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marked biological differences between insecticide resistant and susceptible strains of anopheles funestus infected with the murine parasite plasmodium berghei.anopheles funestus is one of the major malaria vectors in africa but research on this species has been restricted due to the lack of viable laboratory colonies. the vectorial capacity of natural populations of an. funestus is well known but its ability to host plasmodium in the laboratory and the development cycle of the parasite within this mosquito species was, until very recently, unknown. in this study we compared laboratory strains of an. funestus that were resistant and susceptible to pyre ...201323782642
a first report of anopheles funestus sibling species in western kenya highlands.understanding disease vector composition is of priority in designing effective disease control programs. in integrated vector control management, understanding of disease vector species among species complexes simplifies priorities for effective control tools selection. this study identified members of the anopheles funestus complex sampled in western kenya from 2002 to 2011 from different breeding sites. larval sampling was carried out using the standard dipper (350ml) in larval habitats in wes ...201323792011
detection of clade types (clades i and ii) within anopheles funestus sensu stricto by the hydrolysis probe analysis (taqman assay).recent studies presented two clades (clades i and ii) within the major malaria vector, anopheles funestus s.s. on the mitochondrial dna. we describe a hydrolysis probe analysis (taqman assay) method for the rapid identification of these two clades.201323758959
asymptomatic plasmodium infection and cognition among primary schoolchildren in a high malaria transmission setting in uganda.asymptomatic parasitemia is common among schoolchildren living in areas of high malaria transmission, yet little is known about its effect on cognitive function in these settings. to investigate associations between asymptomatic parasitemia, anemia, and cognition among primary schoolchildren living in a high malaria transmission setting, we studied 740 children enrolled in a clinical trial in tororo, uganda. parasitemia, measured by thick blood smears, was present in 30% of the children. infecte ...201323589533
an age-size reaction norm yields insight into environmental interactions affecting life-history traits: a factorial study of larval development in the malaria mosquito anopheles gambiae sensu stricto.environmental factors frequently act nonindependently to determine growth and development of insects. because age and size at maturity strongly influence population dynamics, interaction effects among environmental variables complicate the task of predicting dynamics of insect populations under novel conditions. we reared larvae of the african malaria mosquito anopheles gambiae sensu stricto (s.s.) under three factors relevant to changes in climate and land use: food level, water depth, and temp ...201323919132
physical condition of olyset® nets after five years of utilization in rural western kenya.long-lasting insecticidal nets (llins) are a cornerstone of malaria control at present, and millions are used each day across the globe. however, there is limited information about the durability of llins under different conditions of utilization and there is no consensus about when a llin ceases to be protective due to physical deterioration. this knowledge is important for malaria control programmes to plan for procurement and replacement.201323663421
transcriptomic and proteomic responses of sweetpotato whitefly, bemisia tabaci, to thiamethoxam.the sweetpotato whitefly, bemisia tabaci (hemiptera: aleyrodidae), is one of the most widely distributed agricultural pests. although it has developed resistance to many registered insecticides including the neonicotinoid insecticide thiamethoxam, the mechanisms that regulate the resistance are poorly understood. to understand the molecular basis of thiamethoxam resistance, "omics" analyses were carried out to examine differences between resistant and susceptible b. tabaci at both transcriptiona ...201323671574
community perceptions of a malaria vaccine in the kintampo districts of ghana.malaria remains the leading cause of morbidity and mortality in sub-saharan africa despite tools currently available for its control. making malaria vaccine available for routine use will be a major hallmark, but its acceptance by community members and health professionals within the health system could pose considerable challenge as has been found with the introduction of polio vaccinations in parts of west africa. some of these challenges may not be expected since decisions people make are man ...201323651533
insecticide resistance status of anopheles gambiae s.s population from m'bé: a whopes-labelled experimental hut station, 10 years after the political crisis in côte d'ivoire.an experimental hut station built at m'bé in 1998 was used for many years for the evaluation of insecticidal product for public health until the civil war broke out in 2002. breeding sites of mosquitoes and selection pressure in the area were maintained by local farming practices and the west african rice development association (warda, actually africarice) in a large rice growing area. ten years after the crisis, bioassays, molecular and biochemical analyses were conducted to update the resista ...201323641777
using a new odour-baited device to explore options for luring and killing outdoor-biting malaria vectors: a report on design and field evaluation of the mosquito landing box.mosquitoes that bite people outdoors can sustain malaria transmission even where effective indoor interventions such as bednets or indoor residual spraying are already widely used. outdoor tools may therefore complement current indoor measures and improve control. we developed and evaluated a prototype mosquito control device, the 'mosquito landing box' (mlb), which is baited with human odours and treated with mosquitocidal agents. the findings are used to explore technical options and challenge ...201323642306
a 3d analysis of flight behavior of anopheles gambiae sensu stricto malaria mosquitoes in response to human odor and heat.female mosquitoes use odor and heat as cues to navigate to a suitable landing site on their blood host. the way these cues affect flight behavior and modulate anemotactic responses, however, is poorly understood. we studied in-flight behavioral responses of females of the nocturnal malaria mosquito anopheles gambiae sensu stricto to human odor and heat. flight-path characteristics in a wind tunnel (flow 20 cm/s) were quantified in three dimensions. with wind as the only stimulus (control), short ...201323658792
