Bed Nets Research Articles

Physical durability and insecticidal activity of long-lasting insecticidal nets in Cruzeiro do Sul, Brazil

Vector control is one of the principal strategies used for reducing malaria transmission. Long-lasting insecticidal bed nets (LLINs) are a key tool used to protect populations at risk of malaria, since they provide both physical and chemical barriers to prevent human-vector contact. This study aimed to assess the physical durability and insecticidal efficacy of LLINs distributed in Cruzeiro do Sul (CZS), Brazil, after 4 years of use. A total of 3000 LLINs (PermaNet 2.0) were distributed in high malaria risk areas of CZS in 2007. After 4 years of use, 27 ‘rectangular’ LLINs and 28 ‘conical’ LLINs were randomly selected for analysis. The evaluation of physical integrity was based on counting the number of holes and measuring their size and location on the nets. Insecticidal efficacy was evaluated by cone bioassays, and the amount of residual insecticide remaining on the surface of the LLINs was estimated using a colorimetric method. After 4 years of use, physical damage was highly prevalent on the rectangular LLINs, with a total of 473 holes detected across the 27 nets. The upper portion of the side panels sustained the greatest damage in rectangular LLINs. The overall mosquito mortality by cone bioassay was < 80% in 25/27 rectangular LLINs, with panel A (at the end of the rectangular bednet) presenting the highest mortality (54%). The overall mean insecticide concentration was 0.5 µg/sample, with the bednet roof containing the highest average concentration (0.61 µg/sample). On the conical LLINs, 547 holes were detected, with the bottom areas sustaining the greatest damage. The cone bioassay mortality was < 80% in 26/28 of the conical LLINs. The mean insecticide concentration was 0.3 µg/sample. After 4 years of use, the insecticidal efficacy of the LLINs was diminished to below acceptable thresholds.

Effective use of Insecticides Treated Nets (ITNs) in the Prevention of Malaria among Pregnant women in Sagnarigu Municipality

Effective use of Insecticides Treated Nets (ITNs) in the Prevention of Malaria among Pregnant women in Sagnarigu Municipality

Predictors of placental malaria in HIV-positive and HIV- negative pregnant women in Enugu, South-Eastern Nigeria

Background: Placental malaria has long been recognized as a complication of malaria in pregnancy with serious adverse outcome. Recognition of possible predictors is an effort in the right direction. Aim of the study: The study determined and compared the Predictors of placental malaria in HIV-positive and HIV- negative pregnant women attending antenatal clinics in Poly General Hospital, South-Eastern Nigeria. Material and method: A cross-sectional descriptive study, carried out on 200 HIV positive and 200 HIV negative pregnant women attending antenatal clinics in Poly General Hospital, Enugu, selected using simple random sampling technique between May to December 2023. Placenta blood samples were collected and thick blood films were examined for malaria parasite using Giemsa expert microscopy. A structured self-administered questionnaire was used for data collection and the data analysed using SPSS version 23. Results: The prevalence of malaria in HIV positive and negative pregnant women were 83.5% (167/200) and 75.5%(151/200) respectively (P &lt; 0.001). The HIV positive and HIV negative participants were between 16-45 years of age with majority in the age range of 31-35 years. Mean gestational age of HIV positive and HIV negative participants were 24.3±1.1 and 24.4±1.3 weeks respectively. Placental malaria was significantly associated with rural residence, hemoglobin genotype AA, not receiving intermittent preventive treatment in pregnancy (IPTp), and not sleeping under insecticide-treated bed nets (ITN) ((P&lt;0.001)). Conclusion: The study showed that Placental malaria was significantly associated with rural residence, hemoglobin genotype AA, not receiving intermittent preventive treatment in pregnancy (IPTp), and not sleeping under insecticide-treated bed nets (ITN). Recognition of these significant predictors will enhance review and implementation of strategies for the prevention of malaria in pregnancy.

