Malaria Journal最新文献

{"title":"Genetic polymorphism of circumsporozoite protein of Plasmodium falciparum isolates in children in Brazzaville, Republic of Congo.","authors":"Marcel Tapsou Baina, Jean Claude Djontu, Jacque Dollon Mbama Ntabi, Abel Lissom, Armelie Gomie Kathia Eouasse, Viny Andzi Elenga, Claujens Chastel Mfoutou Mapanguy, Alain Maxime Mouanga, Francine Ntoumi","doi":"10.1186/s12936-025-05502-7","DOIUrl":"https://doi.org/10.1186/s12936-025-05502-7","url":null,"abstract":"<p><strong>Background: </strong>The first WHO-approved malaria vaccines (RTS, S/AS01, and R21/Matrix M) target part of the Plasmodium falciparum circumsporozoite protein (PfCSP), displays a degree of polymorphism that may raise concerns about vaccine efficacy. As a prelude to vaccine implementation, the study here reports investigation on Pfcsp gene polymorphisms in isolates from Congolese individuals in the Republic of Congo.</p><p><strong>Methods: </strong>Blood samples were collected from 202 children infected with P. falciparum during a cross-sectional study from March to October 2021. The full-length Pfcsp gene was amplified by nested PCR and sequenced using the Oxford Nanopore platform.</p><p><strong>Results: </strong>Overall, 30 haplotypes were identified in the N-terminal region of the protein. The A98G mutation was the most frequent (25.6%), while KLKQP was the most conserved motif. In the central repeat region, 50 haplotypes were found, with a predominance of the NANP motif, although some haplotypes contained the NVDP, NEDP and NVNP variants. C-terminal region was highly polymorphic, with 76 haplotypes identified among the 174 sequenced samples. In the C-terminal Th2R region, the major mutations identified included K317E (87.4%) and N321K (83.9%), with a nucleotide diversity of π = 0.16. In the Th3R region, the E357Q (75.9%) mutation was predominant, with a nucleotide diversity of π = 0.08. Neutrality tests revealed contrasting patterns of evolution between the Th2R and Th3R regions.</p><p><strong>Conclusion: </strong>This study provides baseline data on Pfcsp genetic diversity in a defined area of the Republic of Congo. The results highlight the degree of variation in natural parasite populations at gene loci relevant to vaccine-targeted epitopes of (PfCSP) antigen. Further research incorporating immunological data will be needed to conduct in-depth assessments of vaccine efficacy.</p>","PeriodicalId":18317,"journal":{"name":"Malaria Journal","volume":"24 1","pages":"279"},"PeriodicalIF":3.0,"publicationDate":"2025-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12395913/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144959860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing the external validity of mobile phone surveys for monitoring ITN coverage indicators: a comparison with household surveys in Tanzania.","authors":"Matt Worges, Ruth Ashton, Janna Wisniewski, Paul Hutchinson, Hannah Koenker, Tory Taylor, Hannah Metcalfe, Ester Elisaria, Charles Dismas Mwalimu, Peter Gitanya, Frank Chacky, Josh Yukich","doi":"10.1186/s12936-025-05533-0","DOIUrl":"https://doi.org/10.1186/s12936-025-05533-0","url":null,"abstract":"<p><strong>Background: </strong>Insecticide-treated net (ITN) coverage indicators allow country malaria programmes to understand the overall coverage of their ITN distribution activities and can be used to forecast the need for additional ITN procurement and to plan future distribution campaigns. As a result, more frequent data collection could better guide programme strategies, particularly for those strategies operating on an annual framework; however, the high costs and infrequency of national-scale, household surveys limit their practicality for ongoing monitoring. Due to the rapid growth trend of mobile phone ownership in low- and middle-income countries in recent years, mobile phone-based surveys (MPS) have emerged as a comparatively inexpensive alternative to large-scale household surveys.</p><p><strong>Methods: </strong>Contemporaneous to the 2017 Malaria Indicator Survey and the 2022 Demographic and Health Survey, a random digit dial and list-based MPS were conducted in Tanzania, respectively. All surveys allowed for the calculation of the same ITN coverage indicators at the regional level which permitted an assessment of the external validity of the MPS.