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 reported 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 Thailand, eight patients have been reported in
Canada, one in Germany, one in Slovenia, and two in the United Kingdom (UK).
Table: Case definitions for Surveillance of Severe Acute Respiratory
Syndrome (SARS), revised 18 March 2003
A person presenting after 1 February
2003 with history of:
AND one or more of the following:
close contact*, within 10 days
of onset of symptoms, with a person who has been diagnosed with
history of travel, within 10
days of onset of symptoms, to an area in which there are reported
foci of transmission of SARS.
*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). In 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 guidelines
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.