Factors associated with the risk of malaria among children: analysis of 2021 Nigeria Malaria Indicator Survey

BackgroundMalaria remains a burden globally, with the African region accounting for 94% of the overall disease burden and deaths in 2019. It is the major cause of morbidity and mortality among children in Nigeria. Though different environmental factors have been assessed to influence the distribution and transmission of malaria vectors, there is a shortage of information on how they may influence malaria transmission among under-fives in Nigeria.MethodsThis study was based on the secondary data analysis of the Nigeria Malaria Indicator Survey 2021. The study sample comprised 10,645 women (aged 15–49) who delivered a child in the 2 years preceding the survey. The study was restricted to under-fives. Logistic regression was used to identify factors associated with the risk of malaria.ResultsThere was a positive association between the risk of malaria and heard/seen malaria messages in the last 6 months (AOR 1.39, 95% CI 1.19–1.62), houses with walls built using rudimentary materials (AOR = 1.38, 95% CI 1.04–1.83), at least 6 children living in the house (AOR 1.22, 95% CI 1.00–1.49), children being 1 or 2 years old was associated with increased odds (AOR 1.89, 95% CI 1.50–2.34 and AOR 1.89, 95% CI 1.52–2.36), children from households with only treated nets (AOR 1.23, 95% CI 1.04–1.46) and those from the North West or South East regions (AOR 1.50, 95% CI 1.10–2.05 and AOR 1.48, 95% CI 1.01–2.16), respectively. All other predictors were not associated with the risk of malaria.ConclusionThe factors associated with the risk of malaria in this study included sleeping under treated mosquito nets, the age of the children, residing in the northwest and southeast regions, wall construction material, 6 children and above in the household and hearing/seen malaria messages in the last 6 months. Continuous health education and public health interventions, such as the provision of LLITNs, will reduce the risk of malaria and improve the health and well-being of children under 5 years of age.

Facilitators and barriers to integrated malaria prevention in Wakiso district, Uganda: A photovoice study.

Malaria continues to cause significant morbidity and mortality globally, particularly in sub-Saharan Africa. Appropriate combinations of non-chemical and chemical methods of malaria vector control in the context of integrated vector management have been recommended by the World Health Organization. The aim of the study was to explore facilitators and barriers to using integrated malaria prevention in Wakiso district, Uganda. This qualitative study employed photovoice among 20 community members in Kasanje Town Council, Wakiso District. The photos taken by participants for 5 months using smartphones were discussed during monthly meetings with the researchers. The discussions were audio-recorded, and resulting data analysed using thematic analysis with the support of NVivo (2020) QSR International. Findings indicated that various conventional and non-conventional measures were being used for preventing malaria such as: insecticide treated nets; clearing overgrown vegetation; draining stagnant water; mosquito coils; smouldering of cow dung; spraying insecticides; plant repellents near houses; eating of prophylactic herbs; as well as closing doors and windows on houses early in the evening. Facilitators supporting the use of several malaria prevention methods holistically included: low cost and accessibility of some methods such as slashing overgrown vegetation; and support provided for certain methods such as receiving free mosquito nets from the government. Barriers to using several malaria prevention methods holistically included: inadequate knowledge of some methods such as housing improvement; allergic reactions to chemical-based methods such as insecticide treated nets; unaffordability of some methods such as insecticide sprays; and inaccessibility of certain methods such as body repellents. These barriers to integrated malaria prevention need to be addressed to achieve greater impact from the combination of methods in endemic communities.

