Malaria Journal最新文献

{"title":"Systematic review on the cost of seasonal malaria chemoprevention (SMC).","authors":"Anika Ruisch, Miranda Iodice, Ishani Mathur, Sara Harris, Damian G Walker, Richmond Owusu, Justice Nonvignon, Colin Gilmartin","doi":"10.1186/s12936-024-05217-1","DOIUrl":"https://doi.org/10.1186/s12936-024-05217-1","url":null,"abstract":"<p><strong>Background: </strong>Implemented in 17 countries to date, seasonal malaria chemoprevention (SMC) is a recommended strategy to prevent childhood malaria in areas with seasonal transmission of P. falciparum through monthly administration of antimalarial medicines. Understanding the costs and resource requirements of SMC delivery is necessary for effective planning and resource allocation. This systematic literature review aims to assess the evidence on the cost and cost-effectiveness of SMC delivery.</p><p><strong>Methods: </strong>Following PRISMA guidelines, five databases were systematically reviewed to identify evidence on SMC costs and cost-effectiveness published between 2012 and 2023. Studies with defined costing methodologies and cost output measures were included, excluding those relying solely on mathematical modeling. Two reviewers assessed each study for eligibility and extracted cost data, which were adjusted for inflation. Quality assessment was completed using the CHEERS checklist.</p><p><strong>Results: </strong>Six costing studies were identified spanning nine countries. Four studies examined costs during an SMC pilot or introduction, one during scale-up, and one costed newly established SMC campaigns through a multi-country project. Costs were examined at country level with the financial costs per child receiving a full course of SMC ranging from $1.71 to $12.46, while economic costs per child ranged from $2.11 to $29.06. Four studies included a cost effectiveness analysis with incremental cost-effectiveness ratios (ICERs) per clinical malaria case averted ranging from $5.41 to $138.03; ICER per disability-adjusted life year (DALY) averted from $24.51 to $182.88; and ICER per death averted from $688.86 to $18,418.81. Differences in cost estimates stemmed from different factors including variations in cost ingredients, scale of the intervention, and study perspectives.</p><p><strong>Discussion: </strong>The level of detail for reporting SMC costs and cost categories varied greatly by study as did the scale of intervention, limiting comparability as well as an understanding of the complete costs and resource requirements for SMC implementation. Cost evidence is not from mature programs but from pilots or relatively new campaigns. Costs incurred by households and costs of the integrated delivery of SMC with other health interventions were often overlooked. Adopting a standardized costing approach for mature SMC programmes could provide a better understanding of resource requirements and costs while enhancing study comparability across settings, better informing future resource allocation and improving efficiency.</p>","PeriodicalId":18317,"journal":{"name":"Malaria Journal","volume":"23 1","pages":"384"},"PeriodicalIF":2.4,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142854834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of fine-scale malaria strata derived from population survey data collected using RDTs, microscopy and qPCR in South-Eastern Tanzania.","authors":"Issa H Mshani, Frank M Jackson, Elihaika G Minja, Said Abbasi, Nasoro S Lilolime, Faraja E Makala, Alfred B Lazaro, Idrisa S Mchola, Linda N Mukabana, Najat F Kahamba, Alex J Limwagu, Rukia M Njalambaha, Halfan S Ngowo, Donal Bisanzio, Francesco Baldini, Simon A Babayan, Fredros Okumu","doi":"10.1186/s12936-024-05191-8","DOIUrl":"https://doi.org/10.1186/s12936-024-05191-8","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Background: &lt;/strong&gt;Malaria-endemic countries are increasingly adopting data-driven risk stratification, often at district or higher regional levels, to guide their intervention strategies. The data typically comes from population-level surveys collected by rapid diagnostic tests (RDTs), which unfortunately perform poorly in low transmission settings. Here, a high-resolution survey of Plasmodium falciparum prevalence rate (PfPR) was conducted in two Tanzanian districts using rapid diagnostic tests (RDTs), microscopy, and quantitative polymerase chain reaction (qPCR) assays, enabling the comparison of fine-scale strata derived from these different diagnostic methods.