Malaria Prevention Research Articles

Streamlining malaria prevention recommendations for travellers: current and future approaches.

Streamlining malaria prevention recommendations for travellers: current and future approaches.

Challenges in Malaria Control and Prevention in East Africa

Malaria remains a critical public health issue in East Africa, where high transmission rates persist despite extensive control and prevention efforts. This review article explores the multifaceted challenges that hinder effective malaria control and prevention in the region, including the emergence of drug-resistant Plasmodium parasites, insecticide-resistant mosquito vectors, inadequate healthcare infrastructure, socio-economic barriers, and environmental factors. The review methodology involved analyzing recent studies, reports, and data from international health organizations. Drug resistance and vector control are significant issues, with resistance to both anti-malarial drugs and insecticides compromising treatment efficacy and prevention efforts. Additionally, socio-economic factors such as poverty and lack of education, coupled with climate variability and environmental changes, further complicate malaria control. Addressing these challenges requires a coordinated approach that integrates continuous monitoring, healthcare system strengthening, community engagement, and international collaboration. By tackling these issues, East Africa can improve its malaria control efforts and ultimately enhance the health outcomes of its populations. Keywords: Malaria Control, Drug Resistance, Insecticide Resistance, Healthcare Infrastructure, Socio-Economic Barriers.

Malaria Prevalence Rates among Pregnant Women in East Africa: National and Regional Perspectives

Malaria remains a critical public health issue in East Africa, with pregnant women particularly vulnerable to its severe consequences. This review examines the prevalence rates of malaria among pregnant women, providing a comprehensive analysis of national and regional perspectives as well as urban-rural and age-specific variations. By integrating national data with regional insights, the review highlights overarching trends and identifies specific hotspots where malaria transmission is most intense. The study reveals that while national data can guide broad resource allocation and policy decisions, regional data is crucial for pinpointing high-risk areas and tailoring localised interventions. We examine the impact of seasonal variations on pregnant women, including increased transmission during rainy seasons and the geographic distribution of high-risk areas and hotspots. The review also explores the influence of socioeconomic factors, education, housing conditions, and biological determinants on malaria risk among pregnant women. Additionally, it addresses the challenges associated with diagnosing malaria, including the limitations of conventional methods and the need for more sensitive diagnostic tools. The impact of malaria during different trimesters of pregnancy and the complications arising from coinfections, particularly with HIV, receive special attention. The review underscores the necessity of integrated care approaches, improved diagnostic infrastructure, and targeted interventions to mitigate the effects of malaria on maternal and foetal health. The findings advocate for a comprehensive strategy that encompasses geographic and seasonal variations, addresses risk factors, and integrates robust diagnostic and treatment approaches to reduce malaria prevalence and improve health outcomes for pregnant women in East Africa. Keywords: malaria, pregnant women, East Africa, national and regional perspectives

Overview of Malaria in Pregnancy: Challenges and Strategies for Effective Prevention

Malaria in pregnancy is a significant public health issue in sub-Saharan Africa, with 30 million pregnancies at risk each year. Pregnant women are particularly vulnerable due to immunological changes and the placental environment that facilitates parasite sequestration. The predominant malaria parasite, Plasmodium falciparum, is associated with significant maternal and fetal complications. Effective malaria prevention strategies include insecticide-treated nets (ITNs) and intermittent preventive treatment (IPTp) with Sulfadoxine-pyrimethamine. However, adherence to preventive chemotherapy is challenging due to side effects and socioeconomic barriers. Health education programs are crucial for increasing awareness and promoting preventive behaviors. Early diagnosis and prompt treatment are critical for managing severe malaria cases. Environmental and vector control measures, such as indoor residual spraying and larval source management, are vital for reducing mosquito populations and transmission. Nutritional interventions support immune function and overall health. Access to healthcare services, innovative technologies, and cultural and socioeconomic factors are essential for overcoming barriers to malaria prevention and treatment. Continuous monitoring and evaluation are crucial for refining interventions and improving health outcomes. Keywords: Malaria, Pregnancy, Challenges, Strategies, Effective Prevention

Receipt of antimalarials among children aged 6–59 months in Nigeria from 2010 to 2021