Study of Mosquito Borne Deasease Found in Yavatmal Region

Abstract: Mosquito-borne diseases are a significant public health concern in the Yavatmal region of Maharashtra, India. Malaria, dengue fever, and Japanese encephalitis are among the prominent diseases transmitted by mosquitoes in this region. Malaria, caused by the Plasmodium parasite, is endemic in Yavatmal, with transmission occurring mainly during the monsoon and post-monsoon seasons. Dengue fever, caused by the dengue virus and transmitted by Aedes mosquitoes, has seen periodic outbreaks in the region, with increased incidence during the rainy season. Japanese encephalitis, caused by the Japanese encephalitis virus and transmitted by Culex mosquitoes, poses a threat to the population, particularly in rural areas. Several factors contribute to the spread of mosquito-borne diseases in the Yavatmal region, including inadequate sanitation, stagnant water bodies, deforestation, and climate change. Socioeconomic factors such as poverty and limited access to healthcare further exacerbate the problem. Control and prevention efforts in the region primarily focus on vector control measures, including insecticide spraying, larval source management, and the use of bed nets. Community education and awareness campaigns play a crucial role in promoting preventive behaviors such as the use of insect repellents and proper waste disposal. Challenges in addressing mosquito-borne diseases in Yavatmal include inadequate healthcare infrastructure, insufficient funding, and the emergence of insecticide resistance among mosquito populations. Collaborative efforts involving government agencies, healthcare providers, researchers, and community organizations are essential to effectively combat these diseases. Strengthening surveillance systems, improving access to diagnostic and treatment facilities, and implementing integrated vector management strategies are necessary steps towards reducing the burden of mosquito-borne diseases in the Yavatmal region and improving public health outcomes.

A Logistic Regression Model to Predict Malaria Severity in Children

One of the main causes of death around the globe is malaria. Researchers have sought to develop predicting models for malaria outbreaks based on metrological data, climate data and the breeding cycle of plasmodium, the causative agent of malaria. This study predicts the severity of malaria based on environmental and biological factors. A logistic regression model was developed in this study to predict the severity of malaria based on such factors as sickle cell disease, stagnant water, garbage dumps, wet lawns, and the use of treated mosquito nets with an 83.3% accuracy rate. The study was carried out in the Bosomtwe District of Ghana with 417 respondents. It was deduced that although children in the district are highly prone to malaria infection, the severity is very low. The study recommends that not just having a good sample size alone is important during machine learning model development but also having a good sample representation of the various class labels is equally important.

Modeling time to death for under-five children in Malawi using 2015/16 Demographic and Health Survey: a survival analysis

BackgroundMalawi has one of the highest under-five mortality rates in Sub Sahara Africa. Understanding the factors that contribute to child mortality in Malawi is crucial for the development and implementation of effective interventions to reduce child mortality. The aim of this study is to use survival analysis in modeling time to death for under-five children in Malawi. In turn, identify potential risk factors for child mortality and inform the development of interventions to reduce child mortality in the country.MethodThis study used data from all births that occurred in the five years leading up to the 2015/16 Malawi Demographic and Health Survey. The Frailty hazard model was applied to predict infant survival in Malawi. In this analysis, the outcome of interest was death and it had two possible outcomes: "dead" or "alive". Age at death was regarded as the survival time variable. Infants who were still alive at the time of the study as of the day of the interview were considered as censored observations in the analysis.ResultsA total of 17,286 live births born during the 5 years preceding the survey were analysed. The study found that the risk of death was higher among children born to mothers aged 30–39 and 40 or older compared to teen mothers. Infants whose mothers attended fewer than four antenatal care visits were also found to be at a higher risk of death. On the other hand, the study found that using mosquito nets and early breastfeeding were associated with a lower risk of death, as were being male and coming from a wealthier household.ConclusionThe study reveals a notable decline in infant mortality rates as under-five children age, underscoring the challenge of ensuring newborn survival. Factors such as maternal age, birth order, socioeconomic status, mosquito net usage, early breastfeeding initiation, geographic location, and child's sex are key predictors of under-five mortality. To address this, public health strategies should prioritize interventions targeting these predictors to reduce under-five mortality rates.

