Swine flu infects some people every year and is typically found in people who have been in direct contact with pigs, although there have been cases of person-to-person transmission. Symptoms include fever, disorientation, stiffness of the joints, vomiting, and loss of consciousness which may result in death.
The Centers for Disease Control and Prevention (CDC) reports that the symptoms and transmission of the swine flu from human to human is much like seasonal flu -- commonly fever, lethargy, lack of appetite and coughing. Some people with swine flu have also reported runny nose, sore throat, nausea, vomiting and diarrhea. It is believed to be spread between humans through aerial or physical contact -- coughing or sneezing of infected people or by touching something with the virus on it and then touching their own nose or mouth.
Swine flu in humans is most contagious during the first five days of the illness in the infected person, although some people, most commonly children, can remain contagious for up to ten days. Diagnosis can be made by sending a specimen, collected during the first five days, to the CDC for analysis.
The swine flu is susceptible to four drugs licensed in the US: amantadine, rimantadine, oseltamivir and zanamivir; however, for this 2009 outbreak, it is recommended it be treated with oseltamivir and zanamivir. The vaccine for the human seasonal H1N1 flu does not protect against the swine H1N1 flu, even if the virus strains are the same specific variety, as they are antigenically very different.
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. The Mexican fatalities are said to be mainly young adults, a hallmark of pandemic flu. Following a series of reports of isolated cases of swine flu, the first announcement of the outbreak in Mexico was documented on April 23, 2009.
The origins of the new Swine Influenza Virus SIV-H1N1 strain remain unknown. One theory is that Asian and European strains traveled to Mexico in migratory birds or in people, then combined with North American strains in Mexican pig factory farms before jumping over to farm workers. The Mexican health agency acknowledged that the original disease vector of the virus may have been flies multiplying in manure lagoons of pig farms near Perote, Veracruz, owned by Granjas Carroll, a subsidiary of Smithfield Foods.
Some of the cases have been confirmed by the World Health Organization to be due to a new genetic strain of H1N1. The new H1N1 strain has been confirmed in 16 of the deaths and 44 others are being tested as of April 24, 2009.
As of April 25, 2009 19:30 EDT 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 (due to a student trip to Mexico). H1N1 is a subtype of the species influenza A virus.
A variant of H1N1 was responsible for the Spanish flu pandemic that killed some 50 million to 100 million people worldwide from 1918 to 1919.
The seasonal flu tends to kill just a fraction of 1% of those infected. In Mexico, about 71 deaths out of roughly 1,000 cases represents a fatality rate of about 7.1%. The Spanish flu pandemic of 1918, had a fatality rate of about 2.5%.
Statistical projections for this virus pathology based upon the same infection rate as the Spanish flu pandemic and current fatality rate, indicates that as many as 284 million deaths could occur worldwide as a result of the genesis of this new Swine Influenza Virus SIV-H1N1 strain.
At 8 p.m. on Sunday, 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.
There have been five cases of possible swine flu in Canada, according to the Canadian Press. Two are in British Columbia, and three in Nova Scotia. According to the provincial government, four students in Windsor, Nova Scotia have confirmed cases of swine flu.
On April 26, 2009, some schools in the United States announced closures and cancellations related to possibilities that students may have been exposed to swine flu.
According to the CDC, the seasonal influenza strain H1N1 vaccine is thought to be unlikely to provide protection against the new Swine Influenza Virus SIV-H1N1 strain. The virus has been detected in multiple areas, indicating that containment is unlikely; this is exacerbated by the incubation and infectious periods of influenza.
References: Wikipedia (http://en.wikipedia.org/wiki/Swine_flu); NPR broadcast(http://www.npr.org)
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