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Therapeutic efficacy and safety of artemether-lumefantrine combination therapy for the treatment of uncomplicated Plasmodium falciparum malaria at Teda Health Centre, Northwest Ethiopia, 2022/23.

The emergence of Plasmodium falciparum drug resistance against artemisinin-based combination therapy has threatened malaria control efforts. Since malaria control and elimination plans are dependent on these drugs, they must remain efficacious. However, resistance to these drugs was detected in low-transmission settings and is predicted to emerge in high-transmission settings, including in unspecified areas of Ethiopia. Therefore, this study aimed to assess the therapeutic efficacy and safety of artemether-lumefantrine for the treatment of uncomplicated P. falciparum malaria. A single-arm prospective observational study was conducted at Teda Health Centre, Northwest Ethiopia, by following the 2009 World Health Organization efficacy study guidelines from September 2022 to February 2023. Patients with uncomplicated falciparum malaria were conveniently selected and treated with a standard dose of artemether-lumefantrine, along with a single low dose of primaquine. Then clinical and parasitological responses and haemoglobin levels were assessed during the 28-day scheduled follow-up. Blood films were examined and asexual parasites were quantified; axillary temperature was measured; and drug adverse events were assessed throughout the follow-up. Finally, the drug efficacy (adequate clinical and parasitological response) was determined by Kaplan-Meier and per-protocol analyses. The data were analysed using the WHO Excel spreadsheet and SPSS version 25 software. The success rates of PCR uncorrected and corrected Kaplan-Meier analysis on day 28 were 95.8% (95% CI 87.5-98.6) and 97.3% (95% CI 89.4-99.3), respectively. The per-protocol PCR uncorrected and corrected adequate clinical and parasitological responses were 95.5% (95% CI 87.5-99.1) and 97% (95% CI 89.5-99.6), respectively. On day-3, 97% of study participants were free of asexual parasitaemia, and all of them were fever-free on day-2. All of the gametocyte-positive patients at baseline were found to be negative for gametocytes on day-2. Moreover, the baseline mean hemoglobin of 13.10g/dl increased slightly on day-14 to 13.27g/dl but significantly on day-28 to 13.69g/dl in a paired sample t test. All adverse events reported were mild. Artemether-lumefantrine continued to be an efficacious and safe drug for the treatment of uncomplicated Plasmodium falciparum malaria at the Teda Health Centre. unique ID# PACTR202309773069812 at https://pactr.samrc.ac.za on September 1, 2023.

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Comparison of three rapid diagnostic tests for Plasmodium falciparum diagnosis in Ghana.

Accurate diagnosis and timely treatment are crucial in combating malaria. A total of 449 samples were screened forPlasmodium falciparuminfection by expert microscopy, qPCR, and three RDTs, namely Rapigen Biocredit Malaria Ag Pf (detecting HRP2 and pLDH on separate bands), Abbott NxTek Eliminate Malaria Ag Pf (detecting HRP2), and SD Bioline Malaria Ag Pf (detecting HRP2). hrp2/3 deletion typing was done by digital PCR. 45.7% (205/449) individuals tested positive by qPCR for P. falciparum with a mean parasite density of 12.5 parasites/μL. Using qPCR as reference, the sensitivity of microscopy was 28.3% (58/205), the Biocredit RDT was 52.2% (107/205), the NxTek RDT was 49.3% (101/205), and the Bioline RDT was 39.5% (81/205). When only samples with densities > 20 parasites/μL were included (n = 89), sensitivity of 62.9% (56/89) by microscopy, 88.8% (79/89) by Biocredit, 88.8% (79/89) by NxTek, and 78.7% (70/89) by Bioline were obtained. All three RDTs demonstrated specificities > 95%. The limits of detection (95% probability that a sample tested positive) was 4393 parasites/μL (microscopy), 56 parasites/μL (Biocredit, considering either HRP2 or pLDH), 84 parasites/μL (NxTek), and 331 parasites/μL (Bioline). None of the three qPCR-confirmed P. falciparum positive samples, identified solely through the pLDH target, or eight samples negative for all RDTs but qPCR-positive at densities > 20 parasites/µL carried hrp2/3 deletions. The Biocredit and NxTek RDTs demonstrated comparable diagnostic efficacies. All three RDTs performed better than microscopy.

