Search Results (514)

Yersinia pestis is the etiological agent of plague, a severe and often fatal disease in humans when left untreated. Because of the high genetic clonality of Y. pestis, high-resolution genotyping assays are necessary to differentiate between individual strains. Here, we report on the development and validation of a robust and reproducible core-genome multilocus sequence typing (cgMLST) assay for Y. pestis comprising 3139 gene targets, enabling high-resolution typing at the strain level. The assay was validated using 222 publicly available Y. pestis genomes, including 45 recently sequenced outbreak isolates from Madagascar and 21 isolates from Mongolia. The cgMLST analysis revealed primary clustering aligned with known biovar-associated branches and sub-branches. Additional geographically structured sub-clusters illustrate its application for regional diversification analysis. Yersinia pestis strains from different geographic regions were clearly distinguished, consistent with spatial clustering. Within the analyzed dataset, closely related or epidemiologically linked strains differed by zero to three alleles, suggesting this range as an operational reference for identifying highly similar isolates. The cgMLST showed clustering patterns concordant with previously described single-nucleotide polymorphism (SNP) assays. It therefore provides a standardized high-resolution typing approach, with demonstrated applicability for outbreak investigations, source tracking, and comparative genomic surveillance of Y. pestis. Full article

Madagascar’s expanding blue economy is largely underpinned by seaweed aquaculture, particularly Kappaphycus alvarezii (Cottonii), which offers an alternative to declining small-scale fisheries and strengthens the resilience of coastal socio-ecosystems. Ensuring the sustainability of this economic activity requires effective ecological monitoring of aquaculture sites and surrounding habitats. This study examines and compares the performance of two imaging configurations—an RGB composite derived from a subset of multispectral images capturing red (650 nm), green (560 nm), and blue (450 nm) bands; and a five-band multispectral (MS) image encompassing blue, green, red, red-edge (730 nm), and near-infrared (840 nm) bands—combined with a Random Forest (RF) classification model, for benthic habitat mapping in a seaweed cultivation context. High-resolution orthomosaics (2 cm/pixel) enabled the discrimination of Kappaphycus cultivation plots from three shallow-water habitats: (i) ‘benthic macrophytes’, which comprise: seagrass meadows and benthic macroalgal; (ii) ‘sandy bottom’ and (iii) ‘green algae’. The RF classification achieved an overall accuracy of 87% (Kappa = 0.82) across ~10 hectares. Producer’s accuracy exceeded 80% for Kappaphycus cultivation, green algae, and sandy bottom for both the RGB and MS datasets, indicating strong classification performance. However, early-stage seaweed was occasionally misclassified as benthic macrophytes, likely due to its low biomass and weak spectral signature. This UAS-based approach provided a robust and cost-effective framework for monitoring off-bottom seaweed farms and associated natural habitats. This approach supports sustainable aquaculture development and integrated coastal management in Madagascar and comparable tropical reef socio-ecosystems. Full article

This study investigated whether cooked green beans, a discarded agro-industrial material, can partially replace commercial chicken feed to improve the performance of the edible cricket Gryllus madagascarensis, while accounting for the strong effects of rearing density. A two-by-two factorial experiment was conducted in which crickets were reared at low (500 individuals per box) or high density (2500 individuals per box) and fed either standard chicken feed or the same feed supplemented with cooked green beans, with twenty replicates per treatment. Survival, chicken feed consumption, biomass yield, frass production, efficiency of conversion of ingested feed, and approximate digestibility were measured over the rearing period. Survival increased from 30.0% to 32.9% at low density and from 11.7% to 13.2% at high density, while biomass yield increased from 117.2 g to 129.7 g and from 194.4 g to 231.2 g, respectively. Frass production also increased under supplementation. In contrast, individual body weight was not improved, indicating that higher biomass production resulted mainly from increased survival rather than faster growth. Rearing density remained a major determinant of performance, with low density favoring individual size and survival, and high density maximizing total biomass. Overall, partial replacement of commercial feed with cooked green beans improved survival, biomass yield, and frass production, supporting the use of plant-based wastes to enhance the sustainability of cricket farming. Full article

