The technology of remote sensing is used to assist researchers in performing a variety of tasks better, faster, cheaper and with greater accuracy. Public health scientists and ecoystem researchers have been using remote sensing to assist with predicting and controlling disease outbreaks. However, remote sensing is applicable only with certain diseases. It is useful in monitoring diseases that are spread by a vector, such as mosquitos, whose presence is associated with certain land covers or vegetation types.
An example of the potential of remote sensing for disease control and prediction was demonstrated in the African Disease Environment Prediction Task (ADEPT). The disease, Rift Valley Fever (RVF), is a mosquito-borne virus that infects livestock and humans in east and west-central Africa. Along the banks of rivers and streams in regions subject to outbreaks of RVF are flooded areas called dambos. The dambos fill with stagnant water after prolonged rains. When flooded, dambos provide an excellent habitat for the RVF-carrying mosquito to breed and to mature.
For effective and efficient control of RVF it is critical to know the location of dambos and when they are flooded. Remote sensing can provide such information. Because dambos flood intermittently, the vegetation that grows in them differs from the vegetation around them. Using Landsat Thematic Mapper Imagery (Figure 1) , project scientists demonstrated the efficiency of remote sensing in detecting the vegetation associated with dambos. ( Figure 2 and Figure 3 are aerial and ground photos of the site depicted in [Figure 1], located to the north of Nairobi.) But location is only half the battle. The same satellite system is not suitable to detect when dambos are flooded because of the periodicity of the data collection (every 16 days) and the need to monitor dambos during the rainy season when clouds obscure the view to the ground for passive remote sensing systems. Synthetic Aperture Radar (an active remote sensing system that can look through clouds) was tested by Project ADEPT during a field experiment in Kenya in 1989. The radar system, flown on a Navy P-3 aircraft, provided data that, upon evaluation at Ames, produced positive results for the local health agencies involved in controlling this disease.
RESEARCH SITE: Kenya
COLLABORATORS: U.S. Army Medical Research Institute of Infectious Disease; Environmental Research Institute of Michigan; Naval Air Development Cetner; Kenya Trypanosomiasis Research Institute; U.S. Army Medical Research Unit, Kenya.
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