The outbreak of severe acute respiratory syndrome (SARS) continues in the affected areas* [footnote: * WHO has defined affected areas as an area in which local chain(s) of transmission of SARS is/are occurring as reported by the national public health authorities. The list of areas changes over time and the latest update can be found at: Affected Areas - Severe Acute Respiratory Syndrome (SARS)]: Canada (Toronto), China (Guangdong Province, Hong Kong Special Administrative Region of China, Shanxi Province, Taiwan Province), Singapore (Singapore), Vietnam (Hanoi). The agent causing SARS is under intensive international study, but as of today it has not been fully characterized, and there is no vaccine or other prophylaxis available...

The SARS situation in Hong Kong Special Administrative Region has developed features of concern: a continuing and significant increase in cases with indications that SARS has spread beyond the initial focus in hospitals. These developments have suggested environmental routes of transmission from a SARS infected person which may be related to contamination of common systems that link rooms or flats together. Despite the implementation of strict measures to control the outbreak, there have continued to be a small number of visitors to Hong Kong who have been identified as SARS cases after their return from Hong Kong. The epidemic in Guangdong Province of China, situated adjacent to Hong Kong, is the largest outbreak of SARS reported and has also shown evidence of spread in the wider community. As a measure of precaution WHO is now recommending that persons travelling to Hong Kong and Guangdong Province of China consider postponing all but essential travel. This temporary recommendation will be reassessed in the light of the evolution of the epidemic in the areas currently indicated, and other areas of the world could become subject to similar recommendations if the situation demands.