Epidemiologic Patterns of Ross River Virus Disease in Queensland, Australia, 2001–2011

Abstract

Ross River virus (RRV) infection is a debilitating disease that has a significant impact on population health, economic productivity, and tourism in Australia. This study examined epidemiologic patterns of RRV disease in Queensland, Australia, during January 2001–December 2011 at a statistical local area level. Spatio-temporal analyses were used to identify the patterns of the disease distribution over time stratified by age, sex, and space. The results show that the mean annual incidence was 54 per 100,000 persons, with a male:female ratio of 1:1.1. Two space-time clusters were identified: the areas adjacent to Townsville, on the eastern coast of Queensland, and the southeast areas. Thus, although public health intervention should be considered across all areas in which RRV occurs, it should specifically focus on high-risk regions, particularly during summer and autumn to reduce the social and economic impacts of RRV infection.

Silent Circulation of Ross River Virus in French Polynesia

“…14 In the only study conducted among blood donors, seroprevalence for RRV antibodies was 8.4% from the 2,952 sera collected in South Australia in 1992. 29 To our knowledge, except for Australia where RRV is the most common and widespread arboviral disease with about 5,000 cases notified annually, 11,30 and to a lesser extent for Fiji, 16,24 there are no recent data about circulation of RRV in the Pacific area.…”

Age has a role in driving host immunopathological response to alphavirus infection

“…Fortunately, infected patients are usually asymptomatic and recover without giving rise to any observable clinical outcomes . However, disease severity in symptomatic patients during the prodromal and acute phases, as well as the frequency of central nervous system involvement, mortality rates and permanent neurological complications in survivors, are disproportionately higher in children and the elderly . During the natural aging process from infancy to old age in humans, the host immune system undergoes a subtle yet progressive change – immunosenescence .…”

“…34,36 However, disease severity in symptomatic patients during the prodromal and acute phases, as well as the frequency of central nervous system involvement, mortality rates and permanent neurological complications in survivors, are disproportionately higher in children and the elderly. 6,[37][38][39][40] During the natural aging process from infancy to old age in humans, the host immune system undergoes a subtle yet progressive changeimmunosenescence. 41,42 Although many studies have identified the possible effects of aging on the immune system, few have associated these effects with alphavirus disease severity.…”

Ross River virus in Australian blood donors: possible implications for blood transfusion safety

“…Because RRV has seasonal variability, samples were collected during "higher risk" months. The month of March appeared to have higher rates of RRV in the Northern Territory and Queensland, 27,28 and this was confirmed by notification data demonstrating a notification peak in March (data available from: http://www9. health.gov.au/cda/source/rpt_3.cfm); therefore, collections commenced during this month for all donor centers ( Fig.…”