RESUMEN
Mosquito nets, particularly insecticide-treated nets, are the most recommended method of malaria control in endemic countries. However, individuals do not always have access to insecticide-treated nets or use them as recommended. The current paper expands on a previous review published in 2011 which highlighted a need for more qualitative research on the reasons for mosquito net non-use. We present a systematic review of qualitative research published in the past decade to assess the growth and quality of qualitative papers about net non-use and examine and update the current understanding. A comprehensive literature search was carried out in MEDLINE, CINAHL, and Global Health, in addition to a citation search of the initial review. Relevant papers were screened and discussed. The critical appraisal assessment tool was used to ensure quality. Thematic synthesis was used to extract, synthesise, and analyse study findings. Compared with the initial review, the results showed a 10-fold increase in qualitative research on the reasons for mosquito net non-use between 2011 and 2021. In addition, the quality of the research has improved, with more than 90% of the papers receiving high scores, using the critical appraisal assessment tool. The reported reasons for non-use were categorised into four themes: human factors, net factors, housing structure, and net access. More than two thirds of the studies (25/39) were led by authors affiliated with institutions in malaria-endemic countries. Despite the distribution of free mosquito nets in malaria-endemic countries, earlier reported challenges remain pertinent. The most common reasons for net non-use across all regions of Malaria endemic countries pertained to human- and net-related factors. The research focus should shift towards intervention studies to address these issues.
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Mosquiteros Tratados con Insecticida , Malaria , Control de Mosquitos , Investigación Cualitativa , Malaria/prevención & control , Humanos , Control de Mosquitos/métodosRESUMEN
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.
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Filariasis Linfática , Mosquiteros Tratados con Insecticida , Insecticidas , Animales , Humanos , Filariasis Linfática/epidemiología , Filariasis Linfática/prevención & control , Mosquitos Vectores , Administración Masiva de Medicamentos , Control de MosquitosRESUMEN
BACKGROUND: Despite remarkable progress in malaria burden reduction, malaria continues to be a major public health problem globally. Ethiopia has been distributing long-lasting insecticidal nets (LLINs) for free and nationwide distribution was completed in 2016. However, evidence suggests that the utilization of LLINs varies from setting to setting and from time to time due to different factors, and up-to-date evidence is required for LLIN related decision-making. Hence, this study was designed to assess LLIN utilization and its determinants in the Southern Nations, Nationalities, and People's Region (SNNPR) of Ethiopia. METHODS: A community-based cross-sectional study was conducted in Southern Ethiopia in 2019. Using multi-stage sampling, a total of 2466 households were included. The region was stratified based on the annual malaria index as high, moderate, low, and free strata. Cluster sampling was then applied to select households from high, moderate, and low strata. Data on LLIN ownership, utilization and different determinant factors were collected using household questionnaire. SurveyCTO was used to collect data and data was managed using Stata 15. Descriptive statistics and multilevel mixed-effects logistic regression were performed to identify the determinants of utilization of LLINs. Effect measures were reported using adjusted odds ratio (AOR) with 95% CI. RESULTS: From a total of 2466 households, 48.7% of households had at least one LLIN. LLIN adequacy based on family size was 23% while it was15.7% based on universal access and 29.2% based on sleeping space. From 1202 households that possessed LLIN(s), 66.0% of households reported that they slept under LLIN the night preceding the survey. However, when the total population in all surveyed households were considered, only 22.9% of household members slept under LLIN the night preceding the survey. Malaria endemicity, educational status, wealth status, and knowledge about malaria were associated with LLINs utilization. In addition, reasons for non-use included perceived absence of malaria, side effects of LLIN, conditions of LLINs, inconvenient space and low awareness. CONCLUSION: Low LLIN coverage and low utilization were noted. A low level of utilization was associated with malaria endemicity, wealth status and level of awareness. Distribution of LLIN and continuous follow-up with community awareness creation activities are vital to improve coverage and utilization of LLINs, and to ensure the country's malaria elimination goal.
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Mosquiteros Tratados con Insecticida , Insecticidas , Malaria , Humanos , Estudios Transversales , Etiopía/epidemiología , Malaria/epidemiología , Malaria/prevención & control , Salud Pública , Control de Mosquitos/métodosRESUMEN
BACKGROUND: Intense pyrethroid resistance threatens the effectiveness of the primary vector control intervention, insecticide-treated nets (ITNs), in Nigeria, the country with the largest malaria burden globally. In this study, the epidemiological and entomological impact of a new type of ITN (piperonyl-butoxide [PBO] ITNs) distributed in Ebonyi State were evaluated. The epidemiological impact was also compared to the impact of standard pyrethroid-only ITNs in Cross River State. METHODS: A controlled interrupted time series analysis was conducted on monthly malaria incidence data collected at the health facility level, using a multilevel mixed-effects negative binomial model. Data were analysed two years before and after the PBO ITN campaign in Ebonyi State (December 2017 to November 2021). A pre-post analysis, with no comparison group, was used to assess the impact of PBO ITNs on human biting rates and indoor resting density in Ebonyi during the high transmission season immediately before and after the PBO ITN campaign. RESULTS: In Ebonyi, PBO ITNs were associated with a 46.7% decrease (95%CI: -51.5, -40.8%; p < 0.001) in malaria case incidence in the 2 years after the PBO ITN distribution compared to a modelled scenario of no ITNs distributed, with a significant decrease from 269.6 predicted cases per 1000 population to 143.6. In Cross River, there was a significant 28.6% increase (95%CI: -10.4, 49.1%; p < 0.001) in malaria case incidence following the standard ITN distribution, with an increase from 71.2 predicted cases per 1000 population to 91.6. In Ebonyi, the human biting rate was 72% lower (IRR: 0.28; 95%CI 0.21, 0.39; p < 0.001) and indoor resting density was 73% lower (IRR: 0.27; 95%CI 0.21, 0.35; p < 0.001) after the PBO ITNs were distributed. CONCLUSIONS: The epidemiological and entomological impact of the PBO ITNs underscore the impact of these ITNs in areas with confirmed pyrethroid resistance. These findings contribute to ongoing research on the impact of new types of ITNs in Nigeria, providing critical evidence for the Nigeria National Malaria Elimination Programme and other countries for future ITN procurement decisions as part of mass ITN campaign planning and malaria programming.
