SARS is caused by an organism having:

Ans: a (Single stranded RNA ) Ref: Ananthanarayan, 7th ed, p. 570SARS is caused by corona virus, which is a SS RNA virus. The new SARS virus is corona virus type 4. SARS spreads by inhalation of the vims present in droplets or aerosols of respiratory secretions of patients.Fecal aerosols also may be infectious.Few points about SARS:Incubation period is under 10 days.The disease starts as fever with cough or other respiratory symptoms. Diarrhoea is sometimes seen.The chest radiograph shows pneumonic changes (death is due to respiratory failure)Reverse transcription PCR has been used for early diagnosisDemonstration of rise in titre of antibodies by ELISA or indirect immunoflourescence test in paired serum samples are useful later.Vims is highly mutable and so vaccine prophylaxis may not be easy.Control has been achieved by strict isolation and quarantine.Note:Only double stranded RNA vims is RHEO vims.Only single standed DNA vims is PARVO vims