Yale University - Department of Epidemiology of Microbial Diseases, University of Manitoba - Department of Infectious Diseases and Medical Microbiology, University of Toronto, Toronto, Canada - Department of Medicine, University of California, Los Angeles (UCLA) - Department of Epidemiology, University of California, Los Angeles (UCLA) - Department of Epidemiology, University of Manitoba, Institut National de Recherche Biomédicale and Yale University - Department of Epidemiology of Microbial Diseases