Public health interventions and SARS spread, 2003

Abstract

The 2003 outbreak of severe acute respiratory syndrome (SARS) was contained largely through traditional public health interventions, such as finding and isolating case-patients, quarantining close contacts, and enhanced infection control. The independent effectiveness of measures to "increase social distance" and wearing masks in public places requires further evaluation. Limited data exist on the effectiveness of providing health information to travelers. Entry screening of travelers through health declarations or thermal scanning at international borders had little documented effect on detecting SARS cases; exit screening appeared slightly more effective. The value of border screening in deterring travel by ill persons and in building public confidence remains unquantified. Interventions to control global epidemics should be based on expert advice from the World Health Organization and national authorities. In the case of SARS, interventions at a country's borders should not detract from efforts to identify and isolate infected persons within the country, monitor or quarantine their contacts, and strengthen infection control in healthcare settings.

Figure

Severe acute respiratory syndrome cases in Singapore, February 25–May 5, 2003. Number of primary cases (light gray) by time from symptom onset to isolation, number of secondary cases infected by such cases (dark gray), and mean number of secondary cases per primary case. Reprinted with permission from Lipsitch M, Cohen T, Cooper B, Robins JM, Ma S, James L, et al. Science 2003;300:1966–70. Copyright 2003 by the American Association for the Advancement of Science. http://www.sciencemag.org