Date of Award

Fall 1-6-2017

Degree Type


Degree Name

Master of Public Health (MPH)


Public Health

First Advisor

Gerardo Chowell

Second Advisor

Shanta Dube


Introduction: Vector-borne infectious diseases represent a major public health problem in both developing and developed nations. In particular, West Nile Virus (WNV), a mosquito-borne disease that can lead to severe disease and death in humans, caused over 2,100 reported cases in the United States last year (CDC, 2016). In Maricopa County, Arizona WNV has caused 474 reported cases during the last five years, with a case-fatality rate at 7.8%.

Aim: To examine the association between weather patterns and incidence of WNV in Maricopa County, AZ from 2007 to 2013.

Methods: We analyzed weekly data on climatological variables and WNV incidence from Maricopa County, AZ. The specific independent variables of interest were precipitation, minimum temperatures, mean temperatures, and maximum temperatures. A full model was generated using multiple linear regression, and a stepwise selection procedure yielded a minimal model.

Results: The full multiple linear regression model explains 45.30% of the observed variance in WNV incidence. The variable showing a significant impact on WNV incidence in this model was rainfall (p <0.0001). Stepwise selection results explained 45.16% of the variance observed in the data. This model included two significant predictors: precipitation and maximum temperature.

Conclusion: Climatic variables, particularly the amount of rainfall and maximum temperatures, significantly influence WNV dynamics in Maricopa County, Arizona. These findings are in line with prior studies and could be useful to guide mosquito control programs in the state of Arizona.