| gametocyte infectivity by direct mosquito feeds in an area of seasonal malaria transmission: implications for bancoumana, mali as a transmission-blocking vaccine site. | infectivity of gametocytemic volunteers living in bancoumana, a village 60 km from bamako, mali, was determined by direct feeds of laboratory-reared anopheles gambiae s. l. gametocytemic adolescents (10-18 years old) were as infectious to mosquitoes as younger volunteers and appear to be a more suitable population for testing transmission-blocking efficacy as compared with adults (> 18 years old). to begin to validate the membrane-feeding assay, sera collected from these same volunteers were sub ... | 1998 | 9749648 |
| origin and prevention of airport malaria in france. | since 1969, 63 cases of airport malaria have been reported in western europe, 24 of which occurred in france. most were due to plasmodium falciparum. in 1994, 7 cases occurred in and around roissy charles de gaulle airport (cdg), showing 4 types of contamination: among employees working on airstrips or opening containers, among residents living near the airport, among people living at some distance from the airport after a secondary transport of vectors, and by vectors transported in luggage. in ... | 1998 | 9754664 |
| biological problems with the replacement of a vector population by plasmodium-refractory mosquitoes. | attempts are being made to backcross into anopheles gambiae s.s. the gene(s) which cause zoophily in anopheles quadriannulatus. such a backcrossed strain might be preferable to a plasmodium-refractory strain as a basis for genetic control because a refractory strain could select for evasion of refractoriness in the wild plasmodium population. the species composition of the malaria vector population in several tanzanian villages was overwhelmingly an. gambiae s.s. in a normal rainy season, but co ... | 1999 | 10697905 |
| [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 ... | 1995 | 8784541 |
| [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 ... | 1995 | 8784548 |
| 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 ... | 1995 | 8826108 |
| 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 ... | 1996 | 8887331 |
| [comparison of the transmission of malaria in 2 epidemiological patterns in senegal: the sahel border and the sudan-type savanna]. | from september 1992 to october 1993 a longitudinal entomological study was carried out in two villages located in different ecological conditions of senegal, a sahelian area and a sudan-type savanna. mosquitoes were sampled by night-bites catches and by daytime pyrethrum spray collections. in both villages anopheles gambiae s.l. is the main vector with an. gambiae in the savanna area of wassadou and an. arabiensis in the sahelian area of thiaye. malaria transmission is mainly seasonal with a man ... | 1995 | 9827082 |
| permethrin-treated bed nets do not have a 'mass-killing effect' on village populations of anopheles gambiae s.l. in the gambia. | in the gambia, the use of permethrin-treated bed nets has led to a reduction in morbidity and mortality from malaria in children. however, no clear evidence has been found for a 'mass-killing effect' on the mosquito vectors as a result of this intervention. two further entomological studies to investigate this phenomenon have been carried out. in one study, 20 villages were paired so that bed nets in one member of each pair were treated with permethrin. in the other, a cross-over design was used ... | 1998 | 9850383 |
| experimental formulations of bacillus sphaericus and b. thuringiensis israelensis against culex quinquefasciatus and anopheles gambiae (diptera: culicidae) in burkina faso. | efficacies of locally produced, sustained release granular formulations of bacillus sphaericus (bs) strain 2362 and b. thuringiensis israelensis (bti) were compared with commercial liquid concentrates of the same bacteria in cesspits and rain-filled puddles in ouagadougou, burkina faso. duration of control was dependent on the product, the transient nature of some sites, and the target mosquito larvae. bs granules applied at the rate of 3.0 g/m2 (30 kg/ha) reduced culex quinquefasciatus say 99% ... | 1999 | 10071494 |
| molecular characterization of pyrethroid knockdown resistance (kdr) in the major malaria vector anopheles gambiae s.s. | pyrethroid-impregnated bednets are playing an increasing role for combating malaria, especially in stable malaria areas. more than 90% of the current annual malaria incidence (c. 500 million clinical cases with up to 2 million deaths) is in africa where the major vector is anopheles gambiae s.s. as pyrethroid resistance has been reported in this mosquito, reliable and simple techniques are urgently needed to characterize and monitor this resistance in the field. in insects, an important mechanis ... | 1998 | 9535162 |
| 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. ... | 1997 | 9083583 |
| 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 ... | 1996 | 9257337 |
| bancroftian filariasis in an irrigation project community in southern ghana. | an epidemiological study to document the endemicity and transmission characteristics of bancroftian filariasis was conducted in an irrigation project community in southern ghana. in a 50% random sample of the population, the prevalence of microfilaraemia was 26.4% and the geometric mean microfilarial intensity among positives was 819 microfilariae/ml of blood. hydrocoele was found in 13.8% of the males aged > or =18 years, and 1.4% of the residents examined, all females, had tymphoedema/elephant ... | 1999 | 10203168 |
| bancroftian filariasis on pemba island, zanzibar, tanzania: an update on the status in urban and semi-urban communities. | cross-sectional clinical, parasitological and entomological surveys for bancroftian filariasis were conducted in konde, chake chake and kengeja, three urban and semiurban communities on pemba island, and the results were compared with similar surveys done 15 years earlier. the overall prevalences of clinical manifestations among males aged 15 years or more (n = 614) was remarkably similar to those recorded 15 years earlier: elephantiasis 1.4% in 1975 and 1.1% in 1990; hydrocele, 22.4% and 21.8%, ... | 1999 | 10320655 |
| electrophysiological investigation of larval water and potential oviposition chemo-attractants for anopheles gambiae s.s. | potential anopheles gambiae s.s. breeding sites were sampled in rural sites in the tanga region of tanzania. sites containing the largest numbers of an. gambiae larvae were small, shaded pools and rice fields. water samples were collected from the larval sites and these, together with ether extracts of the water samples, were active in electro-antennogram (eag) studies with female mosquitoes from a laboratory colony of anopheles (cellia) gambiae kwa. eag response thresholds varied for 10 randoml ... | 2000 | 10945049 |
| malaria, schistosomiasis, and intestinal helminths in relation to microdams in tigray, northern ethiopia. | a survey was undertaken in tigray, northern ethiopia, to assess the prevalence of malaria, schistosomiasis, and intestinal helminths in relation to microdams. the survey took place from march to june 1995, during the dry season, at 41 microdams. at each site the village nearest the dam (within thirty minutes walk) was selected, ten households were randomly chosen, and all family members were examined for malaria and intestinal parasites. the overall study sample was 2271 people, of all age group ... | 1998 | 10376281 |
