Current Malaria Control Strategies Research Articles

Malaria Prevention and Control in Nigeria: Evaluating the Effectiveness of Current Strategies

Malaria has been a significant public health challenge in Nigeria, contributing to high morbidity and mortality rates, particularly among children under five and pregnant women. Despite all efforts made to control and prevent malaria, Nigeria continued to bear a disproportionate share of the global malaria burden. This review critically evaluated the effectiveness of current malaria prevention and control strategies in Nigeria, including the use of insecticide-treated nets (ITNs), indoor residual spraying (IRS), chemoprevention, and public health education campaigns. The methodology involved a comprehensive analysis of peer-reviewed studies, government reports, and data from international health organizations to assess these strategies. The review identified gaps in the implementation of these strategies and explored innovative approaches that could enhance their impact. It also discussed the role of environmental management, community engagement, and the integration of technology in malaria control efforts. The findings suggested that while existing strategies have made significant progress in reducing malaria transmission, challenges such as resistance to insecticides, inconsistent use of preventive measures, and limited healthcare infrastructure hindered their overall effectiveness. The review concluded by proposing recommendations for strengthening malaria prevention and control efforts in Nigeria, with a focus on sustainability, scalability, and community involvement. Keywords: Malaria Control, Insecticide-Treated Nets (ITNs), Indoor Residual Spraying (IRS), Chemoprevention, Environmental Management.

Genetic Diversity of Merozoite Surface Protein-1 and -2 Genes in Plasmodium falciparum Isolates among Asymptomatic Population in Boset and Badewacho Districts, Southern Ethiopia.

The genetic variation of Plasmodium falciparum has been studied to assess local malaria transmission genetic profile using evidence-based intervention measures. However, there are no known previous reports of P. falciparum polymorphism in Badewacho and Boset districts, Southern Ethiopia. The purpose of this study was to determine the genetic diversity of the merozoite surface protein-1 and -2 (msp-1 and msp-2) allelic families in P. falciparum isolates from an asymptomatic populations. This study was conducted from finger-prick blood samples spotted on 3 mm Whatman filter paper collected during a community-based cross-sectional study. Nested polymerase chain reaction amplification was used to type the allelic variants of msp-1 and msp-2. From 669 asymptomatic study participants, a total of 50 samples positive for P. falciparum were included for molecular analysis. Of 50 positive samples, 43 P. falciparum isolates were successfully amplified for the msp-1 and msp-2 allelic families. A total of twelve different allele sizes (75-250 bp) were identified within the three allelic families of msp-1, whereas ten different allele sizes (250-500 bp) were detected within the two allelic families of msp-2. MAD20 had a higher allelic proportion, 65% among allelic families of msp-1, whereas the 3D7 allelic family 90.7% was higher in msp-2. A slightly higher frequency of polyclonal infection 53.5% was found in msp-2 allelic family, whereas a low proportion polyclonal infection 46.5% was found in msp-1 allelic family. The overall mean multiplicity of infection (MOI) for msp-1 and msp-2 was identical (MOI = 1.56). Correspondingly, the expected heterozygosity (He) value for msp-1 (He = 0.23) and msp-2 (He = 0.22) was almost similar. The findings of this study revealed low genetic diversity of the msp-1 and msp-2 allelic families in P. falciparum isolates. However, continued monitoring status of the local genetic diversity profile in the P. falciparum population is required to support current malaria control and elimination strategies.

Protective efficacy of holed and aging PBO-pyrethroid synergist-treated nets on malaria infection prevalence in north-western Tanzania.

