[Material in this section is from CDC, 2013, unless otherwise noted.]
The first SARS travel advisories and alerts were issued by WHO on March 12 and 15, 2003. The purpose of a travel advisory is to provide accurate information about the status of the outbreak and a recommendation against nonessential travel to the area. A travel alert does not advise against travel, but informs travelers of a health concern and provides advice about specific precautions. The goal is to quickly detect and isolate suspected cases and prevent further transmission of the disease. These initial advisories and alerts were updated by WHO on March 27, 2003 to include screening of air passengers departing from certain areas.
On March 29, CDC extended its travel advisory for SARS to include all of mainland China and added Singapore. CDC quarantine staff began meeting planes, cargo ships, and cruise ships coming either directly or indirectly to the United States from China, Singapore, and Vietnam, and also began distributing health alert cards to travelers.
On April 2, 2003, WHO recommended that persons traveling to Hong Kong and Guangdong Province, China consider postponing all but essential travel. This temporary recommendation was reassessed daily.
On April 14, 2003 scientists at CDC announced that they had completed the genome sequence for the coronavirus responsible for SARS.
On April 22, 2003, CDC issued a health alert for travelers to Toronto, Ontario (Canada).
The spread of SARS in Toronto, Canada started from a single case, a woman who had recently returned from China. It is thought that she had a particularly virulent and aggressive form of SARS. The disease spread rapidly outside the initial infected group of hospital workers and their families. A small number of persons appear to have become infected in Toronto during travel there. On April 29, 2003, Canada reported 20 consecutive days without a new case of SARS and a week-old WHO travel advisory was lifted.
- Mainland China
- Beijing and Shanxi Province, China
- Guangdong Province, China
- Hong Kong Special Administrative Region, China
- Toronto, Canada
All travel advisories and alerts were re-examined in three weeks, which is twice the maximum incubation period of SARS.
By May 6, 2003, no new probable cases were reported In the United States in the previous 24 hours, and there was no evidence of ongoing transmission beyond the initial case reports in travelers for more than 20 days. The containment in the United States was successful. Over the ensuing two months, CDC lifted the travel alerts on persons coming from affected foreign countries.
On July 17, 2003, CDC updated the SARS case definition, which reduced the number of U.S. cases by half. The change resulted from excluding cases in which blood specimens that were collected more than 21 days after the onset of illness tested negative.
By December 31, 2003, WHO received reports of SARS from 29 countries and regions; 8,096 persons with probable SARS resulting in 774 deaths. In the United States, eight SARS infections were documented by laboratory testing and an additional 19 probable SARS infections were reported.
On January 13, 2004, CDC issued Notice of Embargo of Civets.* A SARS-like virus had been isolated from civets captured in areas of China where the SARS outbreak originated.
*Civets, a mammal with a catlike body, long legs, a long tail, and a masked face resembling a raccoon or weasel.
On October 5, 2012, the National Select Agent Registry Program declared SARS-coronavirus a select agent. A select agent is a bacterium, virus, or toxin that has the potential to pose a severe threat to public health and safety.