the effect of indoor residual spraying on malaria and anemia in a high-transmission area of northern uganda.indoor residual spraying (irs) with insecticide is now recommended for malaria control in high-transmission settings. however, concerns about insecticide resistance have increased. we conducted a cross-sectional household survey in high-transmission northern uganda in two districts previously sprayed with pyrethroids before documentation of pyrethroid resistance and at least one round of carbamates and in one contiguous district that was not sprayed. parasitemia prevalence among children < 5 yea ...201323458956
impact of indoor residual spraying of lambda-cyhalothrin on malaria prevalence and anemia in an epidemic-prone district of muleba, north-western tanzania.the government of tanzania introduced indoor residual spraying (irs) in muleba district in north-western tanzania after frequent malaria epidemics. malaria parasitological baseline and two cross-sectional follow-up surveys were conducted in villages under the irs program and those not under irs to assess the impact of irs intervention. after two rounds of irs intervention there was a significant reduction of malaria parasitological indices in both two villages. in irs villages overall, parasitem ...201323458959
stable and fluctuating temperature effects on the development rate and survival of two malaria vectors, anopheles arabiensis and anopheles funestus.understanding the biology of malaria vector mosquitoes is crucial to understanding many aspects of the disease, including control and future outcomes. the development rates and survival of two afrotropical malaria vectors, anopheles arabiensis and anopheles funestus, are investigated here under conditions of constant and fluctuating temperatures. these data can provide a good starting point for modelling population level consequences of temperature change associated with climate change. for comp ...201323590860
wild anopheles funestus mosquito genotypes are permissive for infection with the rodent malaria parasite, plasmodium berghei.malaria parasites undergo complex developmental transitions within the mosquito vector. a commonly used laboratory model for studies of mosquito-malaria interaction is the rodent parasite, p. berghei. anopheles funestus is a major malaria vector in sub-saharan africa but has received less attention than the sympatric species, anopheles gambiae. the imminent completion of the a. funestus genome sequence will provide currently lacking molecular tools to describe malaria parasite interactions in th ...201323593423
integrin triplets of marine sponges in the murine and human mhci-cd8 interface and in the interface of human neural receptor heteromers and subunits.based on our theory, main triplets of amino acid residues have been discovered in cell-adhesion receptors (integrins) of marine sponges, which participate as homologies in the interface between two major immune molecules, mhc class i (mhci) and cd8αβ. they appear as homologies also in several human neural receptor heteromers and subunits. the obtained results probably mean that neural and immune receptors also utilize these structural integrin triplets to form heteromers and ion channels, which ...201323556147
a need for better housing to further reduce indoor malaria transmission in areas with high bed net coverage.the suppression of indoor malaria transmission requires additional interventions that complement the use of insecticide treated nets (itns) and indoor residual spraying (irs). previous studies have examined the impact of house structure on malaria transmission in areas of low transmission. this study was conducted in a high transmission setting and presents further evidence about the association between specific house characteristics and the abundance of endophilic malaria vectors.201323497471
the benefits or otherwise of managing malaria cases with or without laboratory diagnosis: the experience in a district hospital in ghana.this study was conducted at the kintampo municipal hospital in ghana to determine whether there was any benefit (or otherwise) in basing the management of cases of suspected malaria solely on laboratory confirmation (microscopy or by rdt) as compared with presumptive diagnosis.201323505457
the impact of host species and vector control measures on the fitness of african malaria vectors.many malaria vector mosquitoes in africa have an extreme preference for feeding on humans. this specialization allows them to sustain much higher levels of transmission than elsewhere, but there is little understanding of the evolutionary forces that drive this behaviour. in tanzania, we used a semi-field system to test whether the well-documented preferences of the vectors, anopheles arabiensis and anopheles gambiae sensu stricto (s.s.) for cattle and humans, respectively, are predicted by the ...201323303548
the genetic architecture of degenerin/epithelial sodium channels in drosophila.degenerin/epithelial sodium channels (deg/enac) represent a large family of animal-specific membrane proteins. although the physiological functions of most family members are not known, some have been shown to act as nonvoltage gated, amiloride-sensitive sodium channels. the deg/enac family is exceptionally large in genomes of drosophila species relative to vertebrates and other insects. to elucidate the evolutionary history of the deg/enac family in drosophila, we took advantage of the genomic ...201323449991
identifying permethrin resistance loci in malaria vectors by genetic mapping.identification of the major loci responsible for insecticide resistance in malaria vectors would aid the development and implementation of effective resistance management strategies, which are urgently needed to tackle the growing threat posed by resistance to the limited insecticides available for malaria control. genome-wide association studies in the major malaria vector, anopheles gambiae, have been hindered by the high degree of within-population structuring and very low levels of linkage d ...201323448678
malariometric indices among nigerian children in a rural setting.malaria contributes to high childhood morbidity and mortality in nigeria. to determine its endemicity in a rural farming community in the south-south of nigeria, the following malariometric indices, namely, malaria parasitaemia, spleen rates, and anaemia were evaluated in children aged 2-10 years. this was a descriptive cross-sectional survey among school-age children residing in a rubber plantation settlement. the children were selected from six primary schools using a multistaged stratified cl ...201323533951
profile of janet hemingway. 201323440199
plasmodium species occurrence, temporal distribution and interaction in a child-aged population in rural burkina faso.malaria can be caused by five plasmodium species. due to their higher prevalence, much of the research concentrates on plasmodium falciparum and plasmodium vivax. in burkina faso, where p. falciparum co-exists with plasmodium malariae and plasmodium ovale, there is not much data about the prevalence of the latter two species across human population. moreover, interactions between co-infecting plasmodium species are not documented. the aim of the current research is to determine species-specific ...201323421809