| [anopheles mascarensis (de meillon, 1947): main vector of malaria in the region of fort-dauphin (south-east of madagascar)]. | anopheles funestus and anopheles gambiae s.l. have been considered until now the major vectors of malaria everywhere in madagascar. anopheles mascarensis, a mosquito native to madagascar, has been identified in sainte-marie island as a secondary vector only. in 1997, an entomological study was carried out to identify the malaria vectors in the area of fort-dauphin, south-east of madagascar. every month, mosquitoes were collected from landing catches on human volunteers (from 7:00 am to 5:00 pm i ... | 1999 | 10399606 |
| [impact of resistance of anopheles gambiae s.s. to permethrin and deltamethrin on the efficacy of impregnated mosquito nets]. | trials to assess the impact of resistance of anopheles gambiae s.s. to permethrin and deltamethrin on the efficacy of insecticide-treated bednets were carried out from october 1997 to april 1998 in six experimental huts at the yaokoffikro testing station in côte d'ivoire. six polyester bednets were used. two bednets were treated with permethrin at a dose of 500 mg/m2 and two with deltamethrin at 25 mg/m2. the remaining two untreated bednets served as controls. the number of anopheles gambiae s.s ... | 1998 | 10399691 |
| [impact of the use of permethrin pre-impregnated mosquito nets on malaria transmission in a hyperendemic village of senegal]. | the efficacy of permethrin-treated bednets was evaluated in wassadou, a hyperendemic village located in the sudanese grasslands of southeast senegal. pretreatment data were collected between 1992 and 1993. bednets were distributed to the whole population in june 1995 and impact of their use on vector populations and malaria transmission was evaluated until november 1995. this period corresponds to the rainy season during which malaria transmission is highest. data were compared with a control vi ... | 1998 | 10399692 |
| [ the aggressive cycle of anopheles gambiae s.s. inside houses and malaria transmission in the bouake region (côte d'ivoire). value of using impregnated mosquito nets]. | the biting indoor cycle of anopheles gambiae s.s. was studied in a rural zone near bouaké from 6 pm to 6 am. the cycle was characterized by a peak between midnight and 1 am (n = 19,181). the parturity rate of biting females regularly increased from 6 pm until 3 am, then remained at a high level up to 6 am (n = 14,239). infected bites were observed from 7 pm to 6 am with a maximum between 0 and 3 am, and 96.7% of them were obtained between 11 pm and 4 am (n = 219). it appears that malaria transmi ... | 1999 | 10472449 |
| elisa detection of malaria sporozoites: false-positive results in anopheles gambiae s.l. associated with bovine bloodmeals. | | 1999 | 10492803 |
| evaluation of a polymerase chain reaction assay for detection of pyrethroid insecticide resistance in the malaria vector species of the anopheles gambiae complex. | a published polymerase chain reaction assay proved reliable for detecting nerve-insensitivity (kdr-type) resistant and susceptible alleles to the pyrethroid insecticide permethrin in the malaria vectors anopheles gambiae s.s. and an. arabiensis and the nonvector species an. quadriannulatus. the assay detects pyrethroid susceptible and resistance alleles mediated by a mutation in region ii of the para-type sodium channel gene, showing that resistance is conferred by pyrethroid target site insensi ... | 1999 | 10612620 |
| host haematological factors influencing the transmission of plasmodium falciparum gametocytes to anopheles gambiae s.s. mosquitoes. | we investigated the relationship between selected host haematological and parasitological parameters and the density and infectivity of plasmodium falciparum gametocytes. 143 individuals (age range 1-62 years) attending an outpatient clinic in farafenni, the gambia, who had peripheral blood gametocytaemia were recruited (mean gametocyte density 123.7/microl, range 5-17,000/microl). of the parameters measured, packed cell volume (pcv), reticulocyte count (retc) and lymphocyte count (lyc) were sig ... | 1999 | 10206267 |
| current distribution of a pyrethroid resistance gene (kdr) in anopheles gambiae complex from west africa and further evidence for reproductive isolation of the mopti form. | in the field, the kdr mutation, involved in pyrethroid resistance, has been found widely distributed in the savanna form of anopheles gambiae s.s., but never in wild populations of the mopti form or an. arabiensis, even in areas where both occur in sympatry with resistant savanna populations. under laboratory conditions, mopti and savanna forms were fully able to interbreed and the kdr mutation was transmissible from one form to the other. both forms appeared to be exposed to pyrethroid selectio ... | 1999 | 10697876 |
| vector-related case-control study of severe malaria in kilifi district, kenya. | a case-control study examined vector-related and environmental parameters associated with severe malaria in kilifi district along the coast of kenya. over an 11-month period, 119 children identified with severe malaria infections at the kilifi district hospital were matched by age with control children who reported to the outpatient clinic with nonsevere infections. intensive mosquito sampling was done in each of the case-control houses over a four-day period, beginning within a week of index ca ... | 1999 | 10344652 |
| seasonal density, sporozoite rates and entomological inoculation rates of anopheles gambiae and anopheles funestus in a high-altitude sugarcane growing zone in western kenya. | an entomological study was conducted on vectors of malaria and their relative contribution to plasmodium falciparum transmission in mumias, a high-altitude site and large-scale sugarcane growing zone in kakamega district, western kenya. anopheles gambiae s.l., the predominant vector species, represented 84% (n=2667) of the total anopheles mosquitoes collected with an. funestus comprising only 16%. polymerase chain reaction (pcr) identified all 600 specimens of the an. gambiae complex tested as a ... | 1998 | 9754665 |
| highland malaria in uganda: prospective analysis of an epidemic associated with el niño. | malaria epidemics in african highlands cause serious morbidity and mortality and are being reported more frequently. weather is likely to play an important role in initiating epidemics but limited analysis of the association between weather conditions and epidemic transmission parameters has been undertaken. we measured entomological variables before and during an epidemic of malaria (which began in february 1998) in a highland region of south-western uganda and analysed temporal variation in we ... | 1999 | 10696401 |
| infection rates in, and the number of plasmodium falciparum genotypes carried by anopheles mosquitoes in tanzania. | naturally fed mosquitoes were collected from houses in a rural village in northern tanzania. the number of plasmodium falciparum oocysts which developed in each was counted, and the number of parasite genotypes carried by a subset was determined by pcr-based techniques. a higher proportion of anopheles gambiae s.l. mosquitoes developed oocysts than of an. funestus but, on average, both species carried similar numbers of parasite genotypes. overall, 68% of the sampled mosquitoes carried more than ... | 1999 | 10707111 |
