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a study of the host selection patterns of the mosquitoes of the kisumu area of kenya.the results of 12,168 precipitin tests on blood meals of mosquitoes of the kano plain caught by a variety of catching techniques indicate that to gain an accurate overall picture of feeding patterns both the indoor and the outdoor biotope must be sampled. cdc light traps operated inside houses and monkswood type light traps operated under the outside eaves of houses were found to collect larger numbers of blood fed specimens from a wider range of species than battery driven aspirators collecting ...19752997
incidence of arbovirus isolated from mosquitoes in the forest region of south cameroun, region of yaoundé .the authors give results of a survey of arboviruses isolated from mosquitoes in the neighborhood of yaoundé, southern cameroon, from 1964 to 1972. during this period of nine years 127.520 female mosquitoes including at least 72 species were collected and processed for attempt of virus isolation. 55 strains belonging to 12 viral types were recovered from at least 19 species of mosquitoes. the appearance of different viruses over the years was quite intermittent. a possible reason for this is the ...197616703
the incidence of mosquitoes feeding on mothers and babies at kisumu, kenya.blood fed mosquitoes were collected inside four bed nets in which mother/child pairs, having different haptoglobin types, slept. the bloodmeals were analysed by gradient gel electrophoresis to determine on which person the mosquitoes had fed. the results suggest that the mothers are fed on much more than babies by both anopheles gambiae s.l. and culex fatigans. in one hut at least 15.2 per cent of the mosquitoes had taken all or part of their bloodmeal elsewhere. a greater number of double feeds ...197825970
assessment of insecticidal impact on the malaria mosquito's vectorial capacity, from data on the man-biting rate and age-composition.the reduction in average age of a vector population after application of a residual insecticide is commonly interpreted under the implicit assumption that the vector population is uniformly exposed to the insecticide. this assumption maximizes the calculated impact of the insecticide on the vectorial capacity. an alternative assumption, namely that the vector population is composed of two subpopulations, one endophilic and exposed, the other exophilic and not exposed, leads to a much smaller cal ...1979312159
studies on multiple feeding by anopheles gambiae s.l. in a sudan savanna area of north nigeria.the detection of haptoglobins in anopheles gambiae s.l. has been used to obtain an estimate of the incidence of multiple feeding for the village of barmawa, garki district, kano state, nigeria. the results indicated that the incidence of multiple feeding was approximately 10% but problems were encountered by the high incidence of ahaptoglobinaemia in the population. in four villages in garki district the incidence of ahaptoglobinaemia varied between 65 and 76% while in young children and personn ...1979555069
evaluation of some parameters of house-leaving behaviour of anopheles gambiae s.l. 1977617923
the impact of propoxur on anopheles gambiae s.1. and some other anopheline populations, and its relationship with some pre-spraying variables.a significant and stable difference in the residual night-biting collection (nbc, observed/expected) of a. gambiae s.l. was observed among different villages of the west african savannah when sprayed for 2 years with propoxur. the residual mosquito density of a given village was positively associated with some of its pre-spraying characteristics: the nbc/psc (pyrethrum spray collections) ratio, the median biting hour, and possibly the proportion of species b. it was not significantly associated ...19761088351
[comparative efficacy of the use of cdc light traps and humans to sampling anopheles populations. results obtained in the area of bignona (senegal)].the simultaneous use for the purpose of comparison of human bait catch and light trap collection for sampling anopheles populations specially the anopheles gambiae s.l. in the area of bignona, senegal shows that: light traps provide more information on the specific composition of anopheles fauna; the performance of light traps and that of human baits are comparable indoor during the period of high density of anopheles. outdoor, light traps catch fourth less females a. gambiae. but the two method ...19921327361
evaluation of the residual efficacy of permethrin-impregnated screens used against mosquitoes in marigat, baringo district, kenya.insecticide-impregnated screens and bednets are gradually finding wider use in malaria control programmes. the efficacy of these devices is dependent on the method of application, the acceptability by the people and effectiveness of the insecticide used. the present studies were carried out to determine the duration of the effectiveness of a permethrin-impregnated wall cloth (mbu cloth) used in the marigat area of baringo district, kenya in order to ensure its effective use. cotton cloth impregn ...19921363445
detection of human antibodies against plasmodium falciparum antigens in blood meals of anopheline mosquitoes.human igg antibodies against plasmodium falciparum asexual stages, gametocytes and sporozoites were detected by indirect fluorescent antibody (ifa) techniques in the blood meals of anopheles gambiae s.l. from a malaria-endemic area of western kenya. field-collected mosquitoes, which had been stored dry for over 2 years, were screened first for human igg by elisa. in 141 blood meal samples from human-fed mosquitoes, the prevalence of stage-specific antibodies was 87.9% for asexual-stage parasites ...19921402862
relationship between body size of adult anopheles gambiae s.l. and infection with the malaria parasite plasmodium falciparum.the influence of adult female body size of anopheles gambiae s.l. on development of midgut and salivary gland infections by the parasite plasmodium falciparum was investigated in a field study carried out in tanzania. the proportion of mosquitoes infected during a blood meal was independent of size. however, the number of oocysts harboured by infected mosquitoes increased with size of the mosquito. the proportion of mosquitoes with sporozoites, and thus potentially infective to humans, was highe ...19921594289
ookinete rates in afrotropical anopheline mosquitoes as a measure of human malaria infectiousness.anopheles gambiae s.1. and an. funestus were sampled for plasmodium spp. ookinetes in two p. falciparum-endemic sites in western kenya. since the ookinete is a transitional stage of short duration, occurring after fertilization and before oocyst development, only females in the half-gravid and gravid stages of blood digestion were examined. preparations of homogenized midguts were spotted onto microslides and examined microscopically after staining with giemsa. overall, ookinetes were detected i ...19921636882