</p><p><strong>Results: </strong>Mean measures of absolute bias, as derived from Bland-Altman analyses, for survey raked estimates of households with at least one bed net of any type and household population with access to a bed net of any type were negative for both surveys. These MPS estimates were, on average, consistently lower than corresponding estimates from the household surveys by 7-8 percentage points. Proportion of households with at least one bed net of any type for every two people was unbiased with measures of 0.02 [95% CI - 0.04, 0.08] for the initial MPS and 0.02 [95% CI - 0.03, 0.06] for the 2022 MPS, following survey raking, relative to the household surveys.</p><p><strong>Conclusions: </strong>MPS consistently underestimated household ITN access compared to contemporaneous household surveys, but the direction and magnitude of bias were stable across years. While this limits their use as a direct substitute for household surveys, MPS may still offer timely, conservative signals of declining coverage where other data are delayed or unavailable. With further validation and potential adjustment for bias, MPS could complement traditional monitoring approaches, especially in contexts where rapid data are needed to guide programme decisions.</p>","PeriodicalId":18317,"journal":{"name":"Malaria Journal","volume":"24 1","pages":"277"},"PeriodicalIF":3.0,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12392589/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144959689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Do women attending antenatal clinics who use only intermittent preventive treatment (IPTp) have higher Plasmodium falciparum prevalence compared to those who used both IPTp and slept under insecticide-treated nets?","authors":"Jesuspower Chikere Madukwe, Ekenedirichukwu Blasingame Ahaneku, Okechukwu Shedrach Onukafor, Sabastine Edokpayi, Precious Chidumga Madukwe, Ngozi Uloma Enwereji, Ellen M Santos","doi":"10.1186/s12936-025-05532-1","DOIUrl":"https://doi.org/10.1186/s12936-025-05532-1","url":null,"abstract":"<p><strong>Background: </strong>As global malaria incidence continues to increase across sub-Saharan Africa, tightening usage of existing prevention strategies is crucial for protection of vulnerable populations. Nigeria alone accounted for more than a quarter of the 247 million cases in 2021. During pregnancy, Intermittent Preventive Treatment (IPTp) and use of Insecticide-treated nets (ITNs) are recommended for malaria prevention.</p><p><strong>Methods: </strong>This study sought to determine whether the combined use of IPTp and ITNs offered better protection from Plasmodium falciparum infection compared to a single strategy alone. A cross-sectional study of 143 pregnant women was carried out among three hospitals across the southern and southeastern regions of Nigeria. IPTp and ITN usage was measured, and P. falciparum prevalence was determined by rapid diagnostic testing.</p><p><strong>Results: </strong>Plasmodium falciparum was detected in 65 (45%) of participants; prevalence was higher among those who used only Intermittent Preventive Treatment (IPTp) (61.2%) compared to those who used both IPTp and slept under ITNs (17.0%). Logistic regression analyses adjusted for gestational week, income, and education revealed that those using IPTp alone were not significantly protected from infection, while those using IPTp and ITNs had 86% reduced odds of infection. This reduction in odds of infection appears to be driven largely by ITN.</p><p><strong>Conclusions: </strong>The results affirm the vital role of ITN usage, both independently and in conjunction with IPT, in mitigating the risk of malaria during pregnancy. Efforts should focus on addressing access barriers, enhancing ITN dissemination through ANC services, and prioritizing educational campaigns highlighting the benefits of combined malaria prevention strategies.