Environmental impact of disease vector control

Control of arthropod vectors of disease encompasses a large realm of science, including the biology and mechanisms of diseases and the ability to control their spread. This combination of studies focuses on the arthropod-borne virus, West Nile virus (WNV), which is endemic in the United States and is maintained in the environment through a bird-mosquito-bird cycle. West Nile virus can incidentally infect humans and other mammals. One means of controlling the spread of this mosquito-borne disease is the systematic use of pesticides to reduce the mosquito population, which in turn has been proven to reduce the number of human and animal infections of the sometimes deadly disease. The first study was performed to understand environmental influence on transmission dynamics of a free-ranging alligator population in Louisiana, USA by surveying for active WNV infection in 93 blood samples from these alligators. Blood samples from alligators were negative for active WNV infection. The second study focused on developing a method to quantify the concentration of a commonly used pesticide in a sediment matrix. The target pesticide was permethrin and we also screened for the pyrethroid synergist piperonyl butoxide (PBO). The combination of these compounds are used in many areas to control the mosquito population that can spread WNV. The third study employed the methodology developed in the second study to quantify permethrin and PBO residues in sediments of playa lakes located in the Lubbock County vicinity. The objective was to assess the fate and transport of permethrin and to identify potential risks or environmental impacts resulting from the control of mosquito vectors.