BackgroundNigeria has the highest malaria burden globally, and anti-malarials have been commonly used to treat malaria without parasitological confirmation. In 2012, Nigeria implemented rapid diagnostic tests (RDTs) to reduce the use of anti-malarials for those without malaria and to increase the use of artemisinin-based combination therapy (ACT) for malaria treatment. This study examined changes in anti-malarial receipt among children aged 6–59 months during a 12-year period of increasing RDT availability.MethodsA cross-sectional analysis was conducted using the Nigeria Malaria Indicator Survey (NMIS) data from 2010 (before RDT implementation in 2012), 2015, and 2021. The analysis assessed trends in prevalence of malaria by survey RDT result, and fever and anti-malarial/ACT receipt in the 2 weeks prior to the survey. A multivariable logistic regression was used to account for the complex survey design and to examine factors associated with anti-malarial receipt, stratified by survey RDT result, a proxy for recent/current malaria infection.ResultsIn a nationally-representative, weighted sample of 22,802 children aged 6–59 months, fever prevalence remained stable over time, while confirmed malaria prevalence decreased from 51.2% in 2010 to 44.3% in 2015 and 38.5% in 2021 (trend test p < 0.0001). Anti-malarial use among these children decreased from 19% in 2010 to 10% in 2021 (trend test p < 0.0001), accompanied by an increase in ACT use (2% in 2010 to 8% in 2021; trend test p < 0.0001). Overall, among children who had experienced fever, 30.6% of survey RDT-positive and 36.1% of survey RDT-negative children had received anti-malarials. The proportion of anti-malarials obtained from the private sector increased from 61.8% in 2010 to 80.1% in 2021 for RDT-positive children; most of the anti-malarials received in 2021 were artemisinin-based combinations. Factors associated with anti-malarial receipt for both RDT-positive and RDT-negative children included geographic region, greater household wealth, higher maternal education, and older children.ConclusionFrom 2010 to 2021 in Nigeria, both malaria prevalence and anti-malarial treatments among children aged 6–59 months decreased, as RDT availability increased. Among children who had fever in the prior 2 weeks, anti-malarial receipt was similar between children with either positive or negative survey RDT results, indicative of persistent challenges in reducing inappropriate anti-malarials uptake.

Prevalence of asymptomatic malaria at the communal level in Burkina Faso: an application of the small area estimation approach

BackgroundIn malaria-endemic countries, asymptomatic carriers of plasmodium represent an important reservoir for malaria transmission. Estimating the burden at a fine scale and identifying areas at high risk of asymptomatic carriage are important to guide malaria control strategies. This study aimed to estimate the prevalence of asymptomatic carriage at the communal level in Burkina Faso, the smallest geographical entity from which a local development policy can be driven.MethodsThe data used in this study came from several open sources: the 2018 Multiple Indicator Cluster Survey on Malaria and the 2019 general census of the population data and environmental. The analysis involved a total of 5489 children under 5 from the malaria survey and 293,715 children under 5 from the census. The Elbers Langjouw and Langjouw (ELL) approach is used to estimate the prevalence. This approach consists of including data from several sources (mainly census and survey data) in a statistical model to obtain predictive indicators at a sub-geographical level, which are not measured in the population census. The method achieves this by finding correlations between common census variables and survey data.FindingsThe findings suggest that the spatial distribution of the prevalence of asymptomatic carriage is very heterogeneous across the communes. It varies from a minimum of 5.1% (95% CI 3.6–6.5) in the commune of Bobo-Dioulasso to a maximum of 41.4% (95% CI 33.5–49.4) in the commune of Djigoué. Of the 341 communes, 208 (61%) had prevalences above the national average of 20.3% (95% CI 18.8–21.2).ContributionsThis analysis provided commune-level estimates of the prevalence of asymptomatic carriage of plasmodium in Burkina Faso. The results of this analysis should help to improve planning of malaria control at the communal level in Burkina Faso.

Field-evolved resistance to neonicotinoids in the mosquito, Anopheles gambiae, is associated with downregulation and mutations of nicotinic acetylcholine receptor subunits combined with cytochrome P450-mediated detoxification.