</p>","PeriodicalId":18317,"journal":{"name":"Malaria Journal","volume":"24 1","pages":"275"},"PeriodicalIF":3.0,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12392500/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144959854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Access versus utilization: determinants of insecticide-treated net non-use in Myanmar.","authors":"Kyawt Mon Win, Kyaw Lwin Show, Jetsumon Sattabongkot, Liwang Cui, Wang Nguitragool, Daniel M Parker, Pyae Linn Aung","doi":"10.1186/s12936-025-05535-y","DOIUrl":"https://doi.org/10.1186/s12936-025-05535-y","url":null,"abstract":"<p><strong>Background: </strong>Vector control has played a pivotal role in malaria control and elimination efforts, with insecticide-treated nets (ITNs) recognized as one of the most effective and widely accepted strategies. This study assessed ITN use and identified factors associated with non-use among individuals with access to ITNs in Myanmar.</p><p><strong>Methods: </strong>Data were drawn from the nationally representative 2015-2016 Myanmar Demographic and Health Survey. Access to ITNs was defined as having at least one ITN per two household members, and ITN use as having slept under an ITN the night before the survey. Descriptive statistics and multivariable logistic regression models were conducted using the \"svyset\" command in STATA to account for the two-stage stratified cluster sampling design.</p><p><strong>Results: </strong>Among 6,140 individuals with access to ITNs, approximately one-third (31.6%, 95% CI 28.3%-35.0%) reported not using them. Factors associated with higher odds of ITN non-use were age 15-34 years (adjusted odds ratio [aOR]: 1.31; 95% CI 1.07-1.61) and ≥ 50 years (aOR: 1.33; 95% CI 1.07-1.67), rural residence (aOR: 1.82; 95% CI 1.10-3.01), and belonging to the fourth wealth quintile, representing higher socioeconomic status (aOR: 1.74; 95% CI 1.06-2.85).</p><p><strong>Conclusions: </strong>Despite having access to ITNs at that time, a substantial proportion of individuals in Myanmar did not use them. These historical findings highlight behavioural and contextual barriers that existed before recent health system disruptions due to political unrest and COVID-19. Although present-day challenges differ, understanding past determinants of ITN non-use remains valuable for designing behaviour change communication (BCC) strategies, especially in regions where ITN distribution remains feasible.</p>","PeriodicalId":18317,"journal":{"name":"Malaria Journal","volume":"24 1","pages":"278"},"PeriodicalIF":3.0,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12395919/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144959758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of the diet of the mosquito Anopheles gambiae on its resistance to deltamethrin.","authors":"Khadidiatou Cissé-Niambélé, Jacob C Koella, Guibéhi Benjamin Koudou","doi":"10.1186/s12936-025-05521-4","DOIUrl":"https://doi.org/10.1186/s12936-025-05521-4","url":null,"abstract":"<p><strong>Background: </strong>While many aspects of the genetic basis of mosquito resistance to insecticides are understood, the degree to which this resistance is affected by environmental parameters such as diet remains unclear. Therefore, two experiments were performed to evaluate how the diet of Anopheles gambiae, that is its sugar and blood meals, influences its resistance to deltamethrin.</p><p><strong>Methods: </strong>The first experiment focused on sugar meals taken from different plants and on the time between the blood meal and the exposure to the insecticide. Mosquitoes had continuous access to Tevethia nerifolia, Ixora coccinea or Mandalium coromandelianum as sugar meals, and half of them received a blood meal. After 15-18 h (i.e., at a time when digestive genes are upregulated) or 60-63 h (i.e., after digestion). They were then exposed to 0.5% deltamethrin for one hour and measured the proportion of mosquitoes that were knocked down during the exposure and that died within the next 24 h. The second experiment examined how the sugar-meal (consisting of the same three plants) interacted with the age at blood feeding. Mosquitoes were blood-fed or left unfed four or 11 days after emergence and exposed to the insecticide 1 day later.</p><p><strong>Results: </strong>In the first experiment, the plant species had no effect on the rates of mortality or knock-down. If the mosquitoes were exposed earlier, blood-feds were 22.7% less likely to die and 10.0% less likely to be knocked down than unfeds, but if they were exposed later, blood-feeding increased mortality by 8.7% and knock-down by 14.0%. In the second experiment, neither the plant nor its interactions with blood meal or age affected mortality, but younger mosquitoes had lower mortality (60.7%) than older ones (66.4%), independently of their blood-meal. Similarly, the plant had no effect on knock-down rate, but the blood meal increased it by 14.5% in young mosquitoes and reduced it by 21.5% in old ones.