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new insights into the population structure of anopheles gambiae s.s. in the gulf of guinea islands revealed by herves transposable elements.transposable elements (tes) are mobile portions of dna that are able to replicate and spread in the genome of many organisms. tes can be used as a means to insert transgenes in insects, being stably inherited throughout generations. anopheles gambiae is the main vector of human malaria in sub-saharan africa. given the extraordinary burden this disease imposes, the mosquito became a choice target for genetic control approaches with the purpose of reducing malaria transmission. in this study, we i ...201323638171
bioefficacy of long-lasting insecticidal nets against pyrethroid-resistant populations of anopheles gambiae s.s. from different malaria transmission zones in uganda.there are major concerns over sustaining the efficacy of current malaria vector control interventions given the rapid spread of resistance, particularly to pyrethroids. this study assessed the bioefficacy of five who-recommended long-lasting insecticidal nets (llins) against pyrethroid-resistant anopheles gambiae field populations from uganda.201323634798
standardizing operational vector sampling techniques for measuring malaria transmission intensity: evaluation of six mosquito collection methods in western kenya.operational vector sampling methods lack standardization, making quantitative comparisons of malaria transmission across different settings difficult. human landing catch (hlc) is considered the research gold standard for measuring human-mosquito contact, but is unsuitable for large-scale sampling. this study assessed mosquito catch rates of cdc light trap (cdc-lt), ifakara tent trap (itt), window exit trap (wet), pot resting trap (prt), and box resting trap (brt) relative to hlc in western keny ...201323631641
molecular characterization of the carbon dioxide receptor in the oriental latrine fly, chrysomya megacephala (diptera: calliphoridae).the blowfly chrysomya megacephala (fabricius) (diptera: calliphoridae) cannot only act as a mechanical vector of various pathogens, but also infest man and animals causing human health problems and economic losses in the livestock and fish industries. as in other insects, olfaction of this species plays an important role in host location and is presumably mediated via transmembrane receptor signaling pathways. here, we isolate and characterize cmeggr1 and cmeggr2, two new members of the chemosen ...201323604565
rapid discrimination between anopheles gambiae s.s. and anopheles arabiensis by high-resolution melt (hrm) analysis.there is a need for more cost-effective options to more accurately discriminate among members of the anopheles gambiae complex, particularly an. gambiae and anopheles arabiensis. these species are morphologically indistinguishable in the adult stage, have overlapping distributions, but are behaviorally and ecologically different, yet both are efficient vectors of malaria in equatorial africa. the method described here, high-resolution melt (hrm) analysis, takes advantage of minute differences in ...023543777
effects of age and size on anopheles gambiae s.s. male mosquito mating success.before the release of genetically-modified or sterile male mosquitoes in an attempt to control local populations of malaria vectors, it is crucial to determine male traits involved in mating success. the effects of male size and age as determinants of male mating success in anopheles gambiae s.s. were measured in the field and under laboratory conditions in burkina faso. first, the body sizes (estimated by wing length) of mating, swarming, and indoor-resting male mosquitoes were compared over a ...201323540115
a shift from indoor residual spraying (irs) with bendiocarb to long-lasting insecticidal (mosquito) nets (llins) associated with changes in malaria transmission indicators in pyrethroid resistance areas in benin.indoor residual spraying (irs) was implemented in the department of ouémé-plateau, southern benin, in 2008 and withdrawn in 2011, when long lasting insecticidal nets (llins) were distributed to the communities that were previously targeted by irs. did the llin strategy provide a better level of protection against malaria transmission than irs?201323497708
netting barriers to prevent mosquito entry into houses in southern mozambique: a pilot study.one of the best ways to control the transmission of malaria is by breaking the vector-human link, either by reducing the effective population size of mosquitoes or avoiding infective bites. reducing house entry rates in endophagic vectors by obstructing openings is one simple way of achieving this. mosquito netting has previously been shown to have this effect. more recently different materials that could also be used have come onto the market. therefore, a pilot study was conducted to investiga ...201323497325
dose-response tests and semi-field evaluation of lethal and sub-lethal effects of slow release pyriproxyfen granules (sumilarv®0.5g) for the control of the malaria vectors anopheles gambiae sensu lato.recently research has shown that larviciding can be an effective tool for integrated malaria vector control. nevertheless, the uptake of this intervention has been hampered by the need to re-apply larvicides frequently. there is a need to explore persistent, environmentally friendly larvicides for malaria vector control to reduce intervention efforts and costs by reducing the frequency of application. in this study, the efficacy of a 0.5% pyriproxyfen granule (surmilarv®0.5g, sumitomo chemicals) ...201323497149
a dynamic model of some malaria-transmitting anopheline mosquitoes of the afrotropical region. ii. validation of species distribution and seasonal variations.the first part of this study aimed to develop a model for anopheles gambiae s.l. with separate parametrization schemes for anopheles gambiae s.s. and anopheles arabiensis. the characterizations were constructed based on literature from the past decades. this part of the study is focusing on the model's ability to separate the mean state of the two species of the an. gambiae complex in africa. the model is also evaluated with respect to capturing the temporal variability of an. arabiensis in ethi ...201323442727
multiple insecticide resistance mechanisms in anopheles gambiae s.l. populations from cameroon, central africa.increasing incidence of ddt and pyrethroid resistance in anopheles mosquitoes is seen as a limiting factor for malaria vector control. the current study aimed at an in-depth characterization of an. gambiae s.l. resistance to insecticides in cameroon, in order to guide malaria vector control interventions.201323433176
experimental hut evaluation of fendona 6sc®-treated bednets and interceptor® long-lasting nets against anopheles gambiae s.l. in burkina faso.malaria prevention relies heavily on insecticide-treated bednets. even though the benefits of bednets have been proven that in most of the studies carried out in africa, their efficacy remains dependent on local conditions. in this study, under field conditions, we evaluated the efficacy of two llins (permanet® vs interceptor® ) and two bednet treatment kits (k-o tab® vs fendona 6sc® ) against anopheles gambiae s.l.201223428523
