1. Department of EpidemiologyBiostatistics, and Occupational Health, McGill University, Montréal, QC, Canada
2. Département de Microbiologie et Infectiologie, Centre Hospitalier de l'Université de Montréal, Montréal, QC, Canada
3. Division of Cancer EpidemiologyMcGill University, Montréal, QC, Canada
4. Departments of Medicine and of EpidemiologyBiostatistics, and Occupational Health, McGill University, Montréal, QC, Canada