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;A cross-sectional survey was conducted in 35 villages in Ulanga and Kilombero districts, south-eastern Tanzania between 2022 and 2023. A total of 7,628 individuals were screened using RDTs (SD-BIOLINE) and microscopy, with two thirds of the samples further analysed by qPCR. The data was used to categorize each district and village as having very low (PfPR &lt; 1%), low (1%≤PfPR &lt; 5%), moderate (5%≤PfPR &lt; 30%), or high (PfPR ≥ 30%) parasite prevalence. A generalized linear mixed model was used to analyse infection risk factors. Other metrics, including positive predictive value (PPV), sensitivity, specificity, parasite densities, and Kappa statistics were computed for RDTs or microscopy and compared to qPCR as reference.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;Significant fine-scale variations in malaria risk were observed within and between the districts, with village prevalence ranging from 0% to &gt; 50%. Prevalence varied by testing method: Kilombero was low risk by RDTs (PfPR = 3%) and microscopy (PfPR = 2%) but moderate by qPCR (PfPR = 9%); Ulanga was high risk by RDTs (PfPR = 39%) and qPCR (PfPR = 54%) but moderate by microscopy (PfPR = 26%). RDTs and microscopy classified majority of the 35 villages as very low to low risk (18-21 villages). In contrast, qPCR classified most villages as moderate to high risk (29 villages). Using qPCR as the reference, PPV for RDTs and microscopy ranged from as low as &lt; 20% in very low transmission villages to &gt; 80% in moderate and high transmission villages. Sensitivity was 62% for RDTs and 41% for microscopy; specificity was 93% and 96%, respectively. Kappa values were 0.7 for RDTs and 0.5 for microscopy. School-age children (5-15 years) had higher malaria prevalence and parasite densities than adults (P &lt; 0.001). High-prevalence villages also had higher parasite densities (Spearman r = 0.77, P &lt; 0.001 for qPCR; r = 0.55, P = 0.003 for microscopy).&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusion: &lt;/strong&gt;This study highlights significant fine-scale variability in malaria burden within and between the study districts and emphasizes the variable performance of the testing methods when stratifying risk at local scales. While RDTs and microscopy were effective in high-transmission areas, they performed poorly in low-transmission settings; a","PeriodicalId":18317,"journal":{"name":"Malaria Journal","volume":"23 1","pages":"376"},"PeriodicalIF":2.4,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142854716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of seasonal malaria chemoprevention on incidence of malaria among children under five years in Kotido and Moroto Districts, Uganda, 2021: time series analysis.","authors":"Andrew Kwiringira, Benon Kwesiga, Richard Migisha, Lilian Bulage, Daniel Kadobera, Damian Rutazaana, Julie R Harris, Alex R Ario, Julius Ssempiira","doi":"10.1186/s12936-024-05220-6","DOIUrl":"https://doi.org/10.1186/s12936-024-05220-6","url":null,"abstract":"<p><strong>Background: </strong>Seasonal malaria chemoprevention (SMC) refers to monthly administration of full treatment courses of anti-malarial medicine to children <5 years during high malaria transmission seasons. SMC has demonstrated effectiveness in Sahel and sub-Sahel countries in Africa. However, it was not implemented in Uganda until April 2021, when the country began SMC in the highly malaria-endemic Kotido and Moroto Districts. This study assessed the effect of SMC on malaria incidence among children <5 years of age in Kotido and Moroto Districts.</p><p><strong>Methods: </strong>An interrupted time-series analysis was conducted using monthly national health data from the Uganda Ministry of Health District Health Information System 2. The monthly data for outpatient (uncomplicated) malaria among children <5 years was extracted for the 52 months before SMC implementation (Jan 2017-Apr 2021) and 8 months during SMC implementation (May-Dec 2021). The monthly incidence of uncomplicated malaria per 1000 children <5 years was computed before and during SMC implementation.</p><p><strong>Results: </strong>In Kotido District, malaria incidence was 693/1000 during SMC implementation period, compared to an expected 1216/1000 if SMC had not been implemented. The mean monthly malaria incidence was 87/1000, compared to an expected mean of 152/1000 if SMC had not been implemented. This represents a statistically significant mean monthly change of -65.4 (95% CI = -104.6, -26.2) malaria cases/1000 during SMC implementation, or a 43.0% decline. In Moroto District, malaria incidence was 713/1000 during SMC implementation period, compared to an expected 905/1000 if SMC had not been implemented. The mean monthly malaria incidence was 89/1000, compared to an expected 113/1000 if SMC had not been deployed. This represents a statistically significant mean monthly change of -24.0 (95% CI = -41.1, -6.8) malaria cases/1000 during SMC implementation, or a 21.2% decline.