Biological and cultural coevolution and emerging infectious disease: Ross River virus in Australia.

Enhanced virulence of pathogens infecting host populations, with no previous exposure thereto, is characteristic of many diseases labelled "emerging" or "resurging". One cause of emergence characteristics can be interpreted as absence of co-evolutionary optimization of interactions between hosts and pathogens. We explore the historical and evolutionary development between Ross River virus (RRV) and its human host in Australia; a mosquito vectored pathogen causing polyarthritic symptoms. Epidemics of RRV have increased in frequency, size and range throughout European settlement. We hypothesise that human cultural evolution contributed to the emergence of RRV in humans, and argue that epidemics of RRV were unlikely to occur in Aboriginal hunter-gatherer societies in Australia's early human history, but only occur in more recent agrarian and industrial societies. A perspective of cultural evolution, in addition to biological evolution, may help with understanding the determinants of disease emergence and resurgence, and inform ongoing development of effective public health interventions.