Kalanchoe daigremontiana, a succulent herbaceous plant in the Crassulaceae family from Madagascar, has gained global popularity as an ornamental and medicinal species. This review examines the traditional uses, phytochemical composition, biological properties, toxicological aspects, and regulatory challenges of K. daigremontiana. The traditional medicinal uses of its leaves and roots include treating burns, rheumatic disorders, hypertension, diabetes, kidney pain, diarrhea, cough, fever, gastric issues, anxiety, inflammation, and cancer. Chemical compounds identified include phenolic acids, flavonoids, tannins, alkaloids, glycosides, saponins, sterols, terpenes, and fatty acids, with phenolic compounds and bufadienolides being predominant. In vitro studies of the crude extracts, bufadienolide-rich fractions, and isolated compounds have shown antioxidant, antibacterial, antifungal, antiviral, antiparasitic, anthelmintic, anti-inflammatory, anticoagulant, anti-aging, cytotoxic, antitumoral, and antiproliferative properties. In vivo studies have demonstrated hepatoprotective, skincare, and cardiac-glycoside-like effects. While crude extracts and bufadienolide-rich fractions have shown toxic effects in 2-week-old chicks, guinea pigs, and Artemia salina, no toxicity has been reported in goats, broiler chickens, laying hens, or human erythrocytes. Although K. daigremontiana-based products are commercially available as dietary supplements with various health claims, these lack scientific validation. Despite the potential pharmaceutical applications of K. daigremontiana, further research is needed to determine its effects, dosage, mechanisms, long-term safety, and side effects, with clinical studies essential to validate its therapeutic potential. Full article

Background: Vitamin D plays an important role in overall health. This study aimed to conduct a pilot screening of serum vitamin D levels in a Malagasy cohort and to compare vitamin D status groups with selected health indicators. Methods: A cross-sectional observational pilot study was performed in two geographically distinct regions of Madagascar—a coastal area and an inland area. In total, 150 individuals underwent a single health screening, including semi-quantitative assessment of serum 25-hydroxyvitamin D, as well as evaluation of glycemic and cholesterol levels, blood pressure, anthropometric parameters, and a brief personal and lifestyle questionnaire. Results: A total of 148 participants (aged 18–88 years) were analyzed. 45.9% of participants had low serum vitamin D levels (<75 nmol/L). Lower vitamin D levels and higher total cholesterol were observed in the coastal group compared to the inland group (p < 0.05). No significant differences were found for most other examined health indicators. In multivariable analysis, age was identified as an important determinant of several outcomes. Vitamin D status did not remain an independent predictor; however, a trend toward an independent association with hypercholesterolemia was observed (p = 0.07), while the association with hyperglycemia was less pronounced (p = 0.11). Conclusions: A substantial proportion of participants exhibited low vitamin D levels despite favorable geographic conditions. The results suggest a potential relationship between vitamin D status and lipid metabolism, although this association did not reach statistical significance after adjustment. These findings provide initial insight into vitamin D status and its potential associations in this setting and may inform future research and public health monitoring. Full article

Background: Many countries in sub-Saharan Africa are at risk of inadequate calcium intake, yet no data exist for vulnerable population groups in Madagascar. We aimed to assess daily calcium intake, the major contributing food sources, and the prevalence of inadequate intake in young children, adolescents, and women of reproductive age. Methods: The 2024 National Micronutrient Survey used a two-stage probabilistic design across all 23 regions. The daily calcium intake was estimated using a food frequency questionnaire that focused on calcium-rich foods that are commonly consumed in Madagascar and the calcium concentration measured in drinking water. Results: Calcium intake was low across all population groups, averaging 200–300 mg/d in adolescents and women and below 180 mg/d in young children. The prevalence of inadequate intake exceeded 96% in every population group. While calcium intake increased with increasing household wealth in children, the opposite pattern was observed for adolescents and women, whose intake decreased with increasing wealth. The main contributors to calcium intake were cassava leaves, cassava roots, small fresh and dried fish eaten with bones, drinking water across all population groups, and breastmilk in young children. Conclusions: The calcium intake is low throughout Madagascar and across all demographic groups. Strategies to improve intake are urgently needed and should include promoting continued breastfeeding and the consumption of calcium-rich, locally available, affordable foods such as small fish eaten with bones and leafy green vegetables, alongside a consideration of wheat flour fortified with calcium. Full article

