Effect of flight connectivity on the introduction and evolution of the COVID-19 outbreak in Canadian provinces and territories.

BACKGROUND: The COVID-19 pandemic has challenged health services and governments in Canada and around the world. Our research aims to evaluate the effect of domestic and international air travel patterns on the COVID-19 pandemic in Canadian provinces and territories. METHODS: Air travel data were obtained through licensed access to the 'BlueDot Intelligence Platform', BlueDot Inc. Daily provincial and territorial COVID-19 cases for Canada and global figures, including mortality, cases recovered and population data were downloaded from public datasets. The effects of domestic and international air travel and passenger volume on the number of local and non-local infected people in each Canadian province and territory were evaluated with a semi-Markov model. Provinces and territories are grouped into large (>100 000 confirmed COVID-19 cases and >1 000 000 inhabitants) and small jurisdictions (≤100 000 confirmed COVID-19 cases and ≤1 000 000 inhabitants). RESULTS: Our results show a clear decline in passenger volumes from March 2020 due to public health policies, interventions and other measures taken to limit or control the spread of COVID-19. As the measures were eased, some provinces and territories saw small increases in passenger volumes, although travel remained below pre-pandemic levels. During the early phase of disease introduction, the burden of illness is determined by the connectivity of jurisdictions. In provinces with a larger population and greater connectivity, the burden of illness is driven by case importation, although local transmission rapidly replaces imported cases as the most important driver of increasing new infections. In smaller jurisdictions, a steep increase in cases is seen after importation, leading to outbreaks within the community. CONCLUSIONS: Historical travel volumes, combined with data on an emerging infection, are useful to understand the behaviour of an infectious agent in regions of Canada with different connectivity and population size. Historical travel information is important for public health planning and pandemic resource allocation.

Association between early childhood otitis media and pediatric inflammatory bowel disease: an exploratory population-based analysis.

OBJECTIVE: To determine whether a diagnosis of otitis media in the first 5 years of childhood is associated with the development of pediatric inflammatory bowel disease (IBD). STUDY DESIGN: This was a nested case-control analysis of a population-based IBD database in Manitoba, Canada. A total of 294 children with IBD diagnosed between 1989 and 2008 were matched to 2377 controls, based on age, sex, and geographic region. The diagnosis of ottis media was based on physician claims. IBD status was determined based on a validated administrative database definition. Multivariate conditional logistic regression models were used to model the association between otitis media and IBD, adjusted for annual physician visits. RESULTS: Approximately 5% of the IBD cases and 12% of the controls did not have an otitis media diagnosis before that IBD case date. By age 5 years, 89% of the IBD cases had at least one diagnosis of otitis media, compared with 82% of the controls. In multivariate analyses, compared with cases and controls without an otitis media diagnosis, individuals with an otitis media diagnosis by age 5 years were 2.8-fold more likely to be an IBD case (95% CI, 1.5-5.2; P = .001). This association was detected in stratified models examining Crohn's disease and ulcerative colitis separately. CONCLUSION: Compared with controls, subjects diagnosed with IBD were more likely to have had at least one early childhood episode of otitis media before their diagnosis. We suspect that otitis media serves as a proxy measure of antibiotic use.