trial of pyrethroid impregnated bednets in an area of tanzania holoendemic for malaria. part 2. effects on the malaria vector population.the malaria vector population consisted mainly of anopheles gambiae s.s. with a small contribution from an. funestus and an. rivulorum. the mosquitoes coming to bite in bedrooms were monitored with light traps set beside untreated bednets. when impregnated bednets were provided for all the other beds in a village the anopheles populations declined but the culex quinquefasciatus populations were unaffected. the survival of an. gambiae (as measured by the mean number of ovarian dilatations) and th ...19911680284
transmission and epidemiology of newly transmitted falciparum malaria in the central highland plateaux of madagascar.the recent reappearance of plasmodium falciparum in the central highland plateaux of madagascar has led to an important increase in both morbidity and mortality in the population. to understand the phenomena that originated this outbreak, and to evaluate the clinical and biological reactions of the population, we conducted entomological surveys during the whole malaria transmission season of 1988. in parallel, 41 individuals presenting with a malaria attack in january were given a curative antim ...19911746977
human malaria infectiousness measured by age-specific sporozoite rates in anopheles gambiae in tanzania.in an area of holoendemic malaria in northern tanzania, anopheles gambiae s.l. females were age-graded by polovodova's method and dissected for sporozoites. age-specific sporozoite rates implied that mosquitoes acquired new infections at all ages. the extrinsic period lasted just over 3 gonotrophic cycles (9-11 days). very high sporozoite rates in the oldest females implied the absence or rarity of genetic refractoriness to infection. a method is described for estimating the proportion of bloodm ...19911852484
[impact of the use of larvivorous fish poecilia reticulata on the transmission of malaria in fir of comoros].field tests were conducted in the grande comore island, federal islamic republic of comoros, in order to evaluate the potential of the larvivorous fish poecilia reticulata for the control of the malaria vector anopheles gambiae s.s. due to the high permeability of soil, anopheles breeding sites in all island occurs only in the man-made water reservoirs. the study was carried out from november 1987 to november 1988 within a framework of a malaria and filariasis control programme, supported by who ...19911952700
[the maintenance of malaria eradication in reunion island (1979-1990)].malaria, which first occurred in reunion in 1868, was eradicated from the island in 1979, as a result of eradication campaigns conducted since 1949. reunion is now in a state of "anophelism without malaria". however, relations with nearby countries with a high malaria potential (madagascar, comoros) are responsible for a regular increase in the number of annual cases of imported malaria. this increase, associated with the appearance of chloroquine-resistance in the indian ocean area, illustrates ...19911958106
anopheles gambiae complex egg-stage survival in dry soil from larval development sites in western kenya.the potential for anopheles egg survival in dry soil from larval development sites was investigated in western kenya. a total of 230 dry soil samples collected in 1987, 1988 and 1989 yielded 126 first-instar anopheles gambiae s.l. larvae from 2 to 5 days after flooding with water. these larvae were from dried animal hoofprints along streams (57.9%), from dried edges of permanent and temporary pools (41.3%) and from dried stream beds (0.8%). larval density was 1.2 larvae/kg of soil from positive ...19902324714
variation in frequency in breeding of anopheles gambiae s.l. and its relationship with in-door adult mosquito density in various localities in accra, ghana.the work reported in this paper was undertaken to determine whether in a large urban area like accra, emerging anopheles gambiae s.l. adults are likely to invade the nearest houses to obtain a blood meal. using data from previous studies, the frequency in breeding was compared with adult density graphically and by scatter diagrams. graphically, frequency in breeding was associated with adult density in eight districts while on the geometric scatter plot, these parameters were associated in ten d ...19902390955
seasonal population changes and malaria transmission potential of anopheles pharoensis and the minor anophelines in mwea irrigation scheme, kenya.a study in 1984 and 1985 showed that anopheles gambiae s.l. and an. pharoensis were the major anophelines in mwea irrigation scheme, kenya, constituting 83.86% and 15.69% of the catch respectively. four minor species made up the remaining 0.45%. the irrigation phase of the rice cultivation cycle in august, which linked the flooding effects of the two rainy seasons, resulted in major population increases of an. pharoensis and enabled continuous breeding for up to 9 months per year. the average of ...19892566271
[the effect of 2 chloroquine-based drug strategies (prevention and therapy of febrile cases] on malaria transmission].a 3 years study was decided in 12 villages of the south-west burkina faso to compare the chemoprophylaxis and the chemotherapy of febrile cases as potential malaria control strategies. during the first year pretreatment data were collected. during the two following years a programme carried out (i) prophylaxis (10 mg chloroquine/kg body weight) was given weekly to all children under 14 years old in 5 villages, and (ii) therapy (10 mg chloroquine/kg body weight) was given in a single dose to all ...19892743528
bancroftian filariasis in the igwun basin, nigeria. an epidemiological, parasitological, and clinical study in relation to the transmission dynamics.a 12-month field and laboratory study was carried out to determine the epidemiology, clinical features, and transmission dynamics of bancroftian filariasis in the igwun basin, nigeria. a total of 1,418 individuals (768 males, and 650 females) were examined for clinical signs of filariasis. 690 day provocative blood samples (dps), and 728 night blood samples (nbs) were examined for microfilaremia. 14.3% of males and 11.1% of females were mf positive. 5.8% of dps, and 19.5% of the nbs were mf posi ...19882901204
[an ecologic study of adult and larval culicidae in a rice field of kou valley, burkino faso].an entomological survey based on collections of human bait mosquitoes and of mosquito larvae was carried out through one year in a rice-field, the kou valley of southwest burkina faso. each year, in this irrigated rice field there are two crops of rice, one during the dry season and another during the wet one. between the two rice cycles irrigation is interrupted and the rice field becomes dry. the rice crop cycle moves through several stages, all of which have positive or negative effects on th ...19882907262
identification of malaria species by elisa in sporozoite and oocyst infected anopheles from western kenya.enzyme-linked immunosorbent assays (elisas) for the circumsporozoite (cs) antigens of plasmodium falciparum, p. malariae, and p. ovale were used to identify species of sporozoite and oocyst infections detected by dissection in anopheles gambiae s.1. and an. funestus collected in western kenya. elisas identified 92.5% of 1,113 salivary gland infections; plasmodium species infections included 79.4% p. falciparum, 3.2% p. malariae, 1.7% p. ovale, and 2 or more plasmodium species were detected in 15 ...19883056055
