- Swine influenza, or swine flu, is caused by influenza viruses that normally infect pigs. It can sometimes be transmitted from pigs to humans.
- Symptoms in humans are similar to regular flu symptoms like fever, cough, and sore throat. It spreads when people with the virus cough or sneeze.
- Treatment involves antiviral drugs, which work best if started within two days of symptoms. Vaccines are also available to prevent swine flu.
2. • swine influenza viruses are usually
introduced into a herd by an
infected pig.
• In a newly infected herd, up to
100% of the animals may become
ill, but most animals recover
within 3–7 days if there are no
secondary bacterial infections or
other complications.
3. • In uncomplicated cases, the case
fatality rate ranges from less than 1%
to 4%.
• Many infections in enzootically
infected herds are subclinical; typical
signs of influenza may occur in only
25% to 30% of the pigs.
4. Swine influenza, also
called pig influenza, swine
flu, hog flu and pig flu, is an
infection caused by any
one of several types of
swine influenza viruses.
5. Swine influenza virus (SIV)
or swine-origin influenza virus (S-
OIV) is any strain of the influenza
family of viruses that
is endemic in pigs. As of 2009, the
known SIV strains include influenza
C and the subtypes of influenza
A known as H1N1, H1N2,
H2N1, H3N1, H3N2, and H2N3.
7. ELECTRON MICROSCOPE IMAGE OF THE REASSORTED H1N1
INFLUENZA VIRUS PHOTOGRAPHED AT THE CDC INFLUENZA
LABORATORY. THE VIRUSES ARE 80–120 NANOMETRES IN DIAMETER
8. The influenza virion is roughly spherical. It
is an enveloped virus; the outer layer is a
lipid membrane which is taken from the
host cell in which the virus multiplies.
Inserted into the lipid membrane are
‘spikes’, which are proteins – actually
glycoproteins, because they consist of
protein linked to sugars – known as HA
(hemagglutinin) and NA (neuraminidase).
9. These are the proteins that
determine the subtype of influenza
virus (A/H1N1, for example).
The HA and NA are important in the
immune response against the virus;
antibodies (proteins made to
combat infection) against these
spikes may protect against
infection.
10. The NA protein is the target of
the antiviral drugs Relenza and
Tamiflu.
Also embedded in the lipid
membrane is the M2 protein,
which is the target of
the antiviral adamantanes ama
ntadine and rimantadine.
11. Swine influenza virus is common
throughout pig populations worldwide.
Transmission of the virus from pigs to
humans is not common and does not
always lead to human flu, often resulting
only in the production of antibodies in
the blood. If transmission does cause
human flu, it is called zoonotic swine flu.
People with regular exposure to pigs are
at increased risk of swine flu infection.
12. Identification of influenza subtypes
became possible, allowing accurate
diagnosis of transmission to
humans. Since then, only 50 such
transmissions have been confirmed.
These strains of swine flu rarely
pass from human to human.
15. People who have swine flu
can be contagious one day
before they have any
symptoms, and as many as 7
days after they get sick.
Kids can be contagious for
as long as 10 days.
16. Symptoms of zoonotic swine flu
in humans are similar to those
of influenza and of influenza-like
illness in general,
namely chills, fever, sore
throat,musclepains,
coughing,weakness,
severe headache, and general
17.
18.
19. • H1N1 flu is also known as swine
flu. It's called swine flu because in
the past, the people who caught it
had direct contact with pigs.
• That changed several years ago,
when a new virus emerged that
spread among people who hadn't
been near pigs.
21. •Swine flu is contagious, and it
spreads in the same way as
the seasonal flu.
• When people who have
it cough or sneeze, they spray
tiny drops of the virus into the
air.
22. • If you come in contact with these
drops or touch a surface (such as a
doorknob or sink) that an infected
person has recently touched, you
can catch H1N1 swine flu.
• Despite the name, you can't catch
swine flu from eating bacon, ham,
or any other pork product.
24. The CDC recommends real
time PCR as the method of
choice for diagnosing H1N1.
The oral or nasal fluid
collection and RNA virus
preserving filter paper card
is commercially available.
25. This method allows a
specific diagnosis of novel
influenza (H1N1) as
opposed to seasonal
influenza.
Near-patient point-of-care
tests are in development.
27. Prevention of swine influenza
has three components:
1. prevention in swine,
2. prevention of transmission to
humans, and
3. prevention of its spread
among humans
28.
29. Thermal imaging camera and screen, photographed in an airport terminal in Greece – thermal
imaging can detect elevated body temperature, one of the signs of the virus H1N1 (swine
influenza).
31. Vaccination (flu pandemic vaccine)
Vaccines are available for different kinds of
swine flu. The U.S. Food and Drug
Administration (FDA) approved the new swine
flu vaccine for use in the United States on
September 15, 2009.
Studies by the National Institutes of
Health show a single dose creates enough
antibodies to protect against the virus within
about 10 days
33. In swine:
As swine influenza is rarely fatal to
pigs, little treatment beyond rest
and supportive care is required.
Instead, veterinary efforts are
focused on preventing the spread of
the virus throughout the farm, or to
other farms.
34. Vaccination and animal management
techniques are most important in
these efforts.
Antibiotics are also used to treat this
disease, which although they have no
effect against the influenza virus, do
help prevent bacterial pneumonia and
other secondary infections in influenza-
weakened herds.
35. In humans:
If a person becomes sick with
swine flu, antiviral drugs can
make the illness milder and
make the patient feel better
faster.
They may also prevent serious
flu complications.
36. For treatment, antiviral drugs work
best if started soon after getting sick
(within two days of symptoms).
Beside antivirals, supportive care at
home or in a hospital focuses on
controlling fevers, relieving pain and
maintaining fluid balance, as well as
identifying and treating any secondary
infections or other medical problems.
37. The U.S. Centers for Disease Control and
Prevention recommends the use of oseltamivir
(Tamiflu) or zanamivir (Relenza) for the
treatment and/or prevention of infection with
swine influenza viruses; however, the majority
of people infected with the virus make a full
recovery without requiring medical attention or
antiviral drugs.
The virus isolated in the 2009 outbreak have
been found resistant
to amantadine and rimantadine.
I
38. n the U.S., on April 27, 2009, the FDA
issued Emergency Use Authorizations to
available Relenza and Tamiflu antiviral
drugs make to treat the swine influenza
virus in cases for which they are currently
unapproved.
The agency issued these EUAs to allow
treatment of patients younger than the
current approval allows and to allow the
widespread distribution of the drugs,
including by volunteers.