| [histopathology of anopheles gambiae s.l. giles, 1902 (diptera, culicidae) subjected to the larvicidal activity of the aqueous extract of persea americana miller, 1768 (lauraceae)]. | larvae of anopheles gambiae treated with an aqueous extract of persea americana suffer important damages of the midgut. the first epithelial cells to be affected are those at the posterior part of the midgut which become hypertrophic after only 30 min. after one hour most of the cells in this part lyse. the cytoplasmic material is then rejected towards the lumen gut, between the peritrophic membrane and the midgut epithelium. subsequently, an almost total cell degeneration is observed. cells of ... | 1998 | 9773205 |
| [efficacy of permethrin-impregnated olyset net mosquito nets in a zone with pyrethroid resistance vectors. ii. parasitic and clinical evaluation]. | the efficacy of permethrin-treated olyset net mosquito nets in preventing transmission and morbidity of malaria was studied in kafine, a village in the rice-growing region of the cote d'ivoire. entomological data demonstrated that permethrin-treated mosquito nets failed to reduce transmission of malaria. laboratory tests showed that anopheles gambiae s.s. in kafine were resistant to permethrin and other pyrethroids. study included a cohort of 163 children under five years of age who did or did n ... | 1999 | 10816747 |
| early warning of malaria epidemics in african highlands using anopheles (diptera: culicidae) indoor resting density. | several highland regions of africa recently have suffered malaria epidemics. because malaria transmission is unstable and the population has little or no immunity, these highlands are prone to explosive outbreaks when densities of anopheles exceed critical levels and conditions favor transmission. if an incipient epidemic can be detected early enough, control efforts may reduce morbidity, mortality, and transmission. here we present three methods (direct, minimum sample size, and sequential samp ... | 2000 | 11004777 |
| the kdr mutation occurs in the mopti form of anopheles gambiae s.s. through introgression. | anopheles gambiae s.s. is a complex of sibling taxa characterized by various paracentric inversions. in west and central africa, where several taxa are sympatric, a kdr mutation responsible for pyrethroid resistance has been described in only one (the s taxon), suggesting an absence of gene flow between them. following a thorough sampling, we have found a kdr mutation in another taxon (m). to establish whether this mutation is the same event or not, the large intron upstream of the kdr mutation ... | 2000 | 11029663 |
| [impact of pyrethrin resistance on the efficacity of impregnated mosquito nets in the prevention of malaria: results of tests in experimental cases with deltamethrin sc]. | the effects of impregnated bednets treated with deltamethrin at a dosage of 25 mg a.i./m2 were evaluated at two testing stations in côte d'ivoire. the first one was located in yaokoffikro, where anopheles gambiae s.s. are resistant to pyrethroids (including deltamethrin), and the second in m'be, close to a large rice-growing area where an. gambiae s.s. are susceptible pyrethroids. in both situations, treating bednets with deltamethrin was very effective in limiting contact between man and vector ... | 2000 | 10863621 |
| non-filarial elephantiasis in the mt. elgon area (kapchorwa district) of uganda. | following reports of a high frequency of elephantiasis in kwen county (kapchorwa district) on the slopes of mt. elgon in uganda, a baseline survey for lymphatic filariasis was carried out in three villages in the affected area. individuals aged 1 year and above were examined for chronic manifestations of lymphatic filariasis, and for specific circulating filarial antigens and microfilariae of wuchereria bancrofti. elephantiasis was observed in all age groups from 10 years and above. the overall ... | 2001 | 11230827 |
| distribution of genetic variation among chromosomal forms of anopheles gambiae s.s: introgressive hybridization, adaptive inversions, or recent reproductive isolation? | a series of four papers in this issue explores the reproductive status of the five chromosomal forms of an. gambiae s.s. using molecular techniques to examine the variation among twelve different genes located throughout the an. gambiae s.s. genome. results of these and previous studies are consistent with a hypothesis of at least partial barriers to gene flow between some chromosomal forms in the ivory coast and other west african countries to the north and west, but introgression between s and ... | 2001 | 11240631 |
| molecular evidence of incipient speciation within anopheles gambiae s.s. in west africa. | we karyotyped and identified by polymerase chain reaction restriction fragment length polymorphism (pcr-rflp) analysis anopheles gambiae s.s. samples collected in several african countries. the data show the existence of two non-panmictic molecular forms, named s and m, whose distribution extended from forest to savannahs. mosquitoes of the s and m forms are homosequential standard for chromosome-2 inversions in forest areas. in dry savannahs, s is characterized mainly by inversion polymorphisms ... | 2001 | 11240632 |
| molecular characterization of ribosomal dna polymorphisms discriminating among chromosomal forms of anopheles gambiae s.s. | the sequence of a 2.3 kb long dna segment derived from the 5'-most end of the ribosomal intergenic spacer was determined in three chromosomal forms of anopheles gambiae s.s. the analysis revealed that the sequence of the mopti form differed from that of the bamako and savanna forms by a total of ten nucleotide substitutions. using these sequence variations we set up a diagnostic polymerase chain reaction (pcr) assay to distinguish mosquitoes belonging to the three chromosomal forms, facilitating ... | 2001 | 11240633 |
| attempts to molecularly distinguish cryptic taxa in anopheles gambiae s.s. | analyses of inversions in polytene chromosomes indicate that, in west africa, anopheles gambiae (sensu stricto) may be a complex of more than a single taxonomic unit, and these units have been called chromosomal forms. in order to determine whether this genetic discontinuity extends to the rest of the genome, as would be expected if reproductive isolation exists, we have sequenced several regions of both the nuclear and mitochondrial genomes. with one exception, we were unable to identify any nu ... | 2001 | 11240634 |
| attraction of anopheles (diptera: culicidae) to volatile chemicals in western kenya. | anopheles gambiae s.l. and anopheles funestus giles are the primary vectors of malaria in east africa. identification of host-location olfactory cues may increase trap sensitivity for vector control and surveillance programs. solid-state army miniature light traps were operated near sleeping humans in huts at night without lights and augmented with the potential attractants: l-lactic acid, limburger cheese volatiles, hexanoic acid, and carbon dioxide. mosquito response varied between species and ... | 2001 | 11296830 |
| characteristics of larval anopheline (diptera: culicidae) habitats in western kenya. | a longitudinal survey of mosquito larval habitats was carried out in asembo bay, western kenya, during the rainy season of 1998. all pools of standing water along a 700-m transect were sampled twice per week. for each habitat, eight environmental variables were recorded and a sample of anopheline larvae was collected for identification. in total, 1,751 anopheles gambiae s.l. and 2,784 anopheles funestus giles were identified. identification of an. gambiae s.l. by polymerase chain reaction (pcr) ... | 2001 | 11296836 |