Two billion pyrethroid long-lasting insecticidal nets (LLINs) have been distributed since 2004 for malaria prevention in Sub-Saharan Africa. Current malaria control strategies rely on an assumed effective 3-year lifespan for LLINs. PBO synergist LLINs are a newly recommended class of net but there is limited information on their life span and long-term protective efficacy in communities. To assess their operational survival, a cohort of 390 PBO LLINs (Olyset Plus) and 367 standard pyrethroid LLIN (Olyset net) from 396 households were followed for 36 months in Western Tanzania. To assess the association between the condition of the LLIN and malaria infection, nets from at least 480 randomly selected households were assessed during malaria prevalence cross-sectional surveys at 4, 9, 16, 21, 28, and 33 months post-distribution. Information on the presence and condition of nets, and demographic information from the household, were collected to evaluate factors influencing net durability. After 3 years less than 17% of nets distributed still remained in the households. The fabric condition was not associated with malaria infection in either type of net. The difference between the net types was highest when nets were between 1-2 years old, when PBO nets appeared to be similarly protective as nets less than a year old, whereas standard nets were considerably less protective as they aged, regardless of fabric condition. There was no statistical difference in the estimated median functional survival time between net types with 1.6 years (95% CI 1.38-1.87) for PBO LLIN and 1.9 years (95% CI 1.67-2.06) for standard LLINs. After 3 years, there was a loss of 55% of permethrin (pyrethroid) content for both nets, and 97% of PBO content was lost in PBO LLIN. These results highlight that functional survival is less than the recommended 3 years for both net types. However, even as the nets age, the PBO nets remained more protective than standard nets, regardless of their condition.

Assessment of Plasmodium falciparum Infection and Fitness of Genetically Modified Anopheles gambiae Aimed at Mosquito Population Replacement

Genetically modified (GM) mosquitoes expressing anti-plasmodial effectors propagating through wild mosquito populations by means of gene drive is a promising tool to support current malaria control strategies. The process of generating GM mosquitoes involves genetic transformation of mosquitoes from a laboratory colony and, often, interbreeding with other GM lines to cross in auxiliary traits. These mosquito colonies and GM lines thus often have different genetic backgrounds and GM lines are invariably highly inbred, which in conjunction with their independent rearing in the laboratory may translate to differences in their susceptibility to malaria parasite infection and life history traits. Here, we show that laboratory Anopheles gambiae colonies and GM lines expressing Cas9 and Cre recombinase vary greatly in their susceptibility to Plasmodium falciparum NF54 infection. Therefore, the choice of mosquitoes to be used as a reference when conducting infection or life history trait assays requires careful consideration. To address these issues, we established an experimental pipeline involving genetic crosses and genotyping of mosquitoes reared in shared containers throughout their lifecycle. We used this protocol to examine whether GM lines expressing the antimicrobial peptide (AMP) Scorpine in the mosquito midgut interfere with parasite infection and mosquito survival. We demonstrate that Scorpine expression in the Peritrophin 1 (Aper1) genomic locus reduces both P. falciparum sporozoite prevalence and mosquito lifespan; both these phenotypes are likely to be associated with the disturbance of the midgut microbiota homeostasis. These data lead us to conclude that the Aper1-Sco GM line could be used in proof-of-concept experiments aimed at mosquito population replacement, although the impact of its reduced fitness on the spread of the transgene through wild populations requires further investigation.

Antimalarial drug resistance molecular makers of Plasmodium falciparum isolates from Sudan during 2015-2017.

