21 August 2003
WHO issues guidance on future public health management of SARS
Jonathan Crofts (email@example.com)
and Valerie Delpech, Health Protection Agency Communicable Disease Surveillance
Centre, London, England.
The World Health Organization (WHO) has published a document
describing the SARS alert criteria and a surveillance approach for the post-outbreak
period of severe acute respiratory syndrome (SARS) (1). The SARS alert is
an operational definition designed to ensure appropriate public health measures
are implemented until SARS has been discounted in patients with atypical pneumonia
or respiratory distress syndrome. The document sets out new clinical and laboratory
case definitions together with recommended public health and infection control
measures for managing a SARS 'alert'. It also provides suggestions for an
approach to enhanced surveillance, guidance on the clinical presentation,
laboratory, and radiological findings to assist clinicians in the diagnosis
WHO recommends three different levels of surveillance for member countries
based on a risk assessment of the recent outbreak of SARS and the potential
for its resurgence:
Potential zone of re-emergence of SARS coronavirus
A country identified as the previous or potential source of a SARS outbreak.
Recommended surveillance: special studies for SARS-CoV infections in human
and animal populations, SARS alert, and enhanced surveillance for SARS.
Those countries which experienced sustained local transmission or entry
of large numbers of SARS cases in the last outbreak. Recommended surveillance:
SARS alert and enhanced surveillance for SARS.
Low risk areas
Those countries who never reported cases or only reported imported cases
or had limited local transmission during the last outbreak. Recommended
surveillance for clusters of 'alert' cases among healthcare workers, other
hospital staff, patients and visitors in the same healthcare unit
The current WHO definition of a SARS alert:
||Two or more healthcare workers in the same healthcare unit fulfilling
the clinical case definition of SARS and with illness in the same 10
Hospital acquired illness in three or more persons (healthcare workers
and/or patients and/or visitors) in the same healthcare unit fulfilling
the clinical case definition of SARS and with onset of illness in the
same 10 day period.
A cumulative total of 8422 SARS cases, with 916 deaths (case fatality rate
11 per cent) attributable to SARS have been reported around the world (3).
The news on 5 July that all known chains of person-to-person transmission
of the severe acute respiratory syndrome (SARS) virus had been broken highlighted
a remarkable public health achievement (2). Following recognition that SARS
posed a global threat in mid-March 2003, the disease was successfully contained
in less than four months. There is much still to be learnt about the epidemiology
and ecology of SARS, however, and resurgence of the disease is a distinct
For the purpose of international reporting of SARS in the post-outbreak
period, WHO requests member states report laboratory confirmed cases only
In June, the European Commission published a document summarising measures
undertaken by EU member states and accession countries to control outbreaks
of severe acute respiratory syndrome (4 and references therein).
Eurosurveillance has updated its SARS web page (http://www.eurosurveillance.org/links/sras-01.asp),
and will continue to add relevant information and new links in the months
- WHO. Communicable Disease Surveillance and Response. Alert, verification
and public health management of SARS in the post-outbreak period. 14 August
- WHO. Communicable Disease Surveillance and Response. Disease outbreak
news: Update 96 - Taiwan, China: SARS transmission interrupted in last outbreak
area, 5 July 2003. (http://www.who.int/csr/don/2003_07_05/en/print.html).
- WHO. Summary table of SARS cases by country 1 November 2002 - 7 August
2003. 15 August 2003. (http://www.who.int/csr/sars/country/en/country2003_08_15.pdf)
- Eurosurveillance Weekly. Control of SARS in the EU: measures undertaken
by member states and accession countries. Eurosurveillance Weekly
2003; 7: 030626 (http://www.eurosurveillance.org/ew/2003/030626.asp)
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