| [chloroquine resistance and malaria control in ivory coast]. | we present here data from the ivory coast on the susceptibility of plasmodium falciparum to chloroquine, obtained since the first chloroquine-resistant strains were discovered in 1987. susceptibility was assessed using the who 7-day field test. almost all the tests were carried out in the capital, adidjan, and in the southern forest zone. the frequency of chloroquine resistance was below 30% in most cases, the actual frequency differing between regions. the frequency of r3 chloroquine-resistant ... | 1998 | 9794040 |
| the rise and fall of malarial sporozoite rates in anopheles gambiae s.l. and an. funestus in north-eastern tanzania, between 1934 and 1999. | the proportion of anopheles mosquitoes found to be carrying plasmodium sporozoites, usually called the 'malarial sporozoite rate', has often been used as a measure of mosquito infectivity. although the sporozoite rates found in anopheles gambiae and an. funestus in muheza, north-eastern tanzania, showed a marked decline between the mid-1930s and the mid-1970s, they then began to rise again. this fall and rise in mosquito infectivity is attributed to the widespread use of antimalarial drugs, whic ... | 2001 | 11454241 |
| lymphatic filariasis in ghana: entomological investigation of transmission dynamics and intensity in communities served by irrigation systems in the upper east region of ghana. | we conducted an entomological study to document the effect of irrigation on the vectors and transmission dynamics of lymphatic filariasis in the upper east region of ghana. mosquitoes were collected by indoor spraying of houses in a cluster of communities located around irrigation projects (tono and vea) and others without reservoirs (azoka). anopheles gambiae s.s. was the dominant species and major vector, followed by an. funestus. anopheles arabiensis constituted 9--14% of the an. gambiae comp ... | 2001 | 11469943 |
| unexpected anthropophagic behaviour in anopheles quadriannulatus. | the strongly anthropophilic behaviour of anopheles gambiae giles sensu stricto (diptera: culicidae), the most important malaria vector in africa, has been demonstrated by field and laboratory studies. other members of the an. gambiae complex express varied degrees of anthropophily. anopheles quadriannulatus (theobald) species a and b are more zoophilic members of the complex and hence are considered to be of no medical importance. olfactometer experiments with an. quadriannulatus species a have ... | 2001 | 11583447 |
| bactericidal effects of sugar-fed antibiotics on resident midgut bacteria of newly emerged anopheline mosquitoes (diptera: culicidae). | a protocol was developed for significantly reducing resident midgut bacteria in newly emerged anopheline mosquitoes using a combination of antibiotics. pupa harvested from colony-reared anopheles gambiae s.l. giles and anopheles stephensi (liston) were placed in cages wiped previously with 70% alcohol and kept under uv light for 24 h. emerging adult mosquitoes were fed for 3 consecutive days on antibiotic solution, consisting of 0.4% gentamicin sulfate and 1% penicillin-streptomycin solution in ... | 2000 | 10730495 |
| absence of insecticide resistance in anopheles gambiae s.l. (diptera: culicidae) after four decades of residual house spraying in gokwe district, zimbabwe. | field tests showed that anopheles gambiae s.l. from 4 villages in gokwe district, midlands province, zimbabwe, were susceptible to 4% ddt, 0.025% deltamethrin, 0.025% alpha-cypermethrin, and 0.1% lambdacyhalothrin. in the laboratory, f1 progeny of field-caught females that were identified as anopheles arabiensis patton were completely susceptible to deltamethrin, alpha-cypermethrin, lambdacyhathrin, and ddt. the use of insecticides in gokwe district has not yet induced detectable resistance in a ... | 2000 | 10730502 |
| malaria in são tomé and príncipe: parasite prevalences and vector densities. | a cross-sectional survey was carried out in 16 localities on the island of são tomé and three on the island of príncipe, at the end of the rainy season of 1997, to determine malaria prevalence and vector densities. blood samples from 664 inhabitants of all ages were examined by optical microscopy (om) and pcr. mosquito collections were made by outdoor landing captures from 21:00-23:00 h. great differences were found between om and pcr readings. om had a sensitivity of 66%, a specificity of 79% a ... | 2000 | 10936578 |
| plasmodium falciparum sporozoites increase feeding-associated mortality of their mosquito hosts anopheles gambiae s.l. | there is some evidence that pathology induced by heavy malaria infections (many oocysts) increases mortality of infected mosquitoes. however, there is little or no published evidence that documented changes in feeding behaviour associated with malaria infection also contribute to higher mortality of infected mosquitoes relative to uninfected individuals. we show here for the first time that, in a natural situation, infection by the sporozoites of the malaria parasite plasmodium falciparum signif ... | 2000 | 10811273 |
| melanization of plasmodium falciparum and c-25 sephadex beads by field-caught anopheles gambiae (diptera: culicidae) from southern tanzania. | the melanization responses of field-captured anopheles gambiae s.l. toward oocysts of the malaria parasite plasmodium falciparum or negatively charged (c-25) sephadex beads were determined. only two of 431 infected mosquitoes harboured melanized oocysts. however, 90% of field-captured mosquitoes melanized c-25 sephadex beads. the effects of age, glucose concentration and blood meal on the melanization response of an an gambiae s.s. laboratory colony toward c-25 beads were also assayed. all newly ... | 2002 | 11931276 |
| [evaluation in test huts of the protective effects of untreated mosquito nets against anopheles gambiae s.s. bites]. | the protection against insect bites afforded by untreated mosquito bed nets was studied at the field stations of yaokoffikro and m'bé in ivory coast. we tested damaged mosquito nets (tear holes covering 0.8% of the total area) in yaokoffikro, undamaged mosquito nets and huts without mosquito nets in m'bé. the blood feeding rate of anopheles gambiae was 70% lower in huts with undamaged mosquito nets than in huts with no mosquito net or a damaged mosquito net. the natural exophilic behavior of the ... | 2000 | 11226938 |
| lymphatic filariasis in uganda: baseline investigations in lira, soroti and katakwi districts. | baseline epidemiological investigations on lymphatic filariasis were conducted for the first time in uganda in 3 communities in the districts of lira (alebtong area), soroti (lwala area) and katakwi (obalanga area), located to the north of lake kyoga at an altitude of 1000-1100 m above sea level. individuals from the communities were examined, in april-august 1998, for wuchereria bancrofti specific circulating antigen (by ict card test), microfilaraemia (by counting chamber and stained blood-sme ... | 2001 | 11355548 |