Current malaria control and elimination strategies rely mainly on efficacious antimalarial drugs. However, drug resistance is a major threat facing malaria control programs. Determination of drug resistance molecular markers is useful in the monitoring and surveillance of malaria drug efficacy. This study aimed to determine the mutations and haplotypes frequencies of different genes linked with antimalarial drug resistance in certain areas in Sudan. A total of 226 dried blood spots (DBS) of microscopically diagnosed P. falciparum isolates were collected from Khartoum and three other areas in Sudan during 2015-2017. Plasmodium falciparum confirmation and multiplicity of infection was assessed using the Sanger's 101 SNPs-barcode and speciation was confirmed using regions of the parasite mitochondria. Molecular genotyping of drug resistance genes (Pfcrt, Pfmdr1, Pfdhfr, Pfdhps, exonuclease, Pfk13, parasite genetic background (PGB) (Pfarps10, ferredoxin, Pfcrt, Pfmdr2)) was also performed. All genotypes were generated by selective regions amplicon sequencing of the parasite genome using the Illumina MiSeq platform at the Wellcome Sanger Institute, UK then genotypes were translated into drug resistance haplotypes and species determination. In total 225 samples were confirmed to be P. falciparum. A higher proportion of multiplicity of infection was observed in Gezira (P<0.001) based on the Sanger 101 SNPs -barcode. The overall frequency of mutant haplotype Pfcrt 72-76 CVIET was 71.8%. For Pfmdr1, N86Y was detected in 53.6%, Y184F was observed in 88.1% and D1246Y was detected in 1.5% of the samples. The most frequently observed haplotype was YFD 47.4%. For Pfdhfr (codons 51, 59,108,164), the ICNI haplotype was the most frequent (80.7%) while for Pfdhps (codons 436, 437, 540, 581, 613) the (SGEAA) was most frequent haplotype (41%). The Quadruple mutation (dhfr N51I, S108N + dhps A437G, K540E) was the highest frequent combined mutation (33.9%). In Pfkelch13 gene, 18 non-synonymous mutations were detected, 7 of them were detected in other African countries. The most frequent Pfk13 mutation was E433D detected in four samples. All of the Pfk13 mutant alleles have not been reported to belong to mutations associated with delayed parasite clearance in Southeast Asia. PGB mutations were detected only in Pfcrt N326S\I (46.3%) and Pfcrt I356T (8.2%). The exonuclease mutation was not detected. There was no significant variation in mutant haplotypes between study areas. There was high frequency of mutations in Pfcrt, Pfdhfr and Pfdhps in this study. These mutations are associated with chloroquine and sulfadoxine-pyrimethamine (SP) resistance. Many SNPs in Pfk13 not linked with delayed parasite clearance were observed. The exonuclease E415G mutation which is linked with piperaquine resistance was not reported.

Knowledge and preventive practices of malaria among pregnant women in Huye district Southern province, Rwanda

Background: Regardless of the accessibility of effective malaria control interventions, malaria has been reported in first place with a 25% morbidity rate in Rwanda, particularly in pregnancy. This study explored knowledge and preventive practices of malaria among pregnant women in Huye district Southern province, Rwanda.Methods: Study design was cross-sectional descriptive, 384 pregnant women living in Tumba sector were recruited. A semi-structured questionnaire was used for data collection, and data were entered in SPSS version 21 for analysis and the Chi-square test was computed for measuring the associations between variables at 5% level of statistical significance.Results: Of the 384 respondents, 340 (88.5%) were married and the mean age was 29.5±6.8 years with 172 (44.8%) aged between 25 and 29 years. Majority 224 (58.4%) had primary level of education and 147 (27.9%) were agricultures. 96 (25%) of respondents had low knowledge whereas 42 (10.9%) had high knowledge and 246 (64.1%) moderate knowledge. 298 (77.6%) were aware and knew that malaria is transmitted by female anopheles and the majority of respondents 323 (84.1%) were using LLINs. Education level, marital status, occupation were associated with malaria knowledge on preventive practices and LLINs utilization (p=0.001).Conclusions: This study revealed satisfactory knowledge of malaria prevention among pregnant women in southern Rwanda despite the poor implementation of current malaria control strategies. There is a need for sustaining and expanding the current LLINs ownership and utilization level and also improving public health education on malaria knowledge, preventive practices, and high health risks behaviors for malaria control and elimination.

