Investigation of the first cases of human-to-human infection with the new swine-origin influenza A (H1N1) virus in Canada

Abstract
The outbreak of human infection due to the novel swine-origin influenza A (H1N1) virus began in Mexico in March 2009. As of July 6, 2009, more than 94 000 laboratory-confirmed cases were reported in over 100 countries, including 7983 cases in Canada. In this report, we describe the epidemiologic and clinical characteristics of the first cluster of reported cases of human-to-human transmission of the new influenza virus in Canada.