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Assessing the therapeutic efficacy of artemether-lumefantrine for uncomplicated malaria in Lagos, Nigeria: a comprehensive study on treatment response and resistance markers.

The burden of malaria persists in sub-Saharan Africa and the emergence of artemisinin resistance has introduced complexity to control efforts. Monitoring the efficacy of artemisinin-based treatment for malaria is crucial to address this challenge. This study assessed treatment efficacy of artemether-lumefantrine (AL) and genetic diversity of Plasmodium falciparum isolates in a Nigerian population. Participants presenting with clinical symptoms of uncomplicated malaria at a health centre in Lagos, Nigeria, were screened for P. falciparum. Enrolled participants were treated with AL and monitored through scheduled check-up visits, clinical and laboratory examinations for 28days. Parasite clearance and genetic diversity were assessed through polymerase chain reaction (PCR) analysis of merozoite surface proteins (msp1 and msp2). The prevalence of drug resistance mutations was assessed by P. falciparum multidrug resistance gene 1 (mdr1) genotyping followed by P. falciparum ubiquitin-specific protease 1 (ubp1) gene sequencing. The PCR-uncorrected treatment outcome revealed 94.4% adequate clinical and parasitological response (ACPR) and 5.6% late parasitological failure (LPF) rates. After PCR correction, no suspected LPF case was detected and ACPR 67/67 (100%) was achieved in all the individuals. Moreover, a high prevalence of wild-type alleles for mdr1 N86Y (93.7%), and mdr1 D1246Y (87.5%) was observed. Genetic diversity analysis revealed predominant K1 allelic family for msp1 (90.2%) and FC27 for msp2 (64.4%). Estimated multiplicity of infection (MOI) was 1.7, with the highest MOI observed in the 5-15years age group. ubp1 sequence analysis identified one nonsynonymous E1528D polymorphism at a low frequency (1.6%). The study demonstrated sustained efficacy of AL for treating uncomplicated P. falciparum malaria. Genetic diversity analysis revealed various allelic types, suggesting occurrences of polyclonal infections. Nonetheless, the detection of a significant ubp1 polymorphism could have future implications for the epidemiology of anti-malarial drug resistance in the population.

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Community participatory mapping of malaria mosquito breeding sites in Mozambique.

The community involvement and the people's knowledge allow detailed information about the distribution, location, and identification of mosquito breeding-sites. Information which is fundamental for their efficient management and elimination. Since participatory mapping has proven to be an effective tool to identify health determinants, the study aimed to apply the methodology to identify and map potential mosquito breeding-sites in Tambai, Nhamatanda, Mozambique. A study was conducted using an open-question guide. Discussions were held with 94 participants within ten focus groups, selected in collaboration with local community leaders. A thematic content analysis was performed. Descriptive statistics were used to characterize sociodemographic data. Geographic Positioning System (GPS) was used to compare and map potential breeding-sites. Children under 5years of age who tested positive for malaria, were georeferenced to the maps. Participants were aware of causes and transmission of malaria, no major differences between groups were observed regarding knowledge and identification of principal potential breeding sites. Gender and age determined specific information, number, and diversity of identified potential breeding sites. A total of 125 potential breeding-sites (36 permanent and 89 temporary) were mapped. Several potential mosquito breeding-sites were identified, located throughout the community, often near house conglomerates and malaria cases. Community participatory mapping could be used to identify potential mosquito breeding-sites by the national malaria control programmes to establish an efficient larval surveillance system, while improving community engagement and control strategies. ClinicalTrials.gov ID: NCT04419766.

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Evaluating trends in damage to attractive targeted sugar baits (ATSBs) deployed during the second year of a two-year Phase III trial in Western Zambia.