A steroid hormone agonist reduces female fitness in insecticide-resistant Anopheles populations

Insecticide based vector control tools such as insecticide treated bednets and indoor residual spraying represent the cornerstones of malaria control programs. Resistance to chemistries used in these programs is now widespread and represents a significant threat to the gains seen in reducing malaria-related morbidity and mortality. Recently, disruption of the 20-hydroxyecdysone steroid hormone pathway was shown to reduce Plasmodium development and significantly reduce both longevity and egg production in a laboratory susceptible Anopheles gambiae population. Here, we demonstrate that disruption of this pathway by application of the dibenzoylhydrazine, methoxyfenozide (DBH-M), to insecticide resistant An. coluzzii, An. gambiae sl and An. funestus populations significantly reduces egg production in both topical and tarsal application. Moreover, DBH-M reduces adult longevity when applied topically, and tarsally after blood feeding. As the cytochrome p450s elevated in pyrethroid resistant Anopheles only bind DBH-M very weakly, this compound is unlikely to be subject to cross-resistance in a field-based setting. Manipulation of this hormonal signalling pathway therefore represents a potential complementary approach to current malaria control strategies, particularly in areas where high levels of insecticide resistance are compromising existing tools.

Determinants of the persistence of malaria in Rwanda

BackgroundMalaria has a considerable impact on the health of the populations of developing countries; indeed, the entire population of Rwanda is at risk of contracting the disease. Although various interventions to control malaria have been implemented in Rwanda, the incidence of malaria has increased since 2012. There is an interest in understanding factors driving its persistence in Rwanda. This study aims at evaluating the effect of socio-economic and environmental factors, seasonality and the use of insecticide-treated mosquito nets (ITNs) on malaria persistence in Rwanda.MethodsThis study analysed data from the 2014–2015 Rwanda Demographic and Health Survey of 11,202 household’s members composed of children under the age of 5 and women aged between 15 and 49. Bivariate analysis was performed between the outcome and each covariate including wealth, altitude, education level, place of residence, and use of ITNs generating percentages. Chi square test was performed to compare malaria negatives and positives on each covariate. Significant variables were subjected to logistic regression analysis to evaluate factors that are significantly associated with malaria at P < 0.05. The analysis was performed in R x64 3.6 and QGIS3.6 was used to map geographical distribution of malaria cases.ResultsThe lowest wealth category was associated with the incidence of malaria [AOR] = 1.54, 95% CI (1.78–2.03). Having a place of residence < 1700 m above sea level (asl) and non-use of ITNs were significantly associated with the incidence of malaria (adjusted odds ratio [AOR] = 2.93, 95% confidence interval [95% CI] 1.94–4.42 and [AOR] = 1.29, 95% C.I (1.03–1.60), respectively). Season and type of residence were not significantly associated with malaria prevalence while women had lower risk of contracting malaria than children.ConclusionIncreased malaria prevalence was associated with lower income, non-compliance with bed-net usage and living below 1700 m of altitude. In addition to current malaria control strategies, potential interventions in individuals with lower income and areas at low altitudes should be taken into consideration when formulating malaria-control strategies, Also use of ITNs to control the spread of malaria should be emphasized.

Prospects and strategies for malaria elimination in the Greater Mekong Sub-region: a qualitative study

BackgroundAs malaria elimination becomes a goal in malaria-endemic nations, questions of feasibility become critical. This article explores the potential challenges associated with this goal and future strategies for malaria elimination in the Greater Mekong Sub-region.MethodsThirty-two semi-structured interviews were conducted with policy makers (n = 17) and principal investigators (n = 15) selected based on their involvement in malaria prevention, control and elimination in the GMS. Interviews were audio-recorded and transcribed for qualitative content (thematic) analysis using QSR NVivo.ResultsAll respondents described current malaria control and elimination strategies, such as case detection and management, prevention and strengthening of surveillance systems as critical and of equal priority. Aware of the emergence of multi-drug resistance in the GMS, researchers and policy makers outlined the need for additional elimination tools. As opposed to a centralized strategy, more targeted and tailored approaches to elimination were recommended. These included targeting endemic areas, consideration for local epidemiology and malaria species, and strengthening the peripheral health system. A decline in malaria transmission could lead to complacency amongst funders and policy makers resulting in a reduction or discontinuation of support for malaria elimination. Strong commitment of policymakers combined with strict monitoring and supervision by funders were considered pivotal to successful elimination programmes.ConclusionAgainst a backdrop of increasing anti-malarial resistance and decreasing choices of anti-malarial regimens, policy makers and researchers stressed the urgency of finding new malaria elimination strategies. There was consensus that multi-pronged strategies and approaches are needed, that no single potential tool/strategy can be appropriate to all settings. Hence there is a need to customize malaria control and elimination strategies based on the better surveillance data.

