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Fine-temporal forecasting of outbreak probability and severity: Ross River virus in Western Australia

  • I. S. KOOLHOF (a1), S. BETTIOL (a2) and S. CARVER (a1)

Health warnings of mosquito-borne disease risk require forecasts that are accurate at fine-temporal resolutions (weekly scales); however, most forecasting is coarse (monthly). We use environmental and Ross River virus (RRV) surveillance to predict weekly outbreak probabilities and incidence spanning tropical, semi-arid, and Mediterranean regions of Western Australia (1991–2014). Hurdle and linear models were used to predict outbreak probabilities and incidence respectively, using time-lagged environmental variables. Forecast accuracy was assessed by model fit and cross-validation. Residual RRV notification data were also examined against mitigation expenditure for one site, Mandurah 2007–2014. Models were predictive of RRV activity, except at one site (Capel). Minimum temperature was an important predictor of RRV outbreaks and incidence at all predicted sites. Precipitation was more likely to cause outbreaks and greater incidence among tropical and semi-arid sites. While variable, mitigation expenditure coincided positively with increased RRV incidence (r 2 = 0·21). Our research demonstrates capacity to accurately predict mosquito-borne disease outbreaks and incidence at fine-temporal resolutions. We apply our findings, developing a user-friendly tool enabling managers to easily adopt this research to forecast region-specific RRV outbreaks and incidence. Approaches here may be of value to fine-scale forecasting of RRV in other areas of Australia, and other mosquito-borne diseases.