the bionomics of anopheles merus (diptera: culicidae) along the kenyan coast.anopheles merus, a sibling species of the anopheles gambiae complex occurs along the east african coast but its biology and role in malaria transmission in this region is poorly understood. we evaluated the blood feeding pattern and the role of this species in malaria transmission in malindi district, coastal kenya.201323410133
dissecting the mechanisms responsible for the multiple insecticide resistance phenotype in anopheles gambiae s.s., m form, from vallée du kou, burkina faso.with the exception of target site mutations, insecticide resistance mechanisms in the principle malaria vector anopheles gambiae, remains largely uncharacterized in burkina faso. here we detected high prevalence of resistance in vallée du kou (vk) to pyrethroids, ddt and dieldrin, moderate level for carbamates and full susceptibility to organophosphates. high frequencies of l1014f kdr (75%) and rdl (87%) mutations were observed showing strong correlation with pyrethroids/ddt and dieldrin resista ...201323380570
assortative mating in mixed swarms of the mosquito anopheles gambiae s.s. m and s molecular forms, in burkina faso, west africa.the molecular form composition of anopheles gambiae giles s.s. (diptera: culicidae) mating swarms and the associated mating pairs (copulae) were investigated during two rainy seasons (july to october, 2005 and july to november, 2006) in the villages of soumousso and vallée du kou (vk7). although the habitats of these villages differ markedly, sympatric populations of m and s molecular forms of an. gambiae s.s. occur in both places periodically. the main aim was to assess the degree to which thes ...201323360106
no evidence for positive selection at two potential targets for malaria transmission-blocking vaccines in anopheles gambiae s.s.human malaria causes nearly a million deaths in sub-saharan africa each year. the evolution of drug-resistance in the parasite and insecticide resistance in the mosquito vector has complicated control measures and made the need for new control strategies more urgent. anopheles gambiae s.s. is one of the primary vectors of human malaria in africa, and parasite-transmission-blocking vaccines targeting anopheles proteins have been proposed as a possible strategy to control the spread of the disease ...201323357581
a dynamic model of some malaria-transmitting anopheline mosquitoes of the afrotropical region. i. model description and sensitivity analysis.most of the current biophysical models designed to address the large-scale distribution of malaria assume that transmission of the disease is independent of the vector involved. another common assumption in these type of model is that the mortality rate of mosquitoes is constant over their life span and that their dispersion is negligible. mosquito models are important in the prediction of malaria and hence there is a need for a realistic representation of the vectors involved.201323342980
response of anopheles gambiae s.l. (diptera: culicidae) to larval habitat age in western kenya highlands.larval control is of paramount importance in the reduction of vector populations. previous observations have suggested that, larvae of anopheles gambiae s.l occur more often in small temporary habitats while other studies showed that long-lasting stable habitats are more productive than unstable habitats. in addition, the physical and biological conditions and stability of larval habitats can change rapidly in natural conditions. therefore, we examined the effect of larval habitat age on product ...201323324330
assessment of anopheles salivary antigens as individual exposure biomarkers to species-specific malaria vector bites.malaria transmission occurs during the blood feeding of infected anopheline mosquitoes concomitant with a saliva injection into the vertebrate host. in sub-saharan africa, most malaria transmission is due to anopheles funestus s.s and to anopheles gambiae s.l. (mainly anopheles gambiae s.s. and anopheles arabiensis). several studies have demonstrated that the immune response against salivary antigens could be used to evaluate individual exposure to mosquito bites. the aim of this study was to as ...201223276246
status of pyrethroid resistance in anopheles gambiae s. s. m form prior to the scaling up of long lasting insecticidal nets (llins) in adzopé, eastern côte d'ivoire.the growing development of pyrethroid resistance constitutes a serious threat to malaria control programmes and if measures are not taken in time, resistance may compromise control efforts in the foreseeable future. prior to long lasting insecticidal nets (llins) distribution in eastern cote d'ivoire, we conducted bioassays to inform the national malaria control programme of the resistance status of the main malaria vector, anopheles gambiae s. s. and the need for close surveillance of resistanc ...201223232083
risk mapping of anopheles gambiae s.l. densities using remotely-sensed environmental and meteorological data in an urban area: dakar, senegal.high malaria transmission heterogeneity in an urban environment is basically due to the complex distribution of anopheles larval habitats, sources of vectors. understanding 1) the meteorological and ecological factors associated with differential larvae spatio-temporal distribution and 2) the vectors dynamic, both may lead to improving malaria control measures with remote sensing and high resolution data as key components. in this study a robust operational methodology for entomological malaria ...201223226351
multiple insecticide resistance in anopheles gambiae s.l. populations from burkina faso, west africa.malaria control programs are being jeopardized by the spread of insecticide resistance in mosquito vector populations. the situation in burkina faso is emblematic with anopheles gambiae populations showing high levels of resistance to most available compounds. although the frequency of insecticide target-site mutations including knockdown resistance (kdr) and insensitive acetylcholinesterase (ace-1(r)) alleles has been regularly monitored in the area, it is not known whether detoxifying enzymes ...201223189131
entomological indices of malaria transmission in chikhwawa district, southern malawi.although malaria is highly prevalent throughout malawi, little is known of its transmission dynamics. this paper describes the seasonal activity of the different vectors, human biting indices, sporozoite rates and the entomological inoculation rate in a low-lying rural area in southern malawi.201223171123
larval density dependence in anopheles gambiae s.s., the major african vector of malaria.anopheles gambiae sensu stricto is the most important vector of malaria in africa although relatively little is known about the density-dependent processes determining its population size. mosquito larval density was manipulated under semi-natural conditions using artificial larval breeding sites placed in the field in coastal kenya; two experiments were conducted: one manipulating the density of a single cohort of larvae across a range of densities and the other employing fewer densities but wi ...201323163565
