Ross River virus disease--the first recorded outbreak?

Arthritogenic Alphaviruses: A Worldwide Emerging Threat?

Arthritogenic alphaviruses are responsible for a dengue-like syndrome associated with severe debilitating polyarthralgia that can persist for months or years and impact life quality. Chikungunya virus is the most well-known member of this family since it was responsible for two worldwide epidemics with millions of cases in the last 15 years. However, other arthritogenic alphaviruses that are as of yet restrained to specific territories are the cause of neglected tropical diseases: O'nyong'nyong virus in Sub-Saharan Africa, Mayaro virus in Latin America, and Ross River virus in Australia and the Pacific island countries and territories. This review evaluates their emerging potential in light of the current knowledge for each of them and in comparison to chikungunya virus.

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.

Ross River virus disease in Australia, 1886-1998, with analysis of risk factors associated with outbreaks

Ross River virus (RR) is a mosquito-borne arbovirus responsible for outbreaks of polyarthritic disease throughout Australia. To better understand human and environmental factors driving such events, 57 historical reports on RR outbreaks between 1896 and 1998 were examined collectively. The magnitude, regularity, seasonality, and locality of outbreaks were found to be wide ranging; however, analysis of climatic and tidal data highlighted that environmental conditions act differently in tropical, arid, and temperate regions. Overall, rainfall seems to be the single most important risk factor, with over 90% of major outbreak locations receiving higher than average rainfall in preceding months. Many temperatures were close to average, particularly in tropical populations; however, in arid regions, below average maximum temperatures predominated, and in southeast temperate regions, above average minimum temperatures predominated. High spring tides preceded coastal outbreaks, both in the presence and absence of rainfall, and the relationship between rainfall and the Southern Oscillation Index and La Niña episodes suggest they may be useful predictive tools, but only in southeast temperate regions. Such heterogeneity predisposing outbreaks supports the notion that there are different RR epidemiologies throughout Australia but also suggests that generic parameters for the prediction and control of outbreaks are of limited use at a local level.