La Crosse encephalitis virus (LAC), a devastating neurologic disease in children living in endemic areas like West Virginia and southwestern Virginia, is maintained through interactions between mosquito vectors and non-human vertebrate reservoir hosts in forests. Changes to interior forest habitat may impact viral dynamics leading ultimately to human disease outbreaks. Forest canopy disturbance (FCD) due to logging is rapidly increasing worldwide, with unknown potential impacts on arboviral transmission dynamics. We hypothesize that FCD will result in ecological changes that ultimately amplify LAC prevalence by altering enzootic transmission cycles. To test this hypothesis, we propose 4 studies: (1) FCD effects on mosquito vector and vertebrate host communities, (2) FCD effects on mosquito host-feeding behavior, (3) LAC vector competence of Cx. pipiens/quinquefasciatus hybrids in southwestern Virginia, and (4) natural prevalence of LAC across FCD study sites. The field component of this study will occur on three replicates of experimental forest disturbance regimes (undisturbed control, intermediate disturbance, and extreme disturbance) in southwestern Virginia. CDC gravid traps will be used to collect mosquitoes and estimate the abundance of native and introduced vector species across FCD sites. Live trapping of small mammals and point counts will be performed to assess the vertebrate community across disturbance regimes. DNA barcoding of mosquito blood meals will be used to determine host-feeding preferences of mosquitoes across the plots. Vector competence studies of Cx. hybrids will be performed in a BSL-2 facility that includes an insectory. A nucleic acid sequence-based amplification assay for LAC will be used to detect antigen in mosquitoes. Plaque reduction neutralization tests will be employed to assess LAC antibody prevalence in mammals. Our long-term goal is to use a mechanistic understanding of how land use change impacts LAC transmission dynamics to develop a predictive model. Such a model can help focus LAC mosquito control efforts and ultimately identify patterns applicable to other emerging bunyaviruses like Rift Valley fever. LAY LANGUAGE: As humans change the landscape, we may be altering disease dynamics. La Crosse encephalitis virus is maintained in forest through interactions between mosquitoes and small mammals. This study aims to determine how different logging techniques may impact the abundance of mosquitoes, small mammals and virus as well as mosquito feeding behavior. We will also perform experiments to assess how efficiently mosquito species can transmit this virus.
| Harris, M Camille; Yang, Fan; Jackson, Dorian M et al. (2015) La Crosse Virus Field Detection and Vector Competence of Culex Mosquitoes. Am J Trop Med Hyg 93:461-7 |
| Harris, M Camille; Dotseth, Eric J; Jackson, Bryan T et al. (2015) La Crosse Virus in Aedes japonicus japonicus mosquitoes in the Appalachian Region, United States. Emerg Infect Dis 21:646-9 |