biochemical characterization of anopheles gambiae srpn6, a malaria parasite invasion marker in mosquitoes.serine proteinase inhibitors of the serpin family are well known as negative regulators of hemostasis, thrombolysis and innate immune responses. additionally, non-inhibitory serpins serve functions as chaperones, hormone transporters, or anti-angiogenic factors. in the african malaria mosquito, anopheles gambiae s.s., at least three serpins (srpns) are implicated in the innate immune response against malaria parasites. based on reverse genetic and cell biological analyses, agsrpn6 limits parasit ...201223152794
decreased proportions of indoor feeding and endophily in anopheles gambiae s.l. populations following the indoor residual spraying and insecticide-treated net interventions in benin (west africa).in many parts of africa as in benin, the main strategies of vector control are based on the scaling-up of long lasting insecticide treated nets (llitns) and indoor residual spraying (irs). the need to understand the biological implications of irs in large scale and full coverage of llitns is paramount. it is in this context that the present study was conducted. it aims to evaluate the effect of a large scale irs using a non-pyrethroid insecticide and full coverage of deltamethrin treated nets on ...201223151270
electric nets and sticky materials for analysing oviposition behaviour of gravid malaria vectors.little is known about how malaria mosquitoes locate oviposition sites in nature. such knowledge is important to help devise monitoring and control measures that could be used to target gravid females. this study set out to develop a suite of tools that can be used to study the attraction of gravid anopheles gambiae s.s. towards visual or olfactory cues associated with aquatic habitats.201223151023
malaria transmission after five years of vector control on bioko island, equatorial guinea.malaria is endemic with year-round transmission on bioko island. the bioko island malaria control project (bimcp) started in 2004 with the aim to reduce malaria transmission and to ultimately eliminate malaria. while the project has been successful in reducing overall malaria morbidity and mortality, foci of high malaria transmission still persist on the island. results from the 2009 entomological collections are reported here.201223146423
species composition of the anopheles gambiae complex across eco-vegetational zones in bayelsa state, niger delta region, nigeria.correct vector identification is an important task in the planning and implementation of malaria vector control programmes. this study was designed to provide baseline information on the species composition and distribution of members of the anopheles gambiae complex in three eco-vegetational zones in bayelsa state, nigeria.201223135011
first report of the l1014s kdr mutation in wild populations of anopheles gambiae m and s molecular forms in burkina faso (west africa).we investigated the occurrence of the l1014f and l1014s kdr mutations in malaria vector populations in burkina faso (west africa). a cross-sectional survey was conducted at 10 sites all located in cotton cultivation areas which are assumed to be the major insecticide resistance selection foci in burkina faso. the hot ligation method was used to detect the two kdr mutations in field collected anopheles gambiae s.l. samples. for the first time in burkina faso the l1014s mutation was identified in ...201323128044
behavioural response of the malaria vector anopheles gambiae to host plant volatiles and synthetic blends.sugar feeding is critical for survival of malaria vectors and, although discriminative plant feeding previously has been shown to occur in anopheles gambiae s.s., little is known about the cues mediating attraction to these plants. in this study, we investigated the role of olfaction in an. gambiae discriminative feeding behaviour.201223069316
additional selection for insecticide resistance in urban malaria vectors: ddt resistance in anopheles arabiensis from bobo-dioulasso, burkina faso.in the city of bobo-dioulasso in burkina faso, anopheles arabiensis has superseded anopheles gambiae s.s. as the major malaria vector and the larvae are found in highly polluted habitats normally considered unsuitable for anopheles mosquitoes. here we show that an. gambiae s.l. adults emerging from a highly polluted site in the city centre (dioulassoba) have a high prevalence of ddt resistance (percentage mortality after exposure to diagnostic dose=65.8% in the dry season and 70.4% in the rainy ...201223049917
insecticide resistance monitoring of field-collected anopheles gambiae s.l. populations from jinja, eastern uganda, identifies high levels of pyrethroid resistance.insecticide resistance in the malaria vector anopheles gambiae s.l. (diptera: culicidae) threatens insecticide-based control efforts, necessitating regular monitoring. we assessed resistance in field-collected an. gambiae s.l. from jinja, uganda using world health organization (who) bioassays. only an. gambiae s.s. and an. arabiensis (≈70%) were present. female an. gambiae exhibited extremely high pyrethroid resistance (permethrin lt50 > 2 h; deltamethrin lt50 > 5 h). female an. arabiensis were ...201223046446
pyrethroid resistance in anopheles gambiae, in bomi county, liberia, compromises malaria vector control.long lasting insecticidal nets (llin) and indoor residual spraying (irs) have both proven to be effective malaria vector control strategies in africa and the new technology of insecticide treated durable wall lining (dl) is being evaluated. sustaining these interventions at high coverage levels is logistically challenging and, furthermore, the increase in insecticide resistance in african malaria vectors may reduce the efficacy of these chemical based interventions. monitoring of vector populati ...201223028724
variation in malaria transmission dynamics in three different sites in western kenya.the main objective was to investigate malaria transmission dynamics in three different sites, two highland villages (fort ternan and lunyerere) and a lowland peri-urban area (nyalenda) of kisumu city. adult mosquitoes were collected using psc and cdc light trap while malaria parasite incidence data was collected from a cohort of children on monthly basis. rainfall, humidity and temperature data were collected by automated weather stations. negative binomial and poisson generalized additive model ...201222988466
protective efficacy of menthol propylene glycol carbonate compared to n, n-diethyl-methylbenzamide against mosquito bites in northern tanzania.the reduction of malaria parasite transmission by preventing human-vector contact is critical in lowering disease transmission and its outcomes. this underscores the need for effective and long lasting arthropod/insect repellents. despite the reduction in malaria transmission and outcomes in tanzania, personal protection against mosquito bites is still not well investigated. this study sought to determine the efficacy of menthol propylene glycol carbonate (mr08), ocimum suave as compared to the ...201222950604