Medical drone delivery (MDD), defined as the use of uncrewed aerial vehicles to transport medical products, is an emerging technological innovation responding to persistent health supply chain challenges in rural and low-resource settings. Within sub-Saharan Africa, MDD systems have demonstrated large-scale success in improving key health outcomes, health supply chain efficiency, and reductions in medical product stockouts and wastage. However, the existing evidence base on the effectiveness of this technology is dominated by quantitative, performance-based evaluations, with limited emphasis on the community-driven mechanisms that shape such outcomes. Drawing on original qualitative research, this article presents a qualitative secondary analysis (QSA) of interview data collected as part of a larger case study on MDD in Madagascar. The QSA, guided by socio-technical systems theory, analyzes a subset of 18 interviews with 23 community-level stakeholders to understand how MDD affects healthcare services in remote regions of the country. Participants reported that MDD led to downstream healthcare improvements in vaccination coverage and malaria-related health outcomes. These improvements were enabled through four interconnected socio-technical mechanisms: (1) improved medical product availability through the mitigation of geographic and transportation barriers, (2) stabilization of vaccine and cold chain transportation, (3) building trust and healthcare-seeking behaviours through predictable service delivery, and (4) reduced physical, mental, and financial burdens experienced by healthcare workers. A final, cross-cutting theme emphasized was the criticality of MDD program continuity, with participants noting that operation disruptions or withdrawals risked reversing benefits and breaking communities’ trust in the health system. By centering lived realities, perceptions, and social processes, this article bridges the gap between predominantly quantitative evidence on MDD systems and the experiences of the communities they are intended to serve. Full article

This study develops and applies a Climate–Water–Health (CWH) Nexus Index to compare multi-dimensional risk trajectories across six African Least Developed Countries, namely, Chad, Democratic Republic of Congo, Lesotho, Madagascar, Niger, and Togo, each representing major climatic regions. Using decadal averages for 2000–2009 and 2010–2020, the study constructs three sub-indices—Climate Risk Index, Water Insecurity Index, and Health Burden Index—and then aggregates them into a composite CWH index. Indicators are harmonized via min–max normalization, and water and health measures are expressed per 100,000 population to ensure cross-country comparability under differing population sizes. The results of the study indicate substantial heterogeneity in both levels and drivers of nexus risk. The CWH risk decreased in most countries from the 2000s to the 2010s, while relative positions shifted as improvements occurred unevenly across dimensions. Sensitivity analysis with equal and dimension-focused weights confirms that core country groupings and extremes are robust to plausible weighting schemes. External consistency checks show a strong negative Pearson correlation between the standard CWH and the Human Development Index in both decades, indicating that higher human development is associated with lower Nexus risk. The proposed framework is transparent, scalable, and suitable for extension to broader African coverage and subnational mapping. Full article

Background/Objectives: Malaria remains a major cause of hospitalization in rural Madagascar, yet data on in-hospital clinical presentation, management, and patient outcomes remain limited. Methods: We conducted a three-year retrospective study (2023–2025) at a rural district hospital in Ambatoboeny, Madagascar, including patients of all ages hospitalized with malaria confirmed by rapid diagnostic testing and microscopy. Sociodemographic, clinical, laboratory, and treatment data were extracted from routine records. Length of hospital stay (LOS) was analyzed continuously and categorized as ≤2, 3–4, or ≥5 days. Seasonal admission patterns and factors associated with LOS were assessed using chi-square or Fisher’s exact tests, and associations with rainfall seasonality were explored using Spearman’s correlation. Results: Among 134 hospitalized patients, median age was 15 years (interquartile range (IQR) 7–25) and 52.2% were female. Plasmodium falciparum predominated (94.0%), while mixed-species infections were identified in 6.0% of cases; 20.1% of cases were classified as severe malaria, including 10.4% with cerebral malaria. Co-infections were frequent (52.2%), most commonly Schistosoma haematobium infection (14.2%) and typhoid fever (12.7%). Intravenous artesunate was initiated in 97.8% of patients; all received paracetamol and 94.8% received intravenous fluids. Median LOS was 2 days (IQR 2–3); 12.7% had prolonged hospitalization (≥5 days). Prolonged LOS was significantly associated with cerebral malaria, high parasitemia (≥5%), blood transfusion, and age < 15 years (all p ≤ 0.034), while co-infection and nutritional status were not. Conclusions: Hospitalized malaria in rural Madagascar presents with heterogeneous clinical phenotypes and a high burden of co-infections. Prolonged LOS is primarily driven by markers of severe disease and supportive care requirements, underscoring the need for early severity recognition and resource planning in low-resource hospitals. Full article