Neonicotinoid insecticides act selectively on their nicotinic receptor targets leading to variable sensitivity among arthropods. This study aimed to investigate the molecular mechanisms underlying contrasting susceptibility to neonicotinoids observed in wild populations of two mosquito sibling species. Bioassays and a synergism test revealed that the sister taxa, Anopheles gambiae and An. coluzzii, from Yaounde, Cameroon, rely on cytochrome P450s to detoxify neonicotinoids and develop resistance. However, contrary to An. coluzzii, An. gambiae populations are evolving stronger resistance to several active ingredients facilitated by mutations and reduced expression of nicotinic acetylcholine receptors. Six mutations were detected in coding sequences of the β1 and α6 subunits, including two substitutions in one of the loops that modulate ligand binding and sensitivity. Allele frequencies were strongly correlated with a susceptibility gradient between An. coluzzii and An. gambiae suggesting that the mutations may play a key role in sensitivity. Messenger RNA expression levels of the β1, α3, and α7 subunits decreased dramatically, on average by 23.27, 17.50, 15.80-fold, respectively, in wild An. gambiae populations compared to a susceptible insectary colony. By contrast, only the β2 and α9-1 subunits were moderately downregulated (5.28 and 2.67-fold change, respectively) in field-collected An. coluzzii adults relative to susceptible colonized mosquitoes. Our findings provide critical information for the application and resistance management of neonicotinoids in malaria prevention.

Determinants of the optimal uptake of sulfadoxine–pyrimethamine doses for intermittent treatment of malaria in pregnancy in urban Nigeria

Malaria is a leading cause of maternal and child mortality in urban Nigeria. Intermittent preventive treatment with sulfadoxine–pyrimethamine (IPTp–SP) during pregnancy can prevent malaria but uptake is suboptimal. This cross-sectional study analyzed secondary data on 1159 urban Nigerian women from the 2015 Malaria Indicator Survey using descriptive statistics and logistic regression. The primary outcome was optimal IPTp–SP uptake (≥ 3 doses). 67% of women took any SP during pregnancy but only 39% took ≥ 3 IPTp–SP doses as recommended. Region and wealth index significantly predicted optimal IPTp–SP uptake while education did not. Women from lower-income regions in the urban areas were less likely to receive optimal IPTp–SP. Strategies to increase IPTp–SP uptake in urban Nigeria should target low-income regions and women of lower socioeconomic status. Logistic regression identified actionable factors for improving antenatal malaria prevention. Optimal IPTp–SP uptake remains suboptimal across urban Nigeria, threatening maternal and child health.

Pooled prevalence of malaria and associated factors among vulnerable populations in Ethiopia: a systematic review and meta-analysis

BackgroundMalaria is a serious, fatal disease, and a high-risk determinant for human health globally. Children, pregnant women, and migrants are vulnerable groups for malaria infection in African regions. Recently, malaria is an endemic disease in Ethiopia.ObjectivesThis study aimed to determine the pooled prevalence of malaria and its determinant factors among the most vulnerable populations in Ethiopia.MethodsElectronic databases, including PubMed, Google Scholar, Web of Science, Semantic Scholar, and Scopus were used for searching articles published since the 2020 Gregorian calendar and onwards. All peer-reviewed Ethiopian journals, health institutions, and Universities were considered for article searching. A PRISMA flow chart and Endnote software were used for article screening, and to remove duplications, respectively. The modified version of the Newcastle–Ottawa Scale was used for potential risk of bias assessments. The heterogeneity among the included studies was evaluated using the indicator of heterogeneity (I2). Egger’s test and funnel plot were used to examine the possible publication bias. A random-effects analysis was used to assess the pooled prevalence of malaria, and its determinant factors with a 95% CI. The screening process, data extraction, and quality assessment were done independently, and any disagreements were resolved through discussions.ResultsA total of twelve studies were included in this study. The pooled malaria prevalence was 11.10% (95% CI: 6.10, 16.11). Stagnant water (AOR: 4.19, 95% CI: 2.47, 7.11), no insecticide-treated net utilization (AOR: 3.15, 95% CI: 1.73, 5.73), and staying outdoors at night (AOR: 5.19, 95% CI: 2.08, 12.94) were the pooled estimated statistically risk factors for malaria prevalence. Whereas, insecticide-treated bed net utilization (AOR: 1.59, 95% CI: 0.23, 10.95) reduces the risk of malaria infection.ConclusionsThe pooled prevalence of malaria is high among vulnerable populations. Creating awareness regarding utilization of insecticide-treated bed nets, and draining stagnant water from the environment are possible interventions to reduce the prevalence of malaria.

