Landscape and vegetation cover associated
with the distribution of Anopheles Aquasalis
malaria vector in Northeastern Venezuela

Investigator:

Sarah Guagliardo

Advisor: Maria Diuk-Wasser

Description:

With approximately 30, 062 cases reported in the year 2006, malaria is endemic in Venezuela. Since the mid-1990s, transmission has been limited to the states of Sucre, Bolivar, Amazonas, Barinas, Delta Amacuro, Apure and Tachira.  In Sucre State in northeastern Venezuela, the vast majority of malaria cases are caused by Plasmodium vivax infection transmitted by the primary vector, Anopheles aquasalis.  Cajigal Municipality in Sucre State is of particular concern, as it has demonstrated increasing rates of malaria infection over the course of the past ten years.  Previous studies have identified areas of high and sustained malaria transmission, termed “hot spots,” which were associated with proximity to and quantity of nearby An. aquasalis breeding sites, among other factors.  It is evident that the most suitable breeding habitat for An. aquasalis mosquitoes in the pre-adult stage is the Avicenia germinans mangrove species.

Accordingly, the purpose of this study is to determine the location of A. germinans and other land cover variables relative to An. aquasalis breeding sites and malaria hot spots using remote sensing technology.  Such information is necessary in order efficiently direct malaria control efforts to geographic areas of greatest need.

A continuous surface habitat suitability map will be created using information from Landsat remotely sensed images and observed vector breeding sites by interpolating these points to the entire region utilizing a Geographic Information System (GIS).  The map will then be used to assess the correlation between habitat suitability and the parasitic index in nearby villages and malaria hot spots as has been done in previous studies.  Logistic regression will be used to assess the degree to which the landscape variables (such as presence of A. germinans) are predictive of mosquito larvae presence.