Swine influenza
(swine flu) is a respiratory disease caused by viruses (influenza viruses) that
infect the respiratory tract of pigs, which caused in nasal secretions, a
barking cough, decreased appetite, and listless behavior. Swine flu produces most of the same
symptoms as human influenza in pigs produced in humans.Swine flu may be about
one to two weeks in pigs, the last to survive.Swine flu virus was first
isolated from pigs in 1930 in the United States and was recognized by pork
producers and veterinarians to cause infections in pigs worldwide. In a series of cases, people have to
be infected with swine flu if they develop close to pigs (eg farmers, pork
processors) associated, and even pig populations was sometimes infection with
human influenza infection. In
most cases there was cross-species infections (swine virus to humans, human
influenza viruses in pigs) in local areas and not cause infection, either
national or global in pigs or humans. Unfortunately,
this inter-species influenza virus had the potential to change.Investigators
believe the strain of swine flu in 2009, first in Mexico seen H1N1 flu should
be called because they infect mainly the people and has two main surface
antigens, H1 (hemagglutinin type 1) and N1 (neuraminidase type 1). Recent polls show that eight RNA
strands of novel H1N1 flu have a strand of human influenza strains, two of the
Avian Influenza (Bird) and strains, five strains of pigs came from. Swine flu spreads from person to
person by inhalation or ingestion of droplets, which is the virus from people
coughing or sneezing, not to disclose it by eating cooked pork products.
H1N1 swine flu virus |
The cause of swine flu is an influenza A virus known as H1N1 type. It is in this form or business,
because two major antigens (H and N) on the surface by immunological methods (H
or hemagglutinin and neuraminidase or N) is detected. In 2011, a new swine flu virus
detected. The new strain of
influenza is infected as AC (H3N2) Only a few people (mostly children), but the
U.S. Department of Health and Human Services (HHS) is to develop a vaccine
against this virus. A separate
article describes some of the details about this new flu virus. In general, all influenza A virus H1N1
have a similar structure, each has a slightly different kind of H and / or
N-structure.
Many researchers now consider that two main series of events may lead to
the swine flu (avian influenza or bird as well) is one of the main causes of
influenza in humans.
First, the influenza virus type A, B, C) enveloped RNA viruses with a segmented
genome, which means that the viral RNA genetic code, not a single strand of
RNA, but exists as eight different RNA segments in influenza virus. A virus of human influenza (or bird),
a cell can infect Porcine Respiratory packaged together with a virus such as
swine flu, some RNA strands of viral replication within the human error limit
of the swine influenza virus. For
example, a cell can contain eight swine flu and flu-eight RNA segments. The total number of species of RNA in
a cell would, 16, four pigs and four against influenza RNA segments into a
single particle could be embedded so that it segmented a viable eight influenza
virus RNA from the 16 types of segments available . Various
combinations of RNA segments in a subtype of the virus of the new (known a
method of antigenic drift) are preferably the ability to infect humans cause,
but have unique characteristics that the swine flu virus (see Figure 1). It is even possible to contain the RNA
strands from birds, swine and human influenza viruses in a virus, if one cell
of the three types of influenza (eg, two avian influenza infected with three
against swine flu, and three RNA
segments of human influenza, a viable new type of eight segments of influenza
virus genome to produce).Formation of a new species is considered to be viral
antigenic shift, small changes within a single segment in influenza virus RNA
is called antigenic drift, and the result of minor changes in the
virus.However, they can collect in time to sufficiently small changes that
generate cumulative change in antigenic composition of the virus over time
(usually years).
Second, pigs can play a unique role as an intermediate host to the types
of swine flu because, new airway cells directly with bird and human influenza
viruses infect other mammals are. Therefore,
pig respiratory cells are probably infected with many types of flu and can
function as a "mixing pot" of the RNA segments of influenza (see
Figure 1). Influenza viruses from
birds infect in general, gastrointestinal cells of many species of birds, are
paid in the feces of birds. Pigs
can take over this virus from the environment, and this seems to be the main
way that avian flu virus RNA segments occur, the population against influenza
viruses to be in mammals.
The symptoms of swine flu are similar to most influenza infections: fever (100
° F or higher), cough, runny nose, fatigue and headache, fatigue reported in
most infected. Some patients also
get nausea, vomiting and diarrhea. In
Mexico, most patients infected with H1N1 initials young adults, so that some
researchers believe that a strong immune response, as they have seen in young
people, can cause collateral damage tissue.