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
characterization of the transcriptome of an ecologically important avian species, the vinous-throated parrotbill paradoxornis webbianus bulomachus (paradoxornithidae; aves).adaptive divergence driven by environmental heterogeneity has long been a fascinating topic in ecology and evolutionary biology. the study of the genetic basis of adaptive divergence has, however, been greatly hampered by a lack of genomic information. the recent development of transcriptome sequencing provides an unprecedented opportunity to generate large amounts of genomic data for detailed investigations of the genetics of adaptive divergence in non-model organisms. herein, we used the illum ...201222530590
functional organization and its implication in evolution of the human protein-protein interaction network.based on the distinguishing properties of protein-protein interaction networks such as power-law degree distribution and modularity structure, several stochastic models for the evolution of these networks have been purposed, motivated by the idea that a validated model should reproduce similar topological properties of the empirical network. however, being able to capture topological properties does not necessarily mean it correctly reproduces how networks emerge and evolve. more importantly, th ...201222530615
artemisinin-based combination therapy does not measurably reduce human infectiousness to vectors in a setting of intense malaria transmission.artemisinin-based combination therapy (act) for treating malaria has activity against immature gametocytes. in theory, this property may complement the effect of terminating otherwise lengthy malaria infections and reducing the parasite reservoir in the human population that can infect vector mosquitoes. however, this has never been verified at a population level in a setting with intense transmission, where chronically infectious asymptomatic carriers are common and cured patients are rapidly a ...201222513162
footprints of positive selection associated with a mutation (n1575y) in the voltage-gated sodium channel of anopheles gambiae.insecticide resistance is an ideal model to study the emergence and spread of adaptative variants. in the african malaria mosquito, anopheles gambiae, this is complemented by a strong public health rationale. in this insect, resistance to pyrethroid and ddt insecticides is strongly associated with the mutations l1014f and l1014s within the para voltage-gated sodium channel (vgsc). across much of west africa, 1014f frequency approaches fixation. here, we document the emergence of a mutation, n157 ...201222493253
selection of mosquito life-histories: a hidden weapon against malaria?there has recently been a substantial decline in malaria incidence in much of africa. while the decline can clearly be linked to increasing coverage of mosquito vector control interventions and effective drug treatment in most settings, the ubiquity of reduction raises the possibility that additional ecological and associated evolutionary changes may be reinforcing the effectiveness of current vector control strategies in previously unanticipated ways.201222471997
a refined estimate of the malaria burden in niger.the health authorities of niger have implemented several malaria prevention and control programmes in recent years. these interventions broadly follow who guidelines and international recommendations and are based on interventions that have proved successful in other parts of africa. most performance indicators are satisfactory but, paradoxically, despite the mobilization of considerable human and financial resources, the malaria-fighting programme in niger seems to have stalled, as it has not y ...201222453027
exploiting the behaviour of wild malaria vectors to achieve high infection with fungal biocontrol agents.control of mosquitoes that transmit malaria has been the mainstay in the fight against the disease, but alternative methods are required in view of emerging insecticide resistance. entomopathogenic fungi are candidate alternatives, but to date, few trials have translated the use of these agents to field-based evaluations of their actual impact on mosquito survival and malaria risk. mineral oil-formulations of the entomopathogenic fungi metarhizium anisopliae and beauveria bassiana were applied u ...201222449130
utilization of combined remote sensing techniques to detect environmental variables influencing malaria vector densities in rural west africa.the use of remote sensing has found its way into the field of epidemiology within the last decades. with the increased sensor resolution of recent and future satellites new possibilities emerge for high resolution risk modeling and risk mapping.201222443452
antibodies to malaria vaccine candidates are associated with chloroquine or sulphadoxine/pyrimethamine treatment efficacy in children in an endemic area of burkina faso.patient immune status is thought to affect the efficacy of anti-malarial chemotherapy. this is a subject of some importance, since evidence of immunity-related interactions may influence our use of chemotherapy in populations with drug resistance, as well as assessment of the value of suboptimal vaccines. the study aim was to investigate relationship between antibodies and anti-malarial drug treatment outcomes.201222439695
first malaria infections in a cohort of infants in benin: biological, environmental and genetic determinants. description of the study site, population methods and preliminary results.malaria infection of the placenta during pregnancy was found to be associated with infant susceptibility to malaria. other factors such as the intensity of malaria transmission and the nutritional status of the child might also play a role, which has not been adequately taken into account in previous studies. the aim of this study was to assess precisely the parts played by environmental, nutritional and biological determinants in first malaria infections, with a special interest in the role of ...201222403339
integrated mosquito larval source management reduces larval numbers in two highland villages in western kenya.in western kenya, malaria remains one of the major health problems and its control remains an important public health measure. malaria control is by either use of drugs to treat patients infected with malaria parasites or by controlling the vectors. vector control may target the free living adult or aquatic (larval) stages of mosquito. the most commonly applied control strategies target indoor resting mosquitoes. however, because mosquitoes spend a considerable time in water, targeting the aquat ...201222607227