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Anopheles , Mosquiteros Tratados con Insecticida , Insecticidas , Análisis de Series de Tiempo Interrumpido , Malaria , Control de Mosquitos , Mosquitos Vectores , Nitrilos , Butóxido de Piperonilo , Piretrinas , Mosquiteros Tratados con Insecticida/estadística & datos numéricos , Butóxido de Piperonilo/farmacología , Nigeria/epidemiología , Incidencia , Piretrinas/farmacología , Malaria/prevención & control , Malaria/epidemiología , Control de Mosquitos/métodos , Control de Mosquitos/estadística & datos numéricos , Insecticidas/farmacología , Humanos , Mosquitos Vectores/efectos de los fármacos , Animales , Anopheles/efectos de los fármacos , Nitrilos/farmacologíaRESUMEN
BACKGROUND: Malaria remains a significant public health threat in Sierra Leone, particularly for pregnant women and their unborn children. Infection during pregnancy can lead to severe consequences, including maternal anaemia, low birth weight, premature birth, and even death. Therefore, preventing malaria during pregnancy is crucial for improving maternal and child health outcomes. This study investigated the predictors of insecticide-treated bed net (ITN) use among pregnant women in Sierra Leone. METHODS: The study analysed the 2019 Sierra Leone Demographic and Health Survey data (SLDHS). The study comprised a total of 900 pregnant women aged 15-49 years, representing the nationally representative sample. A multivariable binary regression analysis was used to explore the predictors of ITN use. The regression results were presented using an adjusted odds ratio (AOR) with 95% confidence intervals (CI). RESULTS: The study found that the prevalence of ITN use among pregnant women was 64.2 [60.4, 67.9] in Sierra Leone. Pregnant women who were married [aOR = 2.02, 95% CI 1.32, 3.07] had higher odds of bed net use than those who were unmarried. Pregnant women with five or more children [aOR = 1.69, 95% CI 1.01, 2.84] had higher odds of mosquito bed net use than those with four and below children. Pregnant women living in the Northern, Northwestern, Southern and Western regions all had lower odds of bed net use than those in the Eastern region, with the lowest odds among those living in the western region [aOR = 0.19, 95% CI 0.09, 0.40]. Pregnant women who were Muslims [aOR = 0.63, 95% CI 0.41, 0.95] had lower odds of mosquito bed net use than Christians. Pregnant women with female household heads [aOR = 0.65, 95% CI 0.44, 0.95] had lower odds of mosquito bed net use than those with male household heads. CONCLUSION: ITN use among pregnant women in Sierra Leone remains suboptimal. Marital status, parity, sex of household head, region and religion were associated with bed net use. The government and policymakers in Sierra Leone should integrate ITN education and distribution into prenatal care services, emphasizing the benefits for both mother and baby-partnering with healthcare providers to raise awareness and encourage consistent use. Involve local leaders, religious figures, and mothers' groups to promote the benefits of ITN during pregnancy. Educate husbands and partners on the importance of ITN use during pregnancy and encourage their support in its consistent use.
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Mosquiteros Tratados con Insecticida , Malaria , Humanos , Sierra Leona/epidemiología , Mosquiteros Tratados con Insecticida/estadística & datos numéricos , Femenino , Adulto , Adulto Joven , Adolescente , Embarazo , Persona de Mediana Edad , Malaria/prevención & control , Malaria/epidemiología , Control de Mosquitos/estadística & datos numéricos , Control de Mosquitos/métodos , Encuestas Epidemiológicas , Mujeres Embarazadas , Estudios TransversalesRESUMEN
BACKGROUND: Long-lasting insecticidal nets (LLINs) have been a widely used malaria prevention method for decades. In South Sudan, LLINs are typically distributed by volunteers who use paper-based systems to collect distribution data. Paper-based systems are simple to use but have a higher occurrence of data inaccuracies and can hinder the timely use of data for decision-making. In 2022, a digital tool was introduced to collect data during the LLIN campaign in Northern Bahr el Ghazal (NBeG). The tool aimed to improve the accuracy of data entry and enable data to be used in real-time for decision making during the campaign. The digital tool was developed with offline functionality and interoperability with DHIS2 tracker version 2.8 in DHIS2 version 2.38. This study assessed the usability of the tool according to user perspectives. METHODS: A questionnaire containing open- and closed-ended questions was conducted with users of the digital tool, supervisors and other key stakeholders in five counties of NBeG. The questionnaire was administered using Malaria Consortium's Projects Results System Android mobile application. Usability was determined through a modified and validated System Usability Scale (SUS) approach. RESULTS: A total of 93 participants responded to the usability questionnaire. The mean (± standard deviation) usability score across 10 SUS-scoring items was 60.91 (12.87), indicating a modest level of usability. The majority of users agreed the tool was useful for managing the LLIN distribution workflow, was easy to use, reduced workload, and supported stock management and real-time campaign monitoring. There was no significant difference in the usability scores across genders, roles, and counties. Respondents with experience of both paper-based and the digital tool tended to express a preference for the digital tool over paper-based systems. The majority of respondents also reported they would recommend the digital tool to colleagues. CONCLUSION: Digital tools are perceived to improve data collection during LLIN campaigns, even in remote areas where network coverage is challenging. Additional improvements can be implemented to overcome operational challenges and improve usability of the tool. Further study is needed to assess the impact of the digital tool on data quality and real-time data use.