Corresponding author
*Authors for correspondence: I. S. Koolhof and S. Carver, School of Biological Sciences, University of Tasmania, Hobart, Tasmania, Australia and School of Medicine, University of Tasmania, Hobart, Tasmania, Australia. (Email: and
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1. Gratz, NG. Emerging and resurging vector-borne diseases. Annual Review of Entomology 1999; 44: 5175.
2. Mackenzie, JS, Gubler, DJ, Petersen, LR. Emerging flaviviruses: the spread and resurgence of Japanese encephalitis, West Nile and dengue viruses. Nature Medicine 2004; 10: 98109.
3. Tipayamongkholgul, M, et al. Effects of the El Nino-Southern Oscillation on dengue epidemics in Thailand, 1996–2005. BioMed Central Public Health. 2009; 9: 115.
4. Naish, S, Hu, W, et al. Weather variability, tides, and barmah forest virus disease in the gladstone region, Australia. Environmental Health Perspectives 2006; 114: 678683.
5. Yu, W, Dale, P, Turner, L, Tong, S. Projecting the impact of climate change on the transmission of Ross River virus: methodological challenges and research needs. Epidemiology and Infection 2014; 142: 20132023.
6. Harley, D, Sleigh, A, Ritchie, S. Ross River virus transmission, infection, and disease: a cross-disciplinary review. Clinical Microbiology Reviews 2001; 14: 909932.
7. Aaskov, J, Fokine, A, Liu, W. Ross River virus evolution: implications for vaccine development. Future Virology 2012; 7: 173178.
8. Australian Government Department of Health. Notifications for all diseases by State & Territory and year ( Accessed 16 September 2016.
9. Kelly-Hope, LA, Purdie, DM, Kay, BH. Ross River virus disease in Australia, 1886–1998, with analysis of risk factors associated with outbreaks. Journal of Medical Entomology 2004; 41: 133150.
10. Russell, RC. Ross river virus: ecology and distribution. Annual Review of Entomology 2002; 47: 131.
11. Carver, S, et al. Influence of hosts on the ecology of arboviral transmission: potential mechanisms influencing dengue, Murray Valley encephalitis, and Ross River virus in Australia. Vector-Borne and Zoonotic Diseases 2009; 9: 5164.
12. Claflin, SB, Webb, CE. Ross River virus: many vectors and unusual hosts make for an unpredictable pathogen. PLoS Pathogens 2015; 11: 15.
13. Woodruff, RE, et al. Early warning of Ross River virus epidemics – combining surveillance data on climate and mosquitoes. Epidemiology 2006; 17: 569575.
14. Tong, S, et al. Climate variability, social and environmental factors, and Ross River virus transmission: research development and future research needs. Environmental Health Perspectives 2008; 116: 15911597.
15. Tall, JA, Gatton, ML, Tong, SL. Ross River virus disease activity associated with naturally occurring nontidal flood events in Australia: a systematic review. Journal of Medical Entomology 2014; 51: 10971108.
16. Jacups, SP, Whelan, PI, Currie, BJ. Ross River virus and Barmah Forest virus infections: a review of history, ecology, and predictive models, with implications for tropical northern Australia. Vector-Borne and Zoonotic Diseases 2008; 8: 283297.
17. Haynes, CD, Ridpath, MG, Williams, MAJ. Monsoonal Australia: Landscape, Ecology and Man in the Northern Lowlands. Rotterdam: A.A. Balkema, 1991.
18. Carver, S, et al. Environmental monitoring to enhance comprehension and control of infectious diseases. Journal of Environmental Monitoring 2010; 12: 20482055.
19. Woodruff, RE, et al. Predicting Ross River virus epidemics from regional weather data. Epidemiology 2002; 13: 384393.
20. Russell, RC. Seasonal activity and abundance of the arbovirus vector Culex annulirostris skuse near echuca, Victoria, in the Murray Valley of southeastern Australia 1979–1985. Australian Journal of Experimental Biology & Medical Science 1986; 64: 97103.
21. Rowbottom, R, et al. Resource limitation, controphic ostracod density and larval mosquito development. PLoS ONE 2015; 10: 113.
22. Lindsay, M, et al. Ross River and Barmah Forest viruses in Western Australia, 2000/01–2003/04: contrasting patterns of disease activity. Arbovirus Research in Australia 2005; 9: 194201.
23. Lindsay, M, et al. Western Australian arbovirus surveillance and research program, Annual Report: 1997–1998. Arbovirus Surveillance and Research Laboratory and the Western Australian Centre for Pathology and Medical Research. Western Australian Government, 1998.
24. McIver, L, et al. A climate-based early warning system to predict outbreaks of Ross River virus disease in the Broome region of western Australia. Australian and New Zealand Journal of Public Health 2010; 34: 8990.
25. Severn, S, Brendan, I. 2013/14 Mosquito Management Annual Report. Mandurah, 2014.
26. Australia Bureau of Statistics. 3218.0 - Regional Population Growth, Australia, 2013–14 ( Accessed 2 February 2016.
27. Brady, OJ, et al. Dengue disease outbreak definitions are implicitly variable. Epidemics 2015; 11: 92102.
28. Abraham, B, Ledolter, J. Statistical Methods for Forecasting. New York: Wiley, 1983.
29. Tong, S, Hu, W. Different responses of Ross River virus to climate variability between coastline and inland cities in Queensland, Australia. Occupational and Environmental Medicine 2002; 59: 739744.
30. Jacups, SP, et al. Determining meteorological drivers of salt marsh mosquito peaks in tropical northern Australia. Journal of Vector Ecology 2015; 40: 277281.
31. Williams, CR, Fricker, SR, Kokkinn, MJ. Environmental and entomological factors determining Ross River virus activity in the River Murray Valley of South Australia. Australian and New Zealand Journal of Public Health 2009; 33: 284288.
32. Burnham, KP, Anderson, DR. Model Selection and Multimodel Inference : A Practical Information-Theoretic Approach. New York: Springer, 2002.
33. Wong, TT. Performance evaluation of classification algorithms by k-fold and leave-one-out cross validation. Pattern Recognition. 2015; 48: 28392846.
34. Meijer, RJ, Goeman, JJ. Efficient approximate k-fold and leave-one-out cross-validation for ridge regression. Biometrical Journal 2013; 55: 141155.
35. Rodriguez, JD, Perez, A, Lozano, JA. Sensitivity analysis of k-fold cross validation in prediction error estimation. IEEE Transactions on Pattern Analysis and Machine Intelligence 2010; 32: 569575.
36. Jacups, SP, et al. Predictive indicators for Ross River virus infection in the Darwin area of tropical northern Australia, using long-term mosquito trapping data. Tropical Medicine & International Health 2008; 13: 943952.
37. Bi, P, Parton, KA. Climate variations and the transmission of Ross River virus infection in coastal and inland region of Queensland: an analysis from Townsville and Toowoomba. Environmental Health 2003; 3: 7380.
38. Hu, W, et al. Difference in mosquito species (Diptera: Culicidae) and the transmission of Ross River virus between coastline and inland areas in Brisbane, Australia. Environmental Entomology 2010; 39: 8897.
39. Hu, W, et al. Development of a predictive model for Ross river virus disease in Brisbane, Australia. The American Journal of Tropical Medicine and Hygiene 2004; 71: 129137.
40. Hu, W, et al. Mosquito species (Diptera: Culicidae) and the transmission of Ross River virus in Brisbane, Australia. Journal of Medical Entomology 2006; 43: 375381.
41. Hu, WB, et al. Rainfall, mosquito density and the transmission of Ross River virus: a time-series forecasting model. Ecological Modelling 2006; 196: 505514.
42. Tong, S, et al. Climatic, high tide and vector variables and the transmission of Ross River virus. Internal Medicine Journal 2005; 35: 677680.
43. Mackenzie, JS, et al. Arboviruses causing human-disease in the Australasian zoogeographic region. Archives of Virology 1994; 136: 447467.
44. Wright, AE, et al. A preliminary investigation of the ecology of arboviruses in the derby area of the Kimberley region, western Australia. Australian Journal of Experimental Biology and Medical Science 1981; 59: 357367.
45. Shire of Derby Council. Shire of Derby/West Kimberly: Shire of Derby ( Accessed 5 May 2016.
46. Jardine, A, Neville, PJ, Lindsay, MD. Proximity to mosquito breeding habitat and Ross River virus risk in the Peel region of Western Australia. Vector-Borne and Zoonotic Diseases 2015; 15: 141146.
47. Lindsay, M, et al. An outbreak of Ross River virus disease in the south-west of Western Australia. Communicable Diseases Intelligence 1996; 20: 136139.
48. Werner, AK, et al. Environmental drivers of Ross River virus in southeastern Tasmania, Australia: towards strengthening public health interventions. Epidemiology and Infection. 2012; 140: 359371.
49. Gatton, ML, Kay, BH, Ryan, PA. Environmental predictors of Ross River virus disease outbreaks in Queensland, Australia. The American Journal of Tropical Medicine and Hygiene 2005; 72: 792799.
50. Geelhoed, E. The Economic Costs of Ross River Virus Infection. Western Australia: Health Department of Western Australia, 1995.
51. Ratnayake, JTB. The Valuation of Social and Economic Costs of Mosquito-transmitted Ross River Virus (Dissertation). Nathan, Queensland: Griffith University, 2005.
52. Mullahy, J. Specification and testing of some modified count data models. Journal of Econometrics 1986; 33: 341365.
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