Continental synchronicity of human influenza virus epidemics despite climactic variation

摘要: The factors that determine the pattern and rate of spread influenza virus at a continental-scale are uncertain. Although recent work suggests epidemics in United States exhibit strong geographical correlation, spatiotemporal dynamics Australia, country continent approximately similar size climate complexity but with far smaller population, not known. Using unique combination large-scale laboratory-confirmed surveillance comprising >450,000 entries genomic sequence data we determined local-level spatial diffusion this important human pathogen nationwide Australia. We used to characterize across Australia during 2007-2016. onset established varied seasons, highly synchronized coinciding emergence antigenically distinct viruses, particularly 2009 A/H1N1 pandemic. was largely between most populous cities, even those separated by distances >3000 km experience vastly diverse climates. In addition, analyzing global phylogeographic patterns show dissemination Australian cities involved multiple introductions from coupled domestic connectivity, rather than through radial geographic dispersal driven work-flow transmission as observed States. comparing structure A B, found these viruses tended occupy different regions, peak perhaps indicative moderate cross-protective immunity or viral interference effects. outbreaks revealed here highlight importance coordinated public health responses event novel, human-to-human transmissible, virus.