Malaria vectors in a traditional dry zone village in Sri Lanka.

Abstract

Abstract. Malaria transmission by anopheline mosquitoes was studied in a traditional tank-irrigation-based riceproducing village in the malaria-endemic low country dry zone of northcentral Sri Lanka during the period August 1994-February 1997. Adult mosquitoes were collected from human and bovid bait catches, bovid-baited trap huts, indoor catches, and pit traps. Mosquito head-thoraces were tested for the presence of Plasmodium falciparum and P. vivax, and blood-engorged abdomens for the presence of human blood by ELISAs. House surveys were done at twoday intervals to record cases of blood film-confirmed malaria among the villagers. A total of 7,823 female anophelines representing 14 species were collected. Trends in anopheline abundance were significantly correlated with rainfall of the preceding month in An. annularis, An. barbirostris, An. subpictus, An. vagus, and An. varuna, but were not significant in An. culicifacies and An. peditaeniatus. Malaria parasite infections were seen in seven mosquito species, with 75% of the positive mosquitoes containing P. falciparum and 25% P. vivax. Polymorph PV247 was recorded from a vector (i.e., An. varuna) for the first time in Sri Lanka. Computations of mean number of infective vector (MIV) rates using abundance, circumsporozoite (CS) protein rate, and human blood index (HBI) showed the highest rate in An. culicifacies. A malaria outbreak occurred from

Hydrological and geomorphological controls of malaria transmission

“…For example, in Sri Lanka the main vector driving malaria transmission is Anopheles culicifacies (Amerasinghe et al, 1999) which readily breeds in streambed pools that are not directly rainfall-fed (Amerasinghe et al, 1997;van der Hoek et al, 1998a). Despite the presence of multiple alternative sources of surface water, van der Hoek et al (2003) found that malaria risk was elevated within a zone up to 750 m from the river.…”

Reducing vector-borne disease by empowering farmers in integrated vector management

“…Paddy fields, irrigation systems and peridomestic environments facilitate breeding of vectors of malaria, lymphatic filariasis, Japanese encephalitis and dengue. [11][12][13][14][15] Additionally, the use of insecticides may cause acute poisoning and leave toxic residues in food; 16,17 resistance may develop in vector populations against the insecticides used for control; 18,19 and biodiversity may be degraded, which may contribute to a resurgence of mosquitoes. 20,21 Therefore, convergence is needed between integrated pest management strategies and integrated vector management strategies to help farmers improve their agricultural practices while minimizing environmental risks to health.…”

Confirmation of Anopheles varuna in vietnam, previously misidentified and mistargeted as the malaria vector Anopheles minimus.

“…varuna has been found infected with P. falciparum and P. vivax by circum- sporozoite ELISA, and it was implicated in a relatively low level of malaria transmission in a traditional tank-irrigationbased rice-producing village. 12,13 The population in Binh Thuan Province of Vietnam, however, is highly zoophilic, and on the basis of this behavior, it cannot be considered as a malaria vector in that area of the country. Moreover, the circumsporozoite ELISA assay on An.…”