Assessing the implementation fidelity, feasibility, and sustainability of community-based house improvement for malaria control in southern Malawi: a mixed-methods study

BackgroundDespite significant success in the fight against malaria over the past two decades, malaria control programmes rely on only two insecticidal methods: indoor residual spraying and insecticidal-treated nets. House improvement (HI) can complement these interventions by reducing human-mosquito contact, thereby reinforcing the gains in disease reduction. This study assessed the implementation fidelity, which is the assessment of how closely an intervention aligns with its intended design, feasibility, and sustainability of community-led HI in southern Malawi.MethodsThe study, conducted in 22 villages (2730 households), employed a mixed-methods approach. Implementation fidelity was assessed using a modified framework, with longitudinal surveys collecting data on HI coverage indicators. Quantitative analysis, employing descriptive statistics, evaluated the adherence to HI implementation. Qualitative data came from in-depth interviews, key informant interviews, and focus groups involving project beneficiaries and implementers. Qualitative data were analysed using content analysis guided by the implementation fidelity model to explore facilitators, challenges, and factors affecting intervention feasibility.ResultsThe results show that HI was implemented as planned. There was good adherence to the intended community-led HI design; however, the adherence could have been higher but gradually declined over time. In terms of intervention implementation, 74% of houses had attempted to have eaves closed in 2016-17 and 2017-18, compared to 70% in 2018–19. In 2016–17, 42% of houses had all four sides of the eaves closed, compared to 33% in 2018–19. Approximately 72% of houses were screened with gauze wire in 2016-17, compared to 57% in 2018-19. High costs, supply shortages, labour demands, volunteers’ poor living conditions and adverse weather were reported to hinder the ideal HI implementation. Overall, the community described community-led HI as feasible and could be sustained by addressing these socioeconomic and contextual challenges.ConclusionOur study found that although HI was initially implemented as planned, its fidelity declined over time. Using trained volunteers facilitated the fidelity and feasibility of implementing the intervention. A combination of rigorous community education, consistent training, information, education and communication, and intervention modifications may be necessary to address the challenges and enhance the intervention’s fidelity, feasibility, and sustainability.

Mosquito Bed Net Use and Burkitt Lymphoma Incidence in Sub-Saharan Africa

Burkitt lymphoma (BL) is one of the most common childhood cancers in sub-Saharan Africa and is etiologically linked to malaria. However, evidence for an effect of malaria interventions on BL is limited. To investigate the potential population-level association between large-scale rollout of insecticide-treated bed nets (ITNs) in sub-Saharan Africa in the 2000s and BL incidence. In this systematic review and meta-analysis, a search was conducted in the Embase, Global Health, and Medline databases and in cancer registry publications between January 1, 1990, and February 27, 2023. All epidemiologic studies on BL incidence rates in children and adolescents aged 0 to 15 years in sub-Saharan African countries where malaria is endemic were identified by 2 reviewers blinded to each other's decision. The systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guideline. Data were extracted independently by 2 reviewers, and quality was scored based on 3 predefined criteria: data collection, case ascertainment, and calculation of person-time at risk. Incidence rates of BL during childhood and mean ITN use in the population. Data were analyzed using a random-effects negative binomial regression model. Of 2333 studies meeting selection criteria, 23 comprising 66 data points on BL incidence were included based on 5226 BL cases from locations with large-scale ITN use in 17 countries. Rates of BL were 44% (95% CI, 12%-64%) lower in the period after ITN introduction compared with before. The adjusted pooled incidence rates of BL were 1.36 (95% CI, 0.88-2.10) and 0.76 (95% CI, 0.50-1.16) per 100 000 person-years before and after introduction of ITNs, respectively. After adjusting for potential confounders, a 1-percentage point increase in mean ITN use in the population in the 10 years before BL data collection was associated with a 2% (95% CI, 1%-4%) reduction in BL incidence. In this systematic review and meta-analysis, large-scale rollout of ITNs in the 2000s was associated with a reduction in BL burden among children in sub-Saharan Africa. Although published data may not be representative of all incidence rates across sub-Saharan Africa, this study highlights a potential additional benefit of malaria control programs.

