Malaria Control Interventions Research Articles

Epidemiological behaviour and interventions of malaria in Niger, 2010–2019: a time-series analysis of national surveillance data

BackgroundMalaria remains a significant public health concern in Niger, with the number of cases increasing from 592,334 in 2000 to 3,138,696 in 2010. In response, a concerted campaign against the disease has been initiated. However, the implementation of these malaria interventions and their association with epidemiological behaviour remains unclear.MethodsA time-series study was conducted in Niger from 2010 to 2019. Multiple data sources concerning malaria were integrated, encompassing national surveillance data, Statistic Yearbook, targeted malaria control interventions, and meteorological data. Incidence rate, mortality rate, and case fatality ratio (CFR) by different regions and age groups were analysed. Joinpoint regression models were used to estimate annual changes in malaria. The changes in coverage of malaria interventions were evaluated.ResultsBetween 2010 to 2019, the incidence rate of malaria decreased from 249.43 to 187.00 cases per 1,000 population in Niger. Niamey had a high annual mean incidence rate and the lowest CFR, while Agadez was on the contrary. Joinpoint regression analysis revealed a declining trend in malaria incidence for all age groups except the 10–24 years group, and the mortality rate and the CFR initially decreased followed by an increase in all age groups. Niger has implemented a series of malaria interventions, with the major ones being scaled up to larger populations during the study period.ConclusionsThe scale-up of multi-interventions in Niger has significantly reduced malaria incidence, but the rise in mortality rate and CFR addresses the challenges in malaria control and elimination. Malaria endemic countries should enhance surveillance of malaria cases and drug resistance in Plasmodium, improve diagnosis and treatment, expand the population coverage of insecticide-treated bed nets and seasonal malaria chemoprevention, and strengthen the management of severe malaria cases.

Clinico-epidemiological profiles & outcome of severe malaria in children under-five in the tribal area of Kalahandi, Odisha.

Severe malaria is a cause of excess mortality and morbidity in children in malaria-endemic areas where indigenous people live. Currently, available reports are all from secondary or tertiary care hospitals across India and some African countries. The objective of this study was to assess the clinical and epidemiological profiles of children under five years in two primary care health centres located in tribal-dominant Thuamul Rampur Block of Kalahandi district, Odisha. The outcome of management of severe malaria in these children was also assessed. A retrospective review of case records of children under five years of age diagnosed and admitted with severe malaria in two non-governmental primary care facilities between 2017 and 2022, was undertaken. There was a declining trend in malaria cases documented in primary care health facilities between January 2017 and June 2022. Of the 4858 cases recorded, 242 (4.9%) had severe malaria, of whom 70.7 per cent (n=171) were children under 5 yr. The median age of the study children was 24 months (16-36). Children aged 1-2 yr had a significantly higher risk of malaria. The majority were tribals (87%), more than half the children presented with neurological manifestations (64.4%), and 49.6 per cent had respiratory manifestations, while 20.5 per cent had severe anaemia (Hb <5 g/dl). Most, 167 (97.7%) severe malaria was due to Plasmodium falciparum. Thirty-two percent of children were severely wasted (WHZ < -3 SD) and 28 per cent were moderately wasted (WHZ <-2 SD). There was no fatality among the 171 children who were managed for severe malaria in the two primary care facilities. In high endemic areas severe malaria is predominantly a disease of under-five children and is caused by P. falciparum. Clinical manifestations of severe malaria in children can be varied and life-threatening. Primary health facilities can manage severe malaria successfully, thereby reducing child mortality. Effective collaboration between malaria control and nutrition intervention programmes is essential for appropriate case management.