dry season reproductive depression of anopheles gambiae in the sahel.the african malaria mosquito, anopheles gambiae, is widespread south of the sahara including in dry savannahs and semi-arid environments where no surface water exists for several months a year. adults of the m form of an. gambiae persist through the long dry season, when no surface waters are available, by increasing their maximal survival from 4 weeks to 7 months. dry season diapause (aestivation) presumably underlies this extended survival. diapause in adult insects is intrinsically linked to ...201222609421
identification and classification of detoxification enzymes from culex quinquefasciatus (diptera: culicidae).molecular characterization of the insecticide resistance has become a hot research topic ever since the first disease transmitting arthropod (anopheles gambiae) genome sequence has unveiled in 2002. a recent publication of the culex quinquefasciatus genome sequence has opened up new opportunities for molecular and comparative genomic analysis of multiple mosquito genomes to characterize the insecticide resistance. here, we utilized a whole genome sequence of cx. quinquefasciatus to identify puta ...201222715314
haemoglobin variants and plasmodium falciparum malaria in children under five years of age living in a high and seasonal malaria transmission area of burkina faso.genetic factors play a key role in determining resistance/susceptibility to infectious disease. susceptibility of the human host to malaria infection has been reported to be influenced by genetic factors, which could be confounders if not taken into account in the assessment of the efficacy of interventions against malaria. this study aimed to assess the relationship between haemoglobin genotypes and malaria in children under five years in a site being characterized for future malaria vaccine tr ...201222559271
cholinergic and non-cholinergic functions of two acetylcholinesterase genes revealed by gene-silencing in tribolium castaneum.we compared biological functions of two acetylcholinesterase genes (tcace1 and tcace2) in tribolium castaneum, a globally distributed major pest of stored grain products and an emerging model organism, by using rna interference. although both genes expressed at all developmental stages and mainly in the brain, the transcript level of tcace1 was 1.2- to 8.7-fold higher than that of tcace2, depending on developmental stages. silencing tcace1 in 20-day larvae led to 100% mortality within two weeks ...201222371826
predicting the current and future potential distributions of lymphatic filariasis in africa using maximum entropy ecological niche modelling.modelling the spatial distributions of human parasite species is crucial to understanding the environmental determinants of infection as well as for guiding the planning of control programmes. here, we use ecological niche modelling to map the current potential distribution of the macroparasitic disease, lymphatic filariasis (lf), in africa, and to estimate how future changes in climate and population could affect its spread and burden across the continent. we used 508 community-specific infecti ...201222359670
spatially explicit analyses of anopheline mosquitoes indoor resting density: implications for malaria control.the question of sampling and spatial aggregation of malaria vectors is central to vector control efforts and estimates of transmission. spatial patterns of anopheline populations are complex because mosquitoes' habitats and behaviors are strongly heterogeneous. analyses of spatially referenced counts provide a powerful approach to delineate complex distribution patterns, and contributions of these methods in the study and control of malaria vectors must be carefully evaluated.201222348131
intermittent preventive treatment with sulfadoxine-pyrimethamine does not modify plasma cytokines and chemokines or intracellular cytokine responses to plasmodium falciparum in mozambican children.cytokines and chemokines are key mediators of anti-malarial immunity. we evaluated whether intermittent preventive treatment in infants with sulfadoxine-pyrimethamine (ipti-sp) had an effect on the acquisition of these cellular immune responses in mozambican children. multiple cytokines and chemokines were quantified in plasma by luminex, and antigen-specific cytokine production in whole blood was determined by intracellular cytokine staining and flow cytometry, at ages 5, 9, 12 and 24 months.201222280502
dry season determinants of malaria disease and net use in benin, west africa.to achieve malaria eradication, control efforts have to be sustained even when the incidence of malaria cases becomes low during the dry season. in this work, malaria incidence and its determinants including bed net use were investigated in children of under 5 years of age in 28 villages in southern benin during the dry season.201222291987
changes in malaria morbidity and mortality in mpumalanga province, south africa (2001-2009): a retrospective study.malaria remains a serious epidemic threat in mpumalanga province. in order to appropriately target interventions to achieve substantial reduction in the burden of malaria and ultimately eliminate the disease, there is a need to track progress of malaria control efforts by assessing the time trends and evaluating the impact of current control interventions. this study aimed to assess the changes in the burden of malaria in mpumalanga province during the past eight malaria seasons (2001/02 to 2008 ...201222239855
importance of factors determining the effective lifetime of a mass, long-lasting, insecticidal net distribution: a sensitivity analysis.long-lasting insecticidal nets (llins) reduce malaria transmission by protecting individuals from infectious bites, and by reducing mosquito survival. in recent years, millions of llins have been distributed across sub-saharan africa (ssa). over time, llins decay physically and chemically and are destroyed, making repeated interventions necessary to prevent a resurgence of malaria. because its effects on transmission are important (more so than the effects of individual protection), estimates of ...201222244509
identification and characterization of two chitin synthase genes in african malaria mosquito, anopheles gambiae.chitin synthase (chs) represents an attractive target site for combating insect pests as insect growth and development are strictly dependent on precisely tuned chitin biosynthesis and this pathway is absent in humans and other vertebrates. current knowledge on chs in insects, especially their structures, functions, and regulations is still very limited. we report the identification and characterization of two chitin synthase genes, agchs1 and agchs2, in african malaria mosquito, anopheles gambi ...201222683441
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