</p><p><strong>Conclusion: </strong>These results underline the complex role of the mosquitoes' diet on their response to insecticides.</p>","PeriodicalId":18317,"journal":{"name":"Malaria Journal","volume":"24 1","pages":"276"},"PeriodicalIF":3.0,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12392489/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144959880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bionomics of Anopheles stephensi across the urban-rural landscapes of Eastern Ethiopia.","authors":"Teshome Degefa, Daibin Zhong, Ming-Chieh Lee, Hailu Merga, Ephrem Abiy, Xiaoming Wang, Guofa Zhou, Tsigereda Kifle, Delenasaw Yewhalaw, Guiyun Yan","doi":"10.1186/s12936-025-05527-y","DOIUrl":"10.1186/s12936-025-05527-y","url":null,"abstract":"<p><strong>Background: </strong>Invasion and spread of Anopheles stephensi in sub-Saharan Africa poses a threat to malaria control and elimination efforts in the continent. This study aimed to determine the distribution and bionomics of An. stephensi across the urban-rural landscapes of eastern Ethiopia.</p><p><strong>Methods: </strong>Entomological surveillance was conducted in urban, peri-urban and rural settings of Dire Dawa and Awash Sebat Kilo from June to November 2022. Anopheles immature stages were collected using standard dippers. Adult mosquitoes were collected using CDC light traps, Prokopack aspirator and BG-pro traps. Mosquitoes were identified to species using morphological identification keys and polymerase chain reaction (PCR). Enzyme-linked immunosorbent assay was used to determine mosquito blood meal sources and Plasmodium sporozoite infection. The WHO tube bioassays were used to assess susceptibility of An. stephensi to pyrethroids, carbamates and organophosphates. Knockdown resistance (kdr) and acetyl cholinesterase (ace-1) target site mutations were analysed.</p><p><strong>Results: </strong>A total of 16,135 Anopheles immature stages were collected. Anopheles stephensi comprised 95.3%, 79.0% and 47.8% of the Anopheles larvae collected from urban, peri-urban and rural settings, respectively. Anopheles stephensi was the predominant species (95.8%) in artificial habitats, followed by Anopheles arabiensis (4.0%). In natural habitats, An. arabiensis was predominant (82.7%), followed by An. stephensi (5.8%) and other species (11.5%). Among the 259 adult Anopheles mosquitoes collected, An. stephensi constituted 56.8%, An. arabiensis 42.9%, and Anopheles coustani 0.4%. The human, bovine, goat, chicken and dog blood indices of An. stephensi were 18.9%, 27.0%, 35.1%, 8.1% and 2.7%, respectively. The overall sporozoite rates were 2.0% for An. stephensi and 1.0% for An. arabiensis. Anopheles stephensi showed resistance to all tested insecticides, with a low frequency (< 0.4%) of kdr alleles and no ace-1 mutation detected.</p><p><strong>Conclusion: </strong>Anopheles stephensi breeds in both artificial and natural habitats across urban, peri-urban and rural settings in eastern Ethiopia, with a preference for urban environments. It exhibits opportunistic feeding behaviour. The predominance of An. stephensi over the native vector, An. arabiensis, along with its susceptibility to Plasmodium infection, suggests that this species may contribute to the malaria resurgence in eastern Ethiopia. These findings will support malaria control programmes in planning vector control strategies that target the diverse larval habitats of An. stephensi. Further research is needed to develop innovative vector control and surveillance tools to address the challenge of insecticide resistance in An. stephensi and to effectively monitor its behaviour.