Modeling and optimal control of COVID-19 and malaria co-infection based on vaccination

&lt;p&gt;Malaria is a serious health problem in Africa, and the ongoing COVID-19 pandemic has affected the implementation of key malaria control interventions. This jeopardizes the gains made in malaria. As a result, a new co-infection model of COVID-19 and malaria is constructed, and the role of vaccination in COVID-19-malaria co-infection is analyzed. The existence and stability of the equilibria of each single infection are first studied by their respective basic reproduction numbers. When the basic reproduction numbers $ R_{C0} $ and $ R_{M0} $ are both below unity, the COVID-19-malaria-free equilibrium is locally asymptotically stable. Sensitivity analysis reveals that the main parameters affecting the spread of diseases are their respective disease transmission rate and vaccine efficacy. Further, we introduce the effect of vaccination rate and efficacy on controlling the co-infected population. It also shows that under the condition of a low recovery rate caused by the shortage of medical resources, improving the vaccination rate and effectiveness of vaccines has a positive impact on suppressing diseases. The model is then extended into an optimal control system by introducing prevention and treatment measures for COVID-19 and malaria. The results suggest that applying each strategy alone can reduce the scale of co-infection, but strategy A increases the number of malaria cases and strategy B prolongs the period of COVID-19 infection. Measures to control COVID-19 must be combined with efforts to ensure malaria control is maintained.&lt;/p&gt;

Dramatic resurgence of malaria after 7 years of intensive vector control interventions in Eastern Uganda.

Tororo District, Uganda experienced a dramatic decrease in malaria burden from 2015-19 during 5 years of indoor residual spraying (IRS) with carbamate (Bendiocarb) and then organophosphate (Actellic) insecticides. However, a marked resurgence occurred in 2020, which coincided with a change to a clothianidin-based IRS formulations (Fludora Fusion/SumiShield). To quantify the magnitude of the resurgence, investigate causes, and evaluate the impact of a shift back to IRS with Actellic in 2023, we assessed changes in malaria metrics in regions within and near Tororo District. Malaria surveillance data from Nagongera Health Center, Tororo District was included from 2011-2023. In addition, a cohort of 667 residents from 84 houses was followed from August 2020 through September 2023 from an area bordering Tororo and neighboring Busia District, where IRS has never been implemented. Cohort participants underwent passive surveillance for clinical malaria and active surveillance for parasitemia every 28 days. Mosquitoes were collected in cohort households every 2 weeks using CDC light traps. Female Anopheles were speciated and tested for sporozoites and phenotypic insecticide resistance. Temporal comparisons of malaria metrics were stratified by geographic regions. At Nagongera Health Center average monthly malaria cases varied from 419 prior to implementation of IRS; to 56 after 5 years of IRS with Bendiocarb and Actellic; to 1591 after the change in IRS to Fludora Fusion/SumiShield; to 155 after a change back to Actellic. Among cohort participants living away from the border in Tororo, malaria incidence increased over 8-fold (0.36 vs. 2.97 episodes per person year, p<0.0001) and parasite prevalence increased over 4-fold (17% vs. 70%, p<0.0001) from 2021 to 2022 when Fludora Fusion/SumiShield was used. Incidence decreased almost 5-fold (2.97 vs. 0.70, p<0.0001) and prevalence decreased by 39% (70% vs. 43%, p<0.0001) after shifting back to Actellic. There was a similar pattern among those living near the border in Tororo, with increased incidence between 2021 and 2022 (0.93 vs. 2.40, p<0.0001) followed by a decrease after the change to Actellic (2.40 vs. 1.33, p<0.001). Among residents of Busia, malaria incidence did not change significantly over the 3 years of observation. Malaria resurgence in Tororo was temporally correlated with the replacement of An. gambiae s.s. by An. funestus as the primary vector, with a marked decrease in the density of An. funestus following the shift back to IRS with Actellic. In Busia, An. gambiae s.s. remained the primary vector throughout the observation period. Sporozoite rates were approximately 50% higher among An. funestus compared to the other common malaria vectors. Insecticide resistance phenotyping of An. funestus revealed high tolerance to clothianidin, but full susceptibility to Actellic. A dramatic resurgence of malaria in Tororo was temporally associated with a change to clothianidin-based IRS formulations and emergence of An. funestus as the predominant vector. Malaria decreased after a shift back to IRS with Actellic. This study highlights the ability of malaria vectors to rapidly circumvent control efforts and the importance of high-quality surveillance systems to assess the impact of malaria control interventions and generate timely, actionable data.

