Remote sensing and geographic information systems as decision support tools for malaria control in the Republic of Korea

Cost-comparisons are a necessary component of decision-making in the control of vector-borne disease. Remote sensing and geographical information systems (GIS) were used to estimate the size of vector larval habitats to allow a cost comparison of chemoprophylaxis and larviciding, two malaria control methods currently being considered for use in the Republic of Korea (ROK).Two U.S. Army camps (Cp Casey and Cp Greaves) were selected as research sites. The cost of chemoprophylaxis was estimated for each population assuming a 19-week treatment regimen consisting weekly chloroquine chemoprophylaxis with terminal primaquine treatment, a single pre-treatment G-6-PD deficiency test, and a 50% turnover in personnel during the malaria transmission season. Annual cost of chemoprophylaxis was Larval habitats were sampled from June through September, 2000. Anopheline larvae were reared to the adult stage and identified using adult and pupal morphological characteristics. Gene sequencing and random amplification of polymorphic DNA (RAPD) analyses were performed to confirm the identification of the mosquitoes. Both molecular work and pupal morphology indicated that most of the anophelines collected during the study were Anopheles sinensis Wiedemann and that the abundance of other anopheline species is generally overestimated by adult keys.The size of vector larval habitats within the 1-km flight range of An. sinensis around the two U.S. Army camps was determined using satellite-acquired images, and the cost of treating those areas with an insect-growth regulator was estimated. At Cp Greaves, the cost of the requisite three larvicidal applications exceeded the cost of chemoprophylaxis by a factor of four, but at Cp Casey, chemoprophylaxis was about 21 times as expensive as larviciding due to the larger number of at-risk personnel and the smaller size of the vector habitats.This study demonstrates the usefulness of remote sensing and GIS as decision support tools for estimating costs of vector control methods used in the control of vector-borne disease. Such information can then serve as one component of the decision-making process for the design and implementation of disease prevention strategies.