</p>","PeriodicalId":18317,"journal":{"name":"Malaria Journal","volume":"24 1","pages":"274"},"PeriodicalIF":3.0,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12375276/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144959841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Between-and within-socioeconomic groups temporal inequality in the uptake of malaria prevention strategies among pregnant women and under-five children in Ghana (2003-2022).","authors":"Denis Okova, Akim Tafadzwa Lukwa, Marian Edusei, Paidamoyo Bodzo, Christian Atta-Obeng, Plaxcedes Chiwire, Charles Hongoro","doi":"10.1186/s12936-025-05512-5","DOIUrl":"https://doi.org/10.1186/s12936-025-05512-5","url":null,"abstract":"<p><strong>Background: </strong>Malaria remains a leading cause of morbidity and mortality among pregnant women and children under five in sub-Saharan Africa. Despite over two decades of efforts including insecticide-treated net (ITN) distribution and intermittent preventive treatment in pregnancy (IPTp), universal and equitable coverage has not been achieved. In Ghana, coverage disparities persist, particularly along socioeconomic and geographic lines. This study investigates temporal trends and decomposes both within-group and between-group socioeconomic inequalities in ITN use and IPTp coverage among children and pregnant women in Ghana.</p><p><strong>Methods: </strong>This study analysed nationally representative data from the Ghana Demographic and Health Surveys (2003, 2008, 2014, and 2022), focusing on ITN use among pregnant women and children under five, and IPTp uptake. Inequality was assessed using the Erreygers normalized concentration index (ENCI) and the Theil index (GE 2). Theil indices were then decomposed to quantify within- and between-group contributions by socioeconomic status (SES) and residence (urban versus. rural).</p><p><strong>Results: </strong>ITN use among under-five children increased modestly from 58.1% (2003) to 62.9% (2022); among pregnant women, usage fluctuated but returned to 60% in 2022. IPTp coverage rose markedly from 0.85% (2003) to 60% (2022). ENCI values showed that ITN use was consistently pro-poor, becoming more concentrated among the poor over time (e.g., ENCI for pregnant women: - 0.04 in 2003 to - 0.32 in 2022). In contrast, IPTp coverage shifted to a pro-rich distribution from 2008 onwards. Theil decomposition revealed that most observed inequalities were driven by within-group disparities (e.g., within SES or residence categories), though between-group inequality increased over time particularly for IPTp. For example, in 2022, 85% of ITN inequality among pregnant women was within SES groups, while 18% was attributable to between-group differences.</p><p><strong>Conclusion: </strong>Despite overall improvements in malaria prevention uptake, substantial socioeconomic inequalities persist especially within social and geographic subgroups. Equity-focused strategies must complement national-level efforts by addressing barriers specific to underserved populations, including informal urban settlements and remote rural communities. Policymakers must prioritize targeted, locally responsive interventions to reduce both within- and between-group disparities and achieve Ghana's malaria elimination and health equity goals.</p>","PeriodicalId":18317,"journal":{"name":"Malaria Journal","volume":"24 1","pages":"273"},"PeriodicalIF":3.0,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12372236/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144959769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Insights from LLIN post-distribution monitoring surveys in the malaria transmission foci of the Dominican Republic: implications for quantification and distribution strategies.","authors":"Gilda Ventura, María Yinet Santos Félix, Natalia Tejada Bueno, Nicole Michelén Ströfer, Jose Luis Cruz Raposo, Ángel Solís, Rafael German Barrios Parra, Lucía Fernández Montoya","doi":"10.1186/s12936-025-05406-6","DOIUrl":"https://doi.org/10.1186/s12936-025-05406-6","url":null,"abstract":"<p><strong>Background: </strong>Long-lasting insecticidal nets (LLINs) have been distributed and installed in the Dominican Republic since 2008, and they remain the main vector control intervention used to pursue malaria elimination in the country. However, LLIN performance remains unclear due to a lack of monitoring over the past decade.</p><p><strong>Methods: </strong>A cross-sectional household survey was conducted to monitor LLIN coverage, access, use, physical integrity, washing and drying practices, and the time people go to bed and wake up in the two main malaria foci of the country: Azua (4-6 months post-distribution and installation) and San Juan (one year post-distribution and installation).