</p><p><strong>Conclusion: </strong>Implementation of SMC substantially reduced the incidence of uncomplicated malaria among children <5 years in Moroto and Kotido Districts. Scaling up SMC in other districts with high malaria transmission could reduce malaria on a large scale across Uganda.</p>","PeriodicalId":18317,"journal":{"name":"Malaria Journal","volume":"23 1","pages":"389"},"PeriodicalIF":2.4,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142854719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Placental malaria and adverse pregnancy outcomes in Majang Zone of Gambella Region, Southwest Ethiopia: a histopathological and molecular study.","authors":"Aklilu Alemayehu, Hallelujah Getachew, Abdo Kedir, Melese Abere, Ahmed Zeynudin, Joseph Beyene, Delenasaw Yewhalaw","doi":"10.1186/s12936-024-05201-9","DOIUrl":"https://doi.org/10.1186/s12936-024-05201-9","url":null,"abstract":"<p><strong>Background: </strong>Placental malaria (PM) is characterized by Plasmodium parasite sequestration in the placenta. It is responsible for various adverse pregnancy outcomes, including maternal anaemia and low birth weight (LBW). This study aimed to assess prevalence and risk factors of PM, and gestational malaria (GM), together with the prevalence of congenital malaria (CM), maternal anaemia, and LBW among parturient women attending delivery ward of Metti Health Centre (Metti HC) in Majang Zone of Gambella Region, Southwest Ethiopia.</p><p><strong>Methods: </strong>A cross-sectional study involving 180 parturient women attending delivery ward of Metti HC was conducted from November 2022-March 2023. Sociodemographic, obstetric, and anti-malarial intervention data were collected. Capillary, placental and cord blood, and placental biopsy were collected to diagnose malaria using rapid diagnostic test (RDT), microscopy, quantitative polymerase chain reaction (qPCR), and histopathology. Haemoglobin concentration and blood group of the mother and weight of the newborn were determined. Statistical analyses were done by SPSS Version 26.0. Multivariable logistic regression analysis and Chi-square test were done to identify risk factors. Results were presented in text, tables and graphs.</p><p><strong>Results: </strong>The prevalence of GM, PM, CM, maternal anaemia, and LBW was 24.4% (95% CI 18.1-30.1), 34.4% (95% CI 27.4-41.4), 5.0% (95% CI 2.4-8.8), 41.7% (95% CI 34.6-49.0) and 27.8% (95% CI 21.6-34.6), respectively. Risk factors of GM were: presence of malaria history within the previous year (AOR: 5.10; 95% CI 1.64-15.83), lack of indoor residual spray (IRS) within the previous year (AOR: 2.98; 95% CI 1.05-8.45), and lack of antenatal care (ANC) contact during the index pregnancy (AOR: 3.96; 95% CI 1.44-10.87). Risk factors of PM were: presence of malaria history within the previous year (AOR: 2.98; 95% CI 1.05-8.45), and lack of ANC contact during the index pregnancy (AOR: 4.83; 95% CI 1.91-12.18). The risk of CM (p < 0.001), maternal anaemia (p < 0.001) and LBW (p < 0.001) increased with GM and PM.</p><p><strong>Conclusion: </strong>There is high prevalence of GM, PM, maternal anaemia, and LBW in the study area. The presence of GM and PM increased the risk of maternal anaemia, CM, and LBW. The identified risk factors should be considered to mitigate malaria among parturient women and its adverse outcomes.</p>","PeriodicalId":18317,"journal":{"name":"Malaria Journal","volume":"23 1","pages":"379"},"PeriodicalIF":2.4,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142854729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Researchers' perspectives on the integration of molecular and genomic data into malaria elimination programmes in Africa: a qualitative study.","authors":"Paulina Tindana, Daniel Enos Sekwo, Leonard Baatiema, Abdoulaye Djimde","doi":"10.1186/s12936-024-05205-5","DOIUrl":"https://doi.org/10.1186/s12936-024-05205-5","url":null,"abstract":"<p><strong>Background: </strong>Malaria remains a significant public health concern, despite global efforts to combat the disease with highest burden in Africa. Reports of emerging artemisinin partial- resistance in East Africa emphasize the importance of molecular data to guide policy decisions. Hence the need for researchers to collaborate with National control programmes to conduct genomics surveillance of malaria to inform malaria control and elimination policies. This study explored genomic researchers' views on engaging with national control programmes to aid malaria elimination efforts in Africa.