Global travel patterns and risk of measles in Ontario and Quebec, Canada: 2007–2011

BMC Infectious Diseases

Research Article

Rose Eckhardt¹  Jennifer Miniota¹  Vladimir Gilca²  Gillian Lim³  Shelly Bolotin³  Sarah E. Wilson⁴  Shelley L. Deeks⁴  Natasha S. Crowcroft⁵  Kamran Khan⁶ 

[1] Centre for Research on Inner City Health, Keenan Research Centre, Li Ka Shing Knowledge Institute, Toronto, ON, Canada;Institut national de santé publique du Québec, Québec, QC, Canada;Université Laval, Laval, QC, Canada;Public Health Ontario, Toronto, ON, Canada;Public Health Ontario, Toronto, ON, Canada;Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada;Public Health Ontario, Toronto, ON, Canada;Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada;Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada;St Michael’s Hospital, Department of Medicine, Division of Infectious Diseases, Toronto, ON, Canada;Centre for Research on Inner City Health, Keenan Research Centre, Li Ka Shing Knowledge Institute, Toronto, ON, Canada;Faculty of Medicine, Division of Infectious Diseases, University of Toronto, Toronto, ON, Canada;

关键词: Epidemiology;    Measles;    Outbreaks;    Surveillance;    Travel;    Vaccine-preventable diseases;   

DOI  :  10.1186/s12879-015-1039-0

 received in 2014-11-17, accepted in 2015-07-17,  发布年份 2015

来源: Springer

【 摘 要 】

BackgroundIn 2011 the largest measles outbreak in North America in a decade occurred in Quebec, Canada with over 700 cases. In contrast, measles activity in neighbouring province Ontario remained low (8 cases). Our objective was to determine the extent to which the difference could be explained by differing travel patterns.MethodsWe explored the relationship between measles cases over 2007–2011, by importation classification, in Quebec and Ontario in relation to global travel patterns to each province using an ecological approach. Global measles exposure was estimated by multiplying the monthly traveler volume for each country of origin into Quebec or Ontario by the yearly measles incidence rate for the corresponding country. Visual inspection of temporal figures and calculation of Pearson correlation coefficients were performed.ResultsGlobal measles exposure was similar in Ontario and Quebec. In Quebec, there was a nearly perfectly linear relationship between annual measles cases and its global measles exposure index over 2007–2011 (r = 0.99, p = 0.001). In contrast, there was a non-significant association in Ontario. The 2011 rise in Quebec’s index was largely driven by a dramatic increase in measles activity in France the same year.ConclusionsGlobal measles activity was associated with measles epidemiology in Quebec. Global measles exposure risk is higher in Ontario than Quebec. Differences in measles epidemiology between Ontario and Quebec from 2007–2011 are not explained by greater exposure in Quebec. A combination of alternative factors may be responsible, including differences in population susceptibility.

【 授权许可】

CC BY   
© Wilson et al. 2015