Understanding the fine-scale heterogeneity and spatial drivers of malaria transmission in Kenya using model-based geostatistical methods

Malaria remains a public health concern. Monitoring the fine-scale heterogeneity of the malaria burden enables more targeted control efforts. Although malaria indicator surveys (MIS) have been crucial in evaluating the progress of malaria control interventions, they are only designed to provide a cross-sectional national and regional malaria disease burden. Recent advances in geostatistical methods allow us to interpolate national survey data to describe subnational disease burden that is crucial in informing targeted control. A binomial geostatistical model employing Markov chain Monte Carlo (MCMC) parameter estimation methods is used to understand the spatial drivers of malaria risk in Kenya and to predict malaria risk at a fine-scale resolution, including identifying hotspots. A total of 11,549 children aged six months to 14 years from 207 clusters were sampled in this survey and used in the present analysis. The national malaria prevalence based on the data was 8.4%, with the highest in the lake endemic zone (18.1%) and the lowest in the low-risk zone (&lt;1%). The analysis shows that elevation, proportion of insectcide treated net (ITN) distributed, rainfall, temperature and urbanization covariates are all significant predictors of malaria transmission. The 5x5 Km resolution maps show that malaria is heterogeneous in Kenya, with hotspot areas in the lake endemic area, the coastal areas, and some parts of the shores of Lake Turkana and Kajiado. The high-resolution malaria prevalence maps produced as part of the analysis have shown that Kenya has additional malaria hotspots, especially in areas least expected. These findings call for a rethinking of malaria burden classification in some regions for effective planning, implementation, resource mobilization, monitoring, and evaluation of malaria interventions in the country.

Analysis of the socio-economic and cultural factors affecting malaria prevention in provinces with high malaria prevalence in Zambia

Malaria, which is endemic in all the provinces of Zambia, remains one of the leading causes of morbidity and mortality. Records of the high prevalence of malaria is evident in Northern, Eastern, Muchinga and Luapula provinces, despite the implementation of malaria control and prevention strategies aimed at interrupting the disease transmission, which includes the use of treated mosquito nets, indoor residual spraying, presumptive, and treatment therapy among others. These provinces' socio-cultural and economic factors were explored to ascertain if they might contribute to the altered effectiveness of malaria control interventions that have proved successful in other provinces. This study analysed the socio-cultural and economic factors affecting malaria prevention in provinces with high malaria prevalence in Zambia. A descriptive cross-sectional study was conducted. An interviewer-administered questionnaire was administered to selective households in the four study provinces. 1,580 people participated in the study, with a response rate of 98.8%. 684 were male, and 896 were female. Findings suggest practices and beliefs concerning socio-cultural and economic factors influence the success of malaria control interventions in the provinces. Low levels of education and lack of it, directly impacted the understanding of malaria prevention, transmission, and interventions. Self- medication, use of leftover medicines, and seeking treatment late were attributed to low-income levels in all the four provinces. Type of housing and occupation exposed individuals to malaria infection. Tailoring malaria preventive measures to the socio-cultural and economic practices of the provinces will help reduce malaria cases in the provinces.

Malaria asymptomatic carriage in the Sahelian region: the challenge associated to young adults

Abstract Background Mali and Senegal have made important efforts to control malaria. After a period of decline, the number of cases has remained stable for several years. Asymptomatic carriage acting as a reservoir could explain malaria persistence despite malaria control. Mass drug administration (MDA) is a candidate intervention that could help to accelerate the decreasing of malaria transmission if favourable epidemiologic context and good adherence are met. We aimed to update asymptomatic reservoir description along a Sahelian ecological gradient and study MDA acceptability. Methods We conducted an open cohort in 8 villages in Mali and Senegal including all household members sampled aged &amp;gt;6 months. We measured P. falciparum infections prevalence by qPCR in 4 surveys: 2 in dry season 2021, 1 in rainy season 2021 and 1 in dry season 2022. We measured prospective acceptability of MDA in cohort aged ≥15 years in Senegal by questionnaire. We explored risk factors associated to asymptomatic infections and acceptability score with multilevel logistic and linear models. Results We included 168 households and 1428 participants in at least 1 survey. In preliminary results, prevalence of P. falciparum infections was 11% in dry season 2021 in Senegal, 20% in central Mali and 60% in Northern Mali. Young adults between 15 to 24 years old were more likely to carry asymptomatic infections in dry season compared to children &amp;lt;5 years old (OR = 5.74 [2.99;11.04]). MDA presented a good acceptability with a mean score of 3.5 (score between -7 and 7). Young adults had lower acceptability compared to older participants (β=−1.07 [-1.82,-0.32]). Conclusions Young adults were important asymptomatic carriers in Senegal and Mali but were less likely to accept to participate in MDA. Key messages • Young adults represent a public health challenge that need to be address to reach malaria elimination. • Specific sensibilization could be implement to improve adherence to malaria control interventions.

