Influenza A virus subtype H1N1 Called Swine Flu: 2009

Sunday, December 27, 2009

What is 2009 H1N1 (swine flu)?

2009 H1N1 (sometimes called “swine flu”) 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.

H1N1 (swine Flu)

H1N1 Flu (Swine Flu)

Also called: Swine flu
Swine flu is an infection caused by a virus. It's named for a virus that pigs can get. People do not normally get swine flu, but human infections can and do happen. The virus is contagious and can spread from human to human. Symptoms of swine flu in people are similar to the symptoms of regular human flu and include fever, cough, sore throat, body aches, headache, chills and fatigue.

There are antiviral medicines you can take to prevent or treat swine flu. There is a vaccine available to protect against swine flu. You can help prevent the spread of germs that cause respiratory illnesses like influenza by

Covering your nose and mouth with a tissue when you cough or sneeze. Throw the tissue in the trash after you use it.
Washing your hands often with soap and water, especially after you cough or sneeze. You can also use alcohol-based hand cleaners.
Avoiding touching your eyes, nose or mouth. Germs spread this way.
Trying to avoid close contact with sick people.
Staying home from work or school if you are sick

Swine Influenza

Swine influenza (also called swine flu, hog flu, or pig flu) is an infection by any one of several types of swine influenza virus. Swine influenza virus (SIV) is any strain of the influenza family of viruses that is endemic in pigs. As of 2009, the known SIV strains include influenza C and the subtypes of influenza A known as H1N1, H1N2, H3N1, H3N2, and H2N3.

Swine influenza virus is common throughout pig populations worldwide. Transmission of the virus from pigs to humans is not common and does not always lead to human influenza, often resulting only in the production of antibodies in the blood. If transmission does cause human influenza, it is called zoonotic swine flu. People with regular exposure to pigs are at increased risk of swine flu infection. The meat of an infected animal poses no risk of infection when properly cooked.

During the mid-20th century, identification of influenza subtypes became possible, allowing accurate diagnosis of transmission to humans. Since then, only 50 such transmissions have been confirmed. These strains of swine flu rarely pass from human to human. Symptoms of zoonotic swine flu in humans are similar to those of influenza and of influenza-like illness in general, namely chills, fever, sore throat, muscle pains, severe headache, coughing, weakness and general discomfort. The recommended time of isolation is about five days.

Sunday December 27, 2009 -----A(H1N1) vaccine by March/April 2010

Here’s that update on flu vaccines in Malaysia you’ve been waiting for.

HOW long more do we have to wait for a publicly-available A(H1N1) influenza vaccine? Anytime from March to April, says Sanofi-Aventis medical manager (Malaysia/Singapore/Brunei) Dr Shree Jacob.

If this is news to you, it’s probably, and understandably, because you were caught up in Christmas festivities and didn’t manage to catch our news report about it on Friday

Seasonal, not pandemic

The formulation due to arrive in March/April is the routinely produced southern hemisphere trivalent seasonal influenza vaccine, which arrives every year around the same time.

This year, it will contain a component that is protectective against the A(H1N1) strain currently circulating. The new formulation is different from the expedited pandemic A(H1N1) monovalent vaccine that is due to arrive in January.

“Monovalent” here means the pandemic flu vaccine contains just one viral strain ie the A(H1N1) strain everybody has been so worried about. “Trivalent” means the seasonal flu vaccine contains three viral strains.

One of the three strains is the A/California/7/2009-like strain, which the World Health Organisation (WHO) recommended for inclusion in the seasonal vaccine back in Sept.

This strain closely resembles the A(H1N1) strain currently circulating and will protect recipients against it, confirms technical officer with the WHO Representative Office for Brunei Darussalam, Malaysia, and Singapore, Dr Harpal Singh.

Available, at a price

Unlike the pandemic A(H1N1) vaccine due to arrive in Jan, which will only be available from public hospitals and clinics to frontliners and high-risk groups, the new seasonal vaccine will be available as usual to the general public (as long as they can pay for it) through private hospitals and clinics that stock it.