[larvivorous capacity of barbus pobeguini and possibility of using this in the fight against anopheles gambiae s.l].permanent breeding sites for anopheles gambiae s.l. were found to occur in the urban area of ouagadougou and to have some importance in the maintenance of vector populations. in these breeding places barbus pobeguini was found widespread and larvivorous as indicated by the presence of remnants of a. gambiae in its stomach contents. the use of b. pobeguini would avoid the introduction of non-local larvivorous fishes. a series of trials carried out in laboratory conditions with b. pobeguini of dif ...19883271991
detection and anatomical localization of plasmodium falciparum circumsporozoite protein and sporozoites in the afrotropical malaria vector anopheles gambiae s.l.salivary glands from anopheles gambiae s.l. collected in burkina faso, west africa, were analyzed by both microscopic examination and immunoradiometric assay to determine the plasmodium falciparum sporozoite rates. using the same mosquito samples, the immunoassay revealed positive salivary glands with low sporozoite loads, which were frequently missed by microscopy. a closer agreement between both techniques was found using salivary glands with high sporozoite loads. we also found a number of mo ...19873318517
field observations on the use of anti-sporozoite monoclonal antibodies for determination of infection rates in malaria vectors.samples of indoor-resting anopheles gambiae s.1. from mali and burkina faso (west africa) were processed in order to compare plasmodium falciparum sporozoite rates obtained by immunoradiometric assay (irma) with circumsporozoite (cs) monoclonal antibody and by microscope examination of salivary glands. the immunological method provided sporozoite rates always higher than those obtained by microscope examination. this result does not appear to be related to cross-reactions involving non-sporozoit ...19863332042
cs antigen localization in malaria vectors: hypothetical refractoriness to transmission observed in the field.indoor resting anopheles gambiae s.l. were collected in two villages near ouagadougou, burkina faso, and processed to investigate the presence and distribution of plasmodium sporozoites. salivary glands were dissected, examined by phase contrast microscopy and further processed by irma in order to reveal the presence of the circumsporozoite (cs) antigen of p. falciparum. the corresponding thoraces were homogenized and processed by irma. in the village characterized by the higher inoculation rate ...19863332304
[a longitudinal entomologic survey on the transmission of malaria in ouagadougou (burkina faso)].a longitudinal entomological malaria survey was carried out in five zones of the town of ouagadougou, burkina faso, and in three neighbouring villages. the main vector is anopheles gambiae s.l. with an. funestus having a role in some localities during the dry season. pyrethrum spray catches were carried out once or twice per month to determine variations in vector density. inoculation rates were estimated from the number of blood-fed vectors per man and from the sporozoite rates. larval sampling ...19863455529
[dispersion of anopheles gambiae s.l. in an urban zone of ouagadougou (burkina faso)].dispersion of anopheles gambiae s.l. from larval breeding places was examined in the town of ougadougou, burkina faso. a suitable study area was chosen, characterized by high concentration of larval breeding places along a water reservoir. mosquito density per room was calculated from the results of pyrethrum spray catches carried out on a series of seven groups of collecting stations along a transect from 100 to 1050 m from the water reservoir area. high density and uniform distribution of hous ...19863455531
[chromosomal study of anopheles gambiae and anopheles arabiensis in ouagadougou (burkina faso) and various neighboring villages].adult females of anopheles gambiae s.1. were collected by pyrethrum spray catch in ouagadougou (burkina faso, formerly upper volta) and in four neighbouring villages. the collections have been carried out mostly during the 1984 rainy season. monthly collections in some sampling sites allowed a preliminary longitudinal study. by analysis of nurse cell polytene chromosomes in adult females, an. gambiae s.str. and an. arabiensis were identified in the study area. both species showed polymorphisms f ...19863455532
insecticide susceptibility levels of anopheles gambiae s.l. in the area of ouagadougou, burkina faso.tests to evaluate the susceptibility level in anopheles gambiae s.1. from ouagadougou and two nearby villages have been carried out. anopheles gambiae s.1. larvae from ouagadougou showed complete susceptibility to organophosphates and carbamates, and adults showed low-level resistance to ddt. nine percent survival of adult an. gambiae s.1. to one-hour exposure of 4% ddt was observed in samples from zagtouli village while in those from koubri village, where dieldrin also was tested, resistance to ...19863455533
laboratory and field efficacy of bacillus thuringiensis var. israelensis and bacillus sphaericus against anopheles gambiae s.l. and culex quinquefasciatus in ouagadougou, burkina faso.two wettable powders (bactimos and vectobac) and one flowable concentrate (teknar) of bacillus thuringiensis var. israelensis (b.t.i.) and primary powders of bacillus sphaericus isolates 1593 and 2362 were evaluated (laboratory) against field-collected larvae of anopheles gambiae s.l. and culex quinquefasciatus in ouagadougou, burkina faso. bactimos, vectobac and a corn-cob b.t.i. formulation (abg-6138g) were field tested against cx. quinquefasciatus and an. gambiae s.l. the isolates of b. sphae ...19873504891
studies on insecticide susceptibility of anopheles gambiae s.1. and culex quinquefasciatus in the area of ouagadougou, burkina faso (west africa).tests to evaluate the susceptibility level in anopheles gambiae s.1. and culex quinquefasciatus from ouagadougou and two nearby villages have been carried out. anopheles gambiae s.1. larvae from ouagadougou showed complete susceptibility to organophosphates and carbamates, and adults showed low level resistance to ddt. nine percent survival of adult an. gambiae s.1. to one hour exposure of 4% ddt was observed in samples from zaghtouli village while in those from koubri village, where dieldrin al ...19863507503
field evaluation of an enzyme-linked immunosorbent assay (elisa) for plasmodium falciparum sporozoite detection in anopheline mosquitoes from kenya.an enzyme-linked immunosorbent assay (elisa) using a monoclonal antibody that recognizes a repetitive epitope on the circumsporozoite protein of plasmodium falciparum was used in kenya to assess malaria infections in anopheles gambiae s.l. and an. funestus. the elisa confirmed that 88% of 44 sporozoite-positive gland dissections were p. falciparum. the elisa infection rate of 18.6% (n = 736) for individually tested mosquitoes for both species was significantly higher than the 10.4% (n = 537) sal ...19873555134
[levels of sensitivity of anopheles gambiae s.l. to traditional insecticides and evaluation of the efficiency of bacillus thuringiensis var. israelensis and bacillus sphaericus]. 19863752796
[laboratory observation of inversion polymorphisms originating from the crossing of various populations of anopheles gambiae s.s]. 19863752798