igg responses to the gsg6-p1 salivary peptide for evaluating human exposure to anopheles bites in urban areas of dakar region, sénégal.urban malaria can be a serious public health problem in africa. human-landing catches of mosquitoes, a standard entomological method to assess human exposure to malaria vector bites, can lack sensitivity in areas where exposure is low. a simple and highly sensitive tool could be a complementary indicator for evaluating malaria exposure in such epidemiological contexts. the human antibody response to the specific anopheles gsg6-p1 salivary peptide have been described as an adequate tool biomarker ...201222424570
low and seasonal malaria transmission in the middle senegal river basin: identification and characteristics of anopheles vectors.during the last decades two dams were constructed along the senegal river. these intensified the practice of agriculture along the river valley basin. we conducted a study to assess malaria vector diversity, dynamics and malaria transmission in the area.201222269038
factors contributing to urban malaria transmission in sub-saharan africa: a systematic review.sub-saharan africa suffers by far the greatest malaria burden worldwide and is currently undergoing a profound demographic change, with a growing proportion of its population moving to urban areas. urbanisation is generally expected to reduce malaria transmission; however the disease still persists in african cities, in some cases at higher levels than in nearby rural areas. objective. this paper aims to collate and analyse risk factors for urban malaria transmission throughout sub-saharan afric ...201223125863
mermithid nematodes found in adult anopheles from southeastern senegal.over two dozen mermithid nematodes have been described parasitizing mosquitoes worldwide, however, only two species were found in africa. mermithid nematodes kill their mosquito host upon emergence, which suggests that they could be developed as biological control agents of mosquitoes. both romanomermis culicivorax and romanomermis iyengari have been reared for mass release to control numerous anopheles species vector populations, and in one instance this may have led to reduced malaria prevalen ...201222741946
evidence for population-specific positive selection on immune genes of anopheles gambiae.host-pathogen interactions can be powerful drivers of adaptive evolution, shaping the patterns of molecular variation at the genes involved. in this study, we sequenced alleles from 28 immune-related loci in wild samples of multiple genetic subpopulations of the african malaria mosquito anopheles gambiae, obtaining unprecedented sample sizes and providing the first opportunity to contrast patterns of molecular evolution at immune-related loci in the recently discovered goundry population to thos ...201223275874
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
a new chromosomal phylogeny supports the repeated origin of vectorial capacity in malaria mosquitoes of the anopheles gambiae complex.understanding phylogenetic relationships within species complexes of disease vectors is crucial for identifying genomic changes associated with the evolution of epidemiologically important traits. however, the high degree of genetic similarity among sibling species confounds the ability to determine phylogenetic relationships using molecular markers. the goal of this study was to infer the ancestral-descendant relationships among malaria vectors and nonvectors of the anopheles gambiae species co ...201223055932
analysis of ovary-specific genes in relation to egg maturation and female nutritional condition in the mosquitoes georgecraigius atropalpus and aedes aegypti (diptera: culicidae).analysis of the reproductive physiology of anautogenous mosquitoes at the molecular level is complicated by the simultaneity of ovarian maturation and the digestion of a blood meal. in contrast to anautogenous mosquitoes, autogenous female mosquitoes can acquire greater nutrient stores as larvae and exhibit higher ovarian production of ecdysteroids at adult eclosion. these features essentially replace the role of a blood meal in provisioning the first batch of eggs and initiating egg development ...201223238126
a community-wide study of malaria reduction: evaluating efficacy and user-acceptance of a low-cost repellent in northern ghana.no mas (nm) mosquito repellent was evaluated in two farming villages (4 km apart) in the kassena nankana district of northern ghana. we determined its efficacy against local malaria vectors, degree of user acceptance, and its effect on malaria prevalence in households using insecticide-treated bed nets. the average protective efficacy of nm against anopheles mosquitoes over 9 hours was 89.6%. controls averaged 86 bites/person/night versus 9 bites/person/night with the use of nm. use of repellent ...201223249683
screening of selected ethnomedicinal plants from south africa for larvicidal activity against the mosquito anopheles arabiensis.this study was initiated to establish whether any south african ethnomedicinal plants (indigenous or exotic), that have been reported to be used traditionally to repel or kill mosquitoes, exhibit effective mosquito larvicidal properties.201222963538
the anopheles gambiae ce5, a tight- and fast-binding thrombin inhibitor with post-transcriptionally regulated salivary-restricted expression.mosquito saliva carries a large number of factors with anti-hemostatic, anti-inflammatory and immuno-modulatory activities. the ce5 protein was initially identified during an anopheles gambiae salivary gland transcriptome study and later shown to share sequence similarity with anophelin, a thrombin inhibitor from the saliva of the new world mosquito anopheles albimanus. the ce5 gene was found to encode different mrna isoforms coexisting in several tissues of both male and female mosquitoes, a hi ...201222617725
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
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
a modified experimental hut design for studying responses of disease-transmitting mosquitoes to indoor interventions: the ifakara experimental huts.differences between individual human houses can confound results of studies aimed at evaluating indoor vector control interventions such as insecticide treated nets (itns) and indoor residual insecticide spraying (irs). specially designed and standardised experimental huts have historically provided a solution to this challenge, with an added advantage that they can be fitted with special interception traps to sample entering or exiting mosquitoes. however, many of these experimental hut designs ...201222347415
