Swine influenza is an infection caused by any one of several types of swine influenza viruses. Swine influenza virus (SIV) or swine-origin influenza virus (S-OIV) is any strain of the influenza family of viruses that is endemic in pigs. As of 2009, the known SIV strains include influenza C and the subtypes of influenza A known as H1N1, H1N2, H2N1, H3N1, H3N2, and H2N3.
The swine flu was initially seen in Mexico in April 2009, where the strain of the particular virus was a mixture from 3 types of strains. Six of the genes are very similar to the H1N2 influenza virus that was found in pigs around 2000.
Swine influenza virus is common throughout pig populations worldwide. Transmission of the virus from pigs to humans is not common and does not always lead to human flu, often resulting only in the production of antibodies in the blood. If transmission does cause human flu, it is called zoonotic swine flu. People with regular exposure to pigs are at increased risk of swine flu infection.
Around the mid-20th century, identification of influenza subtypes became possible, allowing accurate diagnosis of transmission to humans. Since then, only 50 such transmissions have been confirmed. These strains of swine flu rarely pass from human to human. Symptoms of zoonotic swine flu in humans are similar to those of influenza and of influenza-like illness in general, namely chills, fever, sore throat, muscle pains, severe headache, coughing, weakness, shortness of breath, and general discomfort.
It is estimated that in the 2009 flu pandemic 11–21% of the then global population (of about 6.8 billion), or around 700 million to 1.4 billion people, contracted the illness — more in absolute terms than the Spanish flu pandemic. However, with about 150,000–575,000 fatalities, it had a much lower case fatality rate. In August 2010, the World Health Organization declared the swine flu pandemic officially over.
Subsequent cases of swine flu were reported in India in 2015, with over 31,156 positive test cases and 1,841 deaths up to March 2015.News source link to read te entire article. Pandemic News, latest news about (global) epidemic or disease outbreak.