preliminary investigation on the use of a light-trap for sampling malaria vectors in the gambia.light-traps have been used successfully as mechanical sampling tools for insects of agricultural importance but medical entomologists have had only limited success because of the assumption that light-traps would attract vectors, even when sited in open fields well away from hosts. the investigations reported in this paper suggest that vectors are attracted primarily by their hosts and that only when light-traps are placed in the immediate vicinity of hosts, or in the narrow flight paths followe ...19695306720
mosquito production and species succession from an area of irrigated rice fields in the gambia, west africa.the succession of mosquito species and their abundance was observed through one cycle of dry-season irrigated rice cultivation near bansang in the gambia. the study covered a 21-week period, february-june 1975. mosquitoes were sampled using a single suction trap located in a dry field beside the rice fields. few mosquitoes were present before irrigation began. anopheles gambiae s.1., a. rufipes and culex neavei reached peak numbers 4 weeks after full-scale irrigation began and then declined in a ...19836142963
first field trial of an immunoradiometric assay for the detection of malaria sporozoites in mosquitoes.an immunoradiometric assay (irma) using a monoclonal antibody to the major surface protein of plasmodium falciparum sporozoites was used to assess the p. falciparum sporozoite rate in a west african population of anopheles gambiae (s.1.). unlike current dissection techniques, the irma could detect sporozoite antigen in dried as well as fresh mosquitoes. in a controlled comparison, the sensitivity of the irma was comparable that of the dissection technique. additionally, the irma was species spec ...19846383093
vector control operations in the african context.in order to define the scope of vector control as a component of malaria control in the who african region, examples of recent experiences with different vector control methods in this region are reviewed. residual house spraying applied alone or in combination with mass drug administration has failed to interrupt malaria transmission in savanna areas for several technical and administrative reasons. nevertheless, there is evidence that residual house spraying has led to an improvement in genera ...19846397279
oviposition by african malaria vector mosquitoes. ii. effects of site tone, water type and conspecific immatures on target selection by freshwater anopheles gambiae giles, sensu lato.females of anopheles gambiae s. lat., most of which would have been a. gambiae s. str., were collected from houses in coastal kenya and tested for their oviposition preferences using petri dishes in large laboratory cages with lighting equivalent to weak moonlight. significantly more eggs were laid overnight in water over black than over paler tones, and this difference increased as contrast with the surrounding floor was increased. direct observation revealed that over white targets, females ov ...19846486937
[sensitivity of anopheles gambiae s.l. to insecticides in the selingue dam area].in the selingue hydroelectric dam area the an. gambiae complex members are susceptible to ddt, resistant to dieldrin (the adults mainly) and also susceptible to temephos, chlorpyrifos, fenthion, fenitrothion and malathion. the lc50 of the larvae for fenthion is 0.00325 ppm. due to the abundance of an. gambiae s.s. in this area (nearly 98%), it is probable that these data refer mainly to this species. recent cytogenetic studies have shown that this species is composed of three chromosomal types ( ...19846600005
studies on the use of a membrane feeding technique for infecting anopheles gambiae with plasmodium falciparum.an investigation was made of the optimum feeding time when using stirred membrane feeders for infecting anopheles gambiae s.s. with plasmodium falciparum. the aim was to stimulate the natural situation of direct feeding on a host and so enable the malaria susceptibility of different populations of a. gambiae to be assessed. 45 feeds were carried out on blood donated by p. falciparum gametocyte carriers. the results show that only patients with at least 300 gametocytes/mm3 are likely to produce a ...19807010696
plasmodium berghei: selection of mefloquine-resistant parasites through drug pressure in mosquitoes.mefloquine is an antimalarial drug with schizonticidal activity on blood-stage parasites. studies of the role of mefloquine on the development of plasmodium berghei anka in anopheles stephensi have been carried out that showed a dose-dependent effect on the sporogonic cycle of these parasites, with changes in the numbers of oocysts and the extent of sporozoite invasion of salivary glands. in this study, we show that mefloquine-resistant p. berghei anka blood stage parasites could be selected thr ...19957628567
entomological evaluation of the gambia's national impregnated bednet programme.entomological studies were conducted in paired study villages in three of the five study areas used for the epidemiological assessment of the gambia's national impregnated bednet programme. baseline data collected in 1991 were compared with post-intervention data from 1992, when one of each village pair (from areas ii, iii and v) was included in the treatment programme in which villagers' nets were dipped in permethrin. in a longitudinal study, indoor-resting densities of anopheles gambiae s.l. ...19957668914
relationships between plasmodium falciparum transmission by vector populations and the incidence of severe disease at nine sites on the kenyan coast.the transmission of plasmodium falciparum was studied in relation to the incidence of severe malaria infections at nine sites in the kilifi district in kenya. intensive mosquito sampling during a one-year period yielded anopheles gambiae s. l., an. funestus, an. coustani, an. squamosus, an. nili, and an. pharoensis. anopheles gambiae s.l. was the predominant vector, comprising 98.4% of the total anophelines collected. overall, 3.5% of 2,868 an. gambiae s.l. collected indoors and 0.8% of 261 coll ...19957694959
origin of blood meals in indoor and outdoor resting malaria vectors in western kenya.blood meals were obtained from indoor and outdoor resting malaria vectors in three villages of western kenya and tested by sandwich elisa to determine host preferences and their human blood index (hbi). anopheles gambiae s.s. collected indoors at kisian village had a hbi of 0.97 while that of anopheles arabiensis collected at ahero was 0.23. however, the hbi of a. arabiensis varied depending on the availability of outdoor resting shelters. most female a. arabiensis (98.9%) collected outdoors in ...19947709869
detection of falciparum malarial forms in naturally infected anophelines in cameroon using a fluorescent anti-25-kd monoclonal antibody.anopheles gambiae s.s. and an. funestus were sampled in houses located in a plasmodium falciparum-holoendemic site in southern cameroon. the midguts of female mosquitoes in half-gravid or gravid stages of blood digestion were incubated with a fluorescent monoclonal antibody directed against the p. falciparum zygote/ookinete surface protein pfs25 and examined using a fluorescent light microscope. malarial forms were detected in 11.6% of the half-gravid mosquitoes and in 0.0% of the gravid ones (p ...19957741180