</p><p><strong>Methods: </strong>This research employed an exploratory qualitative approach to investigate the views and experiences of malaria genomics researchers across 16 member countries of the Pathogen Genomic Diversity Network Africa (PDNA). In-depth interviews were conducted with each PDNA Principal Investigator, which were recorded, and transcribed verbatim. Subsequently, the data were analysed thematically with NVivo 12 qualitative data analysis software.</p><p><strong>Results: </strong>The study revealed that majority of malaria genomics researchers focused on understanding the genetic composition and adaptation of the malaria parasite, its vector, and human host. Their investigations delved into areas such as drug and insecticide resistance, parasite evolution, host interactions, human host susceptibility to malaria, diversity of vaccine candidates, and molecular surveillance of malaria. Challenges included limited funding, lack of interest and capacity among National Malaria Control Programmes (NMCP) to use research evidence effectively, and difficulties in communicating data implications to policymakers due to the absence of WHO-certified use cases. Despite these obstacles, researchers expressed a keen interest in forming partnerships with NMCPs to integrate genetic data into malaria control efforts in Africa. They also stressed the importance of enhancing researchers' ability to communicate findings to policymakers and local communities through policy briefs and innovative communication strategies.</p><p><strong>Conclusion: </strong>The study underscores the need to strengthen partnerships between genomic researchers and NMCPs to support malaria elimination in Africa. Furthermore, researchers should create practical frameworks for easy integration into WHO reporting formats to facilitate the use of molecular and genomic data in malaria control programme decision-making.</p>","PeriodicalId":18317,"journal":{"name":"Malaria Journal","volume":"23 1","pages":"385"},"PeriodicalIF":2.4,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142854819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating artesunate monotherapy and dihydroartemisinin-piperaquine as potential antimalarial options for prevaccination radical cures during future malaria vaccine field efficacy trials.","authors":"Alphonse Ouédraogo, Daouda Ouattara, San Maurice Ouattara, Amidou Diarra, Emilie S Badoum, Alimatou Hema, Amidou Z Ouédraogo, Denise Hien, Edith C Bougouma, Issa Nébié, Valéry Bocquet, Michel Vaillant, Alfred B Tiono, Sodiomon B Sirima","doi":"10.1186/s12936-024-05198-1","DOIUrl":"https://doi.org/10.1186/s12936-024-05198-1","url":null,"abstract":"<p><strong>Background: </strong>In malaria vaccine clinical trials, immune responses after vaccination may be compromised due to immunosuppression caused by concurrent Plasmodium falciparum infection. This has a direct effect on the protective efficacy of the vaccine being evaluated. Therefore, parasite clearance prior to vaccination is being considered. Drugs with good safety and efficacy profiles and a short posttreatment prophylaxis period should be used. Two antimalarial drugs, artesunate (AS) as monotherapy and dihydroartemisinin-piperaquine (DHAPQ), have been evaluated in order to identify the most suitable option for use in future trials.</p><p><strong>Methods: </strong>A cohort of children aged 1.5-12 years living in the Banfora Health District area was recruited. They were randomly assigned to receive supervised curative doses of AS monotherapy for 7 days or DHAPQ for 3 days. A polymerase chain reaction (PCR) was performed 21 days after treatment to confirm clearance of infection, and only those with a negative PCR were included in the study cohort for a 6-month longitudinal follow-up. Cohort children were actively visited fortnightly to collect blood samples for P. falciparum detection via microscopy and PCR. Passive surveillance was also conducted at the local health facility to record incident malaria episodes that occurred between two active visits.