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Mosquiteros Tratados con Insecticida , Malaria , Control de Mosquitos , Mosquiteros Tratados con Insecticida/estadística & datos numéricos , Sudán del Sur , Control de Mosquitos/métodos , Control de Mosquitos/estadística & datos numéricos , Malaria/prevención & control , Humanos , Encuestas y Cuestionarios , Femenino , Masculino , AdultoRESUMEN
BACKGROUND: Insecticide-treated nets (ITNs) contributed significantly to the decline in malaria since 2000. Their protective efficacy depends not only on access, use, and net integrity, but also location of people within the home environment and mosquito biting profiles. Anopheline mosquito biting and human location data were integrated to identify potential gaps in protection and better understand malaria transmission dynamics in Busia County, western Kenya. METHODS: Direct observation of human activities and human landing catches (HLC) were performed hourly between 1700 to 0700 h. Household members were recorded as home or away; and, if at home, as indoors/outdoors, awake/asleep, and under a net or not. Aggregated data was analysed by weighting hourly anopheline biting activity with human location. Standard indicators of human-vector interaction were calculated using a Microsoft Excel template. RESULTS: There was no significant difference between indoor and outdoor biting for Anopheles gambiae sensu lato (s.l.) (RR = 0.82; 95% CI 0.65-1.03); significantly fewer Anopheles funestus were captured outdoors than indoors (RR = 0.41; 95% CI 0.25-0.66). Biting peaked before dawn and extended into early morning hours when people began to awake and perform routine activities, between 0400-0700 h for An. gambiae and 0300-0700 h for An. funestus. The study population away from home peaked at 1700-1800 h (58%), gradually decreased and remained constant at 10% throughout the night, before rising again to 40% by 0600-0700 h. When accounting for resident location, nearly all bites within the peri-domestic space (defined as inside household structures and surrounding outdoor spaces) occurred indoors for unprotected people (98%). Using an ITN while sleeping was estimated to prevent 79% and 82% of bites for An. gambiae and An. funestus, respectively. For an ITN user, most remaining exposure to bites occurred indoors in the hours before bed and early morning. CONCLUSION: While use of an ITN was estimated to prevent most vector bites in this context, results suggest gaps in protection, particularly in the early hours of the morning when biting peaks and many people are awake and active. Assessment of additional human exposure points, including outside of the peri-domestic setting, are needed to guide supplementary interventions for transmission reduction.
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Anopheles , Insecticidas , Malaria , Animales , Humanos , Kenia , Mosquitos Vectores , Malaria/prevención & controlRESUMEN
BACKGROUND: The use of insecticide-treated nets (ITNs) is a strategy recommended by the World Health Organization (WHO) for malaria prevention. In Nigeria, ITNs have been periodically distributed since 2007 through campaigns. Campaign activities and assets are typically tracked using either a paper-based or digital system. In 2017, a digital approach was introduced in Ondo state for tracking attendance at training sessions as part of the ITN campaign. Following the success of the 2017 introduction, subsequent campaigns planned to digitise other aspects of the campaign to improve accountability and efficiency of the ITN distribution. The COVID-19 pandemic posed additional challenges for the ITN distribution planned for 2021 and adaptations were made to the programme strategy to ensure the campaign could go ahead safely. This article presents lessons and experiences from the 2021 ITN distribution campaign in Ondo state, Nigeria. METHODS: The campaign used RedRose, a customised mobile application, to monitor the planning and delivery of the campaign, collect household information including training personnel and tracking the transfer of ITNs between distribution hubs and households. ITNs were delivered through a single-phase door-to-door distribution strategy. RESULTS: The campaign distributed 2,965,125 ITNs covering 1,057,577 households across Ondo state. The digital application was beneficial for monitoring the quality of implementation and tracking assets and staff to ensure safety.. The single-phase door-to-door approach was more convenient for households compared to fixed-point distribution but increased the workload for mobilization and distribution teams. CONCLUSIONS: Single phase door-to-door strategy using digital tools was an effective method to increase coverage of ITNs while closely tracking the progress of distribution campaigns. High-quality population data are needed to further improve the planning and implementation of ITN campaigns and other health interventions.
