ENVIRONMENTAL EXPOSURE RISK ASSESSMENT OF WEST NILE VIRUS IN CITY PARKS IN FORT WORTH, TEXAS

We partnered with the City of Fort Worth to set up weekly mosquito traps to track West Nile Virus activity in three city parks. We set up traps overnight and picked them up the following morning. Mosquitoes from these traps were then brought back to our lab to be identified and tested for West Nile Virus. Purpose (a): In 2012, Dallas-Fort Worth experienced the largest epidemic of West Nile Virus (WNV) yet, little is known about risk of WNV exposure in park users, despite conceivably high degree of interaction between WNV reservoir avian hosts and vector mosquitoes. The purpose of this study was to assess environmental risk exposures of WNV in city parks and identify species composition of mosquitoes in Fort Worth. Methods (b): Three city parks with high public activities and/or vegetation were selected to assess environmental risk of exposure to WNV. The CDC light trap with CO2 was employed to collect mosquitoes, and proven or potential vector mosquitoes were tested for WNV infection by Reverse-Transcriptase Polymerase Chain Reaction. Results (c): A total of 502 mosquitoes of 4 proven or potential WNV vector species were tested. No mosquitoes had WNV infection. 18 mosquito species were collected. The average number of mosquitoes collected per trap night was 24.4. Conclusions (d): The low number of proven and potential WNV vectors and no evidence of WNV activities in the vector population indicate negligible risk of environmental exposure to WNV in the 2013 season. However, high variation of exposure risk to WNV warrants continuing effort to assess the exposure risk to WNV in environmental settings with high public activities like city parks.