Between February and June 2003, the city of Toronto ordered more than 15,000 people into quarantine to contain outbreaks of the SARS (severe acute respiratory syndrome) virus. People who had been exposed to the virus, many of them friends and relatives of SARS patients or of travelers who had recently been to Asia, were ordered to stay in their homes for an average of 10 days. The quarantine has been credited with stopping the spread of the virus, which killed 43 people in Canada in those four months, but the psychological effects of quarantine have not been well studied. Researchers from the University of Toronto conducted a survey of people just after they came out of quarantine to see how they were doing.

What the researchers wanted to know: How did being quarantined affect people in Toronto during the SARS epidemic?

What they did: The researchers advertised the study on local television and through media releases and asked people to complete the survey once they were released from quarantine. The Web-based survey asked people if they understood why they were quarantined, if they knew what they were supposed to do, whether they followed the directions given by authorities, and how they got their information. The researchers also used psychological tests to determine the level of mental and emotional trauma from being in quarantine. The eventual sample consisted of 129 people, who went on the Internet to complete the survey.

What they found: Seventy percent of the people in quarantine understood why they had been there, and most were notified either by employers or the media that they should go into quarantine. Only 9 percent were told they needed to be in quarantine by public-health officials, and these people were less likely than those told by bosses or the media to know why they were being quarantined. Most people adhered to the rules of the quarantine, including wearing a surgical mask and not leaving home, though they were less likely to take their temperature twice a day as the rules mandated. About 30 percent of the subjects had symptoms of post-traumatic stress disorder, and these people were likely to also have had depression just after emerging from quarantine.

What it means to you: The Toronto quarantines last year were the first in North America in more than 50 years, so this isn't exactly a daily occurrence—but with the new threats of SARS and bioterrorism, it's worthwhile to know how quarantine affects people. However, this study is one of the first to look at the effects on the people being quarantined; most studies look at how quarantine helped control a disease or how to improve quarantine compliance.

Caveats: The people who answered the questionnaire were only a very small percentage of the total number of those who were quarantined and probably not representative of the group as a whole. Those surveyed had to have access to the Internet (skewing the sample to the wealthier and better educated), and many of them were healthcare workers (perhaps because they are more sensitive to these issues). In addition, the study looked only at two psychological effects, post-traumatic stress disorder and depression. More research would need to be done, the authors say, to figure out the full psychological impact of quarantine.

Find out more: A fact sheet with information about SARS and the quarantine is available from the Toronto city government. Information about the history of the disease in Toronto is available on the Centers for Disease Control and Prevention website, which also has a page with facts about SARS in general.

Read the article: Hawryluck, L. et al. "SARS Control and Psychological Effects of Quarantine, Toronto, Canada." Emerging Infectious Diseases. July 2004, Vol. 10, No. 7, pp. 1206–1212.

The article is available online at www.cdc.gov