Continental synchronicity of human influenza virus epidemics despite climactic variation
(A) Epidemic onset timing per location of laboratory-confirmed influenza A cases 2007–2016. Each circle on the map represents a distinct location (i.e. postcode) and the timing (week) of epidemic onset in each location is represented in color. The size of the circle represents the total number of cases in that location during that year. A black ‘X’ illustrates the location of the first sustained outbreak for each year. (B) The mean week of influenza A epidemic onset timing (as well as 25% and 75% quartiles) within metro postal areas in eight major cities: Darwin, Townsville, Brisbane, Sydney, Perth, Adelaide, Melbourne and Hobart. Dashed, grey horizontal lines indicate the 25% and 75% quartiles of overall onset times from these eight cities. The percentage of Australia’s population in each city is noted as of 2016.