[aspects of malaria in a village of the humid savannah of the ivory coast].malaria is a major cause of morbidity and mortality in ivory coast. this fact justifies further epidemiological investigations to define regional features and allow implementation of the most suitable control measures. to this end, a study focusing on transmission of malaria was conducted between january and may 1993 concurrently with malarial parasite identification in allokoukro, a village in the humid savannah in the central region of ivory coast. two vectors of malaria were found in the vill ...19947746125
[effectiveness of coils and mats for protection against malaria vectors in cameroon].the evaluation of the effectiveness of coils and mats on mosquitoes, especially malaria vectors was carried out in the southern cameroon. the study was performed in the nsimalen village from november 1993 to august 1994. two brands of coils: timor and moon tiger containing 0.15% w/w of esbiothrin and two brands of mats: ars mats (containing d-allethrin) and moon tiger (with s biothrin and diethyl-toluamide) were tested. the evaluation was based on night catches on human bait inside houses. a cat ...19957780671
mapping the densities of malaria vectors within a single village.small scale spatial variation and temporal heterogeneity in mosquito densities can have important consequences for disease transmission, but the extreme variation which is observed in populations of malaria vectors makes it difficult to obtain good predictions of densities for short time periods over limited areas. we have applied bayesian techniques derived for use in cancer epidemiology in order to map densities of anopheles gambiae s.l. and a. funestus in a tanzanian village where there is in ...19957785522
the effect of woodsmoke on the feeding and resting behaviour of anopheles gambiae s.s. 19947810390
selection of biting sites on man by two malaria mosquito species.while searching for blood, female mosquitoes pass through a behavioural process involving responses to visual, physical and chemical properties of the host. temperature and humidity are thought to dominate mosquito orientation near the host. we observed that biting of two malaria mosquito species, i.e. anopheles atroparvus (van thiel) and anopheles gambiae s.s. (giles) preferentially occurs on different body regions of a naked motionless human host. their preference for the head and foot regions ...19957843335
malaria prevalence is inversely related to vector density in the gambia, west africa.baseline epidemiological and entomological studies were conducted in 5 different areas of the gambia before the introduction of a national malaria control programme, the objective of which was to treat all the bed nets belonging to people living in primary health care villages with insecticide. all malariometric indices used (parasite density, parasite rates, splenomegaly, and packed cell volume) indicated that malaria transmission was more intense in the east of the country than elsewhere. high ...19947886754
ecological genetic studies in the chromosomal form mopti of anopheles gambiae s.str. in mali, west africa.among the sibling species of the afrotropical anopheles gambiae complex, the nominal taxon (an. gambiae s.str.) is the major malaria vector. its bionomics suggest a man-dependent speciation process which involves, in west africa, various incipient species chromosomally recognized by different combinations of 2r paracentric inversions. one of the most recent evolutionary steps of such a speciation process appears to be the chromosomal form mopti, which is associated with dry season irrigation in ...19947896141
a new odour-baited trap to collect host-seeking mosquitoes.a new odour-baited entry trap which releases an air stream containing chemical cues collected from a bait, has been used successfully to collect west african mosquito species, most of them important vectors of malaria, such as anopheles gambiae s.l. and an. funestus. 85% of the yield consisted of live, unfed and partially fed specimens. the trap has some practical and theoretical advantages over similar sampling techniques.19937915027
relationship between prevalence and intensity of plasmodium falciparum infection in natural populations of anopheles mosquitoes.wild-caught anopheles gambiae s. l. and an. funestus were dissected and their midguts were examined for the presence of plasmodium falciparum oocyst infections. the mean intensity of infection and the prevalence of infected mosquitoes were determined for each sample, with one sample representing the mosquitoes caught in a single house at any given time. the patterns of infection were investigated using the relationships between prevalence, intensity, and variance within samples, and were found t ...19947943543
malaria in a rural area of sierra leone. iii. vector ecology and disease transmission.studies were undertaken on the role of anopheles gambiae and an. funestus in the transmission of malaria in four villages in a high-rainfall, forested area in the bo district of southern sierra leone. anopheles gambiae s.s., identified chromosomally as the forest form, was the most important vector, with a mean annual sporozoite rate, based on elisa, of 7.4%. anopheles funestus, which was found in considerably lower numbers, was mainly a dry season vector, with an annual sporozoite rate of 11.4% ...19947944670
do mosquito coils and killer sticks work against anopheles gambiae sensu lato mosquitoes in zimbabwe?tests against anopheles gambiae s. 1. mosquitoes (malaria transmitting mosquitoes) were carried out in chegutu, chiredzi and kamhororo (gokwe). these tests were done in relatively closed rural huts and experimental huts. the tests demonstrated that a one hour exposure to smoke from the burning of insecticidal coils contain 0.3 pc pyrethrin, achieve 100 pc knockdown of mosquitoes. mosquito killer sticks gave 85 pc knockdowns with 30 pc recoveries and less than 10 pc recoveries for the coils. with ...19947954723
the dielmo project: a longitudinal study of natural malaria infection and the mechanisms of protective immunity in a community living in a holoendemic area of senegal.the dielmo project, initiated in 1990, consisted of long-term investigations on host-parasite relationships and the mechanisms of protective immunity in the 247 residents of a senegalese village in which malaria is holoendemic. anopheles gambiae s.l. and an. funestus constituted more than 98% of 11,685 anophelines collected and were present all year round. inoculation rates of plasmodium falciparum, p. malariae, and p. ovale averaged respectively 0.51, 0.10, and 0.04 infective bites per person p ...19948074247
field testing an enzyme-linked synthetic oligonucleotide probe for identification of anopheles gambiae s.s. and an. arabiensis.tests were carried out in kenya to determine whether the enzyme-linked synthetic oligonucleotide probe (pana 1) developed for identifying species of the anopheles gambiae complex could be used under field conditions. the an. arabiensis male-specific pana 1 probe was able to identify all male larval instars and adult males. however, the non-radioactive assay was not sufficiently sensitive to identify male sperm dna in all the mated female an. arabiensis. although the ratio of an. arabiensis to an ...19938122921
