SARS-COV

Severe acute respiratory syndrome (SARS) is a communicable, potentially fatal infectious

viral disease, caused by a new strain of corona virus. It is a sérious form of viral pneumonia

caused by the SARS corona virus. The virus that causes SARS was first identified in 2003. The

World Health Organization has designated SARS a global health threat an outbreak occurred

from 2002 to 2003, but the disease is no longer circulating.

A virus known as SARS-associated corona virus (SARS-COV) causes the ilness. Corona

viruses commonly cause mild to moderate upper-respiratory illness in humans, but can cause

respiratory, gastrointestinal, liver and neurologic diseases in animals. SARS corona virus is a

positive and single stranded RNA virus belonging to a family of enveloped corona viruses. Its

genome is about 29.7 kb, which is one of the largest among RNA viruses. SARS is similar to

other corona viruses in that its genome expression starts with translation of two large open

reading frames (ORFs) 1a and 1b, which are two polyproteins.

Symptoms and Signs

The most common symptoms in patient progressing to SARS include:

Fever, malaise, chills, headache, myalgia, dizziness, cough, sore throat and running

nose.

In some cases, there is rapid deterioration with low oxygen saturation and acute

respiratory distress requiring ventilatory support.

Chest X-ray finding typically begin with a small, unilateral patchy shadowing and

progress over 1-2 days to become bilateral and generalized, with interstitial!

confluent infiltratioon.

Incubation Period:

ne incubation period has been estimated to be 2 to 7 days, commonly 3 to 5 days.

Mode of Transmission

The primary mode of transmission appears to be through direct or indirect contact of

mucous membranes of eyes, nose, or mouth with respiratory droplets or fomites.

SARS can spread when an infected person sneezes, coughs, or comes into tace-to-race

contact with someone else.

The virus is shed in stools but the role of faecal-oral transmission is unknown.

The natural reservoir appears to be the horseshoe bat (which eats and drops fruits

ingested by civets, the earlier presumed reservoir and a likely amplifying host).

The SARS virus can survive for hours on common surfaces outside the human body and

up to four days in human waste.

The virus can survive at least 24 hours on a plastic surface at room temperature and can

live for extended periods in the cold.

Management of SARS 

There is no confirmed treatment that works for every person who has SARS

Severe cases require intensive support.

Antibiotics are ineffective as SARS is a viral disease. Although a number of different

agents such as; ribavirin (400-600 mg/day and 4 gm/day), lopinavir/ritonavir (400 mg/

100 mg), interferon type 1, intravenous immunoglobulin and systemic corticosteroids

were used to treat SARS patients during the 2003 epidemic

Suspected cases of SARS must be isolated, preferably in negative pressure rooms, with

complete barrier nursing precautions taken for any necessary contact with these patients.

Prevention and Control of SARS:

Currently researchers are working on a vaccine for SARS, but there have been no human

trials for any potential vaccine. The preventive measures for SARS control are appropriate

detection and protective measures which include:

Prompt identification of persons with SARS, their movements and contacts

Effective isolation of SARS patients in hospitals

Appropriate protection of medical staff treating these patients.

Comprehensive identification and isolation of suspected SARS cases.

Simple hygienic measures such as; hand-washing after touching patients, use of

appropriate and well-fitted masks and introduction of infection control measures,

Exit screening of international travellers.

Timely and accurate reporting and sharing of information with other authorities ang/

governments.