Border Screening for SARS
Border Screening for SARS
With the rapid international spread of severe acute respiratory syndrome (SARS) from March through May 2003, Canada introduced various measures to screen airplane passengers at selected airports for symptoms and signs of SARS. The World Health Organization requested that all affected areas screen departing passengers for SARS symptoms. In spite of intensive screening, no SARS cases were detected. SARS has an extremely low prevalence, and the positive predictive value of screening is essentially zero. Canadian screening results raise questions about the effectiveness of available screening measures for SARS at international borders.
The first cases of severe acute respiratory syndrome (SARS) in Canada were recognized almost simultaneously in Vancouver and Toronto. In Toronto, the index case was diagnosed on March 13, 2003, when a cluster of SARS cases was identified and traced back to a traveler from Hong Kong, who arrived in Canada on February 23, 2003. Two epidemic waves of SARS occurred in Toronto, which resulted in a national total of 251 probable cases with 43 deaths.
In the period that followed the initial reports of this new syndrome from Hong Kong and Vietnam, the disease spread rapidly to other countries by international airline travelers. On March 12, 2003, the World Health Organization (WHO) issued a global health alert in response to the clusters of SARS in the Hong Kong Special Administrative Region, China, Vietnam (Hanoi City), and Singapore. WHO recommended increased national and international vigilance to recognize and report suspected cases of SARS. Subsequently, on March 15, 2003, WHO issued the first of several international travel advisories that identified major locations where SARS transmission was substantial and ongoing and advised international travelers about travel to affected areas. On March 27, 2003, WHO recommended that affected areas begin screening departing airline passengers for symptoms suggestive of SARS.
Health Canada monitored the spread of this new syndrome through the WHO-Health Canada Global Public Health Intelligence Network and regular communications with other international and Canadian provincial and territorial public health agencies. As soon as the rapid, international spread of SARS became evident and after SARS was imported into Canada, Health Canada undertook a variety of measures designed to limit importation and exportation of disease and the spread of the disease within Canada. We describe the measures taken to mitigate the spread of SARS and provide data on the effectiveness of these measures.
With the rapid international spread of severe acute respiratory syndrome (SARS) from March through May 2003, Canada introduced various measures to screen airplane passengers at selected airports for symptoms and signs of SARS. The World Health Organization requested that all affected areas screen departing passengers for SARS symptoms. In spite of intensive screening, no SARS cases were detected. SARS has an extremely low prevalence, and the positive predictive value of screening is essentially zero. Canadian screening results raise questions about the effectiveness of available screening measures for SARS at international borders.
The first cases of severe acute respiratory syndrome (SARS) in Canada were recognized almost simultaneously in Vancouver and Toronto. In Toronto, the index case was diagnosed on March 13, 2003, when a cluster of SARS cases was identified and traced back to a traveler from Hong Kong, who arrived in Canada on February 23, 2003. Two epidemic waves of SARS occurred in Toronto, which resulted in a national total of 251 probable cases with 43 deaths.
In the period that followed the initial reports of this new syndrome from Hong Kong and Vietnam, the disease spread rapidly to other countries by international airline travelers. On March 12, 2003, the World Health Organization (WHO) issued a global health alert in response to the clusters of SARS in the Hong Kong Special Administrative Region, China, Vietnam (Hanoi City), and Singapore. WHO recommended increased national and international vigilance to recognize and report suspected cases of SARS. Subsequently, on March 15, 2003, WHO issued the first of several international travel advisories that identified major locations where SARS transmission was substantial and ongoing and advised international travelers about travel to affected areas. On March 27, 2003, WHO recommended that affected areas begin screening departing airline passengers for symptoms suggestive of SARS.
Health Canada monitored the spread of this new syndrome through the WHO-Health Canada Global Public Health Intelligence Network and regular communications with other international and Canadian provincial and territorial public health agencies. As soon as the rapid, international spread of SARS became evident and after SARS was imported into Canada, Health Canada undertook a variety of measures designed to limit importation and exportation of disease and the spread of the disease within Canada. We describe the measures taken to mitigate the spread of SARS and provide data on the effectiveness of these measures.
