Investigation of West Nile Encephalitis in NYC


Durland Fish, PI,
Hilary Rosen

Yale School of Medicine, Department of Epidemiology and Public Health


There are two components to the West Nile Virus Project:
  1. the establishment of a risk map based on clinical case data, vegetation and population density in the greater New York City area;
  2. the correlation between mosquito breeding sites, larval habitats, and adult mosquito host seeking behaviors in the Bronx Zoo with respect to vegetation and proximity to specific hosts
  3. .

The risk map will be constructed using WNV case and mosquito collection site data that were acquired in the form of paper maps from the New York State Department of Public Health and the New York City Department of Health. These maps were last updated on October 29, 1999 and are based on the 1999 epidemic. Access to the exact addresses of patients could not be acquired because of patient confidentiality issues. Population density data was acquired from the ESRI database and information on landcover classes and vegetation were acquired from the 28 Digital Orthophoto Quadrangles (DOQ)s and the Landsat 7 image of New York City, Westchester County and Nassau County.

The mosquito behavior project is based on the field data collected and acquired daily from the Bronx Zoo. Different mosquito species vary on their preferences for breeding sites, oviposition sites, and host seeking behaviors. The species found in natural larval sites and oviposition traps will be analyzed based on their proximity to certain hosts (mammal, avian etc.) at the zoo, as well as light trap data. This will be done in an effort to characterize and understand if there is a spatial correlation between larval/oviposition sites and adult host seeking mosquitoes of the same species. This may help determine how far the mosquitoes are traveling to seek hosts. The DOQs and the Landsat 7 image will be used to determine relative vegetation differences within the zoo as well as potential breeding sites for different mosquitoes. The project is interesting because of the unique characteristics of the Bronx Zoo that is a highly vegetated area with great plant and animal diversity in the middle of an urban environment.

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5 June 2000