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Mosquiteros Tratados con Insecticida , Malaria , Control de Mosquitos , Nigeria , Mosquiteros Tratados con Insecticida/estadística & datos numéricos , Malaria/prevención & control , Humanos , Control de Mosquitos/métodos , Control de Mosquitos/estadística & datos numéricos , COVID-19/prevención & control , Femenino , Preescolar , Niño , Masculino , Lactante , Adolescente , Adulto , Persona de Mediana Edad , Adulto JovenRESUMEN
BACKGROUND: Uganda grapples with a considerable malaria burden, reporting prevalence rates of over 33% in some regions. To address this, the Uganda Ministry of Health employs audiovisual platforms for disseminating malaria prevention messages. However, the impact of these messages on pregnant women's knowledge of malaria prevention remains insufficiently explored. This paper therefore emphasizes the influence of audiovisual messages on the knowledge of malaria prevention measures among pregnant women in Uganda. METHODS: Secondary data obtained from the Uganda Malaria Indicator Survey (MIS) 2018-2019 was used for this analysis. Women aged 15-49 were included in the study. A total of 8868 women were selected using a two-stage sample design. The two stages of selection included clusters and households. Women who were currently pregnant were included in the study, resulting in a weighted sample of 721 women. Propensity score-matched analysis was used to evaluate the impact of access to malaria messages on knowledge of prevention measures. RESULTS: The study revealed that 39% [95% CI 34.0-44.2] of pregnant women were exposed to malaria messages before the survey. Those exposed had a 17.2% higher knowledge [ATT = 0.172; 95% CI 0.035-0.310] of using mosquito nets for prevention compared to those unexposed. Among women exposed, radios accounted for most form of access to mass media campaigns [64.8, 95% CI 57.0-71.8] followed by interpersonal communication [45.0, 95% CI 37.6-52.6], community health workers [38.8, 95% CI 29.6-48.8], community events [21.4, 95% CI 15.8-28.3], and social mobilization [18.3, 95% CI 12.7-25.8]. CONCLUSION: Results highlight the importance of radios in spreading important malaria prevention messages to pregnant women. Being exposed to these messages is linked to increased awareness and knowledge about the proper use of insecticide-treated bed nets (ITNs) for preventing malaria. This finding underscores the importance of evaluating different channels for mass media campaigns to ensure the effective delivery of information about malaria prevention to the intended audiences.
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Conocimientos, Actitudes y Práctica en Salud , Malaria , Medios de Comunicación de Masas , Mujeres Embarazadas , Puntaje de Propensión , Humanos , Femenino , Uganda , Malaria/prevención & control , Adulto , Adolescente , Adulto Joven , Embarazo , Medios de Comunicación de Masas/estadística & datos numéricos , Persona de Mediana Edad , Mujeres Embarazadas/psicología , Promoción de la Salud/métodosRESUMEN
BACKGROUND: Insecticide-treated nets (ITNs) are the backbone of anti-malarial vector control in Papua New Guinea (PNG). Over recent years the quality and performance of ITNs delivered to PNG decreased, which has likely contributed to the stagnation in the malaria control effort in the country. The present study reports results from the first 24 months of a durability study with the ITN product Yahe LN® in PNG. METHODS: The durability study was conducted in four villages on the northern coast of PNG, in an area with high malaria parasite transmission, following WHO-recommended methodology adapted to the local scenario. A cohort of n = 500 individually identifiable Yahe® ITNs was distributed by the PNG National Malaria Control Programme from October to December 2021. Insecticidal efficacy of the ITNs was tested using cone bioassays with fully pyrethroid susceptible Anopheles farauti colony mosquitoes at baseline and at 6 months intervals, alongside evaluation of physical integrity and the proportion of ITNs lost to follow-up. A questionnaire was used to collect information on ITN end user behaviour, such as the frequency of use and washing. The observations from the durability study were augmented with simulated laboratory wash assays. RESULTS: Gradual uptake and replacement of previous campaign nets by the communities was observed, such that at 6 months 45% of all newly distributed nets were in use in their designated households. Insecticidal efficacy of the Yahe® nets, expressed as the percent 24 h mortality in cone bioassays decreased from 91 to 45% within the first 6 months of distribution, even though > 90% of study nets had never been washed. Insecticidal efficacy decreased further to < 20% after 24 months. ITNs accumulated physical damage (holes) at a rate similar to previous studies, and 35% were classified as 'too torn' by proportional hole index after 24 months. ITNs were lost to follow-up such that 61% of cohort nets were still present after 24 months. Laboratory wash assays indicated a rapid reduction in insecticidal performance with each consecutive wash such that average 24 h mortality was below 20% after 10 washes. CONCLUSION: Yahe® ITNs are not performing as per label claim in an area with fully pyrethroid susceptible vectors, and should be investigated more comprehensively and in other settings for compliance with currently recommended durability and efficacy thresholds. The mass distribution of low quality ITN products with variable performance is one of the major ongoing challenges for global malaria control in the last decade.
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Anopheles , Mosquiteros Tratados con Insecticida , Insecticidas , Malaria , Control de Mosquitos , Mosquitos Vectores , Papúa Nueva Guinea , Mosquiteros Tratados con Insecticida/estadística & datos numéricos , Animales , Anopheles/efectos de los fármacos , Control de Mosquitos/métodos , Control de Mosquitos/estadística & datos numéricos , Insecticidas/farmacología , Malaria/prevención & control , Mosquitos Vectores/efectos de los fármacos , HumanosRESUMEN
BACKGROUND: A quasi-experimental comparative trial will be designed in Burkina Faso. The study will compare the use and preferences for two groups types of insecticide-treated nets textile: polyester-based and polyethylene-based, according to their use and preferences in selected health districts. These health districts will be selected in three eco-climate zones (Sahelian, dry savannah and wet savannah) in the country. These findings will inform decisions on future net procurements for national malaria control programme in 2025. METHODS: Quantitative surveys and qualitative data collection will be carried out to gather information on the type of net textile most commonly used and preferred by the community. They will be performed between the end of the dry season and the early rainy season. The quantitative surveys involved household interviews with households and individuals' questionnaires, while the qualitative data collection involved in-depth individual interviews and focus group discussions to explore and clarify some key evaluation criteria. A total of 9450 insecticide-treated nets were surveyed for quantitative survey purposes. For the qualitative study, 48 in-depth individual interviews and 12 focus group discussions were carried out. A mixed model approach combining the results from quantitative surveys and qualitative studies will be used for decision-making on the type of insecticide-treated net preference. CONCLUSION: This methodological approach will be used by the National Malaria Control Programme to conduct this study on determinants of net use in Burkina Faso in order to provide robust evidence across diverse settings. This mixed-methods approach for data collection and analysis could be used in other countries to provide evidence that would help to increase the uptake of insecticide-treated nets, the main vector control tool in Africa.