Present and Future Associations Between Precipitation, Temperature, and Malaria Prevalence in Mali

Present and Future Associations Between Precipitation, Temperature, and Malaria Prevalence in Mali

Prospect of Social Marketing in Enhancing the Acquisition and Utilization of Insecticide Treated Nets (ITNs) for the Prevention of Malaria in a Rural Area of Imo State, South-Eastern Nigeria

Background Proper utilization of Insecticide Treated Nets (ITNs) has been shown to be very effective in preventing malaria and in reducing the incidence of the disease. Getting people to buy and utilize ITNs has proven very difficult especially in low-income settings of sub-Saharan Africa where the disease is endemic. This research work, therefore assesses the effectiveness of the application of social marketing strategies in encouraging the acquisition and utilization of ITNs. Focus of the Article The marketing mix concept which is usually referred to as the 4Ps of social marketing-price, place, product and promotion-were put to test to identify how the respondents will respond to variation in any of them. The research aims to assess the people’s response to a favorable change in the price of ITNs, product quality, product location and target advertisement. Research Question The research questions that this study aimed to answer is; will the introduction of the traditional marketing mix of social marketing help drive the acquisition and utilization of ITNs by the people in rural communities of Imo State, Nigeria? Program Design/Approach The research report contained in this manuscript is targeted at health products (tangible and intangible) marketing researchers in resource-limited settings. These researchers who may not be able to afford the acquisition of large quantity health products like the ITNs to conduct their study can adopt the method employed in this study. Here the “prospect” of using social marketing strategies like the traditional marketing mix, to determine a possible increase in the acquisition and utilization of ITNs by the people. Importance to the Social Marketing Field This study describes how researchers in low-and-middle income countries could conduct a social marketing research on tangible products such as the ITN without really selling ITNs. The people’s intent to buy and use ITNs were assessed. More than 10 previous studies from as far back as 1999 were assessed, none of them employed the current methodology. Methodology This study was a descriptive cross-sectional study where a multi-stage sampling technique was employed to recruit the study participants. Results It was found that 55.1% had ITNs, good utilization rate of 80.6% was recorded among those who possessed ITNs. Using the social marketing principle to assess respondents’ intent to own and use ITNs, an increase of 27.2%, 38.1%, 31.3%, and 35.9% will be achieved if the cost of acquiring ITNs becomes affordable, when ITNs become accessible, when practical guidance on use was provided, and when quality was improved. The study also revealed that, the vigorous pursue of social marketing techniques can enhance the sales of ITNs and its usage among the people. Recommendation for Research or Practice This study has justified the usefulness of social marketing in engendering positive behavioural change where people can be motivated to adopt a health innovation. It is therefore recommended that health innovations and products must be sold to the people using social marketing strategies as this has been proven not only to encourage adoption/acquisition, but also utilization.

High prevalence and risk factors associated with asymptomatic malaria among children in Nkwen village, Northwest Region, Cameroon

BackgroundIn endemic locations, asymptomatic malaria is a major contribution to the rise in clinical malaria. In order to achieve the goal of interrupting malaria transmission, control programmes should take into consideration carriers of asymptomatic malaria parasite. Hence, the purpose of this study was to look at the prevalence and risk factors of asymptomatic malaria in children in Nkwen village.MethodsUsing a cross-sectional and community-based design, conducted between June and December 2022, a total of 246 children were enrolled after obtaining informed and signed consent from parents and/ or guardians. To collect data, pre-tested, closed-ended, structured questionnaires were used, ensuring the accuracy and reliability of the information gathered. A digital thermometer with infrared forehead capability was used to take participants’ body temperature, providing precise measurements and respondents with temperature < 37.5 °C, and not presenting any symptoms or indicators of malaria were included in the study, ensuring the focus on asymptomatic cases. Blood samples were collected by venipuncture and screened for the presence of asymptomatic parasitaemia using blood smear microscopy and nested polymerase chain reaction (PCR). Data was entered into Microsoft Excel worksheet and analysed using SPSS version 23 software. Logistic regression models were carried out to explore the risk factors associated with asymptomatic malaria at household and individual levels and statistically significant association was considered at a p-value < 0.05.ResultsA total of 246 healthy children were examined for asymptomatic malaria infection using microscopy and PCR. Of the examined children, 65.9% (162/246) were malaria positive by PCR while 59.3% (146/246) were malaria positive by microscopy. Considering both diagnostic methods, females had a greater prevalence of asymptomatic malaria than males. In logistic analysis, the risk of developing asymptomatic malaria was associated several factors: previous malaria episode (OR = 5.14; CI 2.94–9.01), family history of malaria (OR = 3.86; CI 2.21–6.74), homestead near swampy areas (OR = 3.56; CI 2.10–10.61), non-utilization of insecticide treated nets (OR = 4.36; CI 2.53–7.5), non-usage of indoor residual spray (IRS) (OR = 6.67; CI 3.75–11.86) and opened eaves (OR = 3.86; CI 2.21–6.74). No associations were established between asymptomatic malaria and the following factors: age group (p > 0.05), gender (p > 0.05) and type of wall construction (p > 0.05).ConclusionThe high rate of asymptomatic malaria in this study is a significant problem and may jeopardize the current malaria control effort. Personal and house-level risk factors were linked with asymptomatic malaria. Therefore, it should be considered when evaluating and restructuring more successful malaria elimination tactics to accomplish the intended goals of malaria control.

