[Source: US Centers for Disease Control and Prevention (CDC), Emerging Infectious Diseases Journal, full page: (LINK). Abstract, edited.]
Volume 25, Number 12—December 2019 / Research
Epidemiologic, Entomologic, and Virologic Factors of the 2014–15 Ross River Virus Outbreak, Queensland, Australia
Cassie C. Jansen, Martin A. Shivas, Fiona J. May, Alyssa T. Pyke, Michael B. Onn, Kerryn Lodo, Sonja Hall-Mendelin, Jamie L. McMahon, Brian L. Montgomery, Jonathan M. Darbro, Stephen L. Doggett, and Andrew F. van den Hurk
Author affiliations: Communicable Diseases Branch, Queensland Government Department of Health, Herston, Queensland, Australia (C.C. Jansen, K. Lodo); Brisbane City Council, Fortitude Valley, Queensland, Australia (M.A. Shivas, M.B. Onn); Metro North Hospital and Health Service, Windsor, Queensland, Australia (F.J. May); Forensic and Scientific Services, Queensland Government Department of Health, Coopers Plains, Queensland, Australia (A.T. Pyke, S. Hall-Mendelin, J.L. McMahon, A.F. van den Hurk); Metro South Hospital and Health Service, Coopers Plains (B.L. Montgomery); Queensland Institute of Medical Research Berghofer, Herston (J.M. Darbro); University of Sydney and Westmead Hospital, Sydney, New South Wales, Australia (S.L. Doggett)
Australia experienced its largest recorded outbreak of Ross River virus (RRV) during the 2014–15 reporting year, comprising >10,000 reported cases. We investigated epidemiologic, entomologic, and virologic factors that potentially contributed to the scale of the outbreak in Queensland, the state with the highest number of notifications (6,371). Spatial analysis of human cases showed that notifications were geographically widespread. In Brisbane, human case notifications and virus detections in mosquitoes occurred across inland and coastal locations. Viral sequence data demonstrated 2 RRV lineages (northeastern genotypes I and II) were circulating, and a new strain containing 3 unique amino acid changes in the envelope 2 protein was identified. Longitudinal mosquito collections demonstrated unusually high relative abundance of Culex annulirostris and Aedes procax mosquitoes, attributable to extensive freshwater larval habitats caused by early and persistent rainfall during the reporting year. Increased prevalence of these mosquitoes probably contributed to the scale of this outbreak.
Keywords: Ross River Virus; Mosquitoes; Culex spp.; Aedes spp.; Queensland; Australia.