Weather and West Nile Virus Threat in Illinois

Shown by Climate Division

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Experimental Climate Division WNV Threat Model

Since the 2001 introduction of West Nile Virus (WNV) into Illinois, it is estimated that more than 200,000 cases have occurred and Illinois has the 3rd highest number of the more severe human WNV neural disease cases. The risk of exposure to WNV appears to increase under hot / dry summertime conditions. WNV affects citizens across the state, and while two county-level predictive models exist (one for Cook, and one for Champaign County) the model results cannot be easily extrapolated to other regions of Illinois. THe goal of this research is to develop and validate a WNV threat predictive model that can be used throughout the state of Illinois, eventually throughout the Midwest and US, and perhaps apply these same techniques to other climate-related health or issues.

Components of this model will include: 1) climate divisions as the basic spatial unit to aggregate non-homogenous WNV human and mosquito case sampling, as well as daily weather data. 2) Graphical displays of accumulated daily temperature and precipitation departures from normal for high and low WNV case years for comparison with current weather conditions, 3) Computation of statistics based on differences from daily 30-year averages, rather than based on degree days. 4) Incorporation of 10-day daily temperature and 3-day daily precipitation forecasts to increase the lead time of model usefulness.

The number of human cases is somewhat related to popoulation, with climae division 02 (including the Chicago Metro Area) having the largest population and climate divisons 03, 07 and 09 having the least popoulation. The years with high and low cases per climate division were selected after the number of cases were normalized by the 2009 population of CD_02. In addition to population, other non-climate effects such as mosquito habitat, use and effectiveness of mosquito control, as well as human, bird and mosquito behavior, can affect the number of cases, leading to uncertainy in year to year results and some subjectivity in selection of high and low case years.

As the summer season progresses, the web site may change to become more user-friendly. Click a climate division for season-to-date WNV weather and threat graphics.

References

Alto, B.W., E.J. Muturi, and R.L. Lampman, 2012: Nutrition and density-dependence in Culex pipiens. Med Vet Entomol 26 (4): 396-406.

Gu, W.D., R.L. Lampman, N.M. Krasavin, R.J. Novak, 2006: Spatio-temporal analyses of West Nile virus transmission in Culex mosquitoes in Northern Illinois, USA, 2004. Vector-borne Zoonotic Dis. 6(1), 91-98.

Gu, W.D., T.R. Unnasch, C.R. Katholi, R.L. Lampman, R.J. Novak, 2008: Fundamental issues in mosquito surveillance for arboviral transmission. Trans Royal Soc Trop. Med. Hyg. 102, 817-822.

Kunkel, K.E., R.J. Novak, R.L. Lampman, and W. Gu, 2006: Modeling the impact of variable climatic factors on the crossover of Culex restuans and Culex pipiens (diptera: culicidae), Vectors of West Nile Virus in Illinois. Amer. J. Tropical Medicine and Hygiene, 74(1), 168-173.

Lampman, R.L., N.M. Krasavin, M.P. Ward, T.A. Beveroth, E.W. Lankau, B.W. Alto, E.J. Muturi, and R.J. Novak, 2013: West Nile Virus Infection Rates and Avian Serology in East-Central Illinois. J. of the American Mosquito Control Assoc., 29(2), 108-122.

Lampman, R.L., N.M. Krasavin, M. Szyska, R.J. Novak, 2006. A comparison of two West Nile virus detection assays (TaqMan reverse transcriptase polymerase chain reaction and VecTest antigen assay) during three consecutive outbreaks in northern Illinois, J. Am. Mosq. Control Assoc., 22(1), 76-86.

Lampman, R L., M. Slamecka, N. Krasavin, K.E. Kunkel, and R.J. Novak, 2006: Culex population dynamics and West Nile virus transmission in east central Illinois. Journal of the American Mosquito Control Assoc., 22, 390-400.

Muturi, E.J., R.L. Lampman, K. Costanzo, and B.W. Alto, 2011: Effect of Temperature and Insecticide Stress on Life-History Traits of Culex restuans and Aedes albopictus (Diptera: Culicidae). Journal of Medical Entomology 48(2):243-250.

Peterson, L.R., P.J. Carson, B.J. Biggerstaff, B. Custer, S.M. Borchardt, and M.P. Busch, 2013: Estimated cumulative incidence of West Nile virus infection in US adults, 1999-2010. Epidemiol. Infect., 141, 591-595.

Ruiz, M.O., L.F. Chaves, G.L. Hamer, T. Sun, W.M. Brown, E.D. Walker, L. Haramis, T.L. Goldberg, and U.D. Kitron, 2010: Local impact of temperature and precipitation on the West Nile virus infection in Culex species mosquitoes in northeast Illinois, USA. Parasites and Vectors, 3(19), 1-16.

Staples, J.E., M. Shankar, J.J. Sejvar, M.I. Meltzer, and M. Fischer, 2014: Initial and long term costs of patients hospitalized with West Nile virus disease, Amer. Soc. Trop. Med. Hyg., (in press).

Westcott, N.E., S.D. Hilberg, R.L. Lampman, B. W. Alto, A. Bedel, E.J. Muturi, H. Glahn, M. Baker, K.E. Kunkel, and R.J. Novak, 2011: Predicting the Seasonal Shift in Mosquito Populations Preceding the Onset of the West Nile Virus in Central Illinois, Bulletin of the American Meteorological Society, 92,1173-1180.

Collaborators

Jeff Blackford, Environmental Health Division, Champaign-Urbana Public Health District

Sam Dorevitch, Division of Environmental and Occupational Health Sciences, University of Illinois at Chicago School of Public Health Institute for Environmental Science and Policy

Linn Haramis, Division of Public Health, Illinos Department of Public Health

Rich Lampman, Medical Entomology Laboratory, Illinois Natural History Survey, Prairie Research Institute, University of Illinois at Urbana-Champaign

Juma Muturi, Medical Entomology Laboratory, Illinois Natural History Survey, Prairie Research Institute, University of Illinois at Urbana-Champaign

Marilyn O'Hara Ruiz, Geographic Information Systems and Spatial Epidemiology Lab, Department of Pathobiology, University of Illinois at Urbana-Champaign

Scott Scallion, Statistical Modeling Branch, Meteorological Development Laboratory, National Weather Service Office of Science & Technology, National Oceanic and Atmospheric Adminstraion (NOAA)