Use of Insecticide-Treated Bed Nets and Incidence of Burkitt Lymphoma

Use of Insecticide-Treated Bed Nets and Incidence of Burkitt Lymphoma

Factors Associated with Anaemia in Under-five Children in Zambia; Secondary Analysis of the 2021 Malaria Indicator Survey Data

Introduction: Anaemia is one of the major public health concerns in many developing countries including Zambia. Unless it is acute, the consequences of anaemia are not immediate but have long-term debilitating effects such as growth and intellectual retardation. As such it does not receive the necessary attention it deserves. This study aimed to assess the prevalence and associated factors of anaemia in under-five children in Zambia.&#x0D; Methods: This study was a secondary analysis of the 2021 Malaria Indicator Survey. We extracted data from the datasets at the National Malaria Elimination Centre after obtaining permission from the Ministry of Health. The extracted data was analysed in STATA 14, summarised in frequencies, cross-tabulations between independent variables and the outcome and multivariable logistic regression was used to assess the associations between variables and anaemia.&#x0D; Findings: The prevalence of anaemia was found to be 53.8%. Anaemia was found to be associated more with children below one year compared to older children, children whose household heads had no or only have primary education compared to those with secondary or tertiary education and in the northern parts of the country such as Luapula and Northern provinces compared to the southern province. Further anaemia was more common in those with malaria than those without malaria and those with febrile illnesses than those without febrile illnesses. In addition, anaemia was less common in those who slept under insecticide-treated nets.&#x0D; Conclusion: Anaemia in Zambia has been found to be higher than the average in Southern Africa, it is associated with younger age groups, poverty conditions and where diseases like malaria and other febrile illnesses are more common than where they are not. The use of interventions like insecticide-treated nets is associated with reduced prevalence of anaemia.

Temperature, mosquito feeding status and mosquito density influence the measured bio-efficacy of insecticide-treated nets in cone assays

BackgroundThe WHO cone bioassay is routinely used to evaluate the bioefficacy of insecticide-treated nets (ITNs) for product pre-qualification and confirmation of continued ITN performance during operational monitoring. Despite its standardized nature, variability is often observed between tests. We investigated the influence of temperature in the testing environment, mosquito feeding status and mosquito density on cone bioassay results.MethodsCone bioassays were conducted on MAGNet (alphacypermethrin) and Veeralin (alphacypermethrin and piperonyl butoxide (PBO)) ITNs, using laboratory-reared pyrethroid-resistant Anopheles funestus sensu stricto (FUMOZ strain) mosquitoes. Three experiments were conducted using standard cone bioassays following WHO-recommended test parameters, with one variable changed in each bioassay: (i) environmental temperature during exposure: 22–23 °C, 26–27 °C, 29–30 °C and 32–33 °C; (ii) feeding regimen before exposure: sugar starved for 6 h, blood-fed or sugar-fed; and (iii) mosquito density per cone: 5, 10, 15 and 20 mosquitoes. For each test, 15 net samples per treatment arm were tested with four cones per sample (N = 60). Mortality after 24, 48 and 72 h post-exposure to ITNs was recorded.ResultsThere was a notable influence of temperature, feeding status and mosquito density on An. funestus mortality for both types of ITNs. Mortality at 24 h post-exposure was significantly higher at 32–33 °C than at 26–27 °C for both the MAGNet [19.33% vs 7%; odds ratio (OR): 3.96, 95% confidence interval (CI): 1.99–7.87, P < 0.001] and Veeralin (91% vs 47.33%; OR: 22.20, 95% CI: 11.45–43.05, P < 0.001) ITNs. Mosquito feeding status influenced the observed mortality. Relative to sugar-fed mosquitoes, The MAGNet ITNs induced higher mortality among blood-fed mosquitoes (7% vs 3%; OR: 2.23, 95% CI: 0.94–5.27, P = 0.068) and significantly higher mortality among starved mosquitoes (8% vs 3%, OR: 2.88, 95% CI: 1.25–6.63, P = 0.013); in comparison, the Veeralin ITNs showed significantly lower mortality among blood-fed mosquitoes (43% vs 57%; OR: 0.56, 95% CI: 0.38–0.81, P = 0.002) and no difference for starved mosquitoes (58% vs 57%; OR: 1.05, 95% CI: 0.72–1.51, P = 0.816). Mortality significantly increased with increasing mosquito density for both the MAGNet (e.g. 5 vs 10 mosquitoes: 7% vs 12%; OR: 1.81, 95% CI: 1.03–3.20, P = 0.040) and Veeralin (e.g. 5 vs 10 mosquitoes: 58% vs 71%; OR 2.06, 95% CI: 1.24–3.42, P = 0.005) ITNs.ConclusionsThe results of this study highlight that the testing parameters temperature, feeding status and mosquito density significantly influence the mortality measured in cone bioassays. Careful adherence to testing parameters outlined in WHO ITN testing guidelines will likely improve the repeatability of studies within and between product testing facilities.Graphical