resistance of anopheles gambiae s.s. to pyrethroids in côte d'ivoire. 19938129474
species composition and inversion polymorphism of the anopheles gambiae complex in some sites of ghana, west africa.samples of anopheles gambiae s.1. were collected from eight localities belonging to four of the five main ecological strata of ghana. analysis of ovarian polytene chromosomes revealed the presence of a. gambiae s.s. in all the sites studied, while a. arabiensis was detected only in the extreme northern locality of navrongo and a. melas in some southern sites. anopheles arabiensis showed a degree of inversion polymorphism comparable to the one observed in other west african countries. the analysi ...19948203292
the ecology and behaviour of the forest form of anopheles gambiae s.s.studies on the ecology of anopheles gambiae s.s. and the transmission of malaria were undertaken in a high rainfall forested area in southern sierra leone. anopheles gambiae s.s., identified by chromosomal techniques as the forest form, was the only malaria vector in the study village. surprisingly, rice fields or swamps were not favoured breeding places for this species; breeding mainly occurred in temporary pools. the mean annual sporozoite rate of an. gambiae s.s. determined by elisa was 3.9% ...19938233612
polytene chromosome microdissection and molecular genome mapping in drosophila and other dipterans.we are constructing a molecular physical map of the drosophila melanogaster genome, using microdissection of polytene chromosomes as a source of region specific probes applied to direct mapping work. chromosome microdissection has been used for a low resolution map of the anopheles gambiae s.s. genome.19938233623
evaluation of light traps for sampling anopheline mosquitoes in kilifi, kenya.anopheline mosquitoes were sampled inside houses, where residents slept under untreated bednets, by cdc light traps and human-biting catches to evaluate light traps as a means for determining human exposure to malaria vectors in kilifi district, kenya. mosquitoes were sampled during 2 all-night collections by light traps and one all-night biting catch in a series of 262 houses. collections yielded 1,721 anopheles gambiae s.l. and 46 an. funestus, and 60.3% of the houses were negative for anophel ...19938245934
visual assessment of sporozoite elisa results is as reliable as a plate reader in determining infection rates in field samples of anopheles gambiae s.s. 19938266421
entomological risk factors for severe malaria in a peri-urban area of the gambia.a study was undertaken of possible entomological risk factors for severe malaria in a peri-urban area of the gambia. households of children who had experienced a severe or a mild attack of malaria and of matched controls were visited and their characteristics recorded. mosquitoes were then collected in the bedrooms of study subjects using both insecticide spray catches and light traps. mud-walled buildings and bedrooms without ceilings were found more frequently in the households of children who ...19938311575
bloodfeeding behavior of anopheles gambiae s.l. and anopheles funestus in kilifi district, kenya.blood meal samples were tested by elisa for 534 anopheles gambiae s.l. and 76 anopheles funestus collected from 25 sites in kilifi district, kenya. human igg was detected in 94.4% of the an. gambiae s.l. and in 90.8% of the an. funestus. no samples were positive for cow and only a few were positive for goat. both species fed predominantly on humans irrespective of host availability. at these sites on the kenyan coast, the high degree of human-feeding by malaria vectors contributes to the efficie ...19938350080
low-level plasmodium falciparum transmission and the incidence of severe malaria infections on the kenyan coast.the transmission of plasmodium falciparum was studied in relation to the incidence of severe malaria infections at sokoke and kilifi town, kilifi district, kenya. intensive mosquito sampling during a one-year period yielded anopheles gambiae s.l., an. funestus, and an. coustani. anopheles gambiae s.l. was the predominant vector, comprising 87.9% and 97.9% of the total anophelines collected in sokoke and kilifi town, respectively. the proportion of an. gambiae s.l. with p. falciparum sporozoite i ...19938357087
prospects for the use of larvivorous fish for malaria control in ethiopia: search for indigenous species and evaluation of their feeding capacity for mosquito larvae.because of problems with drug and insecticide resistance, the national organization for the control of malaria and other vectorborne diseases, ethiopia, has embarked on a programme of research on alternative malaria control methods, including the use of biological control agents, such as larvivorous fish. the objectives of the study were to identify indigenous larvivorous fish species which could be potential candidates for use as biological control agents; to extend knowledge of their distribut ...19938429570
experimental infection of anopheles gambiae s.s., anopheles freeborni and anopheles stephensi with plasmodium malariae and plasmodium brasilianum.susceptibility to infection of 2 strains of anopheles gambiae s.s., an. freeborni and an. stephensi, was determined for 2 closely related malaria parasites, plasmodium malariae and p. brasilianum. neither strain of an. gambiae supported development of oocyst densities as great as the other 2 anopheline mosquitoes. the zan strain of an. gambiae s.s. from zanzibar was more susceptible to infection with the strain of p. malariae from uganda than the g-3 strain of an. gambiae s.s. from the gambia. a ...19938468576
baseline entomological data for a pilot malaria control program in equatorial guinea.entomological studies conducted on the island of bioko and the mainland province, río muni, in equatorial guinea provided baseline data for a pilot malaria control program. the main species collected resting in houses at low density were anopheles gambiae s.l. giles and anopheles funestus giles. an. gambiae s.l. density increased during the rainy season, whereas an. funestus populations remained stable during both dry and wet seasons. both species tended to be endophilic and were not collected r ...19938510123
malaria epidemiology in the province of moyen ogoov, gabon.in the course of epidemiological and immunological baseline studies parasitological surveys were conducted, in 1992, in three localities situated in our near rain forest in the area of lambaréné, gabon, western central africa. anopheles gambiae s.s. and a. funestus are considered to be the main vectors of malaria. the three localities represent strata with obvious differences in the intensity of malaria transmission. the lowest parasite rates were recorded in the village around the albert-schwei ...19958525289
vectorial capacity and entomological inoculation rates of anopheles gambiae in a high rainfall forested area of southern sierra leone.we report the first study of gonotrophic cycle duration, survival rates, pre-gravid rates, vectorial capacity and chromosomal polymorphism of anopheles gambiae s.s. in sierra leone. in the village of bayama in the southern province, an. gambiae was the only species found to be naturally infected with plasmodium falciparum and it constituted 99.7% of 22,541 anopheline mosquitoes caught. chromosomal studies revealed only an. gambiae s.s. out of 66 females examined for chromosomal polymorphism, 61 ...19958533019