pyrethroid resistance in anopheles gambiae from the rubber cultivated area of niete, south region of cameroon.anti-vector intervention remains the most effective way of controlling malaria. although in cameroon and elsewhere focus is on the use of long-lasting insecticidal nets and indoor residual spraying, the efficacy of both methods greatly depends on the continuing susceptibility of the vectors to the insecticides used. the emergence and spread of insecticide resistance in the major malaria vectors constitute a huge challenge to control programmes. consequently, routine monitoring and evaluation of ...201222935317
effect of swamp cultivation on distribution of anopheline larval habitats in western kenya.malaria resurgence in highland regions of east africa has been on increase. the spatio-temporal distribution of larval habitats of malaria vectors determines the distribution of adult vectors, hence, disease transmission. vector's ecology is necessary for strategic vector control through effective plan for source reduction. mapping of the larval habitats is necessary for targeted control measures. the purpose of this study is to assess and compare the spatial and seasonal variations in anophelin ...022898476
modeling the role of environmental variables on the population dynamics of the malaria vector anopheles gambiae sensu stricto.the impact of weather and climate on malaria transmission has attracted considerable attention in recent years, yet uncertainties around future disease trends under climate change remain. mathematical models provide powerful tools for addressing such questions and understanding the implications for interventions and eradication strategies, but these require realistic modeling of the vector population dynamics and its response to environmental variables.201222877154
bio-efficacy of selected long-lasting insecticidal nets against pyrethroid resistant anopheles arabiensis from south-western ethiopia.the emergence and spread of insecticide resistance in the major african malaria vectors anopheles gambiae s.s. and anopheles arabiensis may compromise control initiatives based on insecticide-treated nets (itns) or indoor residual spraying (irs), and thus threaten the global malaria elimination strategy.201222871143
pyrethroid resistance in anopheles gambiae s.s. and anopheles arabiensis in western kenya: phenotypic, metabolic and target site characterizations of three populations.field and laboratory investigations revealed phenotypic, target site and metabolic resistance to permethrin in an anopheles gambiae s.s. (diptera: culicidae) population in bungoma district, a region in western kenya in which malaria is endemic and rates of ownership of insecticide-treated bednets are high. the sensitivity of individual an. gambiae s.l. females as indicated in assays using world health organization (who) test kits demonstrated reduced mortality in response to permethrin, deltamet ...201222861380
[late impact of lambdacyhalothrin-treated nets on kdr allelic frequency in anopheles gambiae s.s. (diptera: culicidae) from northern côte-d'ivoire].nets treated with lambdacyhalothrin 15 mg a.i./m2 were distributed in four villages of korhogo area in northern côte-d'ivoire, and four other villages without nets were followed as controls. mosquitoes were collected every three months from june 1999 to august 2000 in the villages, and then tested to determine their genotypes for kdr mutation l1014f conferring cross-resistance to pyrethroids and ddt and for m and s molecular forms of anopheles gambiae s.s. the frequencies of the resistant allele ...201222814881
three years of insecticide resistance monitoring in anopheles gambiae in burkina faso: resistance on the rise?a longitudinal anopheles gambiae s.l. insecticide-resistance monitoring programme was established in four sentinel sites in burkina faso. for three years, between 2008 and 2010, who diagnostic dose assays were used to measure the prevalence of resistance to all the major classes of insecticides at the beginning and end of the malaria transmission season. species identification and genotyping for target site mutations was also performed and the sporozoite rate in adults determined.201222799568
development of an allele-specific, loop-mediated, isothermal amplification method (as-lamp) to detect the l1014f kdr-w mutation in anopheles gambiae s. l.malaria control relies heavily on treated bed nets and indoor residual spraying with pyrethroid insecticides. unfortunately, the resistance to pyrethroid insecticides, mainly due to the kdr mutation, is spreading in the main malaria vector anopheles gambiae s.l., decreasing the insecticides' efficacy. to manage the insecticide resistance rapidly and flexibly, simple and effective tools for the early detection of resistant mosquitoes are needed. this study aimed to develop an allele-specific, loo ...201222770418
population dynamics of anopheles gambiae s.l. in bobo-dioulasso city: bionomics, infection rate and susceptibility to insecticides.historical studies have indicated that an. gambiae s.s. is the predominant malaria vector species in bobo-dioulasso the second biggest city of burkina faso (west africa). however, over the last decade, an. arabiensis appears to be replacing an. gambiae s.s. as the most prevalent malaria vector in this urban setting. to investigate this species transition in more detail the present study aims to provide an update on the malaria vector composition in bobo-dioulasso, and also the plasmodium infecti ...201222721002
evidence of carbamate resistance in urban populations of anopheles gambiae s.s. mosquitoes resistant to ddt and deltamethrin insecticides in lagos, south-western nigeria.resistance monitoring is essential in ensuring the success of insecticide based vector control programmes. this study was carried out to assess the susceptibility status of urban populations of anopheles gambiae to carbamate insecticide being considered for vector control in mosquito populations previously reported to be resistant to ddt and permethrin.201222686575
change in composition of the anopheles gambiae complex and its possible implications for the transmission of malaria and lymphatic filariasis in north-eastern tanzania.a dramatic decline in the incidence of malaria due to plasmodium falciparum infection in coastal east africa has recently been reported to be paralleled (or even preceded) by an equally dramatic decline in malaria vector density, despite absence of organized vector control. as part of investigations into possible causes for the change in vector population density, the present study analysed the anopheles gambiae s.l. sibling species composition in north-eastern tanzania.201222681999