Health Education about Malaria for the Nabire Community

Nabire Regency with a total of 1,082 cases. In 2021, there was an increase in malaria cases, reaching 2,456 positive cases of malaria, of which the largest number of cases were in Nabire District with a total of 1,248 positive cases. To reduce the high number of malaria cases, the Nabire Regency Government issued Regent Regulation number 48 of 2019 concerning the Malaria Control Center, but in its implementation there are obstacles faced by the Health Service, namely the lack of community support and the lack of supporting infrastructure in implementing malaria control policies. The aim of community service activities carried out in Nabire Regency is to increase public knowledge and awareness in eradicating malaria. The population of this community service is the Nabire community using counseling methods through community leaders such as village elders, RT, RW and health cadres. The method for solving problems uses several methods and fishbone diagrams. The implementation that has been carried out in this community service is conducting a Forum Group Discussion (FGD) with community leaders consisting of health problems, namely malaria related to community compliance with healthy behavior such as using mosquito nets or installing coarse wire, using mosquito poison, keeping the house clean. After conducting the FGD, we first conducted education regarding malaria prevention through leaflets to community leaders. Health education to the community regarding malaria was assisted by community leaders who participated in the FGD. Community figures who assist in delivering health education are village elders, RT, RW and health cadres. As a result, 85% of community service activities aimed at increasing community knowledge were successful, the community became more knowledgeable about preventing malaria and improving their health. The Conclusion of this research is this community service program was implemented, and resulted in a change in accordance with the output target, namely knowledge about eradicating malaria, especially how to prevent it. It is hoped that the counseling provided can be carried out regularly and applied in people's lives so that the incidence of malaria can decrease.

Contextual factors related to vector-control interventions for malaria: a scoping review and evidence and gap map protocol.

This scoping review will identify existing literature regarding contextual factors relevant to vector-control interventions to prevent malaria. We will use the findings of the scoping review to produce an interactive evidence and gap map. The map will assist in the priority setting, development, and conduct of targeted systematic reviews. These systematic reviews seek to assist the Vector Control and Insecticide Resistance Unit of the World Health Organization's Global Malaria Programme by informing recommendation development by their Guidelines Development Group. Malaria contributes substantially to the global burden of disease, with an estimated 247 million cases and 619,000 deaths in 2021. Vector-control is key in reducing malaria transmission. Vector-control interventions directly target the mosquito, reducing the potential for parasite infections. These interventions commonly include insecticides used in indoor residual spraying or insecticide-treated nets and larval source management. Several new vector-control interventions are under evaluation to complement these. In addition to estimating the effects of interventions on health outcomes, it is critical to understand how populations at risk of malaria consider them in terms of their feasibility, acceptability, and values. Eligible studies will have assessed the contextual factors of feasibility or acceptability of the interventions of interest, or the valuation of the outcomes of interests. These assessments will be from the perspective of people who receive (residents) or deliver (workers or technicians) the vector-control intervention for the purpose of preventing malaria. We will conduct this scoping review in accordance with the JBI methodology for scoping reviews and report in line with the Preferred Reporting Items for Systematic Reviews and Meta-analyses extension for Scoping Reviews (PRISMA-ScR). We will construct the evidence and gap map following guidance from the Campbell Collaboration.

