Swine Flu

What is Swine Flu?

Swine Influenza also known as H1N1 flu, Swine flu, Pig and Hog flu is a respiratory disease caused by virus commonly found in pigs throughout the world. Most commonly it is due to H1N1 influenza subtype but sometimes H1N2, H3N1, and H3N2 can also be responsible. The major difference is that the current virus has strains of bird and pig viruses in it, and humans have very low or negligible immunity to it. That is what has made it more likely to become a pandemic virus (that can cause a global outbreak) as it could easily spread from human to human. Swine flu can look like a normal fever as its symptoms are similar to normal human influenza like cold and cough, sore throat, body aches, headaches, chills and fatigue. If diagnosed eairler treatment can be done to avoide further complications.
For confirmed case of Swine flu Oseltamivir (Tamiflu) or zanamivir (Relenza) are administered for treatment of virus infection.

Swine influenza virus is very common in pigs worldwide. Approximately 1%-4% of pigs get infected and die from it. The main mode of spread among pigs either direct or indirect contact. In many parts of the world pigs are vaccinated against it.

Types

The Influenza viruses causing sickness in humans are classified into three types - A, B and C. Type A is most common in pigs and C is rare. Influenza B has not been reported in pigs.

Swine influenza is commonly of the H1N1 influenza subtype, but sometimes they can come from other types, such as H1N2, H3N1, and H3N2.The recent outbreak of swine flu in humans is of the H1N1 type which is not as dangerous as some other types. It is caused by a new virus that has changed in ways that allow it to spread from person to person and it’s happening among people who haven’t had any contact with pigs.

Normaly swineflu virus do not transmit from pigs to human and do not cause swineflu, althuough if it happens, antibodies are produced in human blood.

To distinguish from viruses that infects pigs and the seasonal influenza A H1N1 viruses that have been in circulation for many years, The World Health organization (WHO)calls it “pandemic (H1N1) 2009.” The CDC calls H1N1 illness “H1N1 flu”.

Its official name or scientific name is H1N1 influenza A. The H means hemagglutinin and the N means neuraminidase and the 1s refer to their antibody type. Influenza A is a genus of the Orthomyxoviridae family of viruses, and refers to the fact that the virus is first identified in an animal, usually a pig or a bird. When put together, they describe the 2009-2010 swine flu virus.

Some important things to note:

* Generally Swine flu virus transmits through direct contact with respiratory secretions like coughing and sneezing of a infected person close or near to you.

* Swine flu is likely contagious from one day upto seven days if a person get sick with its symptoms.

* Surfaces such as a doorknob, drinking glass or kitchen counter can also be contaminated if droplets from cough or sneez fall on them. But these germs survive for only few hours.

* People who are in regular exposure to pigs have increased risk of getting swineflu.

* The swineflu vaccine developed by GlaxoSmithKline is called Pandemrix and the vaccine developed by Baxter is known as Celvapan.

Finally, transmission of the virus doesn’t require you to come into contact with pigs. It can pass from one human to another. According to the CDC (Center for Disease Control), there is some evidence that people who do come into contact regularly with pigs may be immune to this virus.

H1N1 Symptoms

H1N1 is also a influenza virus similar to that causes seasonal fever. The major difference is that the current virus has components of both pig and bird viruses in it, and humans don’t have any immunity to it. The symptoms of swine flu are very similar to cold flu, but there are some different swineflu symptoms which are indicated in infected person.

Swine flu symptoms include :

*fever, which is usually high, but unlike seasonal influenza, is sometimes absent.

* cough.

* runny nose or stuffy nose.

* sore throat.

* body aches.

* headache.

* chills.

* fatigue or tiredness, which can be extreme.
* Neurological problems .

* diarrhea and vomiting, sometimes, but more commonly seen than with seasonal flu.

Nearly everyone infected with H1N1 or swineflu show atleast two to three of these symptoms but only high level lab tests can definitively show whether person is infected or not. State health departments can do these tests in major health care centers or special cells for diagonosis of Swine flu.

According to reports of WHO Clinical findings or the clinical picture of severly infected cases are very different to that seen in seasonal influenza.

In severly infected cases the condition of the patients starts getting deterioted within 3 to 5 days after the onset of symptoms. It is so fast that many patients progress to respiratory failure within 24 hours.