olfactory responses of host-seeking anopheles gambiae s.s. giles (diptera: culicidae). 19958533668
movement of anopheles gambiae s.l. malaria vectors between villages in the gambia.movement of mosquitoes belonging to the anopheles gambiae complex (mixed wild populations of an.arabiensis, an.gambiae and an.melas) between three neighbouring rural villages in the gambia was investigated by mark-release-recapture. a total of 12,872 mosquitoes were collected in bednets, marked with a magenta fluorescent powder and released over a 15-day period in one of the villages. a further 15,507 mosquitoes were collected in exit traps, marked with a yellow powder and released over the same ...19958541594
the effect of permethrin-impregnated wall-curtains on malaria transmission and morbidity in the suburbs of maputo, mozambique.the effect of nylon-netting wall-curtains impregnated with 0.5 g permethrin/m2 upon the biting rate of malaria vectors (anopheles gambiae s.l. and an. funestus) and on the plasmodium falciparum parasite rate, and morbidity due to malaria in children under five and between five and fourteen years was tested in the maputo area. the curtains significantly lowered biting rates of both vector species inside curtained houses, but reduced inside resting and outside biting only in an. funestus. the perc ...19958592765
some observations on the biting behavior of anopheles gambiae s.s., anopheles arabiensis, and anopheles funestus and their implications for malaria control.studies were carried out in three villages in western kenya on the biting behavior of anopheles gambiae s.s., anopheles arabiensis, and anopheles funestus. blood feeding behavior and departure from houses were studied under the impact of permethrin-impregnated eaves-sisal curtains. only 2-13% of the female vector population was collected biting before 2200 hr. over 90% of the villagers went to bed by 2100 hr. an. funestus was 6.6-8.2 times more likely to bite people indoors than outdoors, while ...19968631382
frequent blood-feeding and restrictive sugar-feeding behavior enhance the malaria vector potential of anopheles gambiae s.l. and an. funestus (diptera:culicidae) in western kenya.natural blood-feeding and sugar-feeding behaviors were investigated for populations of anopheles gambiae s.l. and an. funestus giles at 2 sites in western kenya. during peak levels of malaria parasite transmission, > 85% of 1,569 indoor-resting females contained fresh blood meals. findings that up to 55.4% of blood-fed resting females and 72.0% of host-seeking females had either stage iv or v oocytes provided strong evidence that females were refeeding before oviposition. such gonotrophic discor ...19968699456
[epidemiology and control of malaria in the federal islamic republic of comoros].malaria constitutes a major public health problem in the federal islamic republic of comoros. this problem is relatively recent from the historical point of view of the archipelago. it represents 15 to 30% of the hospitalization cases and 15 to 20% of the registered deaths in the pediatric services. the epidemiological data collected show that the characteristics of malaria transmission continue for the stable type; however, the epidemiological situation varies from one island to another. the pr ...19958784541
[control of malaria re-emergence in reunion].réunion is currently posed with the operational problem of the last phase of the struggle against malaria, that is the consolidation and the maintenance of the state of cradication. the native parasite was eliminated, but the risk of resurgence of malaria remains on the island. this risk is even increasing from year to year because of the following: 1) the regular increase of the number of travellers originating from countries with malaria and consequently, the increase in the number of imported ...19958784548
malaria in côte d'ivoire wet savannah region: the entomological input.a two years study has been carried out in alloukoukro, a traditional wet savannah village in the central region of côte d'ivoire. the productive breeding sites of malaria vectors are natural puddles and some man-made shelters around the village. 576 man-nights of capture have identified anopheles gambiae s.l. and an. funestus as vectors of malaria in the study area. the low densities of an. phaorensis and an coustani implies that their possible role in transmission is very negligible. an. gambia ...19958826108
rapid isolation of anopheline mosquito eye-colour mutants, based on larval colour change.a method is presented for the rapid isolation of eye-colour mutants in anopheline mosquitoes based on their inability to undergo a background-stimulated morphological colour change. for application of this method, larval mosquitoes, whose grandfathers had been mutagenized, were reared in black containers and examined with the naked eye en masse during the third or fourth instar. the vast majority of larvae became dark-coloured; however, rare exceptional pale larvae were observed and examined ind ...19968834748
mosquito responses to carbon dioxide in a west african sudan savanna village.mosquito responses to carbon dioxide were investigated in noungou village, 30 km northeast of ouagadougou in the sudan savanna belt of burkina faso, west africa. species of primary interest were the main malaria vectors anopheles gambiae s.s. and an.arabiensis, sibling species belonging to the an.gambiae complex. data for an.funestus, an.pharoensis, culex quinquefasciatus and mansonia uniformis were also analysed. carbon dioxide was used at concentrations of 0.04-0.6% (cf. 0.03% ambient concentr ...19968887331
absence of relationships between selected human factors and natural infectivity of plasmodium falciparum to mosquitoes in an area of high transmission.the effects of sex, age of the human host, patency of asexual and sexual stages and seasonality on infectiousness of plasmodium falciparum to mosquitoes were investigated in a rural village in southern tanzania between 1992 and 1994. villagers from randomized subgroups of households were surveyed for malaria parasites. gametocyte and trophozoite prevalences were age dependent and fluctuated without any clear pattern of seasonality. a sample of 107 participants, selected to include an excess of g ...19968893528
field trial of permethrin impregnated sisal curtains in malaria control in western kenya.a trial to determine the effectiveness of sisal eaves-curtains impregnated with permethrin for malaria control was conducted in the malaria holoendemic western kenya between 1991 and 1993. indoor resting densities of anopheles gambiae s.l. and anopheles funestus were reduced by 90.9% and 93.8% respectively in protected houses. the entomological inoculation rate (eir) was reduced by 72% in the intervention village. there was no significant reduction in vector longevity or survival as shown by the ...19968997865