| land use change alters malaria transmission parameters by modifying temperature in a highland area of uganda. | as highland regions of africa historically have been considered free of malaria, recent epidemics in these areas have raised concerns that high elevation malaria transmission may be increasing. hypotheses about the reasons for this include changes in climate, land use and demographic patterns. we investigated the effect of land use change on malaria transmission in the south-western highlands of uganda. from december 1997 to july 1998, we compared mosquito density, biting rates, sporozoite rates ... | 2000 | 10810021 |
| bifenthrin: a useful pyrethroid insecticide for treatment of mosquito nets. | bifenthrin, a pyrethroid insecticide already used in agriculture was evaluated in laboratory conditions against susceptible and pyrethroid resistant mosquitoes, as a potential insecticide for treatment of mosquito nets. two laboratory strains of anopheles gambiae s.s. giles, the major malaria vector in africa, and two of culex quinquefasciatus say, a major pest mosquito in urban areas, were used. compared with other pyrethroids such as permethrin and deltamethrin, the intrinsic toxicity of bifen ... | 2002 | 12061451 |
| dynamics of the malaria-vector populations in coastal lagos, south-western nigeria. | an entomological study was carried out in coastal lagos, south-western nigeria, to explore the role of anopheles gambiae s.l. and an. moucheti in the transmission of plasmodium falciparum in this holo-endemic area. mosquitoes were caught, on human bait at night and by pyrethrum-spray catches during the day, twice a month throughout 2000. of the 1812 anopheles mosquitoes collected, an. gambiae s.l., the predominant vector species, represented 78.7% while the other 21.3% were an. moucheti. the res ... | 2002 | 11989536 |
| malaria infection, morbidity and transmission in two ecological zones southern ghana. | a one year survey was conducted in 1992 to compare malaria infection, morbidity and transmission patterns between a coastal savannah community (prampram) and a community (dodowa) in the forest zone in southern ghana. the study population of 6682 at prampram and 6558 at dodowa were followed up in their homes once every two weeks and all episodes of clinical malaria recorded. blood films for microscopy were prepared from 600 participants randomly selected in each community in april and in august r ... | 1995 | 12160443 |
| infection of malaria (anopheles gambiae s.s.) and filariasis (culex quinquefasciatus) vectors with the entomopathogenic fungus metarhizium anisopliae. | current intra-domiciliary vector control depends on the application of residual insecticides and/or repellents. although biological control agents have been developed against aquatic mosquito stages, none are available for adults. following successful use of an entomopathogenic fungus against tsetse flies (diptera: glossinidae) we investigated the potency of this fungus as a biological control agent for adult malaria and filariasis vector mosquitoes. | 2003 | 14565851 |
| [dynamics of malaria transmission in kafiné, a rice growing village in a humid savannah area of côte d'ivoire]. | a study on malaria transmission based on samples of mosquitoes caught on human subjects was conducted from february to august 1995 in the rice growing area of kafine, a village located in the niakaramandougou district of northern côte d'ivoire. the village is surrounded by 117,500 acres of rice fields. irrigation is sub-permanent in the rice field and harvests number two a year. during the 6 months of the study, 12.353 mosquitoes were caught. the average biting rate was 118.8 bites per man per n ... | 2002 | 12012955 |
| how reliable are light traps in estimating biting rates of adult anopheles gambiae s.l. (diptera: culicidae) in the presence of treated bed nets? | the sampling efficiency of light trap catches relative to human bait catches in estimating biting rates of the mosquito anopheles gambiae giles was investigated in two types of community in southern sierra leone: (i) where most of the inhabitants slept under treated bed nets; and (ii) where most of the inhabitants slept without bed nets. the number of female a. gambiae mosquitoes caught in these communities by light trap was strongly correlated (r > or = 0.72) with those from corresponding human ... | 2002 | 12020364 |
| status of pyrethroid resistance in anopheles gambiae sensu lato. | the present study confirms the presence of pyrethroid resistance among anopheles gambiae s.l mosquitos in côte d'ivoire and reports the observation of such resistance in two other countries in west africa (benin and burkina faso). malaria vector populations from cameroon (central africa), senegal (west africa) and botswana (southern africa) were found to be susceptible to pyrethroids. in the most resistant mosquito populations, resistance to permethrin was associated with reduced mortality, not ... | 1999 | 10212513 |
| [the epidemiology of malaria in the southwestern forests of the ivory coast (tai region)]. | an epidemiological study on malaria was undertaken between july 1995 and july 1996 in two villages (zaïpobly and gahably) and their encampments (kouassikro, hamanikro and konankro), in the south-western forest area of côte d'ivoire (region of taï). the parasitological scheme comprised a total of 2023 tests performed on children aged from 0 to 14 years. the species found were plasmodium falciparum, p. malariae and p. ovale with a proportion of 84%, 14% and 2% respectively. the global parasite pre ... | 2002 | 12145967 |
| traditional use of mosquito-repellent plants in western kenya and their evaluation in semi-field experimental huts against anopheles gambiae: ethnobotanical studies and application by thermal expulsion and direct burning. | ethnobotanical survey in 2 communities in western kenya revealed that the most commonly known repellent plants were ocimum americanum l. (64.1%), lantana camara l. (17.9%), tagetes minuta l. (11.3%) and azadirachta indica a. juss (8.7%) on rusinga island, and hyptis suaveolens poit. (49.2%), l. camara (30.9%) and o. basilicum l. (30.4%) in rambira. direct burning of plants is the most common method of application for o. americanum (68.8%), l. camara (100%) and o. basilicum (58.8%). placing branc ... | 2002 | 12174767 |
| the phenology of malaria mosquitoes in irrigated rice fields in mali. | a field study was carried out in the large-scale rice irrigation scheme of the office du niger in mali to investigate the relation between anopheline mosquito larval development and small-scale differences in irrigation practices, such as water level, irrigation application and irrigation frequency. the objective of the study was to find out if water management can be used as a tool for vector control to reduce the malaria transmission risk. larvae of anopheles gambiae s.s.,; the main malaria ve ... | 2003 | 12505185 |
| genetic differentiation in the african malaria vector, anopheles gambiae s.s., and the problem of taxonomic status. | of the seven recognized species of the anopheles gambiae complex, a. gambiae s.s. is the most widespread and most important vector of malaria. it is becoming clear that, in parts of west africa, this nominal species is not a single panmictic unit. we found that the internal transcribed spacer (its) of the x-linked rdna has two distinct sequences with three fixed nucleotide differences; we detected no heterozygotes at these three sites, even in areas of sympatry of the two its types. the intergen ... | 2002 | 12196401 |