Community knowledge, attitude, practices and beliefs associated with persistence of malaria transmission in North-western and Southern regions of Tanzania

BackgroundDespite 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.MethodsThis 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.ResultsMost 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.ConclusionDespite 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.

Spatial Optimization Methods for Malaria Risk Mapping in Sub-Saharan African Cities Using Demographic and Health Surveys.

Vector-borne diseases, such as malaria, are affected by the rapid urban growth and climate change in sub-Saharan Africa (SSA). In this context, intra-urban malaria risk maps act as a key decision-making tool for targeting malaria control interventions, especially in resource-limited settings. The Demographic and Health Surveys (DHS) provide a consistent malaria data source for mapping malaria risk at the national scale, but their use is limited at the intra-urban scale because survey cluster coordinates are randomly displaced for ethical reasons. In this research, we focus on predicting intra-urban malaria risk in SSA cities-Dakar, Dar es Salaam, Kampala and Ouagadougou-and investigate the use of spatial optimization methods to overcome the effect of DHS spatial displacement. We modeled malaria risk using a random forest regressor and remotely sensed covariates depicting the urban climate, the land cover and the land use, and we tested several spatial optimization approaches. The use of spatial optimization mitigated the effects of DHS spatial displacement on predictive performance. However, this comes at a higher computational cost, and the percentage of variance explained in our models remained low (around 30%-40%), which suggests that these methods cannot entirely overcome the limited quality of epidemiological data. Building on our results, we highlight potential adaptations to the DHS sampling strategy that would make them more reliable for predicting malaria risk at the intra-urban scale.

Stratification and Adaptation of Malaria Control Interventions in Chad.

Malaria remains the leading cause of morbidity and mortality in Chad. The World Health Organization (WHO) has recommended that endemic countries stratify malaria to guide interventions. Thus, the Republic of Chad has initiated a stratification process based on malaria incidence with the aim of defining transmission risk and proposing interventions. We collected routine malaria data from health facilities from 2017-2021, the national survey on malaria indicators, the entomological data of NMCP operational research, the demographic and health surveys, and remote sensing of environmental data. Stratification was based on the adjusted incidence of malaria to guide interventions. The adjusted incidence of malaria was, on average, 374 cases per 1000 people in the country. However, it varied according to health districts. Health districts were stratified into very low malaria incidence (n = 25), low malaria incidence (n = 20), moderate malaria incidence (n = 46) and high malaria incidence (n = 38). Micro-stratification in health districts with very low incidence was carried out to identify districts with incidence <10 cases per 1000 person with a view to a malaria pre-elimination programme. Appropriate malaria control interventions were proposed based on the strata identified. Stratification enables the country to target interventions to accelerate the reduction of the burden caused by malaria with a pre-elimination goal.

Assessment of Compliance with National Guidelines on Diagnosis and Treatment of Malaria among Health Workers in Anambra State, Nigeria

