Infectious Disease in a Warming World: How Weather Influenced West Nile Virus in the United States (2001–2005)

• DOI: 10.1289/ehp.0800487
• Publication Date: 2009-03-16T13:35:45Z
• Authors: Jonathan E. Soverow; Gregory A. Wellenius; David N. Fisman; Murray A. Mittleman
• Keywords: Dew point; Cumulative incidence; West Nile virus

BackgroundThe effects of weather on West Nile virus (WNV) mosquito populations in the United States have been widely reported, but few studies assess their overall impact transmission to humans.ObjectivesWe investigated meteorologic conditions associated with reported human WNV cases States.MethodsWe conducted a case–crossover study 16,298 Centers for Disease Control and Prevention from 2001 2005. The primary outcome measures were incidence rate ratio disease occurrence mean weekly maximum temperature, cumulative dew point precipitation, presence ≥ 1 day heavy rainfall (≥ 50 mm) during month prior symptom onset.ResultsIncreasing temperature similarly significantly 35–83% higher infection over next month. An increase was 9–38% subsequent 3 weeks. at least within week 29–66% same 2 A 20-mm precipitation 4–8% weeks.ConclusionsWarmer temperatures, elevated humidity, increased independent season each others' effects.