H1N1

H1N1

H1N1

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. 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(Vogel et al 2009).

History and background of H1N1

In 1976, there was an outbreak of swine flu at Fort Dix. This virus is not the same as the 2009 outbreak, but it was similar insofar as it was an influenza A virus that had similarities to the swine flu virus. There was one death at Fort Dix. The government decided to produce a vaccine against this virus, but the vaccine was associated with neurological complications (Guillain-Barré syndrome) and was discontinued. Some individuals speculate that formalin, used to inactivate the virus, may have played a role in the development of this complication in 1976. There is no evidence that anyone who obtained this vaccine would be protected against the 2009 swine flu(Phillips et al 2009 ). One of the reasons it takes a few months to develop a new vaccine is to test the vaccine for safety to avoid the complications seen in the 1976 vaccine. New vaccines against any flu virus type are usually made by growing virus particles in eggs. A serious side effect (allergic reaction such as swelling of the airway) to vaccines can occur in people who are allergic to eggs; these people should not get flu vaccines. Individuals with active infections or diseases of the nervous system are also not recommended to get flu vaccines.

The pandemic's statistics

According to WHO statistics, there have been 6071 swine flu-related deaths in humans worldwide as of November 1, 2009. The situation was officially labeled a phase 6 global pandemic in July, which is the peak phase of a pandemic.

A total of 199 countries and territories have now reported H1N1 cases to WHO, with a combined recorded total of 482,300 cases. The actual case number is much larger, however, since countries are no longer required to report individual occurrences of swine flu and many have stopped doing so(Annas 2003).

WHO also reports that the incidence of swine flu is increasing in East Asia. China was previously seeing seasonal flu and H1N1 influenza with roughly equal frequency, but now H1N1 is the predominant type of influenza in the ...