| malaria transmission at a new irrigation project in sri lanka: the emergence of anopheles annularis as a major vector. | malaria transmission was studied in a newly irrigated area of the mahaweli project in the dry zone of sri lanka. observations were performed for a three-month period following the northeast monsoon. parasitemia in the population varied from 20.2% in february to 7% in may, and infection was due to both plasmodium falciparum and p. vivax. night catches of mosquitoes collected with human bait included a high proportion of anopheles annularis. mosquitoes containing sporozoites in the salivary glands ... | 1992 | 1449195 |
| anopheles culicifacies (diptera: culicidae): ddt resistance in sri lanka prior to and after cessation of ddt spraying. | | 1985 | 4045932 |
| assessment of the consequences of the house-spraying of malathion on the interruption of malaria transmission. | marked female anopheles culicifacies were released into an enclosed palm-leaf hut at dusk and survivors recovered the following drawn by hand on several occasions before and after spraying with the insecticide malathion. pre-spray releases yielded only 25-50% recovery which was thought to be due to concealment of resting mosquitoes in the palm-leaf. a mortality of 100% was recorded for over 2 months after spraying the insecticide but after 71 days small numbers of live recoveries were found. the ... | 1983 | 6668635 |
| ovarian development and biting frequency in anopheles culicifacies giles in sri lanka. | in order to determine the duration of the gonotrophic cycle in anopheles culicifacies giles in sri lanka, ovarian development in freshly blood-fed wild-caught females was studied in the laboratory and the findings were compared with mark-and-release recoveries in the field. in specimens of unknown parity at first capture probable feeding intervals of 1, 2 and 3 days (mean: 1.7 - 2.1 days) were found. the release of freshly blood-fed nullipars bred from larvae produced two recaptures from which i ... | 1980 | 7210169 |
| population dynamics of anthropophilic mosquitoes during the northeast monsoon season in the malaria epidemic zone of sri lanka. | mosquito-borne diseases are a major health problem in sri lanka. human biting mosquitoes were collected during the night (18.00-06.00 hours) at nikawehera village, in the malaria endemic intermediate rainfall zone of the country. collections were made at monthly intervals in the period october 1991 to april 1992, which included the main rainy season due to the northeast monsoon (october-january). thirteen anopheles, eleven culex, three aedes, three mansonia and one armigeres species were identif ... | 1994 | 7949318 |
| cytotaxonomical examination for sibling species in the taxon anopheles culicifacies giles in sri lanka. | ovarian polytene chromosomes of anopheles culicifacies collected from different climatic and eco-epidemiological localities were examined to study the composition and distribution of sibling species in sri lanka. during the study period 4328 ovaries were prepared for examination, of which 1937 were suitable for the reading of polytene chromosomes. among these 458 specimens were identified as belonging to species b based on diagnostic inversion on x-chromosome and 1479 definitively were identifie ... | 1996 | 8952171 |
| characteristics of malaria vector breeding habitats in sri lanka: relevance for environmental management. | in and around a village in the anuradhapura district of sri lanka anopheline larvae were sampled from july 1994 to april 1996 in all surface water bodies. samples positive for anopheles culicifacies, the established vector of malaria in sri lanka, and for an. barbirostris, an. vagus, and an. varuna, potential secondary vectors, were characterized by site, exposure to sunlight, substratum, turbidity of the water, presence of vegetation, and presence of fauna. availability of pools of stagnant wat ... | 1998 | 9740294 |
| anopheles culicifacies breeding in sri lanka and options for control through water management. | this paper assesses the options for control of malaria vectors through different water management practices in a natural stream in sri lanka. the association between water level in the stream and breeding of the immature stages of the primary vector anopheles culicifacies was investigated and the feasibility of using existing irrigation infrastructure to reduce the breeding potential discussed. the most feasible option would be to implement a management routine where water is released periodical ... | 1998 | 9821462 |
| risk factors for malaria: a microepidemiological study in a village in sri lanka. | environmental and socioeconomic risk factors for malaria were studied in a village in sri lanka. over a period of one year, all 49 households in the village were visited every alternate day to obtain information on malaria episodes. information on risk factors was obtained through questionnaires and direct observations. age below 17 years (relative risk [rr] = 1.66, 95% confidence interval [95% ci] 1.18-2.35), use of bed nets (rr = 0.16, 95% ci 0.05-0.45) and traditional fumigants (rr = 0.58, 95 ... | 1998 | 9861392 |