There are some warnig signs issued by CDC and advise was given for immediate medical help. These warning signs are -

In Children -

* Fast and hard breathing

* Skin color turning blueish.

* Not drinking enough fluids and unable to eat

* Not interacting properly

* Being so irritable that the child does not want to be held

* Flu-like symptoms that improve and return with fever and cough

* Fever with a rash

* Having no tears when crying

In Adults:

* Difficult and short of breath

* Pain in the chest or abdomen

* Sudden and regular dizziness

* Severe or persistent vomiting or vomiting sensation.

* Low temperature

Diagnosis of Swine Flu

Swine flu A infection is diagnosed when an infected person is most likely to be shedding virus i.e, within the first four to five days of illness (children may shed virus for ten days or longer) during this period respiratory specimens are collected and sent for diagnosis to the state labs.

This is diagnosed clinically by the patient’s history of association with people known to have contracted the disease and also based upon their symptoms.

Tests

A quick test (for example, nasopharyngeal swab sample) is done to see if the patient is infected with influenza A or B virus. Most of the tests can distinguish between A and B types.

The test can be negative (no H1N1 infection) or positive for type A and B. If the test is positive for type B, the flu is not likely to be swine influenza (H1N1). If it is positive for type A, the person could have a conventional influenza strain or swine influenza (H1N1). H1N1 is mainly diagnosed by identifying the particular antigens associated with the virus type.

In general, this test is done in a specialized laboratory and is not done by many doctors clinics or hospital laboratories. However, doctors clinics are able to send specimens to specialized laboratories if necessary.

Is H1N1 a cause of an Epidemic or Pandemic in 2009?

An epidemic is defined as an outbreak of a contagious disease that is rapid and widespread, that affects many individuals at the same time.

The H1N1 influenza A virus spread in Mexico comes under this category. Whereas pandemic is an epidemic that becomes so widespread that it affects a region, continent, or the whole world. As of April 2009,the H1N1 was not declared as pandemic. However,as of June 11, 2009, WHO officials determined that H1N1 2009 influenza A reached WHO level 6 criteria and is now declared as the first flu pandemic in 41 years. Until now, it has reached 74 different countries on every continent except Antarctica but still the severity of the disease has not increased.

Treatment

Antiviral Treatements for Suspected and Confirmed cases.

Suspected Cases.

1.Empiric antiviral treatment is recommended for any ill person suspected to have swine influenza A (H1N1) virus infection.

2.Antiviral treatment with either zanamivir alone or with a combination of oseltamivir and either amantadine or rimantadine should be initiated as soon as possible after the onset of symptoms.

3.Recommended duration of treatment is five days.

4.Antiviral doses and schedules recommended for treatment of swine influenza A (H1N1) virus infection are the same as those recommended for seasonal influenza.

Confirmed Cases

1.For antiviral treatment of a confirmed case of swine influenza A (H1N1) virus infection, either oseltamivir (Tamiflu) or zanamivir (Relenza) may be administered.

2.Recommended duration of treatment is five days.

3.These same antivirals should be considered for treatment of cases that test positive for influenza A but test negative for seasonal influenza viruses H3 and H1 by PCR.

Measures and Preventions

1.Keeping hands clean is the most important step to avoid getting sick and spreading the H1N1 virus. Wash hands with clean water and hand soap.Rub hands together to form lather.

2.Warning! Do not give aspirin (acetylsalicylic acid) to children or teenagers who have the flu; this can cause a rare but serious illness called Reye’s syndrome.

3.Check ingredient labels on over-the-counter cold and flu medications to see if they contain aspirin.

4.Children younger than 2 years of age should not be given over-the-counter cold medications without first speaking with a healthcare provider.

5.The safest care for flu symptoms in children younger than 2 years of age is using a cool-mist humidifier and a suction bulb to help clear away mucus.

6.Over-the-counter cold and flu medications used according to the package instructions may help lessen some symptoms such as cough and congestion. Importantly, these medications will not lessen how infectious a person is.

7.Check with your health care provider or pharmacist if you are taking other over-the-counter or prescription medications not related to the flu.

 Source: www.swineflu.net.in