</p><p><strong>Results: </strong>The percentage of sleeping spaces that could be covered with a LLIN given the LLINs present in the household was 64% in Azua and 63% in San Juan; with any net, coverage was 75% in Azua and 80% in San Juan. Reported LLIN retention was 88.4% in Azua and 80.9% in San Juan. The percentage of people who had access to sleeping under an LLIN was 58.8% in Azua and 65.4% in San Juan. Among people with LLIN access (people with enough LLINs to cover all sleeping spaces in their household), use was 48.8% in Azua and 75% in San Juan; and overall, LLINs use was 32.3% in Azua and 50.5% in San Juan. Most LLINs remained in serviceable physical condition (Azua: 96.4%, San Juan: 88.9%) but those with holes were not repaired. Most LLINs were washed with aggressive products (Azua: 65%, San Juan: 86%), at a frequency that suggests they will be washed more than twenty times in three years (Azua: 52%, San Juan: 73%), and dried under the sun (Azua: 75%, San Juan: 90%).</p><p><strong>Conclusion: </strong>Poor washing and drying practices are prevalent in both areas, low LLIN use was observed in Azua and some LLIN coverage gaps were measured in both foci. Urgent behavioural change strategies are needed to improve LLIN care in both foci and to increase LLIN use in Azua, alongside revisions to LLIN quantification methods to ensure full coverage of all sleeping spaces in use during installation. Heterogeneities in LLINs use across foci suggest the need for monitoring use in each distribution area to identify individual gaps and promptly address them.</p>","PeriodicalId":18317,"journal":{"name":"Malaria Journal","volume":"24 1","pages":"272"},"PeriodicalIF":3.0,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12369129/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144959802","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aspartyl protease inhibition interferes with Plasmodium falciparum asexual blood-stage and early gametocyte development.","authors":"Gamolthip Niramolyanun, Chonnipa Praikongkatham, Rachaneeporn Jenwithisuk, Wanlapa Roobsoong, Jetsumon Sattabongkot, Viriya Pankao, Niwat Kangwanrangsan","doi":"10.1186/s12936-025-05518-z","DOIUrl":"https://doi.org/10.1186/s12936-025-05518-z","url":null,"abstract":"<p><strong>Background: </strong>Plasmodium falciparum is the most influential species of malaria parasites, capable of causing severe illness and mortality, especially in pregnant women and children under the age of 5. Global distribution of disease impacted on billions of endemic people and travellers. Asexual stage and gametocyte cause harmful manifestations, impacting the patients and contributing to the spread of the disease in the community, respectively. Moreover, most recent therapeutic drugs did not affect the gametocyte. The discovery of a new drug with dual actions on both stages could elucidate a cost-effective way to combat malaria. Within a human host, the parasite possesses many activities for its survival, such as invasion, egress, haemoglobin degradation, and protein trafficking, many of which are related to aspartyl protease, revealing the potential for antimalarial drug targets.</p><p><strong>Methods: </strong>Pepstatin A, the representative of the board-spectrum aspartyl protease inhibitor, was utilized to investigate the effects of aspartyl protease inhibition on parasite development. The experiments were separately performed in vitro for different developmental stages of parasites, including the asexual blood-stage, early gametocytes, late gametocytes, and gamete. To demonstrate the effects of pepstatin A, the number of intact parasites and their stage distribution were counted under the microscope and calculated as a percentage of inhibition compared to the control. Additionally, the morphology of pepstatin A-treated parasites was observed to identify cellular alterations in the parasites.</p><p><strong>Results: </strong>Pepstatin A at 100 µM inhibited the asexual stage and early-stage gametocyte development by 47% and 73%, respectively. They exhibited morphological defects, including chromatin condensation, vacuolization and haemozoin clumping in both asexual blood-stage and early-stage gametocyte. However, it could not influence the late-stage gametocyte development and gamete formation.