| screening of anopheles culicifacies population of sri lanka for sibling species a. | a total of 1119 anopheles culicifacies mosquitoes collected from various malaria endemic regions in sri lanka were examined using two dna probes rp217 and rp234, which enable the differentiation of sibling species a from b and c species of an. culicifacies. sibling species a was found to be absent. | 1998 | 10319555 |
| malaria vectors in a traditional dry zone village in sri lanka. | malaria transmission by anopheline mosquitoes was studied in a traditional tank-irrigation-based rice-producing 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 huma ... | 1999 | 10466971 |
| multiple host feeding in field populations of anopheles culicifacies and an. subpictus in sri lanka. | a histological technique was used to detect the multiple blood-feeding of female mosquitoes, within the same gonotrophic cycle, in field populations of the malaria vectors anopheles culicifacies and an. subpictus (diptera: culicidae) at a village in the low country of sri lanka, during 1994-96. among 3306 an. culicifacies and 871 an. subpictus engorged females examined, respectively, 34.4% and 30.4% were multiple-fed. in these two species, double meals accounted for 92.7% and 89.5%, and triple m ... | 1999 | 10484158 |
| anopheles culicifacies y-chromosome dimorphism indicates sibling species (b and e) with different malaria vector potential in sri lanka. | in sri lanka, malaria is transmitted mainly by anopheles culicifacies giles sensu lato (diptera: culicidae). in india, this nominal taxon comprises sibling species a, b, c, d and e, distinguished by their chromosome morphology. species b (identified by polytene chromosome sequence xab, 2g1 + h1) is not such an efficient vector of malaria as other members of the an. culicifacies complex in india. all specimens of an. culicifacies s.l. examined from sri lanka possess xab, 2g1 + h1 polytenes, previ ... | 2000 | 11129709 |
| control of malaria vectors with the insect growth regulator pyriproxyfen in a gem-mining area in sri lanka. | the study was conducted in eight adjacent villages in central sri lanka where there are many shallow pits dug by gem miners that fill with water. these become breeding places of the main malarial vector anopheles culicifacies, and of the second most important vector anopheles subpictus, but not of anopheles varuna, the third most important vector. with the help of local volunteers, data on the adult populations of these three species was collected by various standard methods, and data on the inc ... | 2001 | 11700185 |
| malathion resistance and prevalence of the malathion carboxylesterase mechanism in populations of mosquito vectors of disease in sri lanka. | to determine the levels of malathion resistance and prevalence of the malathion carboxylesterase mechanism among mosquitoes in sri lanka. | 2001 | 11731814 |
| strong association between house characteristics and malaria vectors in sri lanka. | the objective of this study was to determine whether house characteristics could be used to further refine the residual insecticide-spraying program in sri lanka. indoor-resting mosquito densities were estimated in 473 houses based on fortnightly collections over a two-and-a-half-year period. the type of house construction and the exact location of all houses were determined. in a multivariate analysis, distance of less than 750 meters between a house and the main vector-breeding site was strong ... | 2003 | 12641408 |
| towards a risk map of malaria for sri lanka: the importance of house location relative to vector breeding sites. | in sri lanka, the major malaria vector anopheles culicifacies breeds in pools formed in streams and river beds and it is likely that people living close to such breeding sites are at higher risk of malaria than people living further away. this study was done to quantify the importance of house location relative to vector breeding sites for the occurrence of malaria in order to assess the usefulness of this parameter in future malaria risk maps. such risk maps could be important tools for plannin ... | 2003 | 12714550 |
| control of vectors and incidence of malaria in an irrigated settlement scheme in sri lanka by using the insect growth regulator pyriproxyfen. | an evaluation of pyriproxyfen as a larval control agent with the aim of reducing malaria vector populations and incidence of malaria was conducted in 12 villages in an irrigated settlement scheme in the dry zone of central sri lanka. in these villages, there are many pools in the beds of rivers, streams, and irrigation ditches during the dry season of the year. these are the major breeding places of the malaria vectors anopheles culicifacies and an. subpictus. collections of adult mosquitoes wer ... | 2004 | 15669380 |
