Dry weather induces outbreaks of human West Nile virus infections

BMC Infectious Diseases

Research Article

Charles L Wax¹  Guiming Wang²  Jerrold L Belant²  Richard B Minnis³ 

[1] Department of Geosciences, Mississippi State University, Mail stop 5448, Mississippi State, 39762, Mississippi, USA;Department of Wildlife, Fisheries and Aquaculture, Mississippi State University, Mail stop 9690, Mississippi State, 39762, Mississippi, USA;Department of Wildlife, Fisheries and Aquaculture, Mississippi State University, Mail stop 9690, Mississippi State, 39762, Mississippi, USA;United States Department of Agriculture Animal and Plant Health Inspection Service Wildlife Services, 4700 River Road, 20737, Riverdale, MD, USA;

关键词: West Nile Virus;    Credible Interval;    Deviance Information Criterion;    West Nile Virus Infection;    Mosquito Abundance;   

DOI  :  10.1186/1471-2334-10-38

 received in 2009-06-20, accepted in 2010-02-24,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundSince its first occurrence in the New York City area during 1999, West Nile virus (WNV) has spread rapidly across North America and has become a major public health concern in North America. By 2002, WNV was reported in 40 states and the District of Columbia with 4,156 human and 14,539 equine cases of infection. Mississippi had the highest human incidence rate of WNV during the 2002 epidemic in the United States. Epidemics of WNV can impose enormous impacts on local economies. Therefore, it is advantageous to predict human WNV risks for cost-effective controls of the disease and optimal allocations of limited resources. Understanding relationships between precipitation and WNV transmission is crucial for predicting the risk of the human WNV disease outbreaks under predicted global climate change scenarios.MethodsWe analyzed data on the human WNV incidences in the 82 counties of Mississippi in 2002, using standard morbidity ratio (SMR) and Bayesian hierarchical models, to determine relationships between precipitation and human WNV risks. We also entertained spatial autocorrelations of human WNV risks with conditional autocorrelative (CAR) models, implemented in WinBUGS 1.4.3.ResultsWe observed an inverse relationship between county-level human WNV incidence risk and total annual rainfall during the previous year. Parameters representing spatial heterogeneity in the risk of human exposure to WNV improved model fit. Annual precipitation of the previous year was a predictor of spatial variation of WNV risk.ConclusionsOur results have broad implications for risk assessment of WNV and forecasting WNV outbreaks. Assessing risk of vector-born infectious diseases will require understanding of complex ecological relationships. Based on the climatologically characteristic drought occurrence in the past and on climate model predictions for climate change and potentially greater drought occurrence in the future, we suggest that the frequency and relative risk of WNV outbreaks could increase.

【 授权许可】

CC BY   
© Wang et al; licensee BioMed Central Ltd. 2010