (swine flu) virus?

If you are concerned that you may have been exposed, closely monitor your health for the symptoms of H1N1 influenza.

If you come down with flu symptoms, refer to our "What To Do If You Get Flu-like Symptoms" information.

What should I do if I get sick?

If you become ill with influenza-like symptoms, including fever, body aches, runny nose, sore throat, nausea, or vomiting or diarrhea, refer to our "What To Do If You Get Flu-like Symptoms" information.

Treatment

Is there a H1N1 flu (swine flu) vaccine available?

There is no vaccine available right now to protect against swine influenza. Plans are in place to have a vaccine available against H1N1 flu sometime this fall (earliest projections are for mid October 2008) as an additional shot to the seasonal flu vaccine.

Note: The 2008 seasonal flu vaccine WILL NOT provide protection against H1N1.

Will the influenza vaccine I got this year protect me from the H1N1 flu (swine flu) virus?

No. The H1N1 flu (swine flu) virus is not contained in the 2009-2010 flu vaccine. However, it is still recommended that people get vaccinated with the influenza vaccine if they have not done so, because the influenza vaccine can still protect against other circulating influenza viruses.

Additionally, it is recommended that people check their current vaccination status for all other recommended vaccines, including the pneumococcal
(pneumonia) vaccine.

Are there medicines for treating H1N1 flu (swine flu) in humans?

Certain drugs such as oseltamivir (Tamiflu) or zanamivir (Relenza) may help lessen the severity of H1N1 flu (swine flu) in people. These antiviral drugs work best if started within two days of when symptoms start.

What is the availability of medicines (Tamiflu, etc.)? Is there a limited supply? Do all health care facilities have a stockpile?

There is a limited supply of antiviral medications. Clinicians should give priority to those with severe illness and to those at high risk for influenza complications.

Will antiviral medications help to treat H1N1 flu (swine flu)?

Yes. If you believe you are ill with any type of influenza virus, call your doctor for advice.

If I’ve been treated with Tamiflu, how soon can I go back to work, school, etc.?

Tamiflu is an antiviral medication and helps to reduce the spread of the virus in your body. Treatment with Tamiflu doesn’t shorten the time you should be away from work or school. You should not resume normal activities until 24 hours after your fever has subsided.

Going to school, work or other public place?

Should I send my child to school or daycare?

If your child is sick with influenza symptoms, you should keep them home until 24 hours after their fever subsides.

Additionally, as part of any good prevention measure, reinforce with your children the message to: wash their hands frequently; avoid touching their hands to their eyes, mouth, or nose; avoid close contact with others who are sick’ and to cover their own mouth and nose when coughing or sneezing.

If I am sick, should I go to work or other public event, social gathering, etc.?

If you are sick with influenza symptoms, stay home and do not attend public events or social gatherings until 24 hours after you fever subsides. A person can spread the influenza virus to others even before they begin to feel symptoms of being sick. A person may be able to infect another person one day before symptoms start and up to 24 hours after their fever resolves.

There have been confirmed cases of H1N1 at my child’s school, should I keep them home?

All people who have influenza like illness symptoms are being advised to stay home until their fever has resolved. If these recommendations are being followed your children should be fine to attend school.

NOTE: All questions regarding the cancellation of schools and other large mass public
gatherings are the propriety of the Local Health Department and should be referred to them.