Study on bionomics of principal malaria vectors in Kratie province, Cambodia.

A cross-sectional study on bionomics of malaria was carried out in Kamlek village, Snuol rubber plantation, Kratie Province where the population had a high prevalence of malaria. Mosquitos were collected monthly between April to September 1998 from 18.00 hr to 6.00 hr by human bait and animal bait. Survey for larva breeding places was also performed. A total of 13 species of Anopheline mosquitos was collected, manly Anopheles philipinensis, An. aconitus, An. annularis, Ain. barbirostris, An. hyrcanus gr, An. jamesii, An. kawari, An. tesselatus, An. umbrosus and An. vagus. They were in various densities with the latter species being the most abundance. Among the vector species. An. maculatus was the most commonly collected with a density of 0.55 per man per night and peak biting was between 20.00 hr and 21.00 hr. The density of An. minimus and An. dirus were 0.11 and 0.74 per man per night with the peak biting time 24.00-01.00 hr and 20.00-21.00 hr respectively. Observation of host preference and feeding habit revealed An. maculatus to be exophagic, anthropophilic and 20 endophilic while An. minimus was both endophilic and exophagic and anthropophilic. An. dirus was endophilic and anthropophilic, these three species were not found positive for malaria infection. However, due to the limited time of survey and an exceptionally low rainfall in the rainy season, an inadequate sample was obtained for analysis. Therefore further investigation is required for at least a year for more information.

Integration of control measures for malaria vectors in endemic areas of Thailand.

Various vector control measures were applied in different endemic areas in two provinces, Saraburi and Chanthaburi, with comparison among different control measures. Application of IGR (insect growth regurator, pyriproxyfen) was introduced at Wat Tam Pra Pothisat, Tab-Kwang District, Saraburi Province. Some integration measures were performed at villages 6 and 8, Patavee, Makham District, Chanthaburi Province. In Tab-Kwang District with low malaria endemicity at the study site predators were not able to be released due to rapid velocity of running water. IGR could effectively control malaria compared to the basin released predators. Another endemic areas villagers 6 and 8, Patavee, Makham, Chanthaburi Province was chosen. Highly endemic multidrug resistant malaria has been prevalent for many years in this area. Integration of Kanda's trapping system, application of IGR, use of both residual spraying and impregnated bed-net methods with etofenprox successfully interrupted malaria infection. The application of these methods as an integrated control system could be adjusted to environmental conditions. The results of this study suggest rapid effective vector control.