| the swarming and mating behaviour of anopheles gambiae s.s. (diptera: culicidae) from são tomé island. | the swarming and mating behaviours of the forest cytoform of anopheles gambiae s.s. were investigated on 194 evenings and 14 mornings between april 1997 and november 1999 in a peri-urban area of the island of são tomé, west africa. males swarmed 2-3 m above markers of horizontal contrast such as those formed between grass areas and footpaths, or bushes. evening swarms started 2 min before sunset in sheltered sites and a minute or two later in exposed ones. it took approximately 5 mins from the a ... | 2002 | 12546454 |
| resistance of the malaria vector anopheles gambiae s.s. to pyrethroid insecticides, in south-western nigeria. | | 2002 | 12625942 |
| an alternative focus in strategic research on disease vectors: the potential of genetically modified non-biting mosquitoes. | we examine the constraints and the feasibility of field experiments involving the release of genetically modified (gm) pathogen-resistant mosquitoes, and whether there are alternatives to the research line based on the production of refractory strains. the production of a gm mosquito strain characterized instead by obligate primiparous and parous autogeny and by disrupted host seeking and biting behaviour could make the release more acceptable by the general public. genetic transformation should ... | 2002 | 12701373 |
| first report of the kdr mutation in anopheles gambiae m form from burkina faso, west africa. | the kdr mutation, conferring resistance to pyrethroid insecticides, has been reported in several west-african populations of anopheles gambiae s form and in the m form populations from tropical forest of benin. we report the finding of a single m specimen collected in the rice-field area of vallée du kou (burkina faso) showing the mutation at the heterozygous state. the monitoring of kdr mutation in an. gambiae forms/species is of paramount importance to implement effective malaria control tools ... | 2002 | 12701378 |
| repellent activities of stereoisomers of p-menthane-3,8-diols against anopheles gambiae (diptera: culicidae). | four stereoisomers of p-menthane-3,8-diol, which make up the natural product obtained from eucalyptus citriodora, were synthesized through stereoselective procedures. repellency assays showed that all the four were equally active against anopheles gambiae s.s. racemic blends and the diastereoisomeric mixture of all the four isomers were also equally repellent. 1-alpha-terpeneol, with a single hydroxyl function at c-8 and unsaturation at c-8, and menthol, with a single hydroxyl function at c-3, w ... | 2002 | 12349856 |
| the role of agricultural use of insecticides in resistance to pyrethroids in anopheles gambiae s.l. in burkina faso. | agricultural use of insecticides is involved in the selection of resistance to these compounds in field populations of mosquitoes in burkina faso. anopheles gambiae s.l. was resistant to permethrin and ddt in cotton-growing and urban areas, but susceptible in areas with limited insecticide selection pressure (rice fields and control areas). nevertheless, resistance to these insecticides was observed in a village on the outskirts of the rice fields at the end of the rainy season, suggesting that ... | 2002 | 12518852 |
| impact of permethrin-treated bed nets on entomologic indices in an area of intense year-round malaria transmission. | the effect of permethrin-treated bed nets (itns) on malaria vectors was studied as part of a large-scale, randomized, controlled trial in western kenya. indoor resting densities of fed anopheles gambiae s.l. and an. funestus in intervention houses were 58.5% (p = 0.010) and 94.5% (p = 0.001) lower, respectively, compared with control houses. the sporozoite infection rate in an. gambiae s.l. was 0.8% in intervention areas compared with 3.4% (p = 0.026) in control areas, while the sporozoite infec ... | 2003 | 12749481 |
| genetic differentiation of anopheles gambiae s.s. populations in mali, west africa, using microsatellite loci. | anopheles gambiae sensu stricto is a principal vector of malaria through much of sub-saharan africa, where this disease is a major cause of morbidity and mortality in human populations. accordingly, population sizes and gene flow in this species have received special attention, as these parameters are important in attempts to control malaria by impacting its mosquito vector. past measures of genetic differentiation have sometimes yielded conflicting results, in some cases suggesting that gene fl ... | 2002 | 12407210 |
| population genetic structure of the malaria mosquito anopheles arabiensis across nigeria suggests range expansion. | ten microsatellite loci, four located within and six outside chromosome inversions, were employed to study the genetic structure of anopheles arabiensis across the ecological zones of nigeria (arid savannah in the north gradually turns into humid forest in the south). regardless of location within or outside inversions, genetic variability at all loci was characterized by a reduction in both the number of alleles per locus and heterozygosity from savannah to forest. across all loci, all but one ... | 2001 | 11883874 |
| high malaria transmission intensity in a village close to yaounde, the capital city of cameroon. | a 2-yr longitudinal malaria study was undertaken in a suburb of yaounde, the capital city of cameroon, in the village of simbock, approximately 2 km from the city limits. this study allowed assessment of malaria transmission intensity and dynamics in this region before implementation of pyrethroid impregnated bed nets through the national vector control program. anophelines were captured on human volunteers by pyrethrum spray collections and in resting sites outdoors. malaria vectors were anophe ... | 2002 | 11931035 |
| sensitivities of antennal olfactory neurons of the malaria mosquito, anopheles gambiae, to carboxylic acids. | single sensillum recordings on the antennae of female anopheles gambiae s.s. mosquitoes revealed neurons sensitive to aliphatic carboxylic acids within (a) subtype(s) sensilla trichodea. the aliphatic acids, acetic acid, propionic acid, butyric acid, iso-butyric acid and iso-valeric acid evoked an inhibition reaction in one of the cell types recorded from. a different cell type was excited in response to the former aliphatic acids, but showed a broader range of sensitivity, as acids with a longe ... | 1999 | 12770362 |
| anopheles species of the mount cameroon region: biting habits, feeding behaviour and entomological inoculation rates. | there is a lack of data on the anopheles fauna, its biology and the roles played by different vector species in the transmission of malaria in the mount cameroon region. the biting habits, feeding behaviour and entomological inoculation rates of different anopheles species during the dry and rainy season were investigated. a total of 2165 anopheles was collected, 805 in the rainy season and 1360 in the dry season. five anopheles species were identified: anopheles gambiae s.l., an. funestus, an. ... | 2003 | 12828548 |
| spatial and temporal heterogeneity of anopheles mosquitoes and plasmodium falciparum transmission along the kenyan coast. | the seasonal dynamics and spatial distributions of anopheles mosquitoes and plasmodium falciparum parasites were studied for one year at 30 villages in malindi, kilifi, and kwale districts along the coast of kenya. anopheline mosquitoes were sampled inside houses at each site once every two months and malaria parasite prevalence in local school children was determined at the end of the entomologic survey. a total of 5,476 anopheles gambiae s.l. and 3,461 an. funestus were collected. species in t ... | 2003 | 12887036 |
