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 diarrhea.
Can people catch swine flu from eating pork?
No. Swine influenza viruses are not transmitted by food. You can
not 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°F kills the swine flu virus
as it does other bacteria and viruses.
How does swine flu spread?
Influenza viruses can be directly transmitted from pigs to people
and from people to pigs. Human infection with flu viruses from pigs
are most likely to occur when people are in close proximity to infected
pigs, such as in pig barns and livestock exhibits housing pigs at
fairs. Human-to-human transmission of swine flu can also occur.
This is thought to occur in the same way as seasonal flu occurs
in people, which is mainly person-to-person transmission through
coughing or sneezing of people infected with the influenza virus.
People may become infected by touching something with flu viruses
on it and then touching their mouth or nose.
What do we know about human-to-human spread of swine flu?
In September 1988, a previously healthy 32-year-old pregnant woman
was hospitalized for pneumonia and died 8 days later. A swine H1N1
flu virus was detected. Four days before getting sick, the patient
visited a county fair swine exhibition where there was widespread
influenza-like illness among the swine.
In follow-up studies, 76% of swine exhibitors tested had antibody
evidence of swine flu infection but no serious illnesses were detected
among this group. Additional studies suggest that one to three health
care personnel who had contact with the patient developed mild influenza-like
illnesses with antibody evidence of swine flu infection.
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 4 to 5 days of illness
(when an infected person is most likely to be shedding virus). However,
some persons, 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 humans?
There are four different antiviral drugs that are licensed for use
in the US 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 and/or prevention of infection with swine influenza
viruses.
What other examples of swine flu outbreaks are there?
Probably the most well known is an outbreak of swine flu among soldiers
in Fort Dix, New Jersey in 1976. The virus caused disease with x-ray
evidence of pneumonia in at least 4 soldiers and 1 death; all of
these patients had previously been healthy. The virus was transmitted
to close contacts in a basic training environment, with limited
transmission outside the basic training group. The virus is thought
to have circulated for a month and disappeared. The source of the
virus, the exact time of its introduction into Fort Dix, and factors
limiting its spread and duration are unknown. The Fort Dix outbreak
may have been caused by introduction of an animal virus into a stressed
human population in close contact in crowded facilities during the
winter. The swine influenza A virus collected from a Fort Dix soldier
was named A/New Jersey/76 (Hsw1N1).
Is the H1N1 swine flu virus the same as human H1N1 viruses?
No. The H1N1 swine flu viruses are antigenically very different from
human H1N1 viruses and, therefore, vaccines for human seasonal flu
would not provide protection from H1N1 swine flu viruses.
Swine Flu in Pigs
How does swine flu spread among pigs?
Swine flu viruses are thought to be spread mostly through close
contact among pigs and possibly from contaminated objects moving
between infected and uninfected pigs. Herds with continuous swine
flu infections and herds that are vaccinated against swine flu may
have sporadic disease, or may show only mild or no symptoms of infection.
What are signs of swine flu in pigs?
Signs of swine flu in pigs can include sudden onset of fever, depression,
coughing (barking), discharge from the nose or eyes, sneezing, breathing
difficulties, eye redness or inflammation, and going off feed.
How common is swine flu among pigs?
H1N1 and H3N2 swine flu viruses are endemic among pig populations
in the United States and something that the industry deals with
routinely. Outbreaks among pigs normally occur in colder weather
months (late fall and winter) and sometimes with the introduction
of new pigs into susceptible herds. Studies have shown that the
swine flu H1N1 is common throughout pig populations worldwide, with
25 percent of animals showing antibody evidence of infection. In
the U.S. studies have shown that 30 percent of the pig population
has antibody evidence of having had H1N1 infection. More specifically,
51 percent of pigs in the north-central U.S. have been shown to
have antibody evidence of infection with swine H1N1. Human infections
with swine flu H1N1 viruses are rare. There is currently no way
to differentiate antibody produced in response to flu vaccination
in pigs from antibody made in response to pig infections with swine
H1N1 influenza.
While H1N1 swine viruses have been known to circulate among pig
populations since at least 1930, H3N2 influenza viruses did not
begin circulating among US pigs until 1998. The H3N2 viruses initially
were introduced into the pig population from humans. The current
swine flu H3N2 viruses are closely related to human H3N2 viruses.
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
Centers for Disease Control and Prevention 1600 Clifton Rd. Atlanta,
GA 30333, USA
http://www.cdc.gov
More Information about swine
flu ...