Attractive Targeted Sugar Baits (ATSBs) are a proposed new vector control tool for malaria that contain sugar and an ingestion toxicant, and are designed to attract and kill sugar-feeding mosquitoes. During a two-arm cluster randomized Phase III trial conducted in Zambia to test the efficacy of ATSB stations on malaria incidence, ATSB stations deployed on eligible household structures within intervention clusters were routinely monitored to ensure their good physical condition and high coverage. This study investigates trends in prevalence and rate of damage to ATSB stations during year 2 of the two-year trial. The analysis was conducted using monitoring data collected in year 2, which included types of damage observed, location, and date of removal and/or replacement of ATSB stations. The study evaluated temporal trends in the prevalence of overall damage and different damage types among 68,299 ATSB stations deployed. A profile of all ATSB stations installed on each structure was constructed, and spatial analyses conducted on overall damage and different damage types observed on 18,890 structures. Mixed effects regression analyses were conducted to investigate drivers of damage to ATSB stations on these structures. Prevalence of overall damage and different damage types was temporally and spatially heterogeneous. Among damaged ATSB stations observed during monitoring, tears and mold had the highest prevalences on average, with tears maintaining above 50.0% prevalence through most of the monitoring period, while mold prevalence increased steadily during the first few months, peaking in February. Overall, 45.6% of structures had at least one damaged ATSB station, however this varied spatially across the trial site. Both structure characteristics and environmental factors significantly impacted the odds and rate of damage to ATSB stations on structures, including: ATSB stations' level of protection from rainfall and sunshine; roof and wall material of the structure; night-time temperature; rainfall; enhanced vegetation index, and land cover. Damage to ATSB stations in this setting was common and was temporally and spatially heterogeneous. This has implications on operational feasibility, sustainability, and cost of future deployment. Further research is required to understand the mechanisms of damage, and to minimize prevalence and rate of damage to ATSB stations.

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Genomic variation in Plasmodium relictum (lineage SGS1) and its implications for avian malaria infection outcomes: insights from experimental infections and genome-wide analysis.

The globally transmitted avian malaria parasite Plasmodium relictum (lineage SGS1) has been found to infect hundreds of different bird species with differences in infection outcomes ranging from more or less latent to potentially mortal. However, to date basic knowledge about the links between genetic differentiation and variation in infection outcome within this single malaria parasite species is lacking. In this study, two different isolates of SGS1, obtained in the wild from two different host species, were used to investigate differences in their development in the blood and virulence in the experimentally infected canaries. Simultaneously, 258kb of the parasite genome was screened for genetic differences using parasite mRNA and compared between experimental groups. The two isolates showed differences in development and caused mortality as well as effects on the blood parameters of their hosts. Although previous studies using single genes have shown very limited within lineage genetic diversity in the European population of SGS1, 226 SNPs were found across 322 genes, which separated the two experimental groups with a total of 23 SNPs that were fixed in either of the experimental groups. Moreover, genetic variation was found within each experimental group, hinting that each avian malaria infection harbours standing genetic variation that might be selected during each individual infection episode. These results highlight extensive genetic variation within the SGS1 population that is transferred into individual infections, thus adding to the complexity of the infection dynamics seen in these host-parasite interactions. Simultaneously, the results open up the possibility of understanding how genetic variation within the parasite populations is linked to the commonly observed differences in infection outcomes, both in experimental settings and in the wild.

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Novel Plasmodium falciparum histidine-rich protein 2/3 repeat type in Ethiopian malaria infection: does this affect performance of HRP2-based malaria RDT?

Rapid diagnostic tests (RDTs) provide quick, easy, and convenient early diagnosis of malaria ensuring better case management particularly in resource-constrained settings. Nevertheless, the efficiency of HRP2-based RDT can be compromised by Plasmodium falciparum histidine-rich protein 2/3 gene deletion and genetic diversity. This study explored the genetic diversity of PfHRP2/3 in uncomplicated malaria cases from Ethiopia. A cross-sectional study was conducted from June 2022 to March 2023 at Metehara, Zenzelema and Kolla Shele health centres, Ethiopia. Finger-prick blood samples were collected for RDT testing and microscopic examination. For molecular analysis, parasite genomic DNA was extracted from venous blood. Plasmodium falciparum was confirmed using VarATS real time PCR. Additionally, PfHRP2/3 was amplified, and DNA amplicons were sequenced using Oxford Nanopore technology. PfHRP2/3 sequences revealed small variations in the frequency and number of amino acid repeat types per isolate across the three health centres. Twelve and eight types of amino acid repeats were identified for PfHRP2 and PfHRP3, respectively, which had been previously characterized. Repeat type 1, 4 and 7 were present in both PfHRP2 and PfHRP3 amino acid sequences. Type 2 and 7 repeats were commonly dispersed in PfHRP2, while repeat types 16 and 17 were found only in PfHRP3. A novel 17V repeat type variant, which has never been reported in Ethiopia, was identified in six PfHRP3 amino acid sequences. The majority of the isolates, as determined by the Baker's logistic regression model, belonged to group C, of which 86% of them were sensitive to PfHRP2-based RDT. Likewise, PfHRP2-based RDT detected 100% of the isolates in group A (product of type 2 × type 7 repeats ≥ 100) and 85.7% in group B (product of types 2 × type 7 repeats 50-99) at a parasitaemia level > 250 parasite/μl. This study highlights the significant diversity observed in PfHRP2 and PfHRP3 among clinical isolates of Plasmodium falciparum in Ethiopia. This emphasizes the necessity for monitoring of PfHRP2- based RDT efficacy and their repeat type distribution using a large sample size and isolates from various ecological settings.