sustainable malaria control: transdisciplinary approaches for translational applications.with the adoption of the global malaria action plan, several countries are moving from malaria control towards elimination and eradication. however, the sustainability of some of the approaches taken may be questionable. here, an overview of malaria control and elimination strategies is provided and the sustainability of each in context of vector- and parasite control is assessed. from this, it can be concluded that transdisciplinary approaches are essential for sustained malaria control and eli ...201223268712
the feasibility of malaria elimination in south africa.following the last major malaria epidemic in 2000, malaria incidence in south africa has declined markedly. the decrease has been so emphatic that south africa now meets the world health organization (who) threshold for malaria elimination. given the millennium development goal of reversing the spread of malaria by 2015, south africa is being urged to adopt an elimination agenda. this study aimed to determine the appropriateness of implementing a malaria elimination programme in present day sout ...201223253091
the fitness of african malaria vectors in the presence and limitation of host behaviour.host responses are important sources of selection upon the host species range of ectoparasites and phytophagous insects. however little is known about the role of host responses in defining the host species range of malaria vectors. this study aimed to estimate the relative importance of host behaviour to the feeding success and fitness of african malaria vectors, and assess its ability to predict their known host species preferences in nature.201223253167
anopheline larval habitats seasonality and species distribution: a prerequisite for effective targeted larval habitats control programmes.larval control is of paramount importance in the reduction of malaria vector abundance and subsequent disease transmission reduction. understanding larval habitat succession and its ecology in different land use managements and cropping systems can give an insight for effective larval source management practices. this study investigated larval habitat succession and ecological parameters which influence larval abundance in malaria epidemic prone areas of western kenya.201223272215
directionally selected cytochrome p450 alleles are driving the spread of pyrethroid resistance in the major malaria vector anopheles funestus.pyrethroid insecticides are critical for malaria control in africa. however, resistance to this insecticide class in the malaria vector anopheles funestus is spreading rapidly across africa, threatening the success of ongoing and future malaria control programs. the underlying resistance mechanisms driving the spread of this resistance in wild populations remain largely unknown. here, we show that increased expression of two tandemly duplicated p450 genes, cyp6p9a and cyp6p9b, is the main mechan ...201223248325
malaria parasite diversity and transmission intensity affect development of parasitological immunity in a mathematical model.the development of parasitological immunity against malaria affects the ability to detect infection, the efficiency of the local human parasite reservoir at infecting mosquitoes, and the response to reintroduction of parasites to previously cleared areas. observations of similar age-trends in detected prevalence and mean parasitaemia across more than an order-of-magnitude of variation in baseline transmission complicate simple exposure-driven explanations.201223241282
biochemical characterization of chitin synthase activity and inhibition in the african malaria mosquito, anopheles gambiae.chitin synthase (chs) is an important enzyme catalyzing the formation of chitin polymers in all chitin containing organisms and a potential target site for insect pest control. however, our understanding of biochemical properties of insect chss has been very limited. we here report enzymatic and inhibitory properties of chs prepared from the african malaria mosquito, anopheles gambiae. our study, which represents the first time to use a nonradioactive method to assay chs activity in an insect sp ...201223955856
use of a mixture statistical model in studying malaria vectors density.vector control is a major step in the process of malaria control and elimination. this requires vector counts and appropriate statistical analyses of these counts. however, vector counts are often overdispersed. a non-parametric mixture of poisson model (npmp) is proposed to allow for overdispersion and better describe vector distribution. mosquito collections using the human landing catches as well as collection of environmental and climatic data were carried out from january to december 2009 i ...201223185626
implications of bio-efficacy and persistence of insecticides when indoor residual spraying and long-lasting insecticide nets are combined for malaria prevention.bio-efficacy and residual activity of insecticides used for indoor residual spraying (irs) and long-lasting insecticide nets (llins) were assessed against laboratory-reared and wild populations of the malaria vector, anopheles arabiensis in south eastern tanzania. implications of the findings are examined in the context of potential synergies and redundancies where irs and llins are combined.201223164062
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
mapping the receptivity of malaria risk to plan the future of control in somalia.to measure the receptive risks of malaria in somalia and compare decisions on intervention scale-up based on this map and the more widely used contemporary risk maps.201222855625
analysis of genes expression of spodoptera exigua larvae upon acmnpv infection.the impact of autographa californica multicapsid nucleopolyhedrovirus (acmnpv) infection on host gene expression in spodoptera exigua 4th instar larvae was investigated through the use of 454 sequencing-based rna-seq of cdna libraries developed from insects challenged with active acmnpv or heat-inactivated acmnpv.201222860129
increased risks of malaria due to limited residual life of insecticide and outdoor biting versus protection by combined use of nets and indoor residual spraying on bioko island, equatorial guinea.malaria is endemic on bioko island, equatorial guinea, with year-round transmission. in 2004 an intensive malaria control strategy primarily based on indoor residual spraying (irs) was launched. the limited residual life of irs poses particular challenges in a setting with year-round transmission, such as bioko. recent reports of outdoor biting by anopheles gambiae are an additional cause for concern. in this study, the effect of the short residual life of bendiocarb insecticide and of children ...201222835049
identification of distant agouti-like sequences and re-evaluation of the evolutionary history of the agouti-related peptide (agrp).the agouti-like peptides including agrp, asip and the teleost-specific a2 (asip2 and agrp2) peptides have potent and diverse functional roles in feeding, pigmentation and background adaptation mechanisms. there are contradictory theories about the evolution of the agouti-like peptide family as well the nomenclature. here we performed comprehensive mining and annotation of vertebrate agouti-like sequences. we identified a2 sequences from salmon, trout, seabass, cod, cichlid, tilapia, gilt-headed ...201222815886
