What is swine flu?
Swine influenza is a respiratory disease of pigs caused by type A
influenza that regularly causes outbreaks of influenza among pigs.
Swine flu causes high levels of illness and low death rates among
pigs. Swine influenza viruses may circulate in swine throughout the
year, but most outbreaks among swine herds occur during the late
fall and winter months, similar to humans. The classical swine flu
virus, an influenza type A H1N1 virus, was first isolated in a pig
Pigs infected with swine flu may seem tired and have a runny
nose, cough and poor appetite.
What are the symptoms of swine flu in humans?
The symptoms of swine flu in people are expected to be similar to
the symptoms of regular human seasonal influenza and include fever,
lethargy, lack of appetite and coughing. Some people with swine flu
also have reported runny nose, sore throat, nausea, vomiting and
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 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.
Can humans catch swine flu?
Swine flu viruses do not normally infect humans. However,
sporadic human infections with swine flu have occurred. Most
commonly, these cases occur in people with direct exposure to pigs
(e.g., children near pigs at a fair or workers in the swine
industry). In addition, there have been documented cases of one
person spreading swine flu to others. For example, an outbreak of
apparent swine flu infection in pigs in Wisconsin in 1988 resulted
in multiple human infections, and, although no community outbreak
resulted, there was antibody evidence of virus transmission from the
patient to health care workers who had close contact with the
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Can people catch swine flu from eating pork?
No. Swine influenza viruses are not transmitted by
food. You cannot get swine influenza from eating pork or pork
products. Eating properly handled and cooked pork and pork products
is safe. Cooking pork to an internal temperature of 160 degrees F
kills the swine flu virus as it does other bacteria and viruses.
How can human infections with swine influenza be diagnosed?
To diagnose swine influenza A infection, a respiratory specimen
would generally need to be collected within the first four to five
days of illness, when an infected person is most likely to be
shedding virus. However, some people, especially children, may shed
virus for 10 days or longer. Identification as a swine flu influenza
A virus requires sending the specimen to CDC for laboratory testing.
What medications are available to treat swine flu infections in
Four different anti-viral drugs are licensed for use in the U.S.
for the treatment of influenza: amantadine, rimantadine, oseltamivir
and zanamivir. While most swine influenza viruses have been
susceptible to all four drugs, the most recent swine influenza
viruses isolated from humans are resistant to amantadine and
rimantadine. At this time, CDC recommends the use of oseltamivir or
zanamivir for the treatment or prevention of infection with swine
For more information on swine flu, visit
[Text from PDF file from
the Logan County Department
of Public Health]