Bioassay-guided Fractionation of Anti-Leishmania amazonensisExtracts from Ampelozizyphus amazonicus by High-speed Countercurrent Chromatography.

Ampelozizyphus amazonicus Ducke, known as "saracura-mirá" in the Amazon rainforest, is valued for its traditional use in malaria prevention and treatment. The plant's roots and bark are employed for these purposes, while the wood is often overlooked. Given the global importance of leishmaniasis, research focused on A. amazonicus anti-Leishmania amazonensis potential. The ethyl acetate extract from the bark (EAEB) exhibited the most effective inhibition of intracellular amastigote growth with IC50 7.0 µg.mL-1 but showed high toxicity (CC50 9.0 µg.mL-1). The wood ethanol (EW) and ethyl acetate (EAEW) extracts demonstrated promising results against L. amazonensis with IC50 15.8 µg.mL-1 and 10.0 µg.mL-1, CC50 50.5 µg.mL-1 and 22.7 µg.mL-1, respectively. High-speed countercurrent chromatography combined with mass spectrometry off-line detection was employed for the bioassay-guided fractionation of EAEB and EAEW using HEMWat as solvent system. These extracts showed to be rich in saponins and triterpenes, besides minor glycosylated flavonoids. HSCCC was effective in obtaining high purity fractions, leading to the identification of a di-glycosylated triterpene saponin from EAEB, and melaleucic acid from EAEW. These findings highlight A. amazonicus as a potential source for developing new therapeutic alternatives for leishmaniasis and HSCCC as a technique enabling better separation efficiency of complex saponin matrices.

Association between Epstein-Barr virus reactivation and severe malaria in pregnant women living in a malaria-endemic region of Cameroon.

Malaria kills nearly 619,000 people each year. Despite the natural immunity acquired to malaria, pregnant women and children under five die from severe forms of the disease in sub-Saharan Africa. Co-infection with acute Epstein-Barr Virus (EBV) infection has been shown to suppress the anti-malarial humoral responses, but little is known about the impact of EBV reactivation on malaria-associated morbidity. This study investigated the association between EBV reactivation and malaria severity in pregnant women living in a malaria-endemic region in Cameroon. A cross-sectional study was conducted on 220 pregnant women attending antenatal consultations in three health facilities in the West region of Cameroon. Malaria was diagnosed by microscopy, and Plasmodium species were identified by Nested PCR. Plasma samples were analyzed by ELISA for the presence of EBV nuclear antigen, EBV viral capsid antigen, and EBV early antigen to determine EBV reactivation. All statistics were performed using GraphPad Prism and SPSS software. The prevalence of malaria among pregnant women was 23.2%, of which 18.6% were P. falciparum mono-infections and 4.5% mixed infections (3.6% P. falciparum and P. malariae; 0.9% P. falciparum and P. ovale). 99.5% of the women were EBV seropositive, and 13.2% had EBV reactivation. Pregnant women with reactivated EBV were more likely to develop severe malaria than pregnant women with latent EBV (OR 4.33, 95% CI 1.08-17.25, p = 0.03). The median parasitemia in pregnant women with latent EBV was lower than in those with EBV reactivation (2816 vs. 19002 parasites/μL, p = 0.02). Our study revealed that lytic reactivation of EBV may be associated with the severity of malaria in pregnant women. Suggesting that, like acute infection, EBV reactivation should be considered a risk factor for severe malaria in pregnant women in malaria-endemic regions or could serve as a hallmark of malaria severity during pregnancy. Further detailed studies are needed.