efficacy of sunlight-activatable porphyrin formulates on larvae of anopheles gambiae m and s molecular forms and an. arabiensis: a potential novel biolarvicide for integrated malaria vector control.biolarvicides, such as microbial formulations based on bacillus thuringiensis and b. sphaericus, have been found to be highly effective against mosquito larvae and are currently employed as eco-friendly alternatives to synthetic chemical insecticides for vector control. recently, a porphyrin of natural origin has been suggested as a sunlight-activatable larvicide against the dengue vector aedes aegypti. in order to validate the approach for the control of the malaria vector, we tested the photo- ...201222668835
an affordable, quality-assured community-based system for high-resolution entomological surveillance of vector mosquitoes that reflects human malaria infection risk patterns.more sensitive and scalable entomological surveillance tools are required to monitor low levels of transmission that are increasingly common across the tropics, particularly where vector control has been successful. a large-scale larviciding programme in urban dar es salaam, tanzania is supported by a community-based (cb) system for trapping adult mosquito densities to monitor programme performance.201222624853
efficacy of icon® maxx in the laboratory and against insecticide-resistant anopheles gambiae in central côte d'ivoire.long-lasting treatment kits, designed to transform untreated nets into long-lasting insecticidal nets (llins), may facilitate high coverage with llins where non-treated nets are in place. in this study, the efficacy of icon® maxx (syngenta) was evaluated under laboratory conditions and in an experimental hut trial in central côte d'ivoire, where anopheles gambiae s.s. are resistant to pyrethroid insecticides.201222587687
mansonia africana and mansonia uniformis are vectors in the transmission of wuchereria bancrofti lymphatic filariasis in ghana.recent data from ghana indicates that after seven rounds of annual mass drug administration (mda) there is still sustained transmission albeit at low levels in certain areas where anopheles melas, an. gambiae s.s., mansonia and culex species are the main biting mosquitoes. anopheles gambiae s.l. and an. funestus are the known vectors in ghana and a recent report indicated that an. melas could transmit at low level microfilaraemia. however, because an. melas is not found everywhere there was the ...201222564488
the combination of npk fertilizer and deltamethrin insecticide favors the proliferation of pyrethroid-resistant anopheles gambiae (diptera: culicidae).in this laboratory study, we investigated how the biological cycle of anopheles gambiae s.s. (vkpr strain) would be like when grew in an environment containing more or less plant matter (2.5 or 5 g/l) and fertilizer (8-12-8 or 17-23-17 mg/l). half of the environments studied were not exposed to insecticide (control) whereas the other half was submitted to deltamethrin treatment at the concentration of 0.015 mg/l. the bioassays showed that 2.5 g/l of plant matter in water are not sufficient to fe ...022550627
spatial and temporal dynamics of malaria transmission in rural western kenya.understanding the relationship between plasmodium falciparum malaria transmission and health outcomes requires accurate estimates of exposure to infectious mosquitoes. however, measures of exposure such as mosquito density and entomological inoculation rate (eir) are generally aggregated over large areas and time periods, biasing the outcome-exposure relationship. there are few studies examining the extent and drivers of local variation in malaria exposure in endemic areas.201222541138
differential plasmodium falciparum infection of anopheles gambiae s.s. molecular and chromosomal forms in mali.anopheles gambiae sensu stricto (s.s.) is a primary vector of plasmodium falciparum in sub-saharan africa. although some physiological differences among molecular and chromosomal forms of this species have been demonstrated, the relative susceptibility to malaria parasite infection among them has not been unequivocally shown. the objective of this study was to investigate p. falciparum circumsporozoite protein infection (csp) positivity among an. gambiae s.s. chromosomal and molecular forms.201222540973
assessment of the effect of insecticide-treated nets and indoor residual spraying for malaria control in three rural kebeles of adami tulu district, south central ethiopia.in the adami tulu district, indoor residual spraying (irs) and insecticide-treated nets (itns) has been the main tool used to control malaria. the purpose of this study was to assess the effect of irs and itns control strategies in aneno shisho kebele (lowest administrative unit of ethiopia) compared with kamo gerbi (supplied itn only) and jela aluto (no irs and itns), with regards to the prevalence of malaria and mosquito density.201222533789
susceptibility status of malaria vectors to insecticides commonly used for malaria control in tanzania.the aim of the study was to monitor the insecticide susceptibility status of malaria vectors in 12 sentinel districts of tanzania.201222519840
single-nucleotide polymorphisms for high-throughput genotyping of anopheles arabiensis in east and southern africa.anopheles arabiensis patton is one of the principal vectors of malaria in sub-saharan africa, occupying a wide variety of ecological zones. this species is increasingly responsible for malaria transmission in africa and is becoming the dominant vector species in some localities. despite its growing importance, little is known about genetic polymorphisms in this species. multiple sequences of various gene fragments from an. arabiensis isolates from cameroon were obtained from genbank. in total, 2 ...022493848
impact of three years of large scale indoor residual spraying (irs) and insecticide treated nets (itns) interventions on insecticide resistance in anopheles gambiae s.l. in benin.in benin, indoor residual spraying (irs) and long-lasting insecticidal nets (llins) are the cornerstones of malaria prevention. in the context of high resistance of anopheles gambiae to pyrethroids, the national malaria control program (nmcp) has undertaken a full coverage of irs in a no-flood zone in the oueme region, coupled with the distribution of llins in a flood zone. we assessed the impact of this campaign on phenotypic resistance, kdr (knock-down resistance) and ace-1(r) (insensitive ace ...201222490146
update on resistance status of anopheles gambiae s.s. to conventional insecticides at a previous whopes field site, "yaokoffikro", 6 years after the political crisis in côte d'ivoire.at yaokoffikro field site near bouaké, in central côte d'ivoire, a group of experimental huts built in 1996 served over many years for the evaluation of insecticides against highly resistant mosquitoes. breeding sites of mosquitoes and selection pressure in the area were maintained by local farming practices until a war broke out in september 2002. six years after the crisis, we conducted bioassays and biochemical analysis to update the resistance status of anopheles gambiae s.s. populations and ...201222472088
malaria vectors in lake victoria and adjacent habitats in western kenya.the prevalence of malaria among the residents of the lake victoria basin remains high. the environment associated with the lake may maintain a high number of malaria vectors. lake habitats including water hyacinths have been suspected to be the source of vectors. this study investigated whether malaria vectors breed in the lake habitats and adjacent backwater pools. anopheline larvae were collected within the littoral zone of the lake and adjacent pools located along approximately 24.3 km of the ...201222412913