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Composición Familiar , Mosquiteros Tratados con Insecticida , Malaria , Control de Mosquitos , Burkina Faso , Malaria/prevención & control , Humanos , Control de Mosquitos/métodos , Control de Mosquitos/estadística & datos numéricos , Mosquiteros Tratados con Insecticida/estadística & datos numéricos , Polietileno , Poliésteres , Toma de Decisiones , Textiles , Encuestas y CuestionariosRESUMEN
BACKGROUND: Nets containing pyriproxyfen, an insect growth regulator that sterilizes adult mosquitoes, have become available for malaria control. Suitable methods for investigating vector susceptibility to pyriproxyfen and evaluating its efficacy on nets need to be identified. The sterilizing effects of pyriproxyfen on adult malaria vectors can be assessed by measuring oviposition or by dissecting mosquito ovaries to determine damage by pyriproxyfen (ovary dissection). METHOD: Laboratory bioassays were performed to compare the oviposition and ovary dissection methods for monitoring susceptibility to pyriproxyfen in wild malaria vectors using WHO bottle bioassays and for evaluating its efficacy on nets in cone bioassays. Blood-fed mosquitoes of susceptible and pyrethroid-resistant strains of Anopheles gambiae sensu lato were exposed to pyriproxyfen-treated bottles (100 µg and 200 µg) and to unwashed and washed pieces of a pyriproxyfen long-lasting net in cone bioassays. Survivors were assessed for the sterilizing effects of pyriproxyfen using both methods. The methods were compared in terms of their reliability, sensitivity, specificity, resources (cost and time) required and perceived difficulties by trained laboratory technicians. RESULTS: The total number of An. gambiae s.l. mosquitoes assessed for the sterilizing effects of pyriproxyfen were 1745 for the oviposition method and 1698 for the ovary dissection method. Fertility rates of control unexposed mosquitoes were significantly higher with ovary dissection compared to oviposition in both bottle bioassays (99-100% vs. 34-59%, P < 0.05) and cone bioassays (99-100% vs. 18-33%, P < 0.001). Oviposition rates of control unexposed mosquitoes were lower with wild pyrethroid-resistant An. gambiae s.l. Cové, compared to the laboratory-maintained reference susceptible An gambiae sensu stricto Kisumu (18-34% vs. 58-76%, P < 0.05). Sterilization rates of the Kisumu strain in bottle bioassays with the pyriproxyfen diagnostic dose (100 µg) were suboptimal with the oviposition method (90%) but showed full susceptibility with ovary dissection (99%). Wild pyrethroid-resistant Cové mosquitoes were fully susceptible to pyriproxyfen in bottle bioassays using ovary dissection (> 99%), but not with the oviposition method (69%). Both methods showed similar levels of sensitivity (89-98% vs. 89-100%). Specificity was substantially higher with ovary dissection compared to the oviposition method in both bottle bioassays (99-100% vs. 34-48%) and cone tests (100% vs.18-76%). Ovary dissection was also more sensitive for detecting the residual activity of pyriproxyfen in a washed net compared to oviposition. The oviposition method though cheaper, was less reliable and more time-consuming. Laboratory technicians preferred ovary dissection mostly due to its reliability. CONCLUSION: The ovary dissection method was more accurate, more reliable and more efficient compared to the oviposition method for evaluating the sterilizing effects of pyriproxyfen on adult malaria vectors in susceptibility bioassays and for evaluating the efficacy of pyriproxyfen-treated nets.
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Anopheles , Insecticidas , Ovario , Oviposición , Piridinas , Animales , Piridinas/farmacología , Anopheles/efectos de los fármacos , Anopheles/fisiología , Femenino , Oviposición/efectos de los fármacos , Ovario/efectos de los fármacos , Insecticidas/farmacología , Control de Mosquitos/métodos , Mosquitos Vectores/efectos de los fármacos , Bioensayo/métodosRESUMEN
BACKGROUND: Malaria during pregnancy continues to be a significant cause of morbidity and mortality for both infants and mothers, particularly in sub-Saharan African (SSA) countries, despite increased efforts to control it. The utilization of long-lasting insecticide-treated nets (LLINs) during pregnancy is a well-established strategy to reduce the prevalence of malaria. Nonetheless, inadequate adherence remains a persistent challenge in certain regions with high malaria endemicity. This research aimed to assess the effectiveness of long-lasting insecticidal nets in preventing asymptomatic malaria infections among pregnant women attending antenatal care at the Bonassama District Hospital in the Littoral Region of Cameroon. METHODS: A hospital-based cross-sectional study was conducted from March to June 2022. Data on sociodemographic characteristics and LLIN usage were collected through a structured questionnaire, while asymptomatic malaria infections were identified using a PfHRP2/pLDH malaria qualitative rapid diagnostic kit. The relationship between categorical variables was analyzed using the chi-square test and logistic regression at a significance level of 5%. RESULTS: Out of the 411 pregnant women included in the study, 35.4% were diagnosed with malaria. The LLIN utilization rate was 65.1%. The risk of malaria infection was 2.7 times higher (AOR = 2.75, 95% CI = 1.83-4.14, p < 0.001) among women who did not consistently use LLINs compared to those who did. Pregnant women in their first trimester (AOR = 3.40, 95% CI = 1.24-4.64, p = 0.010) and second trimester (AOR = 1.90, 95%CI = 0.99-3.62, p = 0.055) were more likely to sleep under net when compared to those in the third trimester. Younger women 20-29 years (71.4%), those in the first trimester (69.6%) and those who had the nets before pregnancy (68.9%) were amongst those who frequently used use the nets. Among the reasons reported for not frequently using LLINs were heat (55.2%), suffocation (13.6%) and the smell of nets (8.4%). CONCLUSION: The use of LLIN was moderately high among the participants in this study, though still below national target. Age group, religion and gestation period were the major factors determining the use of LLINs. Considering the proven effectiveness of LLINs in reducing malaria morbidity and mortality, it is imperative for the National Malaria Control Programme (NMCP) to remain focused in promoting both LLIN ownership and utilization to achieve the national target of 100% and 80%, respectively.
