|
Spreading :
According to the WHO, the coronavirus, though it can
spread quickly, is actually less contagious than the average influenza
virus in the sense that the virus doesn't spread as easily through air
as other germs. SARS can spread from close person-to-person contact mainly
through respiratory droplet contact. When droplets from the cough or sneeze
of an infected person gets deposited on the mucous membranes of the mouth,
nose, or eyes of persons who are nearby, they may get infected. The virus
also can spread when a person touches a surface or object contaminated
with infectious droplets and then touches his or her mouth, nose, or eye(s). Contact
with bodily secretions from an infected person may also possibly
cause infection. Patients are most infectious 10 days into the illness,
well after their first fever symptoms when the level of the virus is highest
inside the body.
According to Scientists, the virus can last outside
the human body for only a few hours unless the temperature is below freezing. SARS
virus may live on hands, tissues, and other surfaces for up to 6 hours
in respiratory droplets and up to 3 hours after the droplets have dried.
Live virus had even been found in the stool of people with SARS, where
it has been shown to live for up to four days. And the virus may be able
to live for months or years when the temperature is below freezing.
Once inside a human host, the virus attaches itself to
a healthy host cell's outer membrane, injects itself into the cell and
then discards its own outer shell flooding the host with viral material.
Then the virus particle replicates itself by borrowing the host cell's
cellular material. New virus particles multiply within the host cell which
often bursts open and dies. The replicated virus particles thus released
begin attacking other healthy cells. The deadly process continues. Levels
of the virus is highest in patients 10 days into the illness. Of those
infected, the effects are more harmful in the elderly or those with pre-existing
medical conditions.
Diagnosis and Treatment :
SARS in its early stage has the same symptoms as in an
early case of influenza. So it is difficult to distinguish between the
two based on clinical symptoms. A few helpful clues for doctors is that
SARS patients don't usually have
sore throats or runny noses, and in most
cases chest X-rays turn up telltale signs of pneumonia.
No rapid, reliable diagnostic tests yet exists for SARS.
Antibody tests which search for the immune systems response to the virus
in the serum of a patient are still the only accurate way to check whether
the patient is infected or not. But this test is useful only 12-21 days
into the infection. Other tests for detecting SARS virus is the PCR (Polymerase
Chain Reaction) and direct Sars virus isolation. In these tests, samples
of blood, stool, nasal secretions or tissue or fluid are taken from
infected persons and the genes of the virus is allowed to multiply itself
in the laboratory thus detecting/isolating the SARS-CoV. This test is
useful as soon as the patient is infected, but the problem is, an infected
person in his early stages harbour only a very small amount of the SARS
virus which may not be enough and it is extremely difficult to improve
the sensitivity of PCR tests. Some other tests able to detect Sars rapidly
within a few days are being developed by top research organisations.
At present no specific treatment is recommended as the
most efficient for SARS. CDC (Centers for Disease Control and Prevention)
currently recommends that patients with SARS receive the same treatment
that would be used for any patient with serious community-acquired typical
pneumonia. Such treatment may include antibiotics, fluids, analgesics
for pain, Oxygen and respiratory support. Patients may be isolated in
rooms with negative air pressure. Some of them will require mechanical
ventilation. In several locations, treatment includes administration
of antiviral agents such as oseltamivir or ribavirin and the Aids drug
Kaletra on SARS confirmed patients which cuts the ability of the SARS-CoV
to replicate itself. Interferons, proteins used to guard against
infection of healthy cells and prevent the virus from multiplying, may
also be used for treatment. Steroids have also been administered orally
or intravenously to patients in combination with ribavirin and other antimicrobials.
But too much use of Ribavirin have serious side effects including
breaking down of blood vessels. Steroids too is useful only in the
later stages of SARS to fight lung injury, if given too early it might
prolong viral replication. The SARS-CoV is being tested against various
antiviral drugs to see if an effective treatment can be found.
Prevention :
Minimizing contact with people with SARS minimizes the
risk of the disease. Direct contact with people with SARS should be avoided
until at least 10 days after the fever and other symptoms are gone. A
preventive vaccine is still not available and not expected to be available
for at least three years.
Rigorous and early isolation of patients, tracing and
isolation of their family members or people who have been in contact with
them is critical in containing the disease. Using simple preventive measures
like hand-washing frequently with an alcohol based instant hand sanitizer
and using appropriate face masks and goggles are useful for preventing
the spread of the disease. Masks are available in tissue which gets moistened
within an hour and gauze through which particles can pass through, both
of which are next to useless. Surgical masks and N95 heavy duty masks
are the best to keep out the virus particles.
Respiratory secretions should be considered to be infectious,
which means no sharing of food, drink, or utensils. Commonly touched surfaces
can be cleaned with an EPA (Environmental Protection Agency) approved
disinfectant, though no disinfectant have been proved to have the ability
to kill the new coronavirus associated with SARS. Gloves might be
used in handling potentially infectious secretions.
Travelers going to or people living in an area with SARS
should wash their hands frequently and use appropriate face masks. People
should take care to cover their mouth and nose when sneezing or coughing.
Health workers who are more susceptible to the disease (around 20% of
Sars cases were health workers) should make sure that they have the right
equipment to protect themselves, including surgical masks, gowns, gloves
and eye shields etc and use them while examining patients with respiratory
symptoms. In hospitals, patients with respiratory symptoms should be given
surgical masks and asked to wear them and wait in a separate area away
from others. In case of a resurgence, schools, business etc should be
closed, mass transit should be avoided and border checks may be done of
travelers leaving and entering the country. | 