Background: Malaria case management remains a crucial component of malaria control strategies. Despite the introduction of national malaria treatment guidelines and scale-up of malaria control interventions in Nigeria, shreds of evidence have shown some deviations from the guidelines in malaria case management. This study assessed compliance with national guidelines on the diagnosis and treatment of malaria among health workers in Anambra State.&#x0D; Materials and Methods: This comparative, cross-sectional hospital-based study was carried out among 360 healthcare workers selected from six Local Government Areas using a multistage sampling technique. A pre-tested interviewer-administered questionnaire was used to collect data on their socio-demographics and other vital information.&#x0D; Results: The findings of this study revealed that Ninety-eight respondents (54.4%) from public health facilities had adequate knowledge of malaria case management compared to 67 respondents (37.2%) from private health facilities (p=0.001). The overall level of compliance with the national guidelines shows that only 22.2% of the health workers interviewed strictly complied with the national guidelines. It was significantly higher among public healthcare workers (31.7%) compared to 12.8% of private health workers (p&lt;0.001). Training on malaria case management, access to national guidelines, availability of malaria diagnostic tools, and sex of the health workers were associated with compliance with national guidelines in both public and private health facilities (p&lt;0.001).&#x0D; Conclusion: The findings of this study revealed a close similarity between the two health facilities in the level of awareness of the national malaria treatment guidelines, but a remarkable difference in compliance to appropriate case management of malaria between public and private health facilities. Interventions to improve private sector engagement in the implementation of the guidelines, training, and supply of recommended anti-malarial medicines should be intensified.

Magnitude of malaria and associated factors among febrile adults in Siraro District Public Health facilities, West Arsi Zone, Oromia, Ethiopia 2022: a facility-based cross-sectional study

BackgroundDespite significant efforts made to control malaria in Ethiopia, the disease remains one of the top public health problems in the country. Baseline malaria prevalence and associated factor at high malaria area is important to guide malaria control interventions, there was paucity of information regarding the study area. Therefore, the aim of this study was to determine prevalence of malaria and associated factors among febrile adults in Siraro district health facilities, West Arsi Zone, Oromia, Ethiopia.MethodsInstitution-based cross-sectional study was conducted among 317 febrile adult patients at Siraro district health facilities. Structured pre-tested questionnaires were used to collect data. Epi-data version 3.1 and SPSS version 23 were used for data entry and analysis respectively. In order to identify factors associated with malaria infection bivariable and multivariable binary logistic regression analysis was employed, The Adjusted Odds Ratio (AOR) with a 95% confidence interval (CI) and p-value of < 0.05 was computed to show the strength of the association.ResultsThe overall prevalence of malaria at the study area was 130 (41.0%) [(95% CI 35.3–46.7)]. Occupation (being farmer) [(AOR = 6.05; 95% CI 1.38, 26.49)], having poor knowledge on malaria transmission [(AOR = 2.95 95%; CI 1.48–5.88)], house with wood wall [(AOR = 2.71; 95% CI 1.34–5.49)], and number of windows (≥ 3) in the house [(AOR = 6.82; 95% CI 1.05, 44.40)] were identified to be significantly associated with magnitude of malaria in the study area.ConclusionThe prevalence of malaria at the study area was high as compared with the national wide figures. Being farmer, having poor knowledge on malaria transmission, and housing condition (house with wood wall and houses with three and above windows) were found to be significantly associated with malaria infection in the study area. Therefore, there has to be an emphasis on addressing the factors by providing sustainable health education for the communities to improve their housing condition and knowledge of community on the way of malaria prevention.

Resurgence of Malaria Transmission and Incidence after Withdrawal of Indoor Residual Spraying in the District of Koulikoro, Mali.

In Mali, malaria vector control relies mostly on long-lasting insecticidal nets and indoor residual spraying (IRS). From 2008 to 2016, an IRS program was implemented in the district of Koulikoro. After a significant reduction in malaria indicators, IRS was stopped in 2016. This study evaluated the effect of IRS withdrawal on entomological parameters of malaria transmission and incidence in children aged 6 months to 10 years in the district of Koulikoro. Entomological parameters of malaria transmission during the last year of IRS implementation in 2016 were compared with those obtained 2 years after IRS withdrawal in 2018 in two villages of Koulikoro. Mosquito vectors were collected by mouth aspiration and pyrethrum spray catches in the villages to monitor these transmission parameters. A sharp increase (10.8 times higher) in vector abundance after IRS withdrawal was observed. The infection rate of Anopheles gambiae sensu lato to Plasmodium falciparum increased from zero during IRS implementation to 14.8% after IRS withdrawal. The average entomological inoculation rate, which was undetectable before, was 1.22 infected bites per person per month 2 years after IRS was withdrawn, and the cumulative malaria incidence rate observed after IRS was 4.12 times (15.2% versus 3.7%) higher than that observed in 2016 in the villages before IRS withdrawal. This study showed a resurgence of malaria transmission and incidence in the Koulikoro health district after IRS was withdrawn. Thus, to manage the potential consequences of malaria transmission resurgence, alternative approaches are needed when stopping successful malaria control interventions.

