What is swine influenza?
Swine
influenza (also called swine flu or pig flu) is a group of influenza
viruses that usually infects pigs. Infections in humans are uncommon. The
current swine flu which is infecting people is a new strain of influenza A/H1N1.
It is not certain how it developed. It's genetic makeup shows parts of human
flu, avian (bird) flu and swine flu.
What are the symptoms
of swine flu?
The symptoms are expected to be
similar to that of regular human seasonal influenza: fever, lethargy, loss
of appetite and coughing. Some reports indicate infected people may
also have a runny nose, sore throat, nausea, vomiting and diarrhea.
Is there only one type
of swine flu virus?
No. Like all human influenza
viruses, swine influenza viruses change constantly. There are four main
influenza type A virus "subtypes" which have been isolated in pigs: H1N1, H1N2,
H3N2, and H3N1. The most common strain found in pigs is the H1N1 virus. However,
sometimes pigs can be infected with more than one virus type at a time. This
gives the genes from the viruses an opportunity to mix and "reassort" to
form a new virus.
Can humans get sick
with swine flu?
Yes.
Human infections are uncommon, but have occurred in the past.
Human infections with swine flu is more common in individuals who have direct
exposure (close contact) with pigs. The new strain that began circulating in
April 2009 can move from person to person, and so more people than usual
are being infected.
Can swine flu be spread from
human-to-human?
Yes, sometimes. Historical evidence
shows human-to-human transmission of swine flu has occurred. In 1988, in
Wisconsin USA, multiple human infections were reported after an apparent
outbreak of swine flu in pigs. No community outbreak was ever officially
announced, but there was serological evidence to show that the patient (who had
direct contact with infected pigs) transmitted the virus to the treating health
care workers.
The current swine flu H1N1 strain that has infected people in
several countries in 2009 also moves person to person.
Most cases had no contact with pigs.
How does swine flu
spread?
Typically, swine flu can be
spread from pigs to humans, and from humans to pigs. That is more likely
to occur when people have close contact (or are in close proximity)
with infected pigs.
If a swine flu virus mutates to a form that can move from
person-to-person, it is likely to spread in the same ways traditional
seasonal flu spreads between people. It's called “droplet” spread. When an
infectious individual coughs, sneezes, talks, etc. they expel contaminated
droplets. If these droplets get into someone else's mouth, eyes or nose, that
person can become infected with the flu.
These droplets can also get on objects like doorknobs, counters,
desks, armrests etc. People also become infected by touching surfaces that have
the flu virus on it and then touching their nose or mouth. This is why personal
hygiene is critical to staying well.
It may also be possible that influenza spreads via “aerosol”
transmission, where the where the virus floats in the air and infects people
(particularly in crowded places).
Can I catch swine flu
from eating pork or pork products?
No. Swine flu
viruses cannot be transmitted by food. It is safe to eat pork and pork products
that have been properly handled and/or sufficiently cooked. Cooking pork to an
internal temperature of 160°F (or 72°C) kills the swine flu virus as well as
other viruses and bacteria.
Are swine H1N1 viruses
the same has the human H1N1 viruses?
No. Swine flu H1N1 is genetically different from
the human H1N1 strain. It is unlikely the human seasonal vaccine will provide
protection against swine flu H1N1.
This information is reported on the International
SOS website, and has up to date information. International SOS is the world’s
leading provider of medical assistance, international healthcare, security
services and outsourced customer care.
*Posted 4/28/09