Trapping and killing performance of a PermaNet 2.0 hybrid mosquito trapping bednet: an experimental hut evaluation

Background Despite the huge global effort , there has been an increase in malaria morbidity and mortality in sub-Saharan Africa since 2015, from 212 million cases and 429,000 deaths in 2015 to 241 million cases and 627,000 deaths in 2020 mainly because of resistance to insecticide. Therefore, advancing innovative approaches is the only sustainable way to fight malaria. Methods Taking advantage of the behavior of mosquitoes around the net, which is almost 70-90% concentrated on the roof, we have developed a two-compartment mosquito bednet, the so-called T-Net for mass mosquito trapping and killing. In the current study, we investigated in an experimental hut trial, the efficacy of trapping-long-lasting insecticide-treated nets (T-LLINs) against Anopheles gambiae s.l. in an insecticide resistance context. Five different arms have been considered in this study including three positive control arms e.g. PermaNet 2.0 LLIN, Tsara boost LLIN and Interceptor generation 2 (IG2) LLIN), one negative control arm using insecticide-free bednet, and one candidate arm using a hybrid-treated trapping bednet made with PermaNet 2.0 LLIN mounted with an insecticide-free compartment (T-LLIN). Results The highest average daily mortality was recorded with the T-LLIN. In total, 678 mosquitoes were killed by T-LLIN among the 760 collected, i.e. 89.2%. Out of these, 317 were found in the trap compartment, representing 46.75% of mortality directly attributable to the mechanical effect of this net. This added value made it possible to quantify the increased in the killing effect that this net would have over the positive control arms: this would be 58.5% higher than the killing effect of PN2.0, 38% higher than that of Tsara boost and 31.5% higher than that of IG2. Conclusion The current study shows potential to maximize the efficiency of the WHO-recommended LLINs by an addition of an insecticide-free trap compartment on top of the net.

A dynamic game of lymphatic filariasis prevention by voluntary use of insecticide treated nets

Lymphatic filariasis (LF) has been targeted for elimination as a public health concern by 2030 with a goal to keep the prevalence of LF infections under the 1% threshold. While mass drug administration (MDA) is a primary strategy recommended by WHO, the use of insecticide treated nets (ITN) plays a crucial role as an alternative strategy when MDA cannot be used. In this paper, we use imitation dynamics to incorporate human behavior and voluntary use of ITN into the compartmental epidemiological model of LF transmission. We find the equilibrium states of the dynamics and the ITN usage as it depends on epidemiological parameters and the cost of ITNs. We investigate the conditions under which the voluntary use of ITNs can keep the LF prevalence under the 1% threshold. We found that when the cost of using the ITNs is about 105 smaller than the perceived cost of LF, then the voluntary use of ITNs will eliminate LF as a public health concern. Furthermore, when the ITNs are given away for free, our model predicts that over 80% of the population will use them which would eliminate LF completely in regions where Anopheles are the primary vectors.

Monitoring Adverse Effects and Efficacy Associated with Short-Term Mefloquine Chemoprophylaxis: Experience of the Moroccan Level II Hospital in the Democratic Republic of the Congo

Malaria is transmitted by a parasite carried by certain species of Anopheles mosquitoes. The much-debated mefloquine was discovered in the 1970s by U.S. Army researchers. It is widely used to prevent and treat malaria. Our aim is to evaluate the different types of adverse reactions reported by military personnel at the Moroccan hospital in the Democratic Republic of the Congo. This is a prospective, cross-sectional study lasting three months. It was carried out using a three-part questionnaire (patient identification, vector protection used, adverse events reported, and whether or not a malaria attack had occurred). 67 military personnel. The majority of soldiers were men (97.28%), with 95% aged between 26 and 45. 100% of soldiers used mosquito nets and repellents. During the first month of chemoprophylaxis, 30% of soldiers had adverse reactions (60% had nightmares, 30% had asthenia, and 10% had somnolence). From the second month onwards, 50% of soldiers had adverse reactions (65% nightmares, 40% asthenia, 20% memory disorders, 10% somnolence, 5% headaches, and 5% insomnia). Towards the end of the third month, 53% of servicemen experienced adverse reactions (65% nightmares, 40% asthenia, 20% memory disorders, 10% somnolence, 5% headaches, 5% insomnia, and 3% anxiety). During these three months, only one case suffered a malaria attack. Mefloquine is an antimalarial drug commonly used to prevent and treat malaria. It is important to note that chemoprophylaxis alone does not guarantee 100% protection against malaria. Additional measures must therefore be taken, such as wearing long, light clothing, using insecticide-impregnated mosquito nets, and using repellents.

