Severe acute respiratory syndrome. SARS

SARS is a communicable viral disease caused by a new strain of coronavirus. The most common symptoms in patient progressing to SARS include fever, chills, headache myelgia, 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 findings typically begin with a small, unilateral patchy shadowing and progress over 1-2 days to become bilateral and generalized with interstitial or confluent infiltration.

PROBLEM STATEMENT The earliest case was traced to a health care worker in China in late 2002, with rapid spread to Hong Kong, Singapore, Vietnam, Taiwan and Toranto. As of early August 2003, about 8422 cases were reported to WHO from 30 countries with 916 fatalities. INCUBATION PERIOD The incubation period has been estimated to be 2 to 7 days, comonly 3 to 5 days.

MODE OF TRANSMISSION Close contact with the patient and infected material via the eyes, nose and mouth, with infectious respiratory droplets. In Hong Kong sewage, faeces and cockroaches were suspected transmitters. The SARS virus can survive for hours on common surfaces outside the human body, and up to 4 days in human waste. The virus can survive at least for 24 hours on plastic surface at room temperature, and can live for extended periods in the cold.

CASE DEFINITION Is based on current understanding of the clinical features of SARS, and the available epidemiological data and may be revised as new information accumulates. SUSPECT CASE 1. A person presenting after 1 st November 2002 with history of: - High fever (>38 degree C) and -Cough or breathing difficulty and one or more of the following exposures during the 10 days prior to onset of symptoms: -close contact with a person who is a suspect or probable case of SARS -history of travel to a SARS affected area.

2. A person with an unexplained acute respiratory illness resulting in death after 1 st November 2002, but on whom no autopsy has been performed. and one or more of the following exposures during 10 days prior to the onset of symptoms: -close contact with a person who is a suspect or probable case of SARS. -history of travel to an affected area or residing in affected area. PROBABLE CASE 1. A suspect case with radiographic evidence of infiltrates consistent with pneumonia or respiratory distress syndrome on chest X-ray. 2. A suspect case with autopsy finding consistent with the pathology of respiratory distress syndrome without an identifiable cause.

Exclusion criteria A case should be excluded if an alternative diagnosis can fully explain the illness. EPIDEMIOLOGICAL ASPECT Maximum virus excretion from the respiratory tract occurs on about day 10 of illness and then declines. The efficiency of transmission appears to be greatest following exposure to severely ill patients usually during the second week of illness. Children are rarely affected by SARS. To date, there have been 2 reported cases of transmission from children to adults and no report of transmission from child to child. International flights have been associated with the transmission of SARS from symptomatic probable cases to passengers or crew.

PREVENTION 1. Prompt identification of persons with SARS, their movements and contacts. 2.effective isolation of SARS patients in hospitals. 3.appropriate protection of medical staff treating these patients. 4.comprehensive identification and isolation of suspected SARS cases. 5.exit screening of international travelers. 6.timely and accurate reporting and sharing of information with other authorities and governments.

TREATMENT There is no specific treatment for SARS. No clinical improvement has been attributable to the use of antibioics. The antiviral agents ribavirin given intravenously in combination of high dose of corticosteroids may have been responsible for some clinical improvement.