| vectors and malaria transmission in a gem mining area in sri lanka. | anopheline vectors of malaria were studied in the kaluganga gem mining area in the dry zone of central sri lanka. adult mosquitoes were collected using cattle-baited huts and nets, pyrethrum spray sheets, window exit traps and light traps and partial and full-night human landing collections over a period of 17 mo. the collections produced a total of 13,591 anophelines belonging to 14 species. using elisa for circumsporozoite proteins of plasmodium vivax and p. falciparum, anopheles culicifacies, ... | 2004 | 15707286 |
| spatiotemporal distribution of insecticide resistance in anopheles culicifacies and anopheles subpictus in sri lanka. | the malaria situation in sri lanka worsened during the 1990s with the emergence and spread of resistance to the drugs and insecticides used for control. chloroquine resistance has increased rapidly over this period, but adverse changes in malaria transmission are more closely associated with insecticide use rather than drug resistance. insecticide susceptibility tests were routinely carried out in key anopheline vectors across the country for more than a decade. these sentinel data were combined ... | 2005 | 16099009 |
| some characteristics of the larval breeding sites of anopheles culicifacies species b and e in sri lanka. | anopheles culicifacies giles, the major malaria vector in sri lanka, exists as a species complex comprising two sympatric sibling species--species b and e. species e is reported to be the major vector of plasmodium vivax and p. falciparum parasites in sri lanka, whilst species b is a poor or nonvector as in india. knowledge of the breeding habits of the two sibling species can help in designing optimal vector control strategies. hence, a survey was conducted in sri lanka to study the preferentia ... | 2005 | 16161699 |
| physico-chemical characteristics of anopheles culicifacies and anopheles varuna breeding water in a dry zone stream in sri lanka. | selected physico-chemical characteristics of flowing and pooled water in a stream that generated two malaria vectors, anopheles culicifacies s.l. giles and anopheles varuna iyengar, were investigated during august-september 1997 and july 1998 at the upper yan oya watershed in north-central sri lanka. | 2005 | 16161702 |
| food of larval anopheles culicifacies and anopheles varuna in a stream habitat in sri lanka. | no previous studies have been conducted on the natural food of larval anopheles culicifacies s.l. (the major malaria vector) and an. varuna (a secondary vector) in sri lanka. the present study analyzed the contents of guts dissected from larvae collected from pools in a natural stream-cum-irrigation conveyance channel in the upper yan oya watershed in the north central province of the country during august-september 1997 and july 1998. determinations of physicochemical and biological parameters ... | 2005 | 16506563 |
| anopheles culicifacies sibling species b and e in sri lanka differ in longevity and in their susceptibility to malaria parasite infection and common insecticides. | members of the anopheles culicifacies giles complex (diptera: culicidae) are well established as the predominant vectors of malaria in sri lanka. until recently, only sibling species b was reported to be present in sri lanka, which was surprising as species b is a poor vector of malaria in india. this was clarified by the identification through y-chromosome morphology that what was reported as b on the island is really a mixture of b and e. the fecundity, longevity and insecticide resistance of ... | 2006 | 16608500 |
| multiple insecticide resistance mechanisms involving metabolic changes and insensitive target sites selected in anopheline vectors of malaria in sri lanka. | the current status of insecticide resistance and the underlying resistance mechanisms were studied in the major vector of malaria, anopheles culicifacies, and the secondary vector, anopheles subpictus in five districts (anuradhapura, kurunegala, moneragala, puttalam and trincomalee) of sri lanka. eight other anophelines, anopheles annularis, anopheles barbirostris, anopheles jamesii, anopheles nigerrimus, anopheles peditaeniatus, anopheles tessellatus, anopheles vagus and anopheles varuna from a ... | 2008 | 18755020 |
| anopheles culicifacies breeding in brackish waters in sri lanka and implications for malaria control. | anopheles culicifacies is the major vector of both falciparum and vivax malaria in sri lanka, while anopheles subpictus and certain other species function as secondary vectors. in sri lanka, an. culicifacies is present as a species complex consisting of species b and e, while an. subpictus exists as a complex of species a-d. the freshwater breeding habit of an. culicifacies is well established. in order to further characterize the breeding sites of the major malaria vectors in sri lanka, a limit ... | 2010 | 20409313 |