[bio-ecological characteristics of anopheles gambiae s.s. in irrigated rice fields of central côte d'ivoire].this longitudinal entomological survey was conducted between september 2008 and september 2009 in the villages of abokro and yaokoffikro located in an irrigated rice farming area of central côte d'ivoire. the purpose was to investigate the bio-ecological characteristics of anopheles gambiae s.s. during the gonotrophic cycle. in both villages, adult mosquitoes were captured in 72 light traps, collected on humans subjects at a rate of 72 man-night from 6 p.m. to 6 a.m., and knocked down using pyre ...201122393624
the vector population monitoring tool (vpmt): high-throughput dna-based diagnostics for the monitoring of mosquito vector populations.regular monitoring of mosquito vector populations is an integral component of most vector control programmes. contemporary data on mosquito species composition, infection status, and resistance to insecticides are a prerequisite for effective intervention. for this purpose we, with funding from the innovative vector control consortium (ivcc), have developed a suite of high-throughput assays based on a single "closed-tube" platform that collectively comprise the "vector population monitoring tool ...201022347668
effects of co-habitation between anopheles gambiae s.s. and culex quinquefasciatus aquatic stages on life history traits.the effective measures for the control of malaria and filariasis vectors can be achieved by targeting immature stages of anopheline and culicine mosquitoes in productive habitat. to design this strategy, the mechanisms (like biotic interactions with conspecifc and heterospecific larvae) regulating mosquito aquatic stages survivorship, development time and the size of emerging adults should be understood. this study explored the effect of co-habitation between an. gambiae s.s. and cx. quinquefasc ...201222321562
malaria transmission in libreville: results of a one year survey.in gabon, vector transmission has been poorly studied. since the implementation of the roll back malaria recommendations, clinical studies have shown a decline in the burden of malaria in libreville, the capital city of gabon. to better understand the transmission dynamic in libreville, an entomological survey was conducted in five districts of the city.201222321336
[agricultural activities and epidemiology of malaria in soudano-sahelian zone in cameroon].we have comparatively studied the dynamics of malaria transmission in the villages of mokolo-douvar located in the rural area with traditional agriculture and gounougou irrigated rice area, in 2004 august and november and 2006 may and october, to assess vectors biting habits, and malaria inoculation rate and malaria parasite prevalence in cohort of children from 0 to 15 years. mosquitoes were collected by landing catches on volunteers and by pyrethrum spray collections. a total of 5961 anopheles ...201222294407
aging partially restores the efficacy of malaria vector control in insecticide-resistant populations of anopheles gambiae s.l. from burkina faso.abstract: background: the operational impact of insecticide resistance on the effectiveness of long-lasting insecticide nets (llins) and indoor residual spraying (irs) is poorly understood. one factor which may prolong the effectiveness of these tools in the field is the increase in insecticide susceptibility with mosquito age. in this study, llins and irs were tested against young (three to five days) and old (17-19 days) pyrethroid resistant anopheles gambiae s.l. from burkina faso. methods: ...201222269002
the impact of uniform and mixed species blood meals on the fitness of the mosquito vector anopheles gambiae s.s: does a specialist pay for diversifying its host species diet?we investigated the fitness consequences of specialization in an organism whose host choice has an immense impact on human health: the african malaria vector anopheles gambiae s.s. we tested whether this mosquito's specialism on humans can be attributed to the relative fitness benefits of specialist vs. generalist feeding strategies by contrasting their fecundity and survival on human-only and mixed host diets consisting of blood meals from humans and animals. when given only one blood meal, an. ...201222221693
Impact of insecticide-treated bed nets on malaria transmission indices on the south coast of Kenya.ABSTRACT: BACKGROUND: Besides significantly reducing malaria vector densities, prolonged usage of bed nets has been linked to decline of Anopheles gambiae s.s. relative to Anopheles arabiensis, changes in host feeding preference of malaria vectors, and behavioural shifts to exophagy (outdoor biting) for the two important malaria vectors in Africa, An. gambiae s.l. and Anopheles funestus. In southern coastal Kenya, bed net use was negligible in 1997-1998 when Anopheles funestus and An. gambiae s ...201122165904
anopheles gambiae resistance to pyrethroid-treated nets in cotton versus rice areas in mali.the rise and spread of anopheles gambiae s.l. (the major malaria vector sub-saharan africa) resistance to pyrethroids is of great concern owing to the predominant role of pyrethroid-treated nets in the who global strategy for malaria control. use of pyrethroids for agricultural purposes may exert a strong selection pressure, favouring the emergence of insecticide resistance. the objective of this study was to evaluate the efficacy of alpha-cypermethrin treated nets in settings where insecticides ...201122154879
Morphological Differentiation May Mediate Mate-Choice between Incipient Species of Anopheles gambiae s.s.The M and S molecular forms of Anopheles gambiae s.s. have been considered incipient species for more than ten years, yet the mechanism underlying assortative mating of these incipient species has remained elusive. The discovery of the importance of harmonic convergence of wing beat frequency in mosquito mating and its relation to wing size have laid the foundation for exploring phenotypic divergence in wing size of wild populations of the two forms. In this study, wings from field collected mos ...201122132169
Asymmetric introgression between the M and S forms of the malaria vector, Anopheles gambiae, maintains divergence despite extensive hybridization.The suggestion that genetic divergence can arise and/or be maintained in the face of gene flow has been contentious since first proposed. This controversy and a rarity of good examples have limited our understanding of this process. Partially reproductively isolated taxa have been highlighted as offering unique opportunities for identifying the mechanisms underlying divergence with gene flow. The African malaria vector, Anopheles gambiae s.s., is widely regarded as consisting of two sympatric fo ...201122059383
