What is it?
Swine Influenza (swine flu) is a respiratory disease of pigs caused by type A influenza virus that regularly causes outbreaks of influenza in pigs. Swine flu viruses cause high levels of illness and low death rates in pigs. Swine influenza viruses may circulate among swine throughout the year, but most outbreaks occur during the late fall and winter months similar to outbreaks in humans. The classical swine flu virus (an influenza type A H1N1 virus) was first isolated from a pig in 1930.
How many swine flu viruses are there?
Like all influenza viruses, swine flu viruses change constantly. Pigs can be infected by avian influenza and human influenza viruses as well as swine influenza viruses. When influenza viruses from different species infect pigs, the viruses can reassort (i.e. swap genes) and new viruses that are a mix of swine, human and/or avian influenza viruses can emerge. Over the years, different variations of swine flu viruses have emerged. At this time, there are four main influenza type A virus subtypes that have been isolated in pigs: H1N1, H1N2, H3N2, and H3N1. However, most of the recently isolated influenza viruses from pigs have been H1N1 viruses.
1976 U.S. Outbreak
On February 5, 1976, an army recruit at Fort Dix 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 and that this strain of flu appeared to be closely related to the strain involved in the 1918 flu pandemic. Alarmed public-health officials decided that action must be taken to head off another major pandemic. The vaccination program was plagued by delays and public relations problems, but about 24% of the population had been vaccinated by the time the program was canceled.
2007 Philippine Outbreak
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. 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.
2009 Mexico Outbreak
In March and April 2009, more than 1,000 cases of swine flu in humans were detected in Mexico, and more than 80 deaths are suspected to have a connection with the virus. As of April 25, 2009 there are 11 laboratory confirmed cases in the southwestern United States and in Kansas, and several suspected cases in the New York City metropolitan area. The first announcement of the outbreak in Mexico was documented on April 23, 2009. Some of the cases have been confirmed by the World Health Organization to be due to a new genetic strain of H1N1. The new strain has been confirmed in 16 of the deaths and 44 others are being tested as of April 24, 2009. The Mexican fatalities are said to be mainly young adults, a hallmark of pandemic flu.
On April 26, the New Zealand Minister of Health confirmed that 22 students returning from a school trip from Mexico had flu-like symptoms (most likely swine flu). 13 of the students with flu-like symptoms were tested and 10 tested positive for Influenza A, their cases strongly suspected to be the swine flu strain. However there is a possibility that the infected are not infected with the swine flu but other forms of the flu. The government has suggested that citizens of New Zealand with flu-like symptoms should see their physician immediately.
Is there a vaccine for swine flu?
Vaccines are available to be given to pigs to prevent swine influenza. There is no vaccine to protect humans from swine flu. The seasonal influenza vaccine will likely help provide partial protection against swine H3N2, but not swine H1N1 viruses.
(Source: www.wikipedia.org and www.cdc.gov)
Swine Influenza (swine flu) is a respiratory disease of pigs caused by type A influenza virus that regularly causes outbreaks of influenza in pigs. Swine flu viruses cause high levels of illness and low death rates in pigs. Swine influenza viruses may circulate among swine throughout the year, but most outbreaks occur during the late fall and winter months similar to outbreaks in humans. The classical swine flu virus (an influenza type A H1N1 virus) was first isolated from a pig in 1930.
How many swine flu viruses are there?
Like all influenza viruses, swine flu viruses change constantly. Pigs can be infected by avian influenza and human influenza viruses as well as swine influenza viruses. When influenza viruses from different species infect pigs, the viruses can reassort (i.e. swap genes) and new viruses that are a mix of swine, human and/or avian influenza viruses can emerge. Over the years, different variations of swine flu viruses have emerged. At this time, there are four main influenza type A virus subtypes that have been isolated in pigs: H1N1, H1N2, H3N2, and H3N1. However, most of the recently isolated influenza viruses from pigs have been H1N1 viruses.
1976 U.S. Outbreak
On February 5, 1976, an army recruit at Fort Dix 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 and that this strain of flu appeared to be closely related to the strain involved in the 1918 flu pandemic. Alarmed public-health officials decided that action must be taken to head off another major pandemic. The vaccination program was plagued by delays and public relations problems, but about 24% of the population had been vaccinated by the time the program was canceled.
2007 Philippine Outbreak
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. 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.
2009 Mexico Outbreak
In March and April 2009, more than 1,000 cases of swine flu in humans were detected in Mexico, and more than 80 deaths are suspected to have a connection with the virus. As of April 25, 2009 there are 11 laboratory confirmed cases in the southwestern United States and in Kansas, and several suspected cases in the New York City metropolitan area. The first announcement of the outbreak in Mexico was documented on April 23, 2009. Some of the cases have been confirmed by the World Health Organization to be due to a new genetic strain of H1N1. The new strain has been confirmed in 16 of the deaths and 44 others are being tested as of April 24, 2009. The Mexican fatalities are said to be mainly young adults, a hallmark of pandemic flu.
On April 26, the New Zealand Minister of Health confirmed that 22 students returning from a school trip from Mexico had flu-like symptoms (most likely swine flu). 13 of the students with flu-like symptoms were tested and 10 tested positive for Influenza A, their cases strongly suspected to be the swine flu strain. However there is a possibility that the infected are not infected with the swine flu but other forms of the flu. The government has suggested that citizens of New Zealand with flu-like symptoms should see their physician immediately.
Is there a vaccine for swine flu?
Vaccines are available to be given to pigs to prevent swine influenza. There is no vaccine to protect humans from swine flu. The seasonal influenza vaccine will likely help provide partial protection against swine H3N2, but not swine H1N1 viruses.
(Source: www.wikipedia.org and www.cdc.gov)
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