Canadian Environmental Health Atlas

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Public Health Interventions

Public Health Interventions

Control Measures
During the global outbreak of severe acute respiratory syndrome (SARS) in 2003, health officials took a number of steps to control the spread of SARS.  Travelers were screened travellers at international borders (Figure 1). In Toronto, the Ontario Ministry of Health, local public health units, hospitals, and health care providers took a number of steps to control the spread of SARS. Restrictions were placed on hospital visits, cases were identified and isolated quickly, close contacts were quarantined, and infection-control procedures were enhanced. Collectively, the aggressive use of these public health measures contained and controlled the SARS outbreak in Toronto.

Luckily, epidemiological characteristics of SARS limited its spread. There was little natural airborne dissemination and there were few cases in children. In addition, infectivity tended to peak at 2 weeks, when most patients were symptomatic and hospitalized. The absence of pre-symptomatic transmission - where the disease is being spread before people know they are ill - greatly facilitated public health control efforts.1 But while these epidemiological factors limited transmission, infection control was still crucial, as demonstrated by the sharp decline in the number of cases that coincided with the implementation of various infection-control measures (Figure 2).2

Learning from SARS
The rapid containment of SARS is considered a key public health success story. The story also contains lessons about screening, infection control, and international cooperation. In May 2003 a National Advisory Committee on SARS and Public Health was convened to provide a “third-party assessment of current public health efforts and lessons learned for ongoing and future infectious disease control”.3 The committee and the authors of other high-profile reports recommended improvements in public health infrastructure and other long-term strategies to mitigate the effects of future infectious disease outbreaks.34 A direct response to these recommendations was the creation of the Ontario Agency for Health Protection and Promotion (later renamed Public Health Ontario), an arm’s-length agency dedicated to preventing and controlling disease and promoting health in Ontario.