Population genomics and molecular surveillance for Plasmodium falciparum genetic diversities in an endemic area

Current malaria control strategies in endemic areas target eradication and elimination of the disease as well as improving artemisinin combination treatments (ACTs) and vector control. In this era of reducing transmission, molecular surveillance and bioinformatics tools offer great insights for understanding transmission dynamics. This study aims to determine prevalence rates and molecular diversities in Plasmodium falciparum in an endemic area. Polymerase chain reaction was used to determine presence of malaria infection, and presence of mutation in 2 select gene markers of drug resistance was determined by sequencing amplified products in few isolates. The sequence data was mapped unto the plasmodium genome to detect mutations in the genes using 3D7 strain (PF3D7_1343700.1 and PF3D7_0523000.1) as reference sequence. A high asymptomatic parasite rate (43%) was detected with a low frequency of SNPs in Kelch 13, which is not associated with drug resistance. There is a high rate of infection in this area with some mutations which may not directly modulate drug responses but the influence on transmission and impact on parasite's survival remains to be determined.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Eight-year trend analysis of malaria prevalence in Kombolcha, South Wollo, north-central Ethiopia: a retrospective study

BackgroundMalaria is one of the most serious public health problems in the world, and is a major public health problem in Ethiopia. Over the past years, the disease has been consistently reported as the first leading cause of outpatient visits, hospitalization and death in health facilities across the country. This study aimed to assess malaria prevalence trend in the Kombolcha Health Centre.MethodsA retrospective study was carried out in the Kombolcha Health Centre, north-central Ethiopia. Malaria cases reported from 2009 to 2016 were carefully reviewed from the laboratory record books. Interventions that had been taken in each year were collected from the district health bureau and head of Kombolcha Health Centre using checklists.ResultsA total of 27,492 blood films were examined from malaria-suspected patients in the Kombolcha Health Centre from 2009 to 2016. Malaria was confirmed and reported in 2066 (7.52%) of the examined blood films with 258 mean annual cases of. Minimum and maximum cases were reported in 2009 and 2010, respectively. Plasmodium falciparum and P. vivax accounted 60.2% and 35.5% of the cases, respectively. Male patients were more affected (n = 1407; 68.1%) than female ones (n = 659; 31.89%). The highest malaria prevalence (n = 1440; 69.69%) was seen in the 15–45 years age group, followed by those 5–14 years old (n = 303; 14.67%), and finally patients under five years old (n = 217; 10.5%). Malaria cases were at a peak in spring and reduced in the winter season.ConclusionAlthough the current malaria control strategies are effective in decreasing the morbidity and mortality, malaria is still among major public health problems in Ethiopia. Plasmodium falciparum is the dominant species in the study area. However, in recent years P. vivax cases are increasing, indicating that attention should also be given to this species. The efficacy of chloroquine for P. vivax should be evaluated in the study area. Control activities should be continued and scale up.

