CHAART TWF Training Reports: Mvondo

Training Reports for TWF Investigators

Joe-Louis Mvondo, M.D.

Affiliation

Manager, Malaria Control Program
Community Health Department
Ministry of Health, Yaoundé, Cameroon

Project and Training Dates

Malaria in Cameroon
August - September 1998

Background

Malaria, transmitted by Anopheles gambiae and An. funestus, is a major health problem in Cameroon. Long-term studies of malaria transmission risk were conducted in two villages near Yaounde. These villages are similar with respect to population, socioeconomics, and agriculture. Analysis of field data also indicated that although overall geography, climate, flora, and fauna, surrounding each village was similar, total An. gambiae and An. funestus populations were significantly different. It was determined that localized breeding habitat requirements for each species were different. In general, An. gambiae prefer small sunlight collections of water whereas An. funestus breeds in larger permanent water bodies such as marshes and ponds. This difference in preferred breeding habitat suggests that the difference in vector abundance between villages might be explained in terms of small-scale differences in landscape composition which could be characterized by remote sensing data.

Research Objectives Pursued during CHAART Visit

Dr. Mvondo's current research involves endemic disease control related activities (e.g., epidemiological and entomological surveys and vector control programs). Detection of the increase in disease vector populations at a given time and place would help to forecast the likelihood of disease epidemics such as malaria. Remote sensing and geographic information systems (RS/GIS) technologies could be used to forecast these events and assist in the development and implementation of appropriate control measures. Specific objectives include:

Acquire a basic knowledge and expertise in remote sensing (RS) and geographic information systems (GIS), as applied to disease surveillance and control.
Integrate village level malaria entomological and entomological surveillance data with RS/GIS to characterize village level disease transmission risk based on landscape composition.
Develop a remote sensing based countrywide stratification of malaria transmission zones.

Accomplishments

Training in the basics of RS/GIS used Landsat TM data for a region in California since no cloud-free imagery of the study area in Cameroon were available for the period of field data collection. Image rectification and supervised and unsupervised classification were preformed on data of this area. The exercise also involved a field trip to the study area to use a global positioning system to "ground truth" different cover types identified in the imagery. Data from the National Oceanographic and Atmospheric Administration's Advanced Very High Resolution Radiometer (NOAA-AVHRR) at 1-km spatial resolution were also used to characterize the vegetation patterns throughout Cameroon. The vegetation cover of Cameroon exhibits a south-to-north transition from coastal mangrove and tropical rain forest in the south through a tree/brush/grassland, to grassland savanna in the northern portion of the country. These vegetation patterns are determined in large by changing precipitation patterns and can be related to the general patterns of malaria transmission risk. The AVHRR data could therefore be used to develop a countrywide malaria transmission risk map.

Future Plans

Dr. Mvondo continues to be a collaborator with investigators from Georgetown University on a malaria study being funded by the National Institutes of Health through the agency's International Centers for Tropical Disease Research program. He intends to integrate RS/GIS approaches into this research as well as in the design of vector and disease control activities in Cameroon.

Last updated: Apr 2000