Swine H1N1 Flu:2009

Swine H1N1 Flu:2009

Dr.Kedar Karki

Swine flu , now known as the 2009 H1N1 flu, is caused by the orthomyxovirus which usually affects pigs but viral mutations allows the virus to cross species to other hosts like humans. The swine influenza virus (SIV) is another example of cross species viral infection which was previously seen with other Zoonotic infections like in civets to humans SARS or Sudden Acute Respiratory Syndrome and from birds to humans as seen with avian (bird) flu.

Unlike SARS and bird flu, swine flu has mutated to the point where the virus can now spread from human-to-human. This current mutation is the cause of the global scare of the recent 2009 outbreak which is feared to become a pandemic. With the popularity of air travel, infected passengers from one region can easily travel to other nations and result in new outbreaks occurring in regions that were not prone to swine flu.

The current human-to-human transmission of swine flu is caused by droplet spread through the contact with infected body fluids as in saliva or mucus when sneezing.

How is Swine Flu H1N1 Spread?

The incubation period (time between exposure and onset of symptoms) is still uncertain, but it appears to be 3-4 days.

All flus are spread by droplets that spray out as a person sneezes or coughs. You can catch Swine Flu H1N1 or any flu virus if:

1. You are standing within three feet of an uncovered cough or sneeze and droplets make contact with you or if you inhale them.
2. The droplets land on hard surfaces, like a desk top or keyboard. Even after the droplet dries a flu virus could live for over an hour. You can catch the virus by touching an infected surface then touching your eyes, nose, or mouth.
3. You can give to the flu to somebody else by touching their eyes, nose, or mouth if the virus is on your hand.
4. Somebody coughs sneezes or blows their nose into a tissue, and the wet tissue makes contact with their hand or the tissue tears and the contents make contact with their hand. If they touch hard surfaces or shake hands before they wash their hands then they could spread a virus. Flu viruses can also be spread by handling a contaminated cloth handkerchief then touching people or surfaces.
5. An infected person touches their eyes, nose or mouth then touches other surfaces, objects or people before washing their hands.

This is not the same Swine Flu virus people were immunized against in the 1970's. There is a vaccine for the 2009 Swine Flu Influenza A H1N1 virus under development but even with fast tracking it will take months before it is ready for human trial.

Swine Flu H1N1 is not spread by pigs and you cannot catch Swine Flu H1N1 by eating pork or using medications that are derived from pigs (porcine).

Symptoms of Swine Flu

Swine flu infection causes symptoms that are similar to the symptoms of influenza infection as seen during the annual ‘flu’ season. This may result in many cases of swine flu being misdiagnosed as a common cold or the ‘flu’ and if infected persons do not seek professional medical treatment, the infection can spread further in the general population.

The general symptoms of swine flu include:

1. Fever with or without chills.
2. Sore throat.
3. Respiratory symptoms, usually a cough or less frequently as dyspnoea (difficulty breathing) or pneumonia.
4. Fatigue and lethargy
5. Myalgia (general body aches)
6. Headaches
7. Diarrhea
8. Vomiting

The current swine flu epidemic has seen gastrointestinal symptoms like diarrhea and vomiting that are more severe than previous swine flu outbreaks. Unfortunately these gastrointestinal symptoms may often be misdiagnosed as a ‘gastric flu’ and it is important to consult with your medical practitioner if your symptoms persist.

Preventing the Spread of Swine Flu H1N1

According to the CDC, proper hand washing is the most effective means of preventing the spread of disease.

1. Alcohol-based hand sanitizers are also considered effective.
2. Use disposable tissues, clean your hands after every use.
3. Cough into your elbow or shoulder if you do not have a tissue.
4. Preventative treatments (such as Tamiflu) are not recommended for healthy people as this could potentially lead to resistance. Only seek treatment if you have symptoms.
5. People with flu- like symptoms should avoid public places. If your child's school is closed do not place your child in group settings such as daycare.
6. If there are confirmed cases in your area, limit exposure by avoiding public places and clean your hands often while out and upon returning home.
7. An infected person is contagious about 1 day before they have symptoms so follow proper hand washing guidelines or use alcohol based hand sanitizers often to prevent the accidental spread of the flu.
8. The contagious period lasts for about 7 days after symptoms start, probably longer in children.