Severe acute respiratory syndrome is new challenge for medical professionals (page 1 of 3)

Epidemiology:
The disease is caused by RNA containing virus. This is a new virus and there is no antiviral drug available till today to destroy it. On the other hand, the Center for Disease Control (CDC) has announced that they have sequenced SARS virus. Now with this information scientists have begun to target antiviral drugs and vaccines. The sample was taken from SARS infected patient and it was grown in green monkeys kidney cell in order to grow RNA (ribonucleic acid).

The new sequence has 29,727 nucleotides, which places it well within the typical RNA boundaries for Corona virus. Members of this viral family tend to have between 29,000 and 31,000 nucleotides.

Symptoms of SARS:
The illness begins generally with advance fever 100.4°F and up, the equivalent to 38.0°C. Fever often is high, sometimes is associated with chills and rigors. Symptoms like headache, malaise, and muscle weakness are also included. Some patients have reported diarrhea during the fever period.

At the onset of illness, some people have mild respiratory symptoms. After 3 to7 days, a lower respiratory phase begins with the onset of a dry, nonproductive cough or dyspnea (shortness of breath). In 10% to 20% of the cases, the respiratory illness is severe enough to require intubation and mechanical ventilation. Typically, rash and neurological or gastrointestinal findings are absent.

Incubation period:
The incubation period of the SARS virus is typically 2 to 7 days and it can be up to 10 days. Case fatality as per World Health Organization (WHO) is 3%-10%.

Diagnostic Tests:
To diagnose SARS in its early stages, SARS associated Corona Virus (SARS-CoV) detection is essential.

Chest radiographs might be normal during the febrile prodrome (beginning of fever) and throughout the course of illness. However, in a substantial proportion of patients, the respiratory phase is characterized by early focal interstitial infiltrates. Some chest radiographs from patients in the late stages of SARS also have shown areas of consolidation.

Early in the course of disease, the absolute lymphocyte count is often decreased. Overall white blood cell counts have generally been normal or decreased. Early in the respiratory phase, elevated creatine phosphokinase levels (as high as 3,000 IU/L) and hepatic transaminases (two to six times the upper limits of normal) have been noted.

The Center for Disease Control CDC has added laboratory criteria to Case Definition for SARS:
SARS case is laboratory-confirmed if one of the following criteria is met:

• Detection of SARS-CoV RNA by reverse transcriptase-polymerase chain reaction (RT-PCR), which must be confirmed by a second PCR test.

• Detection of antibody to SARS-CoV by indirect fluorescent antibody (IFA) or enzyme-linked immunosorbent assay (ELISA).

• Isolation of SARS-CoV in tissue culture.

• If all of the above mentioned tests are negative within 21 days, the antibody test must be repeated after 21 days.

Transmission:
The transmission of SARS appears to occur predominantly by direct contact with infectious material, including dispersal of large respiratory droplets. However, it is also possible that SARS can be spread through the airborne route. SARS is similar to tuberculosis, where it appears to spread by direct contact with respiratory secretions, but touching contaminated objects is a potential concern.