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Does anthropogenic disturbance affect the ecological transmission drivers of the La crosse virus?

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Tuamami T. Tamini (Creator)
Institution
The University of North Carolina at Greensboro (UNCG )
Web Site: http://library.uncg.edu/
Advisor
Gideon Wasserberg

Abstract: In this study, we applied a comparative ecological approach to evaluate if and how anthropogenic disturbance affects vector species abundance and gonotrophic status within the La Crosse virus (LACV) sylvatic system. We compared the oviposition rate, resting adult abundance, and gonotrophic status between six peridomestic and adjacent forest patch habitats in Haywood County, North Carolina. The peridomestic habitats were historic La Crosse encephalitis case residences. A total of 93,158 eggs were collected with the native Aedes triseriatus being the most common (83.2%) followed by the invasive species Ae. japonicus and Ae. albopictus (15.3% and 1.5%, respectively). A total of 1,040 resting adults were collected with similar relative species abundances. In sites characterized by high densities of artificial containers (i.e., high anthropogenic disturbance), the total number of eggs and adult mosquitoes was higher in the peridomestic habitats. Whereas in sites characterized by low densities of artificial containers (i.e., low anthropogenic disturbance) the total number of eggs and adult mosquitoes was higher in the forested habitats. Similarly, the proportion of gonotrophically active mosquitoes was higher in the highly disturbed peridomestic habitats and lower in the less disturbed forested habitats. This was consistent with our host survey results demonstrating a greater number of potential blood-meal sources (e.g., domestic and sylvatic mammals) in the peridomestic habitats. In terms of habitat preferences, Ae. triseriatus was more commonly found in forested habitat and Ae. japonicus was more common in the peridomestic habitats. However, when stratified by level of anthropogenic disturbance, Ae. triseriatus was found in higher abundance in the highly disturbed peridomestic habitats. Anthropogenic disturbance appeared to increase the abundance of Ae. japonicus in the peridomestic habitats. In conclusion, this study demonstrated that the effects of anthropogenic disturbance on the LACV sylvatic system are not straightforward. Based on vector abundance and gonotrophic status, transmission potential is generally lower in the peridomestic habitat and higher in the forested habitat. However, after stratifying by level of disturbance, it appears that the transmission potential is actually higher in peridomestic habitats that contain higher densities of artificial containers. This increased risk appears to be due to the combined effects of increased population fecundity coupled with a physiologically older population. From a public health perspective, this study reinforces the importance of source reduction (e.g., removal of mosquito breeding-sites) in peridomestic habitats in order to minimize the transmission potential of La Crosse virus.

Additional Information

Publication
Thesis
Language: English
Date: 2011
Keywords
Ecological approach, Gravid, Nulliparous, Parous, Peridomestic
Subjects
Mosquitoes as carriers of disease $z North Carolina $z Haywood County
Mosquitoes $x Research $z North Carolina $z Haywood County
Nature $x Effect of human beings on $z North Carolina $z Haywood County