</p><p><strong>Results: </strong>A total of 513 children were treated. Among these patients, 458 (89.3%) were free of P. falciparum malaria infection on day 21: 87.3% (226/259) in the AS group vs 91.3% (232/254) in the DHAPQ group (p = 0.053). The mean time to first malaria infection by microscopy was 154.9 (2.9) days in the DHAPQ arm and 129.0 (3.9) days in the AS arm (p < 0.01). The incidence rates of clinical malaria episodes during the follow-up period were 0.507 (0.369-0.645) and 0.293 (0.190-0.397) in the AS and DHAPQ arms, respectively (p < 0.05).</p><p><strong>Conclusions: </strong>These findings suggest that although both drugs are effective in clearing P. falciparum infections, AS is likely to cause no more than minimal interference with the evaluation of vaccine efficacy endpoints and could, therefore, be considered for use.</p><p><strong>Trial registration: </strong>NCT04601714.</p>","PeriodicalId":18317,"journal":{"name":"Malaria Journal","volume":"23 1","pages":"377"},"PeriodicalIF":2.4,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142854722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Indoor residual spraying uptake and its effect on malaria morbidity in Ngoma district, Eastern province of Rwanda, 2018-2021.","authors":"Olivier Nsekuye, Samuel S Malamba, Jared Omolo, Ziad El-Khatib, Jean-Louis N Mangara, Dunia Munyakanage, Angela Umutoni, Naomi W Lucchi, Edson Rwagasore, Samuel Rwunganira, Aline Uwimana, Daniel Ntabanganyimana, Jean-Claude Niyoyita, Henri Desire Uwayo, Theoneste Ntakirutimana","doi":"10.1186/s12936-024-05194-5","DOIUrl":"https://doi.org/10.1186/s12936-024-05194-5","url":null,"abstract":"<p><strong>Background: </strong>Indoor residual spraying (IRS) has been implemented in Rwanda in districts with high malaria transmission, including Ngoma District. The first IRS campaign (IRS-1) was conducted in March 2019, ahead of the peak malaria season, followed by a second campaign (IRS-2) in August 2020, targeting 89,331 structures. This study assessed factors influencing IRS uptake and evaluated the impact of IRS interventions on malaria morbidity in Ngoma District, Eastern Province, Rwanda.</p><p><strong>Methods: </strong>A household survey employing multistage cluster sampling design was conducted in May 2021 to randomly select households. A structured questionnaire was administered to the head of household or a designated representative. Logistic regression, adjusted for the complex survey design and weighted for sampling, was used to identify factors associated with IRS uptake. Additionally, secondary data on malaria cases registered in the Rwanda Health Management Information System (RHMIS) from January 2015 to December 2022 were analyzed using interrupted time series analysis to evaluate the effect of IRS on malaria morbidity.</p><p><strong>Results: </strong>A total of 636 households participated in the survey. Households headed by self-employed individuals (aOR = 0.07; 95% CI 0.01-0.55) and unemployed individuals (aOR = 0.18; 95% CI 0.03-0.99) were less likely to take up IRS compared to those headed by farmers. Households receiving IRS information through media channels (aOR = 0.01; 95% CI 0.00-0.17) were less likely to participate compared to those informed by community health workers. From the RHMIS data, 919,843 malaria cases were identified from January 2015 to December 2022. Interrupted time series analysis revealed that the baseline number of adjusted malaria cases was approximately 16,920. The first IRS intervention in March 2019 resulted in a significant reduction of 14,380 cases (p < 0.001), while the second intervention in August 2020 led to a reduction of 2495 cases, though this was not statistically significant (p = 0.098).</p><p><strong>Conclusion: </strong>This study demonstrates the effectiveness of IRS in reducing malaria incidence in Ngoma District and highlights the role of socioeconomic factors and sources of information in influencing IRS uptake. To maximize the impact of IRS and ensure equitable benefits, targeted strategies, enhanced IRS education, and integrated malaria control approaches, including the use of bed nets, are crucial.</p>","PeriodicalId":18317,"journal":{"name":"Malaria Journal","volume":"23 1","pages":"381"},"PeriodicalIF":2.4,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142854741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Asymptomatic Plasmodium falciparum infections and determinants of carriage in a seasonal malaria chemoprevention setting in Northern Cameroon and south Senegal (Kedougou).","authors":"Innocent M Ali, Isaac A Manga, Akindeh M Nji, Valery P Tchuenkam, Peter Thelma Ngwa Neba, Dorothy F Achu, Jude D Bigoga, Babacar Faye, Cally Roper, Colin J Sutherland, Wilfred F Mbacham","doi":"10.1186/s12936-024-05150-3","DOIUrl":"https://doi.org/10.1186/s12936-024-05150-3","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Background: &lt;/strong&gt;Among the several strategies recommended for the fight against malaria, seasonal malaria chemoprevention (SMC) with sulfadoxine-pyrimethamine and amodiaquine combination (SPAQ) targets children 3 months to 5 years in Sahel regions of Africa to reduce mortality and mortality. Since SMC with SPAQ is administered to symptoms-free children for prevention of malaria, it is anticipated that a proportion of asymptomatic parasitaemic children will also be treated and may result in a drop in both the overall population prevalence of asymptomatic malaria infections, subsequent risk of symptomatic malaria infections and transmission. Age-specific carriage of asymptomatic Plasmodium spp. infections (API) was evaluated in target children and adults in Cameroon and Senegal, prior to the 2018 SMC campaign in both countries.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;A baseline household survey was carried out in August 2018 in two areas in Cameroon and one in Senegal just before the beginning of distribution of SPAQ for SMC. The survey included collection of fingerpick blood for malaria rapid diagnostic testing (RDT) and administration of a pre-tested questionnaire on demographics and malaria risk factors to participants. The age-specific prevalence of API in all study sites was analysed, first as a distribution of RDT-positives in 5-year age categories and secondly, with age as a continuous variable in the whole sample, using the Wilcoxon rank sum test. Risk factors for carriage of asymptomatic infections were examined using logistic regression analysis in STATA v.16 and Rv4.1.2.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;In total, 6098 participants were surveyed. In Cameroon, overall prevalence of API was 34.0% (32.1-36.0%) in Adamaoua, and 43.5% (41.0-45.7%) in the North. The median age of RDT positivity was higher in Senegal: 11 years (IQR 7-16) than in Cameroon-Adamaoua: 8 years (4-17) and North: 8 years (4-12) and significantly different between the three study regions. In all three study sites, asymptomatic carriage was significantly higher in the older age group (5-10 in Cameroon, and 7-14 in Senegal), compared to the younger age group, although the median age of participants was lower among RDT-negatives in the North compared to RDT-positives. Health area, gender and last infection within past year significantly confounded the relationship between age and parasite carriage in Adamaoua and Senegal but not in North Cameroon. Absence of bed net and previous infection within one month of the survey all independently predicted carriage of asymptomatic parasites in multivariate regression analysis.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusion: &lt;/strong&gt;Under five years asymptomatic Plasmodium infection in northern Cameroon prior to SMC season remained high in 2018, irrespective of history of SMC implementation in the study areas in Cameroon. Compared to Adamaoua, peak asymptomatic malaria parasite rate was observed in children 5-10 years, which is out of the SMC targe","PeriodicalId":18317,"journal":{"name":"Malaria Journal","volume":"23 1","pages":"386"},"PeriodicalIF":2.4,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142854714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microscopic prevalence and risk factors of asymptomatic malaria in Gorgora, western Dembia, Northwest Ethiopia: exploring hidden threats during minor transmission season.","authors":"Tena Cherkos, Adane Derso, Wossenseged Lemma, Aberham Abere, Teshiwal Deress, Banchamlak Tegegne, Gebeyaw Getnet Mekonnen, Abebe Birhanu, Yalewayker Tegegne","doi":"10.1186/s12936-024-05178-5","DOIUrl":"https://doi.org/10.1186/s12936-024-05178-5","url":null,"abstract":"<p><strong>Background: </strong>Malaria poses a significant public health threat globally, particularly in African regions, where asymptomatic malaria is a considerable logistic problem. Individuals with asymptomatic malaria do not seek treatment, and thus they are invisible to health facilities and represent a substantial hidden reservoir of Plasmodium species. This study aimed to determine the prevalence of asymptomatic malaria and its associated factors in Gorgora, western Dembia district, Northwest Ethiopia.</p><p><strong>Methods: </strong>A community-based cross-sectional study was conducted from May to June 2023 in the Gorgora area, Western Dembia district, Northwest Ethiopia. Data were collected using a semi-structured questionnaire. Giemsa-stained blood smear microscopy was employed for the diagnosis of Plasmodium species. The data were entered into Epi Data version 4.6 and exported to SPSS version 25 for analysis. Bivariate and multivariable binary logistic regression analyses were conducted to identify associated factors.