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Hospitales de Distrito , Mosquiteros Tratados con Insecticida , Malaria Falciparum , Complicaciones Parasitarias del Embarazo , Atención Prenatal , Humanos , Femenino , Camerún/epidemiología , Embarazo , Mosquiteros Tratados con Insecticida/estadística & datos numéricos , Estudios Transversales , Adulto , Atención Prenatal/estadística & datos numéricos , Prevalencia , Malaria Falciparum/prevención & control , Malaria Falciparum/epidemiología , Adulto Joven , Complicaciones Parasitarias del Embarazo/prevención & control , Complicaciones Parasitarias del Embarazo/epidemiología , Adolescente , Control de Mosquitos/métodosRESUMEN
Malaria is a widespread and prevalent disease that affects human population globally, particularly in tropical countries. Malaria is a major health issue in sub-Saharan Africa and it contributes to morbidity and mortality among individuals in Africa. Pregnant women have been also reported as high risk of people been infected with malaria. This review attempted to evaluate the various methods used for health education programs and the effectiveness of the programs in improving ITNs among pregnant women.Methods The search involved various databases; EBCOHOST, MEDLINE, CINAHL, Cochrane library, ScienceDirect, PubMed, SAGE, Sringer link, Web of Science and Wiley Online Library. It was limited to full text research articles that report intervention studies, written in English Language, published between 2003 to 2022. The key words were "malaria", "malaria prevention", "health education", "insecticide-treated nets", "utilization", "pregnant women".Results A total of eleven articles met the inclusion criteria and included in the review. Six studies reported randomized controlled trials (RCTs) while five reported non-randomized controlled trials (NRCT).Conclusions There are evidences from the results which showed that health education programs were improved among pregnant women due to the use of ITNs and LLINS utilization. Furthermore, additional interventions directed at significant others need to be implemented, considering their important role in determining pregnant women's use of ITNs.
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Educación en Salud , Mosquiteros Tratados con Insecticida , Malaria , Humanos , Embarazo , Femenino , Malaria/prevención & control , Educación en Salud/métodos , Mosquiteros Tratados con Insecticida/estadística & datos numéricos , Complicaciones Parasitarias del Embarazo/prevención & controlRESUMEN
BACKGROUND: The National Malaria Elimination Programme implements the mass LLIN Distribution Campaigns in Ghana. Implementation science promotes the systematic study of social contexts, individual experiences, real-world environments, partnerships, and stakeholder consultations regarding the implementation of evidence-informed interventions. In this paper, we assess the core elements of the mass LLIN distribution campaign in a resource constrained setting to learn best implementation practices. Three core domains were assessed through the application of Galbraith's taxonomy (i.e., implementation, content, and pedagogy) for evidence-informed intervention implementation. METHODS: Six districts in two regions (Eastern and Volta) in Ghana participated in this study. Fourteen Focus Group Discussions (FGDs) were conducted across these communities. Eligible participants were purposively sampled considering age, occupation, gender, and care giving for children under 5 years and household head roles. All audio-recorded FGDs were transcribed verbatim, data was assessed and coded through deductive and inductive processes. NVivo software version 13 was used for the coding process. Themes were refined, legitimized, and the most compelling extracts selected to produce the results. RESULTS: Sixty-nine (69) caregivers of children under 5 years and sixty (60) household heads participated in the FGDs. All caregivers were females (69), whilst household heads included more males (41). Core elements identified under implementation domain of the LLIN distribution campaign in Ghana include the registration and distribution processes, preceded by engagement with traditional authorities and continuous involvement of community health volunteers during implementation. For pedagogy domain, core elements include delivery of intervention through outreaches, illustrations, demonstrations, and the use of multiple communication channels. Core elements realized within the content domain include information on effective malaria prevention, and provision of information to enhance their self-efficacy. Yet, participants noted gaps (e.g., misuse) in the desired behavioural outcome of LLIN use and a heavy campaign focus on women. CONCLUSION AND RECOMMENDATIONS: Although the implementation of the mass LLIN distribution campaigns exhibit components of core elements of evidence informed interventions (implementation, content and pedagogy), it has not achieved its desired behavioural change intentions (i.e. continuous LLIN use). Future campaigns may consider use of continuous innovative pedagogical approaches at the community level and lessons learnt from this study to strengthen the implementation process of evidence-based health interventions. There is also the need for standardization of core elements to identify the number of core elements required within each domain to achieve efficacy. ETHICAL APPROVAL: Ethical clearance was obtained from the Ghana Health Service Ethics Review Committee (GHS-ERC: 002/06/21) before the commencement of all data collection.