Better methods, better data: landscaping the priorities for improving methodologies in vector control.

This article addresses the evolving challenges in evaluating insecticide-based tools for vector control. In response to the emergence of insecticide resistance in major malaria vectors, novel chemistries and products are coming to market, and there is a need to review the available testing methodologies. Commonly used methods for evaluating insecticides, such as the World Health Organization (WHO) cone bioassay, are inadequate for the diverse range of tools now available. Innovation to Impact (I2I) has studied the variability in laboratory methods, with the aim of identifying key factors that contribute to variation and providing recommendations to tighten up protocols. The I2I Methods Landscape is a living document which presents a review of existing methods for evaluating vector control tools, with the scope currently extending to insecticide-treated nets (ITNs) and indoor residual sprays (IRS). The review reveals a lack of validation for many commonly used vector control methods, highlighting the need for improved protocols to enhance reliability and robustness of the data that is generated to make decisions in product development, evaluation, and implementation. A critical aspect highlighted by this work is the need for tailored methods to measure endpoints relevant to the diverse modes of action of novel insecticides. I2I envisage that the Methods Landscape will serve as a decision-making tool for researchers and product manufacturers in selecting appropriate methods, and a means to prioritise research and development. We call for collective efforts in the pro-active development, validation, and consistent implementation of suitable methods in vector control to produce the data needed to make robust decisions.

New data on the clupeoids of lakes Mai-Ndombe and Tumba, western Democratic Republic of the Congo, using an integrated approach combining morphology and barcoding

Morphological and molecular comparisons of clupeoid fishes in lakes Tumba and Mai-Ndombe in the Congo Basin revealed that a large-sized form of a common species in Lake Mai-Ndombe had not been distinguished from the small-sized endemic Mai-Ndombe dwarf sprat Nannothrissa stewarti Poll & Roberts, 1976 in ecological studies. The large-sized form differs from the Mai-Ndombe dwarf sprat in several morphological characters and resembles the smalltoothed pellonula Pellonula leonensis Boulenger, 1916, but in barcoding analysis appears more closely related to the bluntnosed sawtooth pellonuline Potamothrissa obtusirostris (Boulenger, 1909). This large-sized form is probably a species new to science but will remain undescribed for now, and is here referred to as Pellonulinae sp. BIG. A slender clupeoid, also from Lake Mai-Ndombe, has recently been referred to as the Lake Tumba dwarf sprat Nannothrissa parva (Regan, 1917), which would be the first record of this species from that lake. Specimens of a slender clupeoid collected from Lake Mai-Ndombe for this study were identified as the losera fangtooth pellonuline Odaxothrissa losera Boulenger, 1899. This is the first confirmed occurrence of this species in Lake Mai-Ndombe, whereas the presence of N. parva could not be confirmed. The phylogenetic analysis strongly supports the genus Nannothrissa as currently delimited, here barcoded for the first time, but also confirms the previously reported mismatch between morphological classification and molecular data in this group. We further note that the Mai-Ndombe dwarf sprat attains a larger size than the maximum size noted in the original description in 1976, and it is suggested that an intense beach-seine fishery that utilises mosquito nets might have led to a population decline followed by decreased intraspecific competition, enhancing individual growth. For the same reason, Pellonulinae sp. BIG might have been less common previously and so remained undetected until now.