thermal limits of wild and laboratory strains of two african malaria vector species, anopheles arabiensis and anopheles funestus.malaria affects large parts of the developing world and is responsible for almost 800,000 deaths annually. as climates change, concerns have arisen as to how this vector-borne disease will be impacted by changing rainfall patterns and warming temperatures. despite the importance and controversy surrounding the impact of climate change on the potential spread of this disease, little information exists on the tolerances of several of the vector species themselves.201222770378
megabase-scale inversion polymorphism in the wild ancestor of maize.chromosomal inversions are thought to play a special role in local adaptation, through dramatic suppression of recombination, which favors the maintenance of locally adapted alleles. however, relatively few inversions have been characterized in population genomic data. on the basis of single-nucleotide polymorphism (snp) genotyping across a large panel of zea mays, we have identified an ∼50-mb region on the short arm of chromosome 1 where patterns of polymorphism are highly consistent with a pol ...201222542971
the complete mitochondrial genomes of two ghost moths, thitarodes renzhiensis and thitarodes yunnanensis: the ancestral gene arrangement in lepidoptera.lepidoptera encompasses more than 160,000 described species that have been classified into 45-48 superfamilies. the previously determined lepidoptera mitochondrial genomes (mitogenomes) are limited to six superfamilies of the lineage ditrysia. compared with the ancestral insect gene order, these mitogenomes all contain a trna rearrangement. to gain new insights into lepidoptera mitogenome evolution, we sequenced the mitogenomes of two ghost moths that belong to the non-ditrysian lineage hepialoi ...201222726496
reliability of rapid diagnostic tests in diagnosing pregnancy-associated malaria in north-eastern tanzania.accurate diagnosis and prompt treatment of pregnancy-associated malaria (pam) are key aspects in averting adverse pregnancy outcomes. microscopy is the gold standard in malaria diagnosis, but it has limited detection and availability. when used appropriately, rapid diagnostic tests (rdts) could be an ideal diagnostic complement to microscopy, due to their ease of use and adequate sensitivity in detecting even sub-microscopic infections. polymerase chain reaction (pcr) is even more sensitive, but ...201222720788
airflow attenuation and bed net utilization: observations from africa and asia.qualitative studies suggest that bed nets affect the thermal comfort of users. to understand and reduce this discomfort the effect of bed nets on temperature, humidity, and airflow was measured in rural homes in asia and africa, as well as in an experimental wind tunnel. two investigators with architectural training selected 60 houses in the gambia, tanzania, philippines, and thailand. data-loggers were used to measure indoor temperatures in hourly intervals over a 12 months period. in a subgrou ...201222704585
impact of pyrethroid resistance on operational malaria control in malawi.the impact of insecticide resistance on insect-borne disease programs is difficult to quantify. the possibility of eliminating malaria in high-transmission settings is heavily dependent on effective vector control reducing disease transmission rates. pyrethroids are the dominant insecticides used for malaria control, with few options for their replacement. their failure will adversely affect our ability to control malaria. pyrethroid resistance has been selected in malawi over the last 3 y in th ...201223118337
simulation of malaria epidemiology and control in the highlands of western kenya.models of plasmodium falciparum malaria epidemiology that provide realistic quantitative predictions of likely epidemiological outcomes of existing vector control strategies have the potential to assist in planning for the control and elimination of malaria. this work investigates the applicability of mathematical modelling of malaria transmission dynamics in rachuonyo south, a district with low, unstable transmission in the highlands of western kenya.201223107070
characterization of a chitin synthase encoding gene and effect of diflubenzuron in soybean aphid, aphis glycines.chitin synthases are critical enzymes for synthesis of chitin and thus for subsequent growth and development in insects. we identified the cdna of chitin synthase gene (chs) in aphis glycines, the soybean aphid, which is a serious pest of soybean. the full-length cdna of chs in a. glycines (aychs) was 5802 bp long with an open reading frame of 4704 bp that encoded for a 1567 amino acid residues protein. the predicted aychs protein had a molecular mass of 180.05 kda and its amino acid sequence co ...201223139631
the effects of oviposition-site deprivation on anopheles gambiae reproduction.the african malaria mosquito, anopheles gambiae, depends on availability of suitable surface water for oviposition. short and long dry spells occur throughout the year in many parts of its range that limit its access to oviposition sites. although not well understood, oviposition-site deprivation has been found to rapidly reduce egg batch size and hatch rate of several mosquito species. we conducted laboratory experiments to assess these effects of oviposition-site deprivation on an. gambiae and ...201223072301
reconsideration of anopheles rivulorum as a vector of plasmodium falciparum in western kenya: some evidence from biting time, blood preference, sporozoite positive rate, and pyrethroid resistance.anopheles gambiae, an. arabiensis, and an. funestus are widespread malaria vectors in africa. anopheles rivulorum is the next most widespread species in the an. funestus group. the role of an. rivulorum as a malaria vector has not been fully studied, although it has been found to be a minor or opportunistic transmitter of plasmodium falciparum.201223050856
human antibody response to anopheles saliva for comparing the efficacy of three malaria vector control methods in balombo, angola.human antibody (ab) response to anopheles whole saliva, used as biomarker of anopheles exposure, was investigated over a period of two years (2008-2009), in children between 2 to 9 years old, before and after the introduction of three different malaria vector control methods; deltamethrin treated long lasting impregnated nets (llin) and insecticide treated plastic sheeting (itps)--zero fly®) (itps-zf), deltamethrin impregnated durable (wall) lining (itps-dl--zerovector®) alone, and indoor residu ...201223028499