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Grupos Focales , Malaria , Investigación Cualitativa , Humanos , Ghana , Femenino , Masculino , Adulto , Malaria/prevención & control , Preescolar , Persona de Mediana Edad , Ciencia de la Implementación , Cuidadores/psicología , LactanteRESUMEN
Epidemiologic data on insecticide exposures and breast cancer risk are inconclusive and mostly from high-income countries. Using data from 1071 invasive pathologically confirmed breast cancer cases and 2096 controls from the Ghana Breast Health Study conducted from 2013 to 2015, we investigated associations with mosquito control products to reduce the spread of mosquito-borne diseases, such as malaria. These mosquito control products were insecticide-treated nets, mosquito coils, repellent room sprays, and skin creams for personal protection against mosquitos. Multivariable and polytomous logistic regression models were used to estimate odds ratios (ORadj) and 95% confidence intervals (CI) with breast cancer risk-adjusted for potential confounders and known risk factors. Among controls, the reported use of mosquito control products were mosquito coils (65%), followed by insecticide-treated nets (56%), repellent room sprays (53%), and repellent skin creams (15%). Compared to a referent group of participants unexposed to mosquito control products, there was no significant association between breast cancer risk and mosquito coils. There was an association in breast cancer risk with reported use of insecticide-treated nets; however, that association was weak and not statistically significant. Participants who reported using repellent sprays were at elevated risks compared to women who did not use any mosquito control products, even after adjustment for all other mosquito control products (OR = 1.42, 95% CI=1.15-1.75). We had limited power to detect an association with repellent skin creams. Although only a few participants reported using repellent room sprays weekly/daily or < month-monthly, no trends were evident with increased frequency of use of repellent sprays, and there was no statistical evidence of heterogeneity by estrogen receptor (ER) status (p-het > 0.25). Our analysis was limited when determining if an association existed with repellent skin creams; therefore, we cannot conclude an association. We found limited evidence of risk associations with widely used mosquito coils and insecticide-treated nets, which are reassuring given their importance for malaria prevention. Our findings regarding specific breast cancer risk associations, specifically those observed between repellent sprays, require further study.
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Neoplasias de la Mama , Repelentes de Insectos , Insecticidas , Malaria , Animales , Humanos , Femenino , Control de Mosquitos , Insecticidas/efectos adversos , Ghana/epidemiología , Neoplasias de la Mama/epidemiología , Neoplasias de la Mama/etiología , Neoplasias de la Mama/prevención & control , Malaria/prevención & control , Repelentes de Insectos/efectos adversosRESUMEN
BACKGROUND: Despite significant decline in the past two decades, malaria is still a major public health concern in Tanzania; with over 93% of the population still at risk. Community knowledge, attitudes and practices (KAP), and beliefs are key in enhancing uptake and utilization of malaria control interventions, but there is a lack of information on their contribution to effective control of the disease. This study was undertaken to determine KAP and beliefs of community members and service providers on malaria, and how they might be associated with increased risk and persistence of the disease burden in North-western and Southern regions of Tanzania. METHODS: This was an exploratory study that used qualitative methods including 16 in-depth interviews (IDI) and 32 focus group discussions (FGDs) to collect data from health service providers and community members, respectively. The study was conducted from September to October 2017 and covered 16 villages within eight districts from four regions of mainland Tanzania (Geita, Kigoma, Mtwara and Ruvuma) with persistently high malaria transmission for more than two decades. RESULTS: Most of the participants had good knowledge of malaria and how it is transmitted but some FGD participants did not know the actual cause of malaria, and thought that it is caused by bathing and drinking un-boiled water, or consuming contaminated food that has malaria parasites without warming it. Reported barriers to malaria prevention and control (by FGD and IDI participants) included shortage of qualified health workers, inefficient health financing, low care-seeking behaviour, consulting traditional healers, use of local herbs to treat malaria, poverty, increased breeding sites by socio-economic activities and misconceptions related to the use of bed nets and indoor residual spraying (IRS). Among the misconceptions, some participants believed that bed nets provided for free by the government came with bedbugs while others reported that free bed nets caused impotence among men. CONCLUSION: Despite good knowledge of malaria, several risk factors, such as socio-economic and behavioural issues, and misconceptions related to the use of bed nets and IRS were reported. Other key factors included unavailability or limited access to health services, poor health financing and economic activities that potentially contributed to persistence of malaria burden in these regions. Relevant policies and targeted malaria interventions, focusing on understanding socio-cultural factors, should be implemented to reduce and finally eliminate the disease in the study regions and others with persistent transmission.
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Conocimientos, Actitudes y Práctica en Salud , Malaria , Masculino , Humanos , Tanzanía , Control de Mosquitos/métodos , Malaria/epidemiología , Factores de RiesgoRESUMEN
BACKGROUND: Mass distributions of long-lasting insecticidal nets (LLINs) have contributed to large reductions in the malaria burden. However, this success is in jeopardy due in part to the increasing pyrethroid-resistant mosquito population as well as low LLINs coverage in various areas because the lifespan of LLINs is often shorter than the interval between replenishment campaigns. New insecticide-treated nets (ITNs) containing pyrethroid and piperonyl-butoxide (PBO) have shown a greater reduction in the incidence of malaria than pyrethroid LLINs in areas with pyrethroid-resistant mosquitoes. However, the durability (attrition, bio-efficacy, physical integrity and chemical retainment) of pyrethroid-PBO ITNs under operational settings has not been fully characterized. This study will measure the durability of pyrethroid-PBO ITNs to assess whether they meet the World Health Organization (WHO) three years of operational performance criteria required to be categorized as "long-lasting". METHODS: A prospective household randomized controlled trial will be conducted simultaneously in Tanzania, India and Côte d'Ivoire to estimate the field durability of three pyrethroid-PBO ITNs (Veeralin®, Tsara® Boost, and Olyset® Plus) compared to a pyrethroid LLIN: MAGNet®. Durability monitoring will be conducted up to 36 months post-distribution and median survival in months will be calculated. The proportion of ITNs: (1) lost (attrition), (2) physical integrity, (3) resistance to damage score, (4) meeting WHO bio-efficacy (≥ 95% knockdown after 1 h or ≥ 80% mortality after 24 h for WHO cone bioassay, or ≥ 90% blood-feeding inhibition or ≥ 80% mortality after 24 h for WHO Tunnel tests) criteria against laboratory-reared resistant and susceptible mosquitoes, and insecticidal persistence over time will be estimated. The non-inferiority of Veeralin® and Tsara® Boost to the first-in-class, Olyset® Plus will additionally be assessed for mortality, and the equivalence of 20 times washed ITNs compared to field aged ITNs will be assessed for mortality and blood-feeding inhibition endpoints in the Ifakara Ambient Chamber Test, Tanzania. CONCLUSION: This will be the first large-scale prospective household randomized controlled trial of pyrethroid-PBO ITNs in three different countries in East Africa, West Africa and South Asia, simultaneously. The study will generate information on the replenishment intervals for PBO nets.