Genetic diversity and multiplicity of Plasmodium falciparum merozoite surface protein 2 in field isolates from Sudan

Background: Malaria is a major health problem, with over one third of worldwide populations currently at risk. Determining the genetic diversity of plasmodium parasites is essential for assessing the efficacy of antimalarial drugs and for future vaccine development. This study investigated the genetic diversity of P. falciparum merozoite surface protein 2 (MSP2), and multiplicity of infection (MOI) in different geographic regions in Sudan. Methods: A total of 271 patients with uncomplicated malaria were recruited from four ecological sites during malaria transmission season, 2011-2013. P. falciparum was confirmed using species specific primers targeting the rDNA gene. All P. falciparum positive samples were genotyped for the major MSP2 allelic families (IC1/3D7 and FC27 MSP2 allele) using nested PCR. Multiplicity of infection and allele frequencies were determined. Results: A total of 241 samples (88.9%) were confirmed positive for P. falciparum. The number of different MSP2 alleles were 14, 15, 13 and 12 in Khartoum, Gezira, River Nile and Red Sea states, respectively. The 3D7 allelic family was more prevalent in the states of Khartoum, Gezira, River Nile and Red Sea compared to the FC27 allelic family. Multiclonal infections were observed in 25.8% of patients, with a mean multiplicity of infection (MOI) of 1.45. MOIs were highest in the age group over 40, with an average of 2 and 1.68 in Khartoum and Gezira states, respectively, however MOIs in River Nile and Red Sea states were higher in age groups below 18, with an average of 1.37 and 1.33, respectively. Conclusions: MSP2 allelic genotyping revealed MOI and diversity of the Sudanese P. falciparum isolates. The results of our study are expected to influence current and future malaria control strategies, since the MOI predicts development of clinical malaria and subsequent efficacy of antimalarial treatment.

Assessment of the effect of larval source management and house improvement on malaria transmission when added to standard malaria control strategies in southern Malawi: study protocol for a cluster-randomised controlled trial

BackgroundDue to outdoor and residual transmission and insecticide resistance, long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) will be insufficient as stand-alone malaria vector control interventions in many settings as programmes shift toward malaria elimination. Combining additional vector control interventions as part of an integrated strategy would potentially overcome these challenges. Larval source management (LSM) and structural house improvements (HI) are appealing as additional components of an integrated vector management plan because of their long histories of use, evidence on effectiveness in appropriate settings, and unique modes of action compared to LLINs and IRS. Implementation of LSM and HI through a community-based approach could provide a path for rolling-out these interventions sustainably and on a large scale.Methods/designWe will implement community-based LSM and HI, as additional interventions to the current national malaria control strategies, using a randomised block, 2 × 2 factorial, cluster-randomised design in rural, southern Malawi. These interventions will be continued for two years. The trial catchment area covers about 25,000 people living in 65 villages. Community participation is encouraged by training community volunteers as health animators, and supporting the organisation of village-level committees in collaboration with The Hunger Project, a non-governmental organisation. Household-level cross-sectional surveys, including parasitological and entomological sampling, will be conducted on a rolling, 2-monthly schedule to measure outcomes over two years (2016 to 2018). Coverage of LSM and HI will also be assessed throughout the trial area.DiscussionCombining LSM and/or HI together with the interventions currently implemented by the Malawi National Malaria Control Programme is anticipated to reduce malaria transmission below the level reached by current interventions alone. Implementation of LSM and HI through a community-based approach provides an opportunity for optimum adaptation to the local ecological and social setting, and enhances the potential for sustainability.Trial RegistrationRegistered with The Pan African Clinical Trials Registry on 3 March 2016, trial number PACTR201604001501493.

Identifying artemisinin resistance from parasite clearance half-life data with a simple Shiny web application.

The emergence of artemisinin-resistant Plasmodium falciparum malaria is a major threat to malaria elimination. New tools for supporting the surveillance of artemisinin resistance are critical for current and future malaria control and elimination strategies. We have developed an open-access, user-friendly, web-based tool to analyse parasite clearance half-life data of P. falciparum infected patients after treatment with artemisinin derivatives, so that resistance to artemisinin can be identified. The tool can be accessed at bit.ly/id_artemisinin_resistance.

Determinants of Malaria Transmission at the Population Level.