Demographic and socioeconomic obstacles to access to malaria services for Myanmar migrants in Thailand

BackgroundTypically mobile and vulnerable, migrants face significant barriers to access to routine malaria prevention, diagnostics and treatment, which leads to unchecked malaria transmission, particularly in border regions with a high population displacement. This study aimed to investigate the demographic and socioeconomic obstacles to access to malaria services among Myanmar migrants residing in the Thailand–Myanmar border areas.MethodsA cross-sectional study was conducted in early 2024 across three districts near the Thailand–Myanmar border. Quantitative data were collected from Myanmar migrants using standardized questionnaires through structured surveys. Data analysis included descriptive statistics and simple and multiple logistic regression models.ResultsOut of 300 participants, approximately a quarter (27.3%) reported adequate access to comprehensive malaria services, including prevention, diagnostics, treatment and malaria-related health information. In multiple logistic regression models, factors associated with inadequate access included Myanmar migrants aged over 60 years (aOR: 7.63, 95% CI 1.74–20.58), accompanied by one to three family members (aOR: 3.33, 95% CI 1.06–8.45), earning monthly incomes below 3000 THB (aOR: 5.13, 95% CI 1.38–19.09) and 3000 to 6000 THB (aOR: 3.64, 95% CI 1.06–12.51), belonging to the Karen ethnicity (aOR: 2.13, 95% CI 1.02–3.84), with poor perception toward malaria (aOR: 2.03, 95% CI 1.03–4.01) and with poor preventive and health-seeking practices (aOR: 5.83, 95% CI 2.71–9.55).ConclusionsA significant proportion of Myanmar migrants encounter demographic and socioeconomic barriers to access to routine malaria services in Thailand. Tailored interventions are required to expand such access, including the recruitment of worksite health volunteers, strengthening the role of ethnic health organizations across the border and collaboration with private sector stakeholders (e.g. farm/company owners) to distribute preventive tools and ensure timely referral of suspected malaria cases to health facilities.

Assessment of knowledge, attitude, and practices toward malaria in the Lunglei district, Mizoram, North-East India

BackgroundThe western districts of Mizoram (Lunglei, Mamit, and Lawngtlai) are malaria hotspots. Understanding the knowledge, attitude, and practices of the tribal communities in Mizoram’s western districts will aid the development of specific interventions.MethodsAn explanatory sequential mixed-method study was conducted from April to November 2023 in the Lunglei district. In a community-based cross-sectional survey of 353 participants, the knowledge, attitude, practices, and care-seeking behaviour toward malaria were assessed using a semi-structured questionnaire. Data was analysed using SPSS version 29 software; univariate variables were presented in percentage, and bivariate and multivariate variables were analysed using the chi-square test and logistic regression, respectively. This was followed by in-depth telephonic interviews of twelve participants, and the data was analysed using NVivo.ResultsOut of the 353 respondents, 77.9%, 82.7%, 55.5%, and 63.2% of the participants had good knowledge, attitude, practices, and care-seeking behaviour, respectively. The in-depth qualitative interviews highlighted the villagers’ good knowledge of the various aspects of malaria transmission, treatment, and prevention practices (indoor residual spraying and use of insecticide-treated nets).ConclusionHigh disease endemicity, awareness programmes and vector control interventions might be contributing to the overall good knowledge, attitude, and practices toward malaria among the villagers. In addition to vector control measures, active parasite surveillance is key to malaria control in this region.

Close Proximity to Mining Is Associated with Increased Prevalence of the Drug Resistance-Associated Mutation dhps540E in Eastern Democratic Republic of the Congo.

Increasing sulfadoxine-pyrimethamine (SP) resistance in the Democratic Republic of the Congo (DRC) has threatened its use for prevention of malaria in one of the most malarious countries in the world. Using geographic information on mining operations in the DRC and genetic data on SP drug resistance markers from the 2013-2014 Demographic and Health Surveys, we evaluated associations between close residence to mining and the presence of mutations conferring resistance to sulfadoxine. Close residential proximity to mining was associated with increased prevalence odds ratio (POR) of the dhps540E mutation (POR: 2.11, 95% uncertainty interval: 1.15-3.96) with adjustments for confounding variables and space. Our findings indicate that exposure to mining is associated with increased presence of an antimalarial drug resistance haplotype that threatens effective use of SP for vulnerable populations. Areas actively engaged in mining could be considered for interventions to reduce the spread of emerging drug resistance in the DRC.

