Figure 1: Epidemic curve of laboratory-confirmed cases of 2009 pandemic influenza (H1N1) virus infection in Manitoba according to final location of treatment (n = 889). The epidemic curve represents the dates of onset for confirmed cases, based on the earliest of the following dates: date of onset of symptoms, date of admission to hospital, date on which investigation form was received, date on which specimen was obtained or date on which report was received. For five additional cases, the date of onset according to this definition occurred before Apr. 2, 2009, and these cases are not represented in the figure. ICU = intensive care unit.