Transmission of malaria from man to mosquito defines the human infectious reservoir of malaria. At the population level this is influenced by a variety of human, parasite, and mosquito vector factors some or all of which may vary depending on the epidemiological setting. Here, we review our current state of knowledge related to human infectiousness to mosquitoes and how current malaria control strategies might be adapted to focus on reducing this. While much progress has been made in malaria control, we argue that an improved understanding of human infectivity will allow more effective use of current control tools and make elimination a more feasible goal.

Spatio-temporal analysis of malaria incidence in the Peruvian Amazon Region between 2002 and 2013

Malaria remains a major public health problem in the Peruvian Amazon where the persistence of high-risk transmission areas (hotspots) challenges the current malaria control strategies. This study aimed at identifying significant space-time clusters of malaria incidence in Loreto region 2002–2013 and to determine significant changes across years in relation to the control measures applied. Poisson regression and purely temporal, spatial, and space-time analyses were conducted. Three significantly different periods in terms of annual incidence rates (AIR) were identified, overlapping respectively with the pre-, during, and post- implementation control activities supported by PAMAFRO project. The most likely space-time clusters of malaria incidence for P. vivax and P. falciparum corresponded to the pre- and first two years of the PAMAFRO project and were situated in the northern districts of Loreto, while secondary clusters were identified in eastern and southern districts with the latest onset and the shortest duration of PAMAFRO interventions. Malaria in Loreto was highly heterogeneous at geographical level and over time. Importantly, the excellent achievements obtained during 5 years of intensified control efforts totally vanished in only 2 to 3 years after the end of the program, calling for sustained political and financial commitment for the success of malaria elimination as ultimate goal.

The Anopheles gambiae transcriptome - a turning point for malaria control.

Mosquitoes are important vectors of several pathogens and thereby contribute to the spread of diseases, with social, economic and public health impacts. Amongst the approximately 450 species of Anopheles, about 60 are recognized as vectors of human malaria, the most important parasitic disease. In Africa, Anopheles gambiae is the main malaria vector mosquito. Current malaria control strategies are largely focused on drugs and vector control measures such as insecticides and bed-nets. Improvement of current, and the development of new, mosquito-targeted malaria control methods rely on a better understanding of mosquito vector biology. An organism's transcriptome is a reflection of its physiological state and transcriptomic analyses of different conditions that are relevant to mosquito vector competence can therefore yield important information. Transcriptomic analyses have contributed significant information on processes such as blood-feeding parasite-vector interaction, insecticide resistance, and tissue- and stage-specific gene regulation, thereby facilitating the path towards the development of new malaria control methods. Here, we discuss the main applications of transcriptomic analyses in An. gambiae that have led to a better understanding of mosquito vector competence.

Malaria morbidity and mortality trends in Manicaland province, Zimbabwe, 2005-2014.

IntroductionZimbabwe targets reducing malaria incidence from 22/1000 in 2012 to 10/1000 by 2017, and malaria deaths to near zero by 2017. As the country moves forward with the malaria elimination efforts, it is crucial to monitor trends in malaria morbidity and mortality in the affected areas. In 2013, Manicaland Province contributed 51% of all malaria cases and 35% of all malaria deaths in Zimbabwe. This analysis describes the trends in malaria incidence, case fatality and malaria outpatient workload compared to the general outpatient workload.MethodsWe analyzed routinely captured malaria data in Manicaland Province for the period 2005 to 2014. Epi Info version 7 was used to calculate chi-square trends for significance and Microsoft Excel was used to generate graphs. Permission to analyze the data was sought and granted by the Provincial Medical Directorate Institutional Review Board of Manicaland and the Health Studies office.ResultsMalaria morbidity data for the period 2005-2014 was reviewed and a total of 947,462 cases were confirmed during this period. However, malaria mortality data was only available for the period 2011-2014 and cumulatively 696 deaths were reported. Malaria incidence increased from 4.4/1,000 persons in 2005 to 116.3/1,000 persons in 2014 (p<0.001). The incidence was higher among females compared to males (p-trend<0.001) and among the above five years age group compared to the under-fives (p-trend<0.001). The proportion of all Outpatient Department attendances that were malaria cases increased 30 fold from 0.3% in 2005 to 9.1% in 2014 (p-trend<0.001). The Case Fatality Rate also increased 2-fold from 0.05 in 2011 to 0.1 in 2014 (p-trend<0.001).ConclusionDespite current malaria control strategies, the morbidity and mortality of malaria increased over the period under review. There is need for further strengthening of malaria control interventions to reduce the burden of the disease.

