House mouse abundance and Ross River virus notifications in Victoria, Australia

Objectives: The number of emerging and re-emerging infectious diseases is increasing. As such, understanding the fundamental ecology of infectious disease is critical. Short-lived highly fecund amplification hosts are implicated to influence disease prevalence, but few empirical examples exist. We examined the relationship between mouse (Mus musculus) abundance and Ross River virus (RRV) incidence in northwest Victoria, Australia. Methods: We determined a biologically plausible distribution overlap of M. musculus, humans, and vector mosquitoes in our study region.We compared M. musculus abundance with human RRV notifications seasonally between 1997 and 2000. Results: Trends in M. musculus and RRV were similar during summer, autumn, and summer plus autumn, but unrelated during winter, spring, and winter plus spring, coinciding with the seasonal abundance and relative absence of the vector, Culex annulirostris. Conclusions: Our results demonstrate a plausible association between M. musculus and RRV incidence, suggesting that short-lived highly fecund amplification hosts may profoundly influence disease transmission. Our results are supported by theoretical studies and empirical evidence from other systems. Further research is warranted to establish a causal relationship between amplification hosts and RRV, and in other infectious disease systems. Implications for the management of infectious disease may exist.