Normally, the seasonal flu vaccine costs below RM100. (Between RM40 and RM60, consultant cardiologist Datuk Dr Khoo Kah Lin told us a while back.)

Their arrival is good news, says recently appointed Health Ministry disease control director Dr Lokman Hakim Sulaiman.

“We very much welcome these new seasonal vaccines, which should also protect against A(H1N1). The public will now have access to the vaccine,” he told Fit4Life.

What is the best way to keep from spreading the virus through coughing or sneezing?

If you are sick with flu-like illness, 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.*)

Keep away from others as much as possible. Cover your mouth and nose with a tissue when coughing or sneezing. Put your used tissue in the waste basket. Then, clean your hands, and do so every time you cough or sneeze.

What can I do to protect myself from getting sick?

This season, there is a seasonal flu vaccine to protect against seasonal flu viruses and a 2009 H1N1 vaccine to protect against the 2009 H1N1 influenza virus (sometimes called “swine flu”). A flu vaccine is the first and most important step in protecting against flu infection. For information about the 2009 H1N1 vaccines, visit H1N1 Flu Vaccination Resources. For information about seasonal influenza vaccines, visit Preventing Seasonal Flu With Vaccination.

There are also everyday actions that can help prevent the spread of germs that cause respiratory illnesses like the flu.

Take these everyday steps to protect your health:

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. If soap and water are not available, use an alcohol-based hand rub.*

•Avoid touching your eyes, nose or mouth. Germs spread this way.

•Try to avoid close contact with sick people.

•If you are sick with flu-like illness, 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.*) Keep away from others as much as possible to keep from making others sick.

How does 2009 H1N1 flu compare to seasonal flu in terms of its severity and infection rates?

With seasonal flu, we know that 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, on average 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% 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 relatively fewer cases and deaths reported in people 65 years and older, 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.

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. Some people may have vomiting and diarrhea. People may be infected with the flu, including 2009 H1N1 and have respiratory symptoms without a fever. Severe illnesses and deaths have occurred as a result of illness associated with this virus.

How severe is illness associated with 2009 H1N1 flu virus?

Illness with 2009 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.

In seasonal flu, certain people are at “high risk” of serious complications. This includes people 65 years and older, children younger than five years old, pregnant women, and people of any age with certain chronic medical conditions. About 70 percent of people who have been hospitalized with this 2009 H1N1 virus have had one or more medical conditions previously recognized as placing people at “high risk” of serious seasonal flu-related complications. This includes pregnancy, diabetes, heart disease, asthma and kidney disease.

Young children are also at high risk of serious complications from 2009 H1N1, just as they are from seasonal flu. And while people 65 and older are the least likely to be infected with 2009 H1N1 flu, if they get sick, they are also at “high risk” of developing serious complications from their illness. See People at High Risk of Developing Flu-Related Complications for more information about who is more likely to get flu complications that result in being hospitalized and occasionally result in death.

CDC laboratory studies have shown that no children and very few adults younger than 60 years old have existing antibody to 2009 H1N1 flu virus; however, about one-third of adults older than 60 may have antibodies against this virus. It is unknown how much, if any, protection may be afforded against 2009 H1N1 flu by any existing antibody.

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.

Can I get H1N1 more than once?

Getting infected with any influenza virus, including 2009 H1N1, should cause your body to develop immune resistance to that virus so it's not likely that a person would be infected with the identical influenza virus more than once. (However, people with weakened immune systems might not develop full immunity after infection and might be more likely to get infected with the same influenza virus more than once.) However, it's also possible that a person could have a positive test result for flu infection more than once in an influenza season. This can occur for two reasons:

1.A person may be infected with different influenza viruses (for example, the first time with 2009 H1N1 and the second time with a regular seasonal flu virus. Most rapid tests cannot distinguish which influenza virus is responsible for the illness. And,
2.Influenza tests can occasionally give false positive and false negative results so it's possible that one of the test results were incorrect. This is more likely to happen when the diagnosis is made with the rapid flu tests. More information about flu diagnosis is available at http://www.cdc.gov/h1n1flu/diagnosis/