</p><p><strong>Conclusion: </strong>The inhibition of aspartyl protease by pepstatin A moderately affected both asexual blood-stage and early-stage gametocyte development. Morphological changes on treated parasites implied the effect of pepstatin A on haemoglobin degradation process, suggesting its potential for reducing the severity of the disease and minimizing malaria transmission. However, further research and development are required to use aspartyl protease as a drug target, focusing on identifying and modifying the drug to be more sensitive and effective.</p>","PeriodicalId":18317,"journal":{"name":"Malaria Journal","volume":"24 1","pages":"271"},"PeriodicalIF":3.0,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12369142/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144959714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of temperature and nutrition stress on Anopheles stephensi, an Indian urban malaria vector.","authors":"Chaitali Ghosh, Naveen Kumar, Soumya Mogaveerthi, Sanjay Lamba, Chethan Kumar Ramanjini, Soumya Gopal Joshi, Priyanka Chandran, Sampath Kumar, Sunita Swain","doi":"10.1186/s12936-025-05402-w","DOIUrl":"https://doi.org/10.1186/s12936-025-05402-w","url":null,"abstract":"<p><strong>Background: </strong>Changing climate and complexity in ecological landscape can potentially expand the geographic distribution of mosquitoes (Diptera: Culicidae) to adapt and transmit various vector-borne diseases, including malaria. Anopheles stephensi is a potential urban malaria vector in the Indian subcontinent. Temperature and nutrients are the important environmental stressors, which influence the life cycle and vectorial competence of mosquitoes.</p><p><strong>Methods: </strong>Three experimental setups were designed in the laboratory by exposing An. stephensi to low-temperature (LT) at 4 °C for eggs and 18 ± 1 °C for larvae to adults, high-temperature (HT) at 35.5 ± 1 °C for all life stages, and low nutrition (NT) at 33 mg/100 larvae. Baseline assays were conducted before each experiment. Stress was induced to eggs, larvae, pupae and adults for 8 consecutive generations, whereas vectorial competence and chromosomal inversion experiments were performed on adult females at the 8th generation. Parameters of life-history traits, including fecundity (number of eggs), egg hatchability (fertility), developmental time, longevity of adults, sex ratio, egg and wing morphometrics, and pupal mass were measured for fitness status. The LT, HT and NT lines were infected with in vitro cultured Plasmodium falciparum parasites to compare the vectorial competence. Ovarian polytene chromosomes of the three stressed lines were analysed to check the structural differences on the chromosomal arms for adaptation due to stress conditions. The predictive mathematical modelling using linear regression was analysed to estimate the number of generations required for the stressed lines to become normal comparable to the control lines.</p><p><strong>Results: </strong>Fecundity, egg hatchability, egg-to-adult developmental time, longevity of adults, egg and wing morphometrics, and pupal mass were decreased in HT and NT lines, whereas these parameters were increased in the LT line. The mosquitoes of HT and NT lines developed faster from egg to adult emergence (~ 7.5 and 11 days, respectively), whereas the duration was longer (~ 25 days) in the LT line. The oocyst infection rates of P. falciparum increased by 1.46 folds in HT, 1.28 folds in LT, and 1.15 folds in NT lines, respectively, compared to the control line. Paracentric inversions were observed on 2 locations on the 3L chromosomal arm of the NT line. Furthermore, the predictive linear model suggested faster adaptation of LT than HT and NT lines.</p><p><strong>Conclusion: </strong>The present transgenerational laboratory-based study on An. stephensi provides novel insights into the effects of stressors on the life cycle, egg and wing size, vectorial competence, chromosomal inversions and adaptation. These findings aid in assessing malaria incidence trends and help in developing suitable intervention measures.</p>","PeriodicalId":18317,"journal":{"name":"Malaria Journal","volume":"24 1","pages":"269"},"PeriodicalIF":3.0,"publicationDate":"2025-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12366060/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144959822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}