SEVERE ACUTE RESPIRATORY SYNDROME – UPDATE Anne-Claire de Benoist and Delia Boccia, European Programme for Intervention Epidemiology Training (EPIET), Public Health Laboratory Service Communicable Disease Surveillance Centre, London, England. On 15 March 2003, the World Health Organization (WHO) stated that the Severe Acute Respiratory Syndrome (SARS), an atypical pneumonia of unknown aetiology, is now “a worldwide health threat” (1). As of 19 March, 264 suspect and probable cases have been r eported to WHO since 1 February 2003 (2). The surveillance case definitions have been modified (table). So far, 56 cases have been reported in Hanoi (Vietnam) and 150 cases in Hong Kong, the two areas where the first cases were reported (3), 31 cases have been notified in Singapore, three in Taiwan, one imported case from Hanoi has been reported in Thailan d, eight patients have been reported in Canada, one in Germany, one in Slovenia, and two in the United Kingdom (UK).

Case definitions for Surveillance of Severe Acute Respiratory Syndrome (SARS), revised 18 March 2003 Suspect Case A person presenting after 1 February 2003 with history of:·high fever (>38º C)AND·one or more respiratory symptoms including cough, shortness of breath, difficulty breathing AND one or more of the following:·close contact*, within 10 days of onset of symptoms, with a person who has been diagnosed with SARS ·history of travel, within 10 days of onset of symptoms, to an area in which there are reported foci of transmission of SARS. Probable Case A suspect case with chest x-ray findings of pneumonia or Respiratory Distress Syndrome OR· A person with an unexplained respiratory illness resulting in death, with an autopsy examination demonstrating the pathology of Respiratory Distress Syndrome without an identifiable cause. *Close contact means having cared for, having lived with, or having had direct contact with respiratory secretions and body fluids of a person with SARS. In addition to fever and respiratory symptoms, SARS may be associated with other symptoms including: headache, muscular stiffness, loss of appetite, malaise, confusion, rash, and diarrhoea. To date, five deaths in the recent outbreak have been reported. Over 90% of the cases are in healthcare workers, of whom most have been in close contact with other cases.

The mode of transmission is not confirmed, but is thought to occur by droplet spread and/or body fluid contact. There is no evidence so far that transmission can occur through casual contact. The incubation period ranges from four to seven days. Although a wide range of laboratory tests have been conducted, no causal agent has yet been found. It has been reported that a virus of the Paramyxoviridae family has been recently identified in samples from some cases (4), but it seems too early at this point to attribute the outbreak to this cause. No recommendation to restrict travel to any country has been issued, but WHO stresses the importance for travellers and airlines to be aware of the main symptoms of the disease (1). Investigations are ongoing in the affected countries. Epidemiologists, and experts in case management, infection control and microbiology from WHO and several European and international organisations are assisting in the management of the outbreak (2). I n Europe, public health institutes are developing national response plans based on WHO recommendations (1). On 18 March, the European Commission convened a meeting of European experts to agree a common response to this outbreak and propose consensus guide lines for advice and information. Updates on the developing situation are also available from WHO, on ProMED, and at the websites of various national public health organisations, including CDC, Health Canada, and the Public Health Laboratory Service in the UK.