the development of insecticide-treated durable wall lining for malaria control: insights from rural and urban populations in angola and nigeria.durable lining (dl) is a deltamethrin-impregnated polyethylene material, which is designed to cover domestic walls that would normally be sprayed with residual insecticide. the operational success of dl as a long-lasting insecticidal substrate will be dependent on a high level of user acceptability as households must maintain correctly installed linings on their walls for several years. preliminary trials were undertaken to identify a material to develop into a marketable wall lining and to asse ...201222989007
the efficacy of vectron 20 wp, etofenprox, for indoor residual spraying in areas of high vector resistance to pyrethroids and organochlorines in zambia.the selection of insecticide resistance in malaria vectors has the potential to compromise any insecticide-based vector control programme. to ensure that the insecticides used for indoor residual spraying and insecticide-treated nets in zambia remain effective and their choice is evidence based, insecticide resistance surveillance and monitoring are essential. this study assessed and compared the residual efficacy of etofenprox (vectron 20 wp), an ether pyrethroid, at 0.1 g/m(2) with pyrethroids ...201224967135
population genetic structure of the malaria vector anopheles funestus, in a recently re-colonized area of the senegal river basin and human-induced environmental changes.anopheles funestus is one of the major malaria vectors in tropical africa. because of several cycles of drought events that occurred during the 1970s, this species had disappeared from many parts of sahelian africa, including the senegal river basin. however, this zone has been re-colonized during the last decade by an. funestus, following the implementation of two dams on the senegal river. previous studies in that area revealed heterogeneity at the biological and chromosomal level among these ...201222950576
positional cloning of rp2 qtl associates the p450 genes cyp6z1, cyp6z3 and cyp6m7 with pyrethroid resistance in the malaria vector anopheles funestus.pyrethroid resistance in anopheles funestus is threatening malaria control in africa. elucidation of underlying resistance mechanisms is crucial to improve the success of future control programs. a positional cloning approach was used to identify genes conferring resistance in the uncharacterised rp2 quantitative trait locus (qtl) previously detected in this vector using f6 advanced intercross lines (ail). a 113 kb bac clone spanning rp2 was identified and sequenced revealing a cluster of 15 p45 ...201222948188
real-time pcr assay for discrimination of plasmodium ovale curtisi and plasmodium ovale wallikeri in the ivory coast and in the comoros islands.plasmodium ovale is one of the five malaria species infecting humans. recent data have shown that the name of this neglected species masks two distinct genotypes also called curtisi and wallikeri. some authors show that these species could be sympatric. these two subspecies are not differentiated by microscopy techniques and malaria rapid diagnostic tests. this diagnostic defect is the result of low parasitaemia, antigenic polymorphism and absence of antibodies performance and requires the use o ...201222947418
malaria control in south africa 2000-2010: beyond mdg6.malaria is one of the key targets within goal 6 of the millennium development goals (mdgs), whereby the disease needs to be halted and reversed by the year 2015. several other international targets have been set, however the mdgs are universally accepted, hence it is the focus of this manuscript.201222913727
anticholinesterase insecticide retrospective.the anticholinesterase (antiche) organophosphorus (op) and methylcarbamate (mc) insecticides have been used very effectively as contact and systemic plant protectants for seven decades. about 90 of these compounds are still in use - the largest number for any insecticide chemotype or mode of action. in both insects and mammals, ache inhibition and acetylcholine accumulation leads to excitation and death. the cholinergic system of insects is located centrally (where it is protected from ionized o ...201222926007
candidate chemosensory genes in female antennae of the noctuid moth spodoptera littoralis.chemical senses are crucial for all organisms to detect various environmental information. different protein families, expressed in chemosensory organs, are involved in the detection of this information, such as odorant-binding proteins, olfactory and gustatory receptors, and ionotropic receptors. we recently reported an expressed sequence tag (est) approach on male antennae of the noctuid moth, spodoptera littoralis, with which we could identify a large array of chemosensory genes in a species ...201222904672
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
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
malaria in east african highlands during the past 30 years: impact of environmental changes.east african highlands are one of the most populated regions in africa. the population densities in the highlands ranged between 158 persons/km(2) in ethiopia and 410 persons/km(2) in rwanda. according to the united nations population fund, the region has the world's highest population growth rate. these factors are likely behind the high rates of poverty among the populations. as there were no employment opportunities other than agricultural, this demographic pressure of poor populations have i ...201222934065
genome organization, phylogenies, expression patterns, and three-dimensional protein models of two acetylcholinesterase genes from the red flour beetle.since the report of a paralogous acetylcholinesterase (ache, ec3.1.1.7) gene in the greenbug (schizaphis graminum) in 2002, two different ache genes (ace1 and ace2) have been identified in each of at least 27 insect species. however, the gene models of ace1 and ace2, and their molecular properties have not yet been comprehensively analyzed in any insect species. in this study, we sequenced the full-length cdnas, computationally predicted the corresponding three-dimensional protein models, and pr ...201222359679
combining next-generation sequencing and microarray technology into a transcriptomics approach for the non-model organism chironomus riparius.whole-transcriptome gene-expression analyses are commonly performed in species that have a sequenced genome and for which microarrays are commercially available. to do such analyses in species with no or limited genome data, i.e. non-model organisms, necessary transcriptomics resources, i.e. an annotated transcriptome and a validated gene-expression microarray, must first be developed. the aim of the present study was to establish an advanced approach for developing transcriptomics resources for ...201223133553
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