Barriers to accessing malaria treatment amongst school-age children in rural Malawi

BackgroundOver the last two decades, many countries have moved from malaria control toward malaria elimination. However, some sub-Saharan African countries, like Malawi, have recently seen a reversal in malaria control progress with reported increases in confirmed malaria cases. This may be the result of inadequate access to effective malaria control interventions by key population groups that perpetuate transmission. This study aimed to assess the barriers to accessing malaria treatment among school-aged children (SAC) in Malawi.MethodsA qualitative study was conducted between September and October 2020, where data were gathered in rural Malawi using free-listing interviews, key-informant interviews, semi-structured interviews and focus group discussions. Purposively sampled participants included SAC, parents of SAC, health workers and key stakeholders at community and district levels. Interviews were digitally recorded and transcribed verbatim. Data were organized using NVivo 12 software and analysed using the thematic method.ResultsThe study recruited 252 participants, with 156 being SAC, equally divided between boys and girls. Health system barriers to malaria treatment included long waiting hours and queues at clinics, frequent stock-outs of medical supplies, and travel time to the facility. Provider barriers included negative attitude and limited service hours. Individual and cultural barriers included fear of malaria tests and beliefs associating witchcraft as the best treatment for malaria. In addition, COVID-19-related barriers included the inability to follow preventive measures, a shift in focus from malaria to COVID-19, and fear of contracting COVID-19 and/or being tested for COVID-19 at the facility.ConclusionsThis study shows most of the barriers to accessing malaria treatment among SAC are similar to those experienced by other population groups. Furthermore, COVID-19 adversely affected SAC’s access to treatment. Interventions that support SAC access to prompt diagnosis and treatment are urgently needed to improve the effective control of malaria.

Rebound of multiple infections and prevalence of anti-malarial resistance associated markers following malaria upsurges in Dielmo village, Senegal, West Africa

BackgroundThanks to the scale up of malaria control interventions, the malaria burden in Senegal has decreased substantially to the point that the National Malaria Control Programme plans to achieve malaria elimination by 2030. To guide such efforts, measuring and monitoring parasite population evolution and anti-malarial drugs resistance is extremely important. Information on the prevalence of parasite mutations related to drug resistance can provide a first signal of emergence, introduction and selection that can help with refining drug interventions. The aim of this study was to analyse the prevalence of anti-malarial drug resistance-associated markers before and after the implementation of artemisinin-based combination therapy (ACT) from 2005 to 2014 in Dielmo, a model site for malaria intervention studies in Senegal.MethodsSamples from both malaria patients and Plasmodium falciparum asymptomatic carriers were analysed with high resolution melting (HRM) technique to genotype P. falciparum chloroquine resistance transporter (Pfcrt) gene haplotypes and multidrug-resistant protein 1 (Pfmdr1) gene at codons N86 and Y184.ResultsAmong the 539 samples analysed, 474, 486, and 511 were successfully genotyped for Pfmdr1 N86, Y184, and Pfcrt, respectively. The prevalence of drug resistance markers was high, particularly during the malaria upsurges. Following the scale-up in bed net distribution, only the mutant (86F-like) variant of Pfmdr1 86 was present while during the malaria upsurges the predominance of two types 86Y-86N (43%) and 86F-like (56%) were observed. Most infections (87%) carried the wild type Y-allele at Pfmdr1 184 during the period of nets scale-up while during the malaria upsurges only 16% of infections had wild type and 79% of infections had mixed (mutant/wild) type. The frequency of the mixed genotypes SVMNT-like_CVMNK and SVMNT-like_CVIET within Pfcrt gene was particularly low during bednet scale up. Their frequency increased significantly (P < 0.001) during the malaria upsurges.ConclusionThis data demonstrated the effect of multiple interventions on the dynamics of drug resistance-associated mutations in the main malaria parasite P. falciparum in an endemic village in Senegal. Monitoring drug resistance markers should be conducted periodically to detect threats of emergence or resurgence that could compromise the efficacy of anti-malarial drugs.