lymphatic filariasis on the coast of ghana.parasitological, clinical and entomological surveys for lymphatic filariasis were carried out in 6 villages and 3 towns on the coast of ghana. few or no filarial infections were observed in the towns or in the villages east of accra. however, wuchereria bancrofti microfilaraemia was common in the 4 western villages, with overall prevalences of 9.2%-25.4% and overall microfilariae (mf) geometric mean intensities of 321-1172 mf/ml of blood. in the same villages, hydrocele affected 8.5%-27.9% of ad ...19969015499
[impact of deltamethrin impregnated mosquito nets on the transmission of malaria in the coastal lagoon area, benin].we have measured the entomological impact of insecticide treated nets on malaria transmission at ganvie, a village in the coastal and lagoon area of benin. the nets we have impregnated belong to the population of this village. men and women of ganvie used the nets everyday against nuisance biting. then, the nets we have impregnated are not experimental nets introduced in the village. we have treated 3,230 nets, that means 79% of the nets of this village which counts 20,000 inhabitants. after tre ...19969053053
detection of plasmodium falciparum sporozoites in naturally infected anopheline species using a fluorescein-labelled dna probe.a dot blot hybridization method was developed to detect plasmodium falciparum sporozoites in naturally infected mosquitoes. a fluorescein-labelled oligomer was used as a probe. initial non-specific hybridization was found to correlate with the presence of blood in the mosquitoes. this was eliminated by allowing digestion of the engorged blood by keeping the mosquitoes in cages for 48 h before processing. the limit of detection of the hybridization assay was estimated to be about 500 sporozoites. ...19979083583
the effects of natural plasmodium falciparum infection on the fecundity and mortality of anopheles gambiae s. l. in north east tanzania.rodent and avian malaria parasites have been reported to have an adverse affect upon the reproductive fitness of mosquitoes. in order to determine whether fecundity reduction occurs in anopheles gambiae s. l. infected with human malaria a study of wild-caught mosquitoes was undertaken in the muheza district of north east tanzania. fully engorged, indoor resting females were collected daily for 4 months and maintained for 5 days. a sporozoite rate of 11.5% was detected for the whole collection an ...19979107019
indoor resting by outdoor biting females of anopheles gambiae complex (diptera:culicidae) in the sahel of northern senegal.three villages in the senegal river basin were selected to study the biting and resting behavior of anopheles gambiae s.l. in relation to human habits, rainfalls, and rice culture irrigation. all inhabitants sleep outside throughout the year, mainly under poor quality bednets. mosquitoes were collected host-seeking during the night on human bait outside and resting during the day inside and outside in pit shelters. an. gambiae s.s. and an. arabiensis fed mainly outside, the only place where host ...19979151491
malaria in mvumi, central tanzania and the in vivo response of plasmodium falciparum to chloroquine and sulphadoxine pyrimethamine.a study on the prevalence of malaria and the response of plasmodium falciparum to chloroquine and sulphadoxine-pyrimethamine was conducted in mvumi area of central tanzania. splenomegaly was observed at a rate of 62% and 36% in children and adults respectively. crude malaria parasite rate was 55.4% in children and 32% in adults. plasmodium falciparum accounted for the highest proportion (62.7%) of the malaria parasites in the area. this malaria parasite was sensitive to standard dosage of either ...19979185387
[role of culex quinquefasciatus in the transmission of bancroftian filariasis in the federal islamic republic of comoros (indian ocean)].in october 1988-january 1989, as a part of a malaria and filariasis control programme in federal islamic republic of comoros an entomological survey was carried out in 19 rural and urban localities of grande comore. anjouan and moheli islands. the potential breeding places were examined and pyrethrum spray catches were made to evaluate the indoor resting densities of mosquitos. a total of 14.578 adult mosquitos potential vectors of filariasis was collected: 94.5% culex quinquefasciatus, 3.5% ano ...19949235195
resting behaviour, ecology and genetics of malaria vectors in large scale agricultural areas of western kenya.in kenya indoor and outdoor resting densities of anopheles arabiensis and anopheles funestus at the ahero rice irrigation scheme, and anopheles gambiae s.s., an. arabiensis and an. funestus at the miwani sugar belt were assessed for 13 months by pyrethrum spray collections in houses and granaries. the vector's house leaving behaviour was evaluated with exit traps and it was noted that early exophily (i.e., deliberate) was not detected in any of the vectors. assortative indoor/outdoor resting beh ...19969257337
[anopheles species and the transmission of malaria in the forest/savannah transition zone in central cameroon].a longitudinal study on malaria vectors and transmission was carried out in a forest-savannah transitional area in cameroon. indoor all night mosquito collections on human bait were performed during one year in two villages: nditam and ngoume. nditam was located in a secondary forest block surrounded by savannah, while ngoume was situated in an ancient forest block. the results showed that at nditam, only one anopheline species was collected, that was anopheles gambiae s.l.. the average daily bi ...19979289252
molecular identification of sympatric chromosomal forms of anopheles gambiae and further evidence of their reproductive isolation.three chromosomal forms of anopheles gambiae s.s., designated as bamako, mopti and savanna, were studied for diagnostic pcr assays based on the analysis of the x-linked ribosomal dna (rdna). the study was performed on a 1.3 kb fragment containing part of the 28s coding region and part of the intergenic spacer region. the amplified material was cut with fourteen restriction enzymes to detect restriction fragment length polymorphisms (rflps). the enzymes tru9i and hhai produced patterns of dna ban ...19979359579
sporozoite loads of naturally infected anopheles in kilifi district, kenya.the number of salivary gland malaria sporozoites (sporozoite load) was determined by hemacytometer counts for 2,055 field-collected anopheles mosquitoes from kilifi district, kenya. of 48 gland-positive anopheles gambiae s.l., sporozoite loads ranged from 125 to 79,875, with a geometric mean of 1,743 sporozoites per infected mosquito. about half of the infected mosquitoes had sporozoite loads < 1,000. following hemacytometer examination of salivary gland samples, the same samples were subsequent ...19979383768
odor-mediated host preferences of west african mosquitoes, with particular reference to malaria vectors.the role of odors in mosquito host preferences was studied in a village near ouagadougou, burkina faso. two odor-baited entry-traps were put beside one another and a choice of host odor-laden air was blown out of them. odors of a human and a calf (of similar mass) were drawn from two tents in which each was separately concealed. allowances were made for trap position, differences in human-subject attractiveness, co2 levels, and trap contamination with alternative host odors. choices for the huma ...19989452293
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