Measles Outbreak Following the Vancouver 2010 Olympic Games Canada, 2010

Background: In March 2010, several cases of measles were identified in Vancouver Coastal Health (VCH), Canada, the hosting health jurisdiction of the Vancouver Winter Olympic Games (February 12-28) where athletes, officials and visitors from over 80 countries gathered. The last locally-acquired case in VCH was in 2007. As endemic measles has been eliminated in Canada, an investigation was initiated to characterize the outbreak and implement prevention and control measures. Methods: Cases with symptoms compatible with measles and/or laboratory confirmation, identified among VCH residents through routine surveillance and contact tracing, were interviewed by public health nurses using a standardized report form. Results: As of June 29, 2010, a total of 22 confirmed cases were identified with isolates from two distinct genotypes, indicating two separate introductions of the virus. Symptom onset dates ranged from March 7 to May 21. The median age was 28 years (range 6 months to 63 years). Over 50% of cases were diagnosed in an acute care facility. The majority (n=20) were unimmunized, partially immunized (one dose), or had unknown immunization history. No source of infection was identified among initial cases; however, during the exposure period, most reported attending large gatherings including ticketed and non-ticketed Olympic events. Secondary household and health care transmission occurred, as well as a low level of community transmission, which subsequently led to a province-wide outbreak. Conclusions: The index cases in this outbreak were likely exposed to visitors from measles endemic countries during the Olympic Games. While mass gatherings may facilitate transmission of communicable diseases, this outbreak highlights the importance of robust routine surveillance post-event, particularly for events of short duration and diseases with long incubation periods and reporting delays. Key words: measles, disease outbreaks, population surveillance Word count: 272 For more information, email the presenter at:

Author (s): 

Teresa W. Leung (1,2), S. Forsting (1), M. Smythe (1), P. Daly (1,3), J. Sandhu (1,3) and R. Gustafson (1,3). 1. Office of the Chief Medical Health Officer, Vancouver Coastal Health, Vancouver, Canada 2. Canadian Field Epidemiology Program, Public He

Presenter (s): 
Ms. Teresa Leung
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