What Causes Swine Flu?

Swine flu, also known as H1N1 influenza, is caused by a subtype of the influenza A virus. This particular subtype is called H1N1 because it contains two key proteins on its surface, hemagglutinin (H) and neuraminidase (N), which play a role in its classification. Swine flu primarily affects pigs but can also be transmitted to humans.

The transmission of swine flu to humans typically occurs through close contact with infected pigs, such as in agricultural settings. However, it can also spread from person to person, similar to how seasonal influenza is transmitted. Human-to-human transmission of the H1N1 virus occurs through respiratory droplets when an infected person coughs or sneezes, or by touching surfaces contaminated with the virus and then touching the face, particularly the nose or mouth.

The H1N1 influenza virus is a mix of genetic material from swine, avian (bird), and human influenza viruses. This mixing of genetic material can lead to the emergence of new strains, which is why H1N1 is considered a zoonotic virus, capable of jumping from animals to humans.

The H1N1 influenza virus responsible for the 2009 swine flu pandemic was a novel strain of the virus that contained genetic elements from pig, bird, and human influenza viruses. It was able to spread easily among humans because most people did not have pre-existing immunity to this specific strain.

Vaccines have been developed to protect against H1N1 influenza, and they are included in seasonal flu vaccines. In addition to vaccination, practicing good hygiene, such as frequent handwashing and covering your mouth and nose when coughing or sneezing, can help reduce the risk of infection and transmission of swine flu and other influenza viruses.