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Mosquiteros Tratados con Insecticida , Malaria , Butóxido de Piperonilo , Piretrinas , Animales , Humanos , Côte d'Ivoire , Resistencia a los Insecticidas , Malaria/prevención & control , Control de Mosquitos/métodos , Butóxido de Piperonilo/farmacología , Estudios Prospectivos , Piretrinas/farmacología , Ensayos Clínicos Controlados Aleatorios como Asunto , TanzaníaRESUMEN
BACKGROUND: Studies have explored the correlates of insecticide-treated nets in Nigeria. The few studies that focused on Northern Nigeria mostly examined individual correlates, but largely ignored the community correlates. Also, the persistence of armed insurgencies in the region calls for more research attention. This study examines the utilization and the associated individual and community factors of insecticide-treated nets in Northern Nigeria. METHODS: The study adopted a cross-sectional design. Data were extracted from the 2021 Nigeria Malaria Indicator Survey (NMIS). A weighted sample size of 6873 women was analysed. The outcome variable was the utilization of insecticide-treated nets. The explanatory variables selected at the individual/household level were maternal age, maternal education, parity, religion, sex of head of household, household wealth, and household size. The variables selected at the community level were the type of place of residence, geo-political zone of residence, the proportion of children under five who slept under a bed net, the proportion of women aged 15-49 who heard malaria media messages, and the community literacy level. Two variables, namely, the number of mosquito bed nets in the household, and the number of rooms used for sleeping were included for statistical control. Three multilevel mixed-effect regression models were fitted. RESULTS: The majority of childbearing women (71.8%) utilized insecticide-treated nets. Parity and household size were the significant individual/household characteristics associated with the utilization of insecticide-treated nets. The proportion of under-five children in the community who slept under mosquito bed nets, and the geopolitical zone of residence were significant community correlates of the use of insecticide-treated nets. In addition, the number of rooms for sleeping, and the number of mosquito bed nets in the households were significantly associated with the utilization of insecticide-treated nets. CONCLUSION: Parity, household size, number of sleeping rooms, number of treated bed nets, geo-political zone of residence, and proportion of under-five children sleeping under bed nets are important associated factors of the utilization of insecticide-treated nets in Northern Nigeria. Existing malaria preventive initiatives should be strengthened to target these characteristics.
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Mosquiteros Tratados con Insecticida , Insecticidas , Malaria , Femenino , Humanos , Embarazo , Estudios Transversales , Composición Familiar , Malaria/prevención & control , Control de Mosquitos , Nigeria , Adolescente , Adulto Joven , Adulto , Persona de Mediana EdadRESUMEN
BACKGROUND: Pyrethroid-chlorfenapyr (CFP) and pyrethroid-piperonyl butoxide (PBO) nets are being scaled across endemic countries to improve control of malaria transmitted by pyrethroid-resistant mosquitoes. CFP is a pro-insecticide requiring activation by mosquito cytochrome P450 monooxygenase enzymes (P450s) while PBO improves pyrethroid potency by inhibiting the action of these enzymes in pyrethroid-resistant mosquitoes. The inhibitory action of PBO against P450s may thus reduce the efficacy of pyrethroid-CFP nets when applied inside the same household as pyrethroid-PBO nets. METHODS: Two experimental hut trials were performed to evaluate the entomological impact of two different types of pyrethroid-CFP ITN (Interceptor® G2, PermaNet® Dual) when applied alone and in combination with pyrethroid-PBO ITNs (DuraNet® Plus, PermaNet® 3.0) against a pyrethroid-resistant vector population in southern Benin. In both trials, all net types were tested as single and double net treatments. Bioassays were also performed to assess the resistance profile of the vector population at the hut site and investigate interactions between CFP and PBO. RESULTS: The vector population was susceptible to CFP but exhibited a high intensity of pyrethroid resistance that was overcame by PBO pre-exposure. Vector mortality was significantly lower in huts with combinations of pyrethroid-CFP nets plus pyrethroid-PBO nets compared to huts with two pyrethroid-CFP nets (74% vs. 85% for Interceptor® G2 and 57% vs. 83% for PermaNet® Dual, p < 0.001). PBO pre-exposure reduced the toxicity of CFP in bottle bioassays suggesting this effect may be partly attributable to antagonism between CFP and PBO. Higher levels of vector mortality were observed in huts with net combinations that included pyrethroid-CFP nets compared to those that did not and highest mortality was achieved when pyrethroid-CFP nets were applied alone as two nets together (83-85%). CONCLUSIONS: This study shows evidence of a reduced performance of pyrethroid-CFP nets when combined with pyrethroid-PBO ITNs compared to when applied alone and higher efficacy with net combinations that included pyrethroid-CFP nets. These findings suggest that in similar contexts, prioritizing distribution of pyrethroid-CFP nets over other net types would maximize vector control impact.