variations of insecticide residual bio-efficacy on different types of walls: results from a community-based trial in south cameroon.determination of residual activity of insecticides is essential information for the selection of appropriate indoor spraying operation. the present study was undertaken to evaluate the residual effect of three candidate insecticide formulations on different indoor surfaces in order to guide future interventions, in the context of cameroon and other african countries.201122047173
kdr-based insecticide resistance in anopheles gambiae s.s populations in.abstract: background: the spread of insecticide resistance in the malaria mosquito, anopheles gambiae is a serious threat for current vector control strategies which rely on the use of insecticides. two mutations at position 1014 of the s6 transmembrane segment of domain ii in the voltage gated sodium channel, known as kdr (knockdown resistance) mutations leading to a change of a leucine to a phenylalanine (l1014f) or to a serine (l1014s) confer resistance to ddt and pyrethroid insecticides in ...201122035176
repellent plants provide affordable natural screening to prevent mosquito house entry in tropical rural settings--results from a pilot efficacy study.sustained malaria control is underway using a combination of vector control, prompt diagnosis and treatment of malaria cases. progress is excellent, but for long-term control, low-cost, sustainable tools that supplement existing control programs are needed. conventional vector control tools such as indoor residual spraying and house screening are highly effective, but difficult to deliver in rural areas. therefore, an additional means of reducing mosquito house entry was evaluated: the screening ...201122022471
Conditions of malaria transmission in Dakar from 2007 to 2010.Previous studies in Dakar have highlighted the spatial and temporal heterogeneity of Anopheles gambiae s.l. biting rates. In order to improve the knowledge of the determinants of malaria transmission in this city, the present study reports the results of an extensive entomological survey that was conducted in 45 areas in Dakar from 2007 to 2010.201122018223
molecular characterization and evolution of a gene family encoding male-specific reproductive proteins in the african malaria vector anopheles gambiae.during copulation, the major afro-tropical malaria vector anopheles gambiae s.s. transfers male accessory gland (mag) proteins to females as a solid mass (i.e. the "mating plug"). these proteins are postulated to function as important modulators of female post-mating responses. to understand the role of selective forces underlying the evolution of these proteins in the a. gambiae complex, we carried out an evolutionary analysis of gene sequence and expression divergence on a pair of paralog gene ...201121978124
Population genetic structure of Anopheles arabiensis and Anopheles gambiae in a malaria endemic region of southern Tanzania.Genetic diversity is a key factor that enables adaptation and persistence of natural populations towards environmental conditions. It is influenced by the interaction of a natural population's dynamics and the environment it inhabits. Anopheles gambiae s.s. and Anopheles arabiensis are the two major and widespread malaria vectors in sub-Saharan Africa. Several studies have examined the ecology and population dynamics of these vectors. Ecological conditions along the Kilombero valley in Tanzania ...201121975087
the role of cow urine in the oviposition site preference of culicine and anopheles mosquitoes.chemical and behavioural ecology of mosquitoes plays an important role in the development of chemical cue based vector control. to date, studies available have focused on evaluating mosquito attractants and repellents of synthetic and human origins. this study, however, was aimed at seasonal evaluation of the efficiency of cow urine in producing oviposition cues to anopheles gambiae s.l. and culex quinquefasciatus in both laboratory and field conditions.201121943071
Field and Laboratory Evaluation of Bioefficacy of an Insect Growth Regulator (Dimilin) as a Larvicide against Mosquito and Housefly Larvae.The inhibitory function of Dimilin (Diflubenzuron), mostly a chitin synthesis regulator, on the ecdysis of mosquitoes (Anopheles gambiae s.l., Culex quinquefasciatus) and housefly was evaluated in the field and in laboratory. Three formulations of Diflubenzuron were evaluated in this study: Dimilin, Wettable powder (25%), Dimilin granules (2%), and Dimilin tablets (2%). The laboratory and field evaluation used different rates of concentrations of these formulations. Generally, at higher dosages ...201121941567
distribution of a knockdown resistance mutation (l1014s) in anopheles gambiae s.s. and anopheles arabiensis in western and southern kenya.in kenya, insecticide-treated mosquito nets (itns) distributed to pregnant women and children under 5 years old through various programs have resulted in a significant reduction in malaria deaths. all of the world health organization-recommended insecticides for mosquito nets are pyrethroids, and vector mosquito resistance to these insecticides is one of the major obstacles to an effective malaria control program. anopheles gambiae s.s. and anopheles arabiensis are major malaria vectors that are ...201121931682
Comparative susceptibility to Plasmodium falciparum of the molecular forms M and S of Anopheles gambiae and Anopheles arabiensis.The different taxa belonging to Anopheles gambiae complex display phenotypic differences that may impact their contribution to malaria transmission. More specifically, their susceptibility to infection, resulting from a co-evolution between parasite and vector, might be different. The aim of this study was to compare the susceptibility of M and S molecular forms of Anopheles gambiae and Anopheles arabiensis to infection by Plasmodium falciparum.201121929746
insecticide resistance and the future of malaria control in zambia.in line with the global trend to improve malaria control efforts a major campaign of insecticide treated net distribution was initiated in 1999 and indoor residual spraying with ddt or pyrethroids was reintroduced in 2000 in zambia. in 2006, these efforts were strengthened by the president's malaria initiative. this manuscript reports on the monitoring and evaluation of these activities and the potential impact of emerging insecticide resistance on disease transmission.201121915314
Dynamics of insecticide resistance in malaria vectors in Benin: first evidence of the presence of L1014S kdr mutation in Anopheles gambiae from West Africa.Insecticide resistance monitoring is essential to help national programmers to implement more effective and sustainable malaria control strategies in endemic countries. This study reported the spatial and seasonal variations of insecticide resistance in malaria vectors in Benin, West Africa.201121910856
efficacy of long-lasting insecticidal nets in use in macha, zambia, against the local anopheles arabiensis population.the mosquito anopheles arabiensis is the primary vector of plasmodium falciparum in macha, zambia. a major portion of zambia's current malaria control programme relies on long-lasting insecticide-treated nets (llins) and indoor residual spraying (irs) with insecticides. currently, the efficacy of these measures against an. arabiensis in macha is unknown, and previous data has shown that an. arabiensis has continued to feed on human hosts, despite high itn coverage. it is possible that this could ...201121880143