| an estimation of the entomological inoculation rate for ifakara: a semi-urban area in a region of intense malaria transmission in tanzania. | an entomological study on vectors of malaria and their relative contribution to plasmodium falciparum transmission in the semi-urban area of ifakara, south-eastern tanzania, was conducted. a total of 32 houses were randomly sampled from the area and light trap catches (ltc) performed in one room in each house every 2 weeks for 1 year. a total of 147 448 mosquitoes were caught from 789 ltc; 26 134 anopheles gambiae s.l., 615 a. funestus, 718 other anophelines and 119 981 culicines. more than 60% ... | 2003 | 12950662 |
| molecular differentiation of colonized human malaria vectors by 28s ribosomal dna polymorphisms. | anopheles gambiae s.s. giles, an. stephensi liston, an. freeborni aitken, and an. quadrimaculatus say are cultured and studied in molecular genetic and transgenic laboratories with increasing frequency. with limited research space, these mosquitoes are often maintained in the same insectary. under these conditions, cross-contamination of colonies can occur and have devastating consequences to affected research programs. we have developed a polymerase chain reaction-based assay targeting the 28s ... | 2004 | 15516651 |
| an island within an island: genetic differentiation of anopheles gambiae in são tomé, west africa, and its relevance to malaria vector control. | islands are choice settings for experimental studies of vector control strategies based on transgenic insects. before considering this approach, knowledge of the population structure of the vector is essential. genetic variation at 12 microsatellite loci was therefore studied in samples of the malaria vector anopheles gambiae s.s., collected from six localities of são tomé island (west africa). the objectives were (i) to assess the demographic stability and effective population size of a. gambia ... | 2003 | 14512957 |
| ring a-seco mosquito larvicidal limonoids from turraea wakefieldii. | five novel limonoids, 1-5, were isolated from the root bark of turraea wakefieldii and were characterized as tecleaninoid derivatives. this is the first report of the natural occurrence of tecleanin-type limonoids with a five-membered-ring a-seco structure for which we propose the name neotecleanins. the relative stereochemical structures of compounds 1-5 were established on the basis of nmr spectroscopy. the absolute stereochemical structure of 5 was confirmed by x-ray diffraction methods. in m ... | 2003 | 14559274 |
| absence of the kdr mutation in the molecular 'm' form suggests different pyrethroid resistance mechanisms in the malaria vector mosquito anopheles gambiae s.s. | field tests conducted on adult anopheles mosquitoes using standard who procedures, diagnostic kits and test papers in south-western nigeria showed pyrethroid (deltamethrin and permethrin) resistance in adult populations of anopheles gambiae sensu stricto. the knock-down resistance (kdr) mutation involved in pyrethroid resistance was only found in the molecular s form of an. gambiae s.s. even in area where both molecular m and s forms occurred in sympatry. the absence of the kdr mutation in the m ... | 2003 | 12753636 |
| differential behaviour of anopheles gambiae sensu stricto (diptera: culicidae) to human and cow odours in the laboratory. | a dual port olfactometer was used to study the response of anopheles gambiae giles sensu stricto to odours of human and animal origin. human odour consisted of human skin emanations collected on a nylon stocking, which was worn for 24 h. this was tested alone or together with 4.5% carbon dioxide, the concentration in human and cattle breath. cattle odours consisted of cow skin emanations and/or carbon dioxide. cow skin emanations were collected by tying a nylon stocking ('cow sock') around the h ... | 2001 | 11587625 |
| insecticide susceptibility status of anopheles gambiae s.l. (diptera: culicidae) in the republic of cameroon. | a large-scale survey of anopheles gambiae giles, 1902 susceptibility to ddt, dieldrin, permethrin, and deltamethrin was conducted in the republic of cameroon. 15 field populations from various geographical areas were tested using world health organization test kits for adult mosquitoes. the laboratory kisumu susceptible reference strain was tested as a control. results showed that dieldrin and ddt resistance was still present in some populations, and indicated permethrin or deltamethrin resistan ... | 2003 | 14680116 |
| comparisons of human-landing catches and odor-baited entry traps for sampling malaria vectors in senegal. | a comparative study of human-landing catches (hlcs) and odor-baited entry traps (obets) for sampling malaria vectors was conducted in two different bioclimatic areas of senegal, the sahelian and sudano-guinean phytogeographic zones, from september to december 2002. mosquitoes were collected by the two methods both indoors and outdoors. the reliability of obet samples was tested by comparing the two methods. overall, hlc was more effective indoors and for surveying the anopheline fauna. both meth ... | 2005 | 15799517 |
| efficacy of mosquito nets treated with a pyrethroid-organophosphorous mixture against kdr- and kdr+ malaria vectors (anopheles gambiae). | in order to prevent the resistance of anopheles gambiae s.l. to pyrethroids from spreading too quickly and to lengthen the effectiveness of insecticide impregnated mosquito nets, it has recently been suggested to use mixtures of insecticides that have different modes of action. this study presents the results obtained with tulle mosquito nets treated with bifenthrin (a pyrethroid) and chlorpyrifos-methyl (an organophosphorous) both separately and in mixture on two strains of an. gambiae, one sen ... | 2003 | 14710633 |
| [epidemiology of malaria in a village of sudanese savannah area in mali (bancoumana). 2. entomo-parasitological and clinical study ]. | we carried out five cross sectional surveys between 1993 and 1994 to assess the epidemiology of malaria in the village of bancoumana, located in the sudanese savannah areas of mali. each survey included a collection of entomological, clinical, parasitological and immunological data. the study population involved 1600 children from six months to 9 years of age. the main vector was anopheles gambiae s.l., man bite rate and entomological inoculation rate were maximum respectively in august (peak of ... | 2003 | 14717049 |
| addition of artesunate to chloroquine for treatment of plasmodium falciparum malaria in gambian children causes a significant but short-lived reduction in infectiousness for mosquitoes. | combination therapy using existing anti-malarials together with artesunate (as) has been advocated as a method to slow the spread of drug resistance. we assessed the effect on plasmodium falciparum transmissibility of the addition of as to chloroquine (cq) in an area of the gambia where resistance to cq is increasing. | 2004 | 14728607 |
| malaria transmission dynamics at a site in northern ghana proposed for testing malaria vaccines. | we studied the malaria transmission dynamics in kassena nankana district (knd), a site in northern ghana proposed for testing malaria vaccines. intensive mosquito sampling for 1 year using human landing catches in three micro-ecological sites (irrigated, lowland and rocky highland) yielded 18 228 mosquitoes. anopheles gambiae s.l. and anopheles funestus constituted 94.3% of the total collection with 76.8% captured from the irrigated communities. other species collected but in relatively few numb ... | 2004 | 14728621 |
