Swine Influenza (swine flu) is a respiratory disease of pigs caused by type A influenza viruses including H1N1 and H3N2. Pigs that contract swine flu suffer from similar symptoms as do humans with influenza.
It has mutated into the "Novel H1N1" (A-H1N1/09, Pandemic Swine Flu) form of the virus, which has the ability to be passed on to humans. This new form is highly contagious and can be passed from person to person and rarely from a person back to pigs.
Human Influenza refers to one of the three major types of flu viruses ( Influenza type A,B,C) endemic to the human population (orthomyxoviridae). These are distinguished from animal flu passed to humans as a result of a mutation in an animal strain that allows it to be able to invade the cells of humans. Diseases that are able to pass from animals to humans are called zoonotic diseases.
Additional Information about Type A Influenza Novel H1N1 (aka A-H1N1/09):- The 2009 Swine Flu is also known by several other names world wide. In the US it is called Swine Flu, 2009 Swine Flu, Novel H1N1, New H1N1 Influenza, A H1N1, and more officially now by the CDC A-H1N1/09 Virus. It has different names in other countries as well, for example: it is called Schweinegrippe in Germany, la Grippe A in France, Mexican Flu in the Netherlands, SOIV (Swine Origin Influenza Virus) in Canada, and la epidemia in Mexico.
- It has genetic material from multiple strains of flu from pigs, one from Eurasian swine flu, also genetic material from North American swine flu, human flu, and Avian (bird) flu. This is called a "quadruple reassortant" virus, meaning it was made by mutations involving four genomes (or sometimes called quintuple if the European and Asian strains are counted separately).
- It has the potential to be a deadly flu, although the first wave has been mild. This is also the way the 1918 Spanish flu (a different H1N1 virus), that was so deadly, began. It became much more virulent in its second wave. The reason that it has potential to be worse than most Type A H1N1 virus strains that humans can get, is that there have not been strains even somewhat similar to this new one in the past, so there is no immunity from hereditary sources or from prior vaccinations or exposure. It is totally new, so people may have much more trouble with it than with the typical seasonal flu viruses. The outbreak seemed to begin in Mexico, but it may have actually started at a pig farm in the US and then mutated to a strain that humans caught and passed to other humans who took it to Mexico.
- A person who has this virus presents with typical seasonal flu symptoms, such as chills, fever, sore throat, and cough. The original Swine flu virus that pigs get does not ordinarily readily transmit from pig to human. It has happened with farm workers in very close contact with the pigs, but it has been rare. Because of the ability of viruses to rapidly evolve and mutate into new and different strains, when there is prolonged contact between humans and infected pigs or their environment, the virus can "morph" into a new kind that humans may also get. Once in the human host, it can then be passed to other people by close human to human contact. See the related questions below for more detail on what caused this unique virus to become infectious to humans.
- The A-H1N1/09 (2009 swine flu) virus is spread on respiratory droplets from uncovered coughs and sneezes, and by direct or close contact with an infected person. However, wearing ordinary surgical masks is not an effective preventive measure since a virus is sub-microscopic and can pass through these masks unfiltered. The masks can, however, be helpful in preventing a person already with the flu from spreading their virus by coughing or sneezing without covering their mouths. The masks will trap the droplets on the inside of the mask. There are respirators and specially designed face masks (N95) that can be effective to prevent the passage of the microbe in the air to you from others, when properly fitted to the face. Avoid people who are sneezing or coughing, keep a distance of approximately 6 feet from an infected person. Be very careful when touching public surfaces that others may have touched, and wash your hands frequently. See the related questions below for more information on protecting yourself from getting the flu, and for the proper method of washing hands to remove germs.
- If given within two days of the first symptoms, the Centers for Disease Control and Prevention (CDC) information says that treatment with either of these two of the anti-viral medications currently on the market, oseltamivir and zanamivir, can be effective in lessening the ability of the virus to invade cells and lessen the severity of the symptoms. Otherwise, the treatment is symptomatic (cough medicine if there is a cough, fever medicine for fever, etc.), the same as for other types of the seasonal flu viruses, unless severe respiratory distress is realized. See the related questions below for more information about treatment for swine flu and symptoms that may require urgent medical attention.
Symptoms: - Fever.
- Cough.
- Sore throat.
- Muscle and joint pain.
- Shortness of breath.
- Nausea and vomiting.
- Diarrhea.
The illness may elevate to a severe respiratory illness within about five days.
H1N1 is a type of influenza (flu) virus. Early on, H1N1 flu was referred to as swine flu. In 2009, H1N1 is
causing illness in countries around the world.