swine flu

Flu

Influenza Virus Avian influenza Flu season Research Vaccine Treatment Genome project H5N1 strain

Swine Flu refers to a subset of Orthomyxoviridae that creates influenza in pigs and are endemic in pigs. This is not a phylogenetics based taxonomic category.

The species of Orthomyxoviridae that can cause flu in pigs are Influenza A virus and Influenza C virus but not all genotypes of these two species infect pigs.^[1]

The known subtypes of Influenza A virus that create influenza in pigs and are endemic in pigs are H1N1, H1N2, H3N1 and H3N2. ^{[2] [3]}

A H1N1 shift crossed over to humans in the early part of the 20th century, causing the Spanish Flu pandemic, which killed up to 50 million people. The death toll was particularly high among young, healthy adults.

The U.S. swine flu scare of 1976

On February 5, 1976, an army recruit at Fort Dix said he felt tired and weak. He died the next day and four of his fellow soldiers were later hospitalized. Two weeks after his death, health officials announced that swine flu was the cause of death. Alarmed public-health officials decided that action must be taken to head off a major pandemic, and they urged that every person in the U.S. be vaccinated for the disease. President Gerald Ford was confronted with a potential swine flu pandemic. The vaccination program was plagued by delays and public relations problems, but about 24% of the population was vaccinated by the time the program was cancelled. ^[4]

An immunopathological reaction to the vaccine in some people is believed to have caused about 500 cases of Guillain-Barré syndrome resulting in death from severe pulmonary complications for 25 people. More people died from the vaccine than died from the swine flu itself.^[4] Other influenza vaccines have not been clearly linked to Guillain-Barré syndrome.^[5]

The Philippine swine flu outbreak of 2007

On August 20, 2007, Department of Agriculture officers investigated the outbreak of swine flu in Nueva Ecija and Central Luzon, Philippines. The mortality rate is less than 10 % for swine flu, if there are no complications like hog cholera. Earlier, or on July 27, 2007, the Philippine National Meat Inspection Service (NMIS) raised a hog cholera "red alert" warning over Metro Manila and 5 regions of Luzon after the disease spread to backyard pig farms in Bulacan and Pampanga, even if these tested negative for the swine flu virus.^[6][7]

See also

• Bird flu
• Dog flu
• Horse flu
• Human flu

Sources

1. ^ Veterinary Sciences Tomorrow article Swine influenza: a zoonosis by Paul Heinen dated 15 September 2003 says "Influenza B and C viruses are almost exclusively isolated from man, although influenza C virus has also been isolated from pigs and influenza B has recently been isolated from seals."
2. ^ Swine Diseases (Chest) - Swine Influenza, Iowa State University College of Veterinary Medicine
3. ^ eurekalert Tips from the Journals of the American Society for Microbiology - Novel H3N1 Swine Influenza Virus Identified in Pigs in Korea
4. ^ ^{a b} The Sky is Falling: An Analysis of the Swine Flu Affair of 1976
5. ^ University of Illinois at Springfield
6. ^ GMA NEWS.TV, DA probes reported swine flu 'outbreak' in N. Ecija
7. ^ GMA NEWS.TV, Gov't declares hog cholera alert in Luzon

Further reading

• The Swine Flu Episode and the Fog of Epidemics by Richard Krause in CDC's Emerging Infectious Diseases Journal Vol. 12, No. 1 January 2006 published December 20, 2005

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