Multimodal pyrethroid resistance in malaria vectors, Anopheles gambiae s.s., Anopheles arabiensis, and Anopheles funestus s.s. in western Kenya.Anopheles gambiae s.s., Anopheles arabiensis, and Anopheles funestus s.s. are the most important species for malaria transmission. Pyrethroid resistance of these vector mosquitoes is one of the main obstacles against effective vector control. The objective of the present study was to monitor the pyrethroid susceptibility in the 3 major malaria vectors in a highly malaria endemic area in western Kenya and to elucidate the mechanisms of pyrethroid resistance in these species. Gembe East and West, ...201121853038
sampling of an.gambiae s.s mosquitoes using limburger cheese, heat and moisture as baits in a homemade trap.abstract:201121835032
[Resistance of Anopheles gambiae s.l. to pyrethroids and DDT at Tiassal+®kro, an irrigated rice-growing village in the southern forest of Ivory Coast.]An assessment of the sensitivity of Anopheles gambiae s.l.to three pyrethroids (alphacypermethrin, permethrin, deltamethrin) and DDT has been carried out with a laboratory strain (Kisumu reference sensitive strain) and a wild strain (Tiassal+®kro strain) using larvae from an irrigated rice-growing area of Tiassal+®kro, located in the southern forest of Ivory Coast. The sensitivity tests were performed according to the standard WHO cylinder tests with adult female A. gambiae s.l. aged 2 to 4 days ...201121818678
evaluating rnalater-« as a preservative for using near-infrared spectroscopy to predict anopheles gambiae age and species.abstract:201121740582
insecticidal activity of the essential oil from fruits and seeds of schinus terebinthifolia raddi against african malaria vectors.alternative insecticides for the control of malaria and filarial vectors are of paramount need as resistance is increasing among classes of insecticides currently in use in the public health sector. in this study, mosquitocidal activity of schinus terebinthifolia essential oil against anopheles gambiae s.s., an. arabiensis and culex quinquefasciatus was assessed in laboratory, semi- field and full- field conditions201121729280
predation efficiency of anopheles gambiae larvae by aquatic predators in western kenya highlands.the current status of insecticide resistance in mosquitoes and the effects of insecticides on non-target insect species have raised the need for alternative control methods for malaria vectors. predation has been suggested as one of the important regulation mechanisms for malaria vectors in long-lasting aquatic habitats, but the predation efficiency of the potential predators is largely unknown in the highlands of western kenya. in the current study, we examined the predation efficiency of five ...201121729269
insecticide susceptibility profile of the principal malaria vector, anopheles gambiae s.l. (diptera: culicidae), in north-central nigeria. 201121715735
Insecticide resistance in malaria vector mosquitoes at four localities in Ghana, West Africa.ABSTRACT:201121679391
malaria prevalence pattern observed in the highland fringe of butajira, southern ethiopia: a longitudinal study from parasitological and entomological survey.abstract: background: in ethiopia, information regarding highland malaria transmission is scarce, and no report has been presented from butajira highland so far whether the appearance of malaria in the area was due to endemicity or due to highland malaria transmission. thus this study aimed to determine the presence and magnitude of malaria transmission in butajira. methods: for parasitological survey, longitudinal study was conducted from october to december 2006. the entomological surveys were ...201121649923
gut content identification of larvae of the anopheles gambiae complex in western kenya using a barcoding approach.although larvae feeding and food source are vital to the development, survival and population regulation of african malaria vectors, the prey organisms of anopheles gambiae larvae in the natural environment have not been well studied. this study used a molecular barcoding approach to investigate the natural diets of anopheles gambiae s.l. larvae in western kenya. gut contents from third- and fourth-instar larvae from natural habitats were dissected and dna was extracted. the 18s ribosomal dna ge ...200821585828
the emergence of insecticide resistance in central mozambique and potential threat to the successful indoor residual spraying malaria control programme.abstract:201121535872
cotton pest management practices and the selection of pyrethroid resistance in anopheles gambiae population in northern benin.abstract:201121489266
the efficacy of actellic 50 ec, pirimiphos methyl, for indoor residual spraying in ahafo, ghana: area of high vector resistance to pyrethroids and organochlorines.insecticide resistance in the main malaria vectors in africa is a major concern for malaria vector control program managers. the most common insecticides used for indoor residual spraying (irs) and treating bed nets are becoming increasingly ineffective. the quest for safer and more effective insecticides for malaria vector control is urgent. this study sought to evaluate the efficacy of actellic 50 ec (pirimiphos methyl), an organophosphate, for irs in ghana, where there is high vector resistan ...201121485386
development of fungal applications on netting substrates for malaria vector control.mosquito resistance to chemical insecticides is considered a serious threat for the sustainable use of contemporary malaria vector control methods. fungal entomopathogens show potential as alternative biological control agents against (insecticide-resistant) anophelines. this study was designed to test whether the fungus, beauveria bassiana, could be delivered to mosquitoes on netting materials that might be used in house screens, such as eave curtains. tests were conducted to determine effects ...201121485366
factors influencing differential larval habitat productivity of anopheles gambiae complex mosquitoes in a western kenyan village.the study was undertaken to characterize factors influencing differential productivity of anopheles gambiae complex mosquitoes at larval habitats in a rural village in western kenya.201121406738
mosquito salivary gland protein preservation in the field for immunological and biochemical analysis.mosquito salivary proteins are involved in several biological processes that facilitate their blood feeding and have also been reported to elicit an igg response in vertebrates. a growing number of studies have focused on this immunological response for its potential use as a biological marker of exposure to arthropod bites. as mosquito saliva collection is extremely laborious and inefficient, most research groups prefer to work on mosquito salivary glands (sgs). thus, sg protein integrity is a ...201121385450
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