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Application of multivariate binary logistic regression grouped outlier statistics and geospatial logistic model to identify villages having unusual health-seeking habits for childhood malaria in Malawi.

Early diagnosis and prompt treatment of malaria in young children are crucial for preventing the serious stages of the disease. If delayed treatment-seeking habits are observed in certain areas, targeted campaigns and interventions can be implemented to improve the situation. This study applied multivariate binary logistic regression model diagnostics and geospatial logistic model to identify traditional authorities in Malawi where caregivers have unusual health-seeking behaviour for childhood malaria. The data from the 2021 Malawi Malaria Indicator Survey were analysed using R software version 4.3.0 for regressions and STATA version 17 for data cleaning. Both models showed significant variability in treatment-seeking habits of caregivers between villages. The mixed-effects logit model residual identified Vuso Jere, Kampingo Sibande, Ngabu, and Dzoole as outliers in the model. Despite characteristics that promote late reporting of malaria at clinics, most mothers in these traditional authorities sought treatment within twenty-four hours of the onset of malaria symptoms in their children. On the other hand, the geospatial logit model showed that late seeking of malaria treatment was prevalent in most areas of the country, except a few traditional authorities such as Mwakaboko, Mwenemisuku, Mwabulambya, Mmbelwa, Mwadzama, Zulu, Amidu, Kasisi, and Mabuka. These findings suggest that using a combination of multivariate regression model residuals and geospatial statistics can help in identifying communities with distinct treatment-seeking patterns for childhood malaria within a population. Health policymakers could benefit from consulting traditional authorities who demonstrated early reporting for care in this study. This could help in understanding the best practices followed by mothers in those areas which can be replicated in regions where seeking care is delayed.

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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.

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The effects of modern housing on malaria transmission in different endemic zones: a systematic review and meta-analysis

BackgroundModern housing has been shown to reduce the risk of malaria infections compared to traditional houses; however, it is unclear if the effects differ in different malaria transmission settings. This study evaluated the effects of modern housing on malaria among different endemic areas.MethodsElectronic databases, clinical trial registries and grey literature were searched for randomized controlled trials, cohort studies, case–control studies, and cross-sectional surveys on housing done between 1987 and 2022. Forest plots were done, and the quality of evidence was assessed using the Grading of Recommendations, Assessments, Development and Evaluation Framework.ResultsTwenty-one studies were included; thirteen were cross-sectional, four were case–control and four were cohort studies. Cohort studies showed an adjusted risk ratio of 0.68 (95% CI 0.48–0.96), and cross-sectional studies indicated an adjusted odds ratio (aOR) of 0.79 (95%CI 0.75–0.83). By endemic transmission regions, the adjusted odds ratio in the high endemic settings was 0.80 (95%CI 0.76–085); in the moderate transmission regions, aOR = 0.76 (95%CI 0.67–0.85) and in the low transmission settings, aOR = 0.67 (95%CI 0.48–0.85).ConclusionsThe evidence from observational studies suggests that there are no differences in the protective effects of modern houses compared to traditional houses on malaria by endemicity level. This implies that good quality modern housing protects against malaria regardless of the malaria transmission settings.

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