Lesser hedgehog tenrecs (Echinops telfairi) are small, nocturnal insectivores from Madagascar that exhibit hibernation and brief torpor bouts. While multiple studies have investigated torpor physiology, no studies have focused on torpor in tenrecs maintained under human care or their recommended husbandry. We surveyed 96 institutions (71.9% response rate) housing 172 tenrecs to assess husbandry, torpor, handling, and associated weight changes. Most institutions reported that torpor occurred annually, typically between October and April, and lasted approximately 5–6 months. Weight distributions differed significantly pre- versus post-torpor, with females and males losing 34.4 g and 20.9 g on average, respectively. Females were heavier than males before and after torpor, the first report of a sex-based weight difference in this species. Most institutions used tenrecs as ambassador animals, and approximately half continued educational programming during torpor. Tenrecs handled more frequently during torpor tended to gain more weight, likely due to increased energy expenditure and compensatory feeding. Tenrecs entered torpor regardless of daylight, temperature, or humidity, with no significant husbandry differences between torpor- and non-torpor-reporting institutions. Torpor is a critical physiological adaptation supporting energy conservation and species survival. Its expression should be supported through appropriate environmental conditions, diet, minimal disturbance, and monitoring. Full article

The 2x2 Demonstrator, a prototype for the Deep Underground Neutrino Experiment (DUNE) liquid argon (LAr) Near Detector, was exposed to the Neutrinos from the Main Injector (NuMI) neutrino beam at Fermi National Accelerator Laboratory (Fermilab). This detector is a prototype of a new modular design for a liquid argon time-projection chamber (LArTPC), comprising a two-by-two array of four modules, each further segmented into two optically isolated LArTPCs. The 2x2 Demonstrator features a number of pioneering technologies, including a low-profile resistive field shell to establish drift fields, native 3D ionization pixelated imaging, and a high-coverage dielectric light readout system. The 2.4-tonne active mass detector is flanked upstream and downstream by supplemental solid-scintillator tracking planes, repurposed from the MINERvA experiment, which track ionizing particles exiting the argon volume. The antineutrino beam data collected by the detector over a 4.5 day period in 2024 include over 30,000 neutrino interactions in the LAr active volume—the first neutrino interactions reported by a DUNE detector prototype. During its physics-quality run, the 2x2 Demonstrator operated at a nominal drift field of 500 V/cm and maintained good LAr purity, with a stable electron lifetime of approximately 1.25 ms. This paper describes the detector and supporting systems, summarizes the installation and commissioning, and presents the initial validation of collected NuMI beam and off-beam self-triggers. In addition, it highlights observed interactions in the detector volume, including candidate muon antineutrino events. Full article

The genus Psiadia (Asteraceae), widely distributed in Madagascar and the Mascarene Islands (Mauritius, La Réunion, Rodrigues), is traditionally used to treat bronchitis, asthma, colds, abdominal pain, and other inflammatory disorders. However, few studies have scientifically validated these traditional medicinal uses. To assess P. dentata as a valuable source of bioactive natural products, a combined ¹H NMR-based metabolomic, molecular networking, and phytochemical study was conducted. Multivariate analysis (PLS-DA) of crude extracts from Psiadia species collected on Reunion Island enabled rapid discrimination of active extracts from P. dentata and revealed two methoxylated flavonoids and one coumarin as metabolites correlated with its antiplasmodial and anti-inflammatory activities. Additionally, UHPLC-DAD-ESI-QTOF-MS/MS molecular networking approach enabled detailed chemical profiling of this species, allowing the annotation of 25 compounds (1–25) in this species. Subsequent phytochemical investigation of P. dentata leaves led to the isolation and identification of 25 metabolites, including nine new diterpenes (26–34), one new coumarin (35), and 15 known compounds (1–8, 11, 18, 19 and 36–39) from the diterpenoid, flavonoid, and coumarin families. The structures of the new compounds were elucidated using spectroscopic methods, including extensive 1D and 2D NMR and HRESIMS analyses. Biological evaluation of the isolated compounds showed that compounds 1, 7, 26 and 27 showed antiplasmodial activity against Plasmodium falciparum (3D7 strain, IC₅₀ = 7.25–13.46 μM). Compounds 7, 26, 27, 31 and 32 inhibited nitric oxide production (IC₅₀ = 0.87–27.71 μM), indicating potential anti-inflammatory effects. Only compound 1 displayed moderate cytotoxicity against HepG2 and HT29 cancer cell lines (IC₅₀ = 25.67 and 18.35 μM, respectively). Full article