Recent increase in low complexity polygenomic infections and sialic acid-independent invasion pathways in Plasmodium falciparum from Western Gambia

BackgroundThe malaria parasite Plasmodium falciparum utilizes multiple alternative receptor-ligand interactions for the invasion of human erythrocytes. While some P. falciparum clones make use of sialic acid (SA) residues on the surface of the human glycophorin receptors to invade the erythrocyte, others use alternative receptors independent of sialic acid residues. We hypothesized that over the years, intensified malaria control interventions and declining prevalence in The Gambia have resulted in a selection of parasites with a dominant invasion pathways and ligand expression profiles.MethodsBlood samples were collected from 65 malaria-infected participants with uncomplicated malaria across 3 years (2015, 2016, and 2021). Genetic diversity was determined by genotyping the merozoite surface protein 2 (msp2) polymorphic gene of P. falciparum. Erythrocyte invasion phenotypes were determined using neuraminidase, trypsin, and chymotrypsin enzymes, known to cleave different receptors from the surface of the erythrocyte. Schizont-stage transcript levels were obtained for a panel of 6 P. falciparum invasion ligand genes (eba175, eba181, Rh2b, Rh4, Rh5, and clag2) using 48 successfully cultured isolates.ResultsThough the allelic heterozygosity of msp2 repeat region decreased as expected with reduced transmission, there was an increase in infections with more than a single msp2 allelotype from 2015 to 2021. The invasion phenotypes of these isolates were mostly SA independent with a continuous increase from 2015 to 2021. Isolates from 2021 were highly inhibited by chymotrypsin treatment compared to isolates from 2015 and 2016. Higher invasion inhibition for 2021 isolates was further obtained following erythrocyte treatment with a combination of chymotrypsin and trypsin. The transcript levels of invasion ligand genes varied across years. However, levels of clag2, a rhoptry-associated protein, were higher in 2015 and 2016 isolates than in 2021 isolates, while Rh5 levels were higher in 2021 compared to other years.ConclusionsOverall, these findings suggest increasing mixed infections with an increase in the use of sialic-acid independent invasion pathways by P. falciparum clinical isolates in the Western part of Gambia.Graphical

Prompt treatment-seeking behaviour varies within communities among guardians of children with malaria-related fever in Malawi

BackgroundIn Malawi, malaria is responsible for 40% of hospital deaths. Prompt diagnosis and effective treatment within 24 h of fever onset is critical to prevent progression from uncomplicated to severe disease and to reduce transmission.MethodsAs part of the large evaluation of the malaria vaccine implementation programme (MVIP), this study analysed survey data to investigate whether prompt treatment-seeking behaviour is clustered at community-level according to socio-economic demographics.ResultsFrom 4563 households included in the survey, 4856 children aged 5–48 months were enrolled. Out of 4732 children with documented gender, 52.2% were female and 47.8% male. Among the 4856 children, 33.8% reported fever in the two weeks prior to the survey. Fever prevalence was high in communities with low socio-economic status (SES) (38.3% [95% CI: 33.7–43.5%]) and low in areas with high SES (29.8% [95% CI: 25.6–34.2%]). Among children with fever, 648 (39.5%) sought treatment promptly i.e., within 24 h from onset of fever symptoms. Children were more likely to be taken for prompt treatment among guardians with secondary education compared to those without formal education (aOR:1.37, 95% CI: 1.11–3.03); in communities with high compared to low SES [aOR: 2.78, 95% CI: 1.27–6.07]. Children were less likely to be taken for prompt treatment if were in communities far beyond 5 km to health facility than within 5 km [aOR: 0.44, 95% CI: 0.21–0.92].ConclusionThe high heterogeneity in prevalence of fever and levels of prompt treatment-seeking behaviour underscore the need to promote community-level malaria control interventions (such as use of long-lasting insecticide-treated nets (LLINs), indoor residual spraying (IRS), intermittent preventive therapy (IPT), presumptive treatment and education). Programmes aimed at improving treatment-seeking behaviour should consider targeting communities with low SES and those far from health facility.