H1N1 cycle |
Some patients develop severe respiratory symptoms, (such as a ventilator
to breathe for the patient) need assistance in breathing.Patients get a
pneumonia (bacterial secondary infections), if the viral infection persists,
and some may develop cramps. Death
often occurs from secondary bacterial infection of the lungs should be used
appropriate antibiotics in these patients. The
usual mortality (death) from influenza A-type is about 0.1%, while the 1918
"Spanish flu" epidemic has had an estimated mortality rate of 2% -20%. A (H1N1) flu in Mexico were about 160
deaths and 2,500 confirmed cases, which would correspond to a mortality rate of
about 6%, but these early data have been revised and mortality worldwide is
currently estimated to be much lower. In
June 2009, the virus had reached 74 countries on all continents except
Antarctica, and in September 2009, the virus had been reported in most
countries (over 200) in the world. Fortunately,
the mortality rate of H1N1 has remained low and similar to normal influenza
(average rate of infant mortality from influenza is projected around 36 000 per
year from H1N1 flu deaths per year determined 90 000 United States was by the
President of the Advisory Committee, but he hasnever approached that number
higher).
Fortunately, although the H1N1 pandemic developed (worldwide) flu virus,
the mortality rate in the U.S. and many other countries, that nearly the usual
number of flu deaths in the world. Speculation
about why the death rate was much lower than expected a greater public awareness
and action that has led to increased hygiene (especially hand washing), a
fairly rapid development of a new vaccine, and the patient self-testing in
isolation, if onset of symptoms . Research continues to develop
data-based answers to these questions.
Swine flu is suspected clinically diagnosed by the history of association with
persons known to the disease and symptoms listed above. In general, a rapid test (eg,
nasopharyngeal swab) performed to determine whether the patient with influenza
A or influenza B infection, most tests can switch between modes to distinguish
A and B. The test may be negative (no flu infection)
or positive for type A and B. If the test is positive for Type B influenza is
not likely to be the swine flu (H1N1). If
it is positive for type A, the person can a conventional flu virus, or swine
flu (H1N1). However, the accuracy
of these tests has been questioned, and the U.S. Centers for Disease Control
and Prevention (CDC) has been no comparative studies of testing completed. But a new test by the CDC and a
commercial company is developing could reliably detect H1N1 in about an hour of
the test has only been in the army.In 2010 the FDA approved a test commercially
available, could detect H1N1 in four hours. Most
of these rapid tests based on PCR-based technology.
Swine flu (H1N1) is definitively by the identification of antigens
associated with the diagnosis of specific virus type. In general, this test is performed in
a specialized laboratory and is not performed by many doctors' offices or
hospital laboratories. However,
doctors' offices in a position to send samples to specialized laboratories, if
necessary. Due to the large
number of new cases of H1N1 swine flu in the 2009-2010 influenza season (the
vast majority of influenza cases [95% -99%] had occurred due to new H1N1
virus), the CDC recommends that hospital "influenza
virus strains of laboratory sent to reference for identification.
The best treatment for influenza infection in humans is prevention by
vaccination. Work from several
laboratories has recently produced vaccines. The
first vaccine was released in early October 2009, a nasal spray vaccine was
approved for use in healthy people aged 2 to 49. The injectable vaccine, influenza H1N1
has killed, has to be available in late October Week 2009. This vaccine was approved for use at
the age of 6 months for older people, including pregnant women. Both vaccines have been by the CDC to
be proved by the conduct of clinical trials that safe and effective vaccines
are approved. However, should
members pointed out that the guidelines vaccines vaccines, as it sometimes will
change the rules.Please refer to the section below titled "Is the H1N1
swine flu can be prevented with a vaccine?”
Almost all vaccines have side effects. Common
side effects of vaccines against H1N1 influenza vaccines are typical and are as
follows:
- Influenza vaccine: pain, redness, slight swelling at the site of shooting,
muscle aches, mild fever, nausea and generally not longer than about 24 hours.
- Nasal spray: runny nose, mild fever, vomiting, headache, wheezing, coughing
and sore throat.
The
vaccine against influenza virus is killed out of particles, so that a person
can not catch the flu taken from a vaccine against influenza.However, the nasal
spray vaccine contains live viruses that have been modified to affect their
ability to replicate in human tissues.People with weakened immune systems
should not be vaccinated with the nasal spray. In addition, most vaccines contain
influenza virus particles grown in eggs, so people should not be allergic to
eggs be vaccinated, unless tested and recommended by their doctor they have
been cleared for it. Like all
vaccines, rare events, in rare cases (eg, swelling, weakness or shortness of
breath) may occur. If symptoms
develop, such as this, the person should seek medical attention immediately.
Two antiviral agents have been reported to prevent or reduce the effects
of swine flu. They are to prevent
zanamivir (Relenza) and oseltamivir (Tamiflu), both of which are also used, or
to reduce symptoms of influenza A and B. This medication should not be used
indiscriminately, because viral resistance, they can and has occurred. They are also not recommended if the
symptoms of the flu already exists for over 48 hours or more, although
hospitalized patients could still be processed by the guideline of 48
hours.Serious infections occurred in some patients, additional measures to
support, such as ventilation support and treatment of other infections such as
pneumonia, which can occur in patients with severe flu infection. The CDC has proposed in its interim
report guidelines that pregnant women can be treated with both anti-viral agents.
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