Plasmodium falciparum population dynamics in East Africa and genomic surveillance along the Kenya-Uganda border

East African countries accounted for ~ 10% of all malaria prevalence worldwide in 2022, with an estimated 23.8 million cases and > 53,000 deaths. Despite recent increases in malaria incidence, high-resolution genome-wide analyses of Plasmodium parasite populations are sparse in Kenya, Tanzania, and Uganda. The Kenyan-Ugandan border region is a particular concern, with Uganda confirming the emergence and spread of artemisinin resistant P. falciparum parasites. To establish genomic surveillance along the Kenyan-Ugandan border and analyse P. falciparum population dynamics within East Africa, we generated whole-genome sequencing (WGS) data for 38 parasites from Bungoma, Western Kenya. These sequences were integrated into a genomic analysis of available East African isolate data (n = 599) and revealed parasite subpopulations with distinct genetic structure and diverse ancestral origins. Ancestral admixture analysis of these subpopulations alongside isolates from across Africa (n = 365) suggested potential independent ancestral populations from other major African populations. Within isolates from Western Kenya, the prevalence of biomarkers associated with chloroquine resistance (e.g. Pfcrt K76T) were significantly reduced compared to wider East African populations and a single isolate contained the PfK13 V568I variant, potentially linked to reduced susceptibility to artemisinin. Overall, our work provides baseline WGS data and analysis for future malaria genomic surveillance in the region.

Why some countries but not others? Urbanisation, GDP and endemic disease predict global SARS-CoV-2 excess mortality patterns

ContextThe global impact of the SARS-CoV-2 pandemic has been uneven, with some regions experiencing significant excess mortality while others have been relatively unaffected. Yet factors which predict this variation remain enigmatic, particularly at large spatial scales.ObjectivesWe aimed to uncover the key drivers of excess mortality across countries and regions to help understand the factors contributing to the varied impacts of the pandemic worldwide.MethodsWe used spatially explicit Bayesian models that integrate environmental, socio-demographic and endemic disease data at the country level to provide robust global estimates of excess SARS-CoV-2 mortality (P-scores) for the years 2020 and 2021.ResultsWe find that urbanization, gross domestic product (GDP) and spatial patterns are strong predictors of excess mortality, with countries characterized by low GDP but high urbanization experiencing the highest levels of excess mortality. Intriguingly, we also observed that the prevalence of malaria and human immunodeficiency virus (HIV) are associated with country-level SARS-CoV-2 excess mortality in Africa and the Western Pacific, whereby countries with low HIV prevalence but high malaria prevalence tend to have lower levels of excess mortality. While these associations are correlative in nature at the macro-scale, they emphasize that patterns of endemic disease and socio-demographic factors are needed to understand the global dynamics of SARS-CoV-2.ConclusionsOur study identifies factors associated with variation in excess mortality across countries, providing insights into why some were more impacted by the pandemic than others. By understanding these predictors, we can better inform global outbreak management strategies, such as targeting medical resources to highly urban countries with low GDP and high HIV prevalence to reduce mortality during future outbreaks.

Performance of rapid diagnostic test, light microscopy, and polymerase chain reaction in pregnant women with asymptomatic malaria in Nigeria

ObjectivesRapid diagnostic tests (RDTs) offer an attractive tool for diagnosing malaria in pregnancy. This study assessed the effectiveness of a Plasmodium falciparum–specific RDT compared with microscopy and polymerase chain reaction (PCR) in diagnosing asymptomatic malaria in pregnant women in southwest Nigeria. MethodsThe study included 406 asymptomatic pregnant women seeking antenatal care. Blood samples were collected and tested using RDT (SD Bioline, Standard Diagnostics Inc. Korea) and light microscopy and confirmed using nested PCR. ResultsThe study revealed that the malaria parasite positivity rate was 8.9% by RDT, 21% by microscopy, and 32% by nested PCR. RDT had a sensitivity of 51.4% and specificity of 69.5%, whereas microscopy had a sensitivity of 65.3% and specificity of 98.2%. The combined testing of microscopy and RDT had a sensitivity and specificity of 100%. The study also showed a high prevalence of mild anemia among participants. ConclusionsDespite the RDT's low sensitivity, its high negative predictive value suggests it could be useful in combination with microscopy in ruling out asymptomatic malaria in pregnancy. Further study will help identify more suitable RDTs for routine malaria diagnosis in Nigeria and strengthen malaria prevention programs in pregnant women.