Process and Methodological Considerations for Observational Analyses of Vector Control Interventions in Sub-Saharan Africa Using Routine Malaria Data.

Progress in malaria control has stalled in recent years. With growing resistance to existing malaria vector control insecticides and the introduction of new vector control products, national malaria control programs (NMCPs) increasingly need to make data-driven, subnational decisions to inform vector control deployment. As NMCPs are increasingly conducting subnational stratification of malaria control interventions, including malaria vector control, country-specific frameworks and platforms are increasingly needed to guide data use for vector control deployment. Integration of routine health systems data, entomological data, and vector control program data in observational longitudinal analyses offers an opportunity for NMCPs and research institutions to conduct evaluations of existing and novel vector control interventions. Drawing on the experience of implementing 22 vector control evaluations across 14 countries in sub-Saharan Africa, as well as published and gray literature on vector control impact evaluations using routine health information system data, this article provides practical guidance on the design of these evaluations, makes recommendations for key variables and data sources, and proposes methods to address challenges in data quality. Key recommendations include appropriate parameterization of impact and coverage indicators, incorporating explanatory covariates and contextual factors from multiple sources (including rapid diagnostic testing stockouts; insecticide susceptibility; vector density measures; vector control coverage, use, and durability; climate and other malaria and non-malaria health programs), and assessing data quality before the evaluation through either on-the-ground or remote data quality assessments. These recommendations may increase the frequency, rigor, and utilization of routine data sources to inform national program decision-making for vector control.

Barriers of Malaria Control Interventions in African and Asian communities: A Comparative Meta-Synthesis Study

Background: The research about malaria mainly focused on clinical, vector biology, and epidemiology quantitative studies. But the qualitative evidence at the community level remains untouched in high transmission countries. The current paper focuses on the qualitative evidence to explore the behavioral and community health barriers of malaria control interventions at the grassroots level using an inter-continental comparative platform. Therefore, we selected qualitative studies from Asian and African continents which hold major high transmission hotspot areas. Methods: We screened qualitative studies that focused in-depth on the barriers of malaria control measures for meta-synthesis, which were published between 2010 and 2020 in the Asian and African countries. We followed PRISMA guidelines to conduct a literature search on 7 databases and the quality of the articles was assessed by the SRQR guide. We conducted thematic synthesis and quantified the themes to assess the proportion of barriers identified in both continents and highlighted the barriers and recommendations using an explanatory framework. Results: We have selected 8 articles, which studied in-depth perceptions, barriers, and challenges of malaria control interventions in both Asian and African communities. The lack of knowledge on malaria, approaching traditional healers for treatment, and corruption in the distribution of insecticide nets were the major identified barriers in Asian countries, whereas lack of knowledge and noncompliance to drugs due to side effects were the major issues reported in African countries. Conclusion: Meta-synthesis is designed to investigate the common phenomena among diverse settings. In this study, we have attempted to pool the commonalities and contrasts in barriers of malaria control interventions in both countries. The results of the review givefirsthand information to the policymakers for revising strategies and priorities for the malaria elimination goals in both developing countries.

Prevalence of malaria parasitaemia among pregnant women at booking in Nigeria.

Malaria is a major public health concern among pregnant women in sub-Saharan Africa. Within the region, Nigeria has the highest malaria cases. This study aimed to determine the prevalence and factors associated with malaria parasitaemia among pregnant women at a booking clinic in Ibadan, Nigeria. A cross-sectional study was conducted between January and April 2021 at the University College Hospital in Ibadan, Nigeria. A sample of 300 pregnant women participated, and anaemia and malaria were diagnosed using packed cell volume and Giemsa-stained blood smears, respectively. Data analysis was done using SPSS 25.0. The study found that 26 (8.70%) pregnant women tested positive for malaria parasitaemia. Factors such as age, religion, level of education, and occupation were significantly related to the prevalence of malaria parasitaemia among pregnant women with p < 0.05. Our study identified a high prevalence of malaria parasitaemia among pregnant women with demographic factors such as age, religion, level of education, and occupation significantly associated. Targeted malaria control interventions for pregnant women with low levels of education and low-income occupations are necessary, with more research needed to evaluate their effectiveness.