EVALUATION OF WEATHER FACTORS FOR ABUNDANCE OF THE PRIMARY WEST NILE VIRUS VECTOR IN FORT WORTH

Purpose (a): INTRODUCTION: Vector-borne diseases like Malaria, Dengue, Japanese Encephalitis, Filariasis and West Nile fever have been affecting millions of people around the world. In vector-borne diseases, vector distribution and abundance is critical factor to predict occurrence and magnitude of a vector-borne disease. West Nile encephalitis is a vector-borne disease of concern in Texas, particularly in the Dallas-Fort Worth region: however, little attempt has been made to associate the abundance of the vector population with local weather patterns. OBJECTIVE: The objective of this study was to associate abundance of the primary West Nile virus vector, Culex quinequefasciatus, with local weather factors in the City of Fort Worth. Methods (b): Abundance of the primary WNV vector mosquito population was monitored by weekly mosquito trappings using CDC gravid mosquito traps. Fifty sites across the City of Fort Worth were selected to estimate abundance of the vector mosquito population and mosquito trappings were conducted from mid-April through end of October. Local weather data from Dallas-Fort Worth International Airport were obtained from the National Climate Data Center. Pearson’s correlation was used to identify a linear relationship and determine the strength association between the mosquito abundance and the various components of weather. Results (c): Analysis showed a peak in the mosquito population during the months of June, July and September while the rest of the months had comparatively lower counts. These mosquito numbers showed to have strong positive linear relationships with weekly average (r = 0.703, p = 0.000), maximum (r = 0.704, p = 0.000) and minimum (r = 0.693, p = 0.000) temperatures and 3 day precipitation (r = 0.439, p = 0.022) while the weekly average wind speed (r = -0.453, p = 0.018) and minimum humidity (r = -0.390, p = 0.045) had significant negative correlations. Linear positive associations were also noticed with the 3 day temperature and collection day temperature averages. Conclusions (d): Weekly temperature averages and 3day precipitation are strongly associated with the abundance of the West Nile virus vector mosquito population while humidity and wind speed showed little effect on the vector abundance. Further analysis will be conducted.