Assessing the reliability of microscopy and rapid diagnostic tests in malaria diagnosis in areas with varying parasite density among older children and adult patients in Nigeria.

Background:Current malaria control strategies are based on early diagnosis and appropriate treatment of malaria cases. The study aimed at comparing the performance of blood film microscopy and rapid diagnostic test (RDT) in Plasmodium falciparum detection in patients ≥6 years of age.Materials and Methods:A total of 154 consecutive pyretic patients aged 6-62 years were enrolled, sampled, and tested for malaria using RDT (first response) and microscopy by Giemsa staining. Genomic DNA was extracted after saponin hemolysis and nested polymerase chain reaction (PCR) was used to detect Plasmodium falciparum. The endpoints were sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).Results:Of the 154 patients, 80 (51.9%) had fever of ≥37.5°C. 106 (68.8%) were positive by First response®, 132 (85.7%) by microscopy, and 121 (78.6%) by PCR. The sensitivity, specificity, PPV, and NPV of first response compared to microscopic method were 82.2%, 100.0%, 100.0%, and 34.3%, respectively, while it was 75.4%, 75.0%, 95.3%, and 31.2%, respectively, when compared to PCR. The sensitivity, specificity, PPV, and NPV of the microscopic method compared to PCR were 92.3%, 50.0%, 90.91%, and 54.5%, respectively. There was a significant difference in the performance of RDT and film microscopy methods (P ≤ 0.05).Conclusion:Microscopy performed better and is more reliable than first response (RDT) in areas with low parasite density among patients ≥6 years of age. Rapid diagnostic tests could be useful in aareas with high parasite density as an alternative to smear microscopy

Combining malaria control with house electrification: adherence to recommended behaviours for proper deployment of solar-powered mosquito trapping systems, Rusinga Island, western Kenya.

To investigate community adherence to recommended behaviours for proper deployment of solar-powered mosquito trapping systems (SMoTS) after 3- to 10-week use. Solar-powered mosquito trapping system, which also provided power for room lighting and charging mobile phones, were installed in houses in Rusinga Island, western Kenya. We used a structured checklist for observations and a semi-structured questionnaire for interviews in 24 homesteads. We also analysed the subject of 224 community calls to the project team for technical maintenance of SMoTS. Most respondents cared for SMoTS by fencing, emptying and cleaning the trap. Our observations revealed that most traps were fenced, clean and in good working condition. A significantly higher proportion of community calls was lighting-related. Lighting was the main reason respondents liked SMoTS because it reduced or eliminated expenditure on kerosene. However, some respondents observed they no longer heard sounds of mosquitoes inside their houses. All respondents reportedly slept under insecticide-treated nets (ITNs) before receiving SMoTS. After receiving SMoTS, most respondents reportedly continued to use ITNs citing that the project advised them to do so. Some beach residents stopped using ITNs because they no longer heard mosquitoes or due to heat discomfort caused by lights. Electricity-related incentives played a greater role in encouraging adherence to recommended behaviours for proper deployment of SMoTS than the potential health benefits in the early stages of the intervention. Although energy-related financial incentives may play a role, they are insufficient to ensure adherence to health advice, even in the short term. Ongoing community engagement and research monitors and addresses adherence to recommended behaviours including continuation of current malaria control strategies.