| relationships between occurrence of anopheles gambiae s.l. (diptera: culicidae) and size and stability of larval habitats. | one potentially important target of malaria vector control is the immature stages of anopheline mosquitoes. to design efficient larval control methods, mechanisms regulating mosquito productivity in natural habitats must be understood. we examined the relationships between pupal occurrence of anopheles gambiae s.l. and size and stability of larval habitats for a period of 1 yr in western kenya. we also examined relationships between abundance of indoor resting anophelines and habitat availabilit ... | 2005 | 15962777 |
| malaria transmission in southern madagascar: influence of the environment and hydro-agricultural works in sub-arid and humid regions. part 1. entomological investigations. | a 4-year entomological study was carried out in southern madagascar to identify malaria vectors, evaluate the transmission and compare the influence of irrigation in the sub-arid and adjacent humid regions. three villages were involved in this entomological survey: androvasoa (located in the natural sub-arid ecosystem), pépiniére (sited at the centre of an irrigated rice scheme in the sub-arid region) and esana (bordered with rice fields in the humid region). mosquitoes were collected inside and ... | 2004 | 14732241 |
| identification and composition of cuticular hydrocarbons of the major afrotropical malaria vector anopheles gambiae s.s. (diptera: culicidae): analysis of sexual dimorphism and age-related changes. | forty-eight cuticular hydrocarbons (chcs) were characterized by gas chromatography-mass spectrometry from the epicuticular surface of the major afrotropical malaria vector anopheles gambiae. the hydrocarbons identified were 14 n-alkanes, 16 monomethyl alkanes, 13 dimethyl alkanes, 5 alkenes, with main-chain lengths ranging from c(17) to c(47), and the results are consistent with those from other culicidae species. qualitative differences were not observed between laboratory pools of three female ... | 2005 | 16320293 |
| evidence for selection of insecticide resistance due to insensitive acetylcholinesterase by carbamate-treated nets in anopheles gambiae s.s. (diptera: culicidae) from côte d'ivoire. | pyrethroid-treated nets are an efficient tool for reducing malaria transmission and morbidity. the recent evolution of pyrethroid resistance in several anopheles species represents a major threat for the future success of roll back malaria in africa. the possible use of nonpyrethroid insecticides, such as carbamates, on nets is a promising alternative solution because these insecticides are effective against susceptible and pyrethroid-resistant populations of anopheles and culex mosquitoes. unfo ... | 2003 | 14765680 |
| cuticular-hydrocarbon discrimination between anopheles gambiae s.s. and an. arabiensis larval karyotypes. | examination of chromatograms of karyotyped larvae of anopheles gambiae s.s. and anopheles arabiensis has revealed that there are differences in the profile of their epicuticular hydrocarbons. a discriminant analysis of the quantitative hydrocarbon data has shown that the an. gambiae mopti 2rbc/bc karyotype from mali could be separated from the forest 2la/a karyotype from liberia in > 80% of cases. similar analysis permitted > 80% separation of individuals of two karyotypes of anopheles arabiensi ... | 2001 | 11784439 |
| effect of temperature on the development of the aquatic stages of anopheles gambiae sensu stricto (diptera: culicidae). | global warming may affect the future pattern of many arthropod-borne diseases, yet the relationship between temperature and development has been poorly described for many key vectors. here the development of the aquatic stages of africa's principal malaria vector, anopheles gambiae s.s. giles, is described at different temperatures. development time from egg to adult was measured under laboratory conditions at constant temperatures between 10 and 40 degrees c. rate of development from one immatu ... | 2003 | 14641976 |
| mating does not affect the biting behaviour of anopheles gambiae from the islands of são tomé and príncipe, west africa. | to determine if mating or gonotrophic age influenced the biting behaviour of anopheles gambiae s.s., a series of all-night landing captures was performed on the islands of são tomé and príncipe in the gulf of guinea. on são tomé 49% and on príncipe 56% of the newly emerged an. gambiae taking their first bloodmeal were virgins. on each island, with the exception of recently mated insects on príncipe, all age-groups had similar biting cycles. the biting cycle on príncipe resembled that observed on ... | 2003 | 14613634 |
| survivorship and distribution of immature anopheles gambiae s.l. (diptera: culicidae) in banambani village, mali. | we observed the survivorship and distribution of larvae and pupae of anopheles gambiae s.l. giles immature stages in three habitats (rock pools, swamp, and puddles) in banambani village. mali, west africa, during the mid-rainy season of 2000. horizontal life tables were constructed for immatures in the laboratory. times spent in the various immature stages were determined, and laboratory survival was measured. vertical life tables were obtained from each habitat. we found large day-to-day variat ... | 2004 | 15185933 |
| inland valley rice production systems and malaria infection and disease in the savannah of côte d'ivoire. | in sub-saharan africa, lowlands developed for rice cultivation favour the development of anopheles gambiae s. l. populations. however, the epidemiological impact is not clearly determined. the importance of malaria was compared in terms of prevalence and parasite density of infections as well as in terms of disease incidence between three agroecosystems: (i) uncultivated lowlands, 'r0', (ii) lowlands with one annual rice cultivation in the rainy season, 'r1' and (iii) developed lowlands with two ... | 2003 | 12753641 |
| olfactory sensitivities of mosquitoes with different host preferences (anopheles gambiae s.s., an. arabiensis, an. quadriannulatus, an. m. atroparvus) to synthetic host odours. | responses of antennal olfactory cells associated with sensilla trichodea were recorded in females of four anopheles species (diptera, culicidae) with different host preferences: the anthropophilic an. gambiae s.s., the opportunistic an. arabiensis, and the zoophilic an. quadriannulatus and an. maculipennis atroparvus. stimuli were vapours of synthetic host-odours: ethanoic, propanoic, butanoic, 3-methyl propanoic, 4-methyl butanoic acid, 1-octen-3-ol, and 3- and 4-methyl phenol. on stimulation w ... | 1999 | 12770275 |
| antennal sensilla of two female anopheline sibling species with differing host ranges. | volatile odors are important sensory inputs that shape the behaviour of insects, including agricultural pests and disease vectors. anopheles gambiae s.s. is a highly anthropophilic mosquito and is the major vector for human malaria in sub-sahara africa, while anopheles quadriannulatus, largely due to its zoophilic behaviour, is considered a non-vector species in the same region. careful studies of olfaction in these sibling species may lead to insights about the mechanisms that drive host prefer ... | 2006 | 16573828 |