</p><p><strong>Results: </strong>Among the 357 individuals who participated in this study, 9.2% (33/357) [95% CI 6.40-12.70: p = 0.000] were confirmed to be infected with Plasmodium species. Plasmodium falciparum and Plasmodium vivax accounted for 66.7% and 33.3%, respectively. Not using bed nets [AOR = 7.3, 95% CI 2.08-23.46, p = 0.006)], previous malaria history [AOR = 2.6, 95% CI 1.01-6.45, p = 0.041], outdoor activities at night [AOR = 8.3, 95% CI 3.21-21.30, p = 0.000], and family size [AOR = 3.3, 95% CI 1.18-9.22, p = 0.023] were significantly associated with asymptomatic malaria (p < 0.05).</p><p><strong>Conclusions: </strong>A considerable proportion of asymptomatic Plasmodium infections was found which likely act as a reservoir of transmission. This has implications for ongoing malaria control programmes that are based on the treatment of symptomatic patients and highlight the need for intervention strategies targeting asymptomatic carriers. Not using bed nets, engaging in outdoor activities at night, and having a family size of more than five increased the odds of developing asymptomatic malaria. The district health office and health extension workers should collaborate to promote the regular use of mosquito bed nets among community residents.</p>","PeriodicalId":18317,"journal":{"name":"Malaria Journal","volume":"23 1","pages":"375"},"PeriodicalIF":2.4,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142854747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatiotemporal dynamics of malaria and climate influence on its incidence in Condorcanqui Province, 2005-2022.","authors":"Milagros Saavedra-Samillán, Fátima Burgos, Flor García Huamán, Hugo O Valdivia, Dionicia Gamboa, Stella M Chenet","doi":"10.1186/s12936-024-05193-6","DOIUrl":"https://doi.org/10.1186/s12936-024-05193-6","url":null,"abstract":"<p><strong>Background: </strong>Amazonas is a region in northern Peru with the second-highest incidence of malaria. Approximately 95% of the cases are reported in the Condorcanqui province, where native communities living along the banks of Santiago River lack access to potable water, sewage, and electricity. This study aimed to analyse malaria's spatial, temporal, and climatic characteristics in Condorcanqui to guide future studies and prevention strategies.</p><p><strong>Methods: </strong>A database provided by DIRESA-Amazonas was evaluated. Database included cases from 44 health facilities serving 112 native communities. According to the malaria control programs implemented in Peru, the study was divided into three periods: 2005-2010, 2011-2016, and 2017-2022. A Spearman correlation analysis was also conducted to assess the relationship between malaria incidence and climate variables.</p><p><strong>Results: </strong>During the study periods, 10,632 cases were reported, including Plasmodium vivax (84.87%), Plasmodium falciparum (14.91%) and Plasmodium malariae (0.23%) infections. Annual incidence rates (AIRs) significantly varied across the study periods (p < 0.001). A significant reduction in malaria incidence occurred during the first period, largely attributed to PAMAFRO programme interventions. Subsequent periods, showed a gradual increase in cases, with a peak of P. vivax in 2019 and the reintroduction of P. falciparum. Males and individuals aged 0-11 years presented the greatest number of cases. Significant correlations were found between malaria incidence and the Oceanic Niño Index (ONI) at lag0 (ρ = 0.14, p = 0.037), corrected precipitation at lag1 (ρ = 0.16, p = 0.020), and minimum wind speed at lag1 (ρ = 0.15, p = 0.024).</p><p><strong>Conclusions: </strong>Malaria incidence in Condorcanqui has increased over the last 5 years, driven by climatic influences such as the ONI, precipitation, and low wind speeds. Without immediate preventive efforts, cases are expected to continue rising. Effective control strategies must tackle the social, economic, and political issues that heighten vulnerability, such as poverty and limited healthcare access. Maintaining control initiatives and tailoring them to local needs will be essential for achieving long-term reductions of malaria in Peru.</p>","PeriodicalId":18317,"journal":{"name":"Malaria Journal","volume":"23 1","pages":"380"},"PeriodicalIF":2.4,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142854842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}