Background: Antimicrobial resistance (AMR), particularly due to extended-spectrum beta-lactamases (ESBL), is a growing threat to public health in sub-Saharan Africa. This study investigates the prevalence, epidemiological characteristics, resistance patterns and resistance dynamic over time of ESBL-producing non-typhoidal Salmonella (NTS) bacteremia in Kisantu, Democratic Republic of Congo (DRC), from 2019 to 2022. Methods: A retrospective observational study used routine bloodstream infection data from the AMR network at Saint Luc Hospital in Kisantu. Blood cultures from suspected bacteremia cases were processed using standard microbiological techniques. Bacterial identification relied on biochemical reactions. Antibiotic susceptibility testing and ESBL-producing NTS detection were performed by disk diffusion following Clinical and Laboratory Standards Institute guidelines. Associations between ESBL production and patient characteristics (age, sex) were assessed using Pearson’s Chi-square test, and annual temporal trends in ESBL-producing NTS from 2019 to 2022 were analyzed by logistic regression using 2019 as the reference year. Results: Of the 19,430 blood cultures, 1681 NTS isolates were identified, and 1568 of these were screened for ESBL. ESBL prevalence was significantly associated with age (p = 0.007), peaking in children under 2 years, but not with sex (p = 0.570). Compared with 2019, the likelihood of isolating ESBL-producing NTS increased markedly through 2022, with adjusted probabilities rising from 58% to 87%, reflecting a strong upward temporal trend. High levels of extensively drug-resistant (94.1%) were observed. No carbapenem resistance was detected. Conclusions: ESBL-producing NTS bacteremia is rising in Kisantu, DRC, mainly affecting children under 2 years. Rising resistance to key antibiotics limits treatment options and highlights the need for strengthened AMR surveillance, optimized antibiotic use, and vaccination strategies. Full article

Background: Bacterial vaginosis and vaginal dysbiosis represent major causes of morbidity among women in sub-Saharan Africa, yet data from Madagascar remain scarce. This study aimed to assess the prevalence and determinants of vaginal bacterial infections among women in northern Madagascar and to explore how vaginal microflora composition reflects broader aspects of reproductive health. Methods: A cross-sectional study was conducted in April 2024 among 159 women (15–80 years) attending a rural second-referral clinic in Manerinerina, Ambatoboeny District. Sociodemographic and hygiene data were obtained through structured questionnaires. Vaginal pH was measured in situ, and Gram-stained smears were evaluated using the Nugent scoring system. The presence of Trichomonas vaginalis, Neisseria gonorrhoeae, and Candida spp. was assessed microscopically. Associations were analyzed using Chi-square or Fisher’s exact tests, with p < 0.05 considered significant. Results: Abnormal vaginal flora was observed in 68.6% of women, including 43.4% with BV (Nugent 7–10) and 25.2% with intermediate flora. Elevated vaginal pH correlated strongly with higher Nugent scores (p < 0.01). T. vaginalis and N. gonorrhoeae were detected in 10.7% and 9.4% of women, respectively, and both were significantly associated with dysbiosis (p = 0.02 and p = 0.04). Poor hygiene practices, vaginal douching (79.1% vs. 64.5%; p = 0.04), and unsafe water sources (p = 0.04) were major behavioral and environmental determinants. Conclusions: Vaginal dysbiosis is highly prevalent among women in northern Madagascar and closely linked to modifiable hygiene behaviors and environmental conditions. In resource-limited settings, Gram-stained microscopy and Nugent scoring remain cost-effective tools for surveillance and patient care. Culturally adapted education, improved water access, and integration of low-cost diagnostics are essential for reducing the burden of vaginal infections in rural Madagascar. Full article

In recent years, Biophytum umbraculum Welw. (Oxalidaceae) has undergone several phytochemical and pharmacological investigations. Although its major phytochemical classes have been characterized, few isolated compounds have been reported. The previously detected phytoconstituents, along with the documented antioxidant and anti-inflammatory activities, both align with a potential antiproliferative effect. This study aims to complement the existing chemotaxonomic profile of B. umbraculum through the isolation and identification of phytoconstituents and to evaluate the antiproliferative potential of its extracts. Hexane, ethyl acetate, and methanolic extracts of B. umbraculum were screened against two human adherent cell lines, breast (MCF-7) and cervical (SiSo) adenocarcinomas, by using the crystal violet staining assay. The hexane extract inhibited both MCF-7 and SiSo cell proliferation with IC₅₀ values of 8.93 ± 0.07 and 14.59 ± 0.08 µg/mL, respectively. The ethyl acetate extract showed activity against both cell lines, with IC₅₀ values of 12.60 ± 0.14 and 13.10 ± 0.04 µg/mL, respectively. However, the methanolic extract was inactive on the MCF-7 cell line and only slightly active on the SiSo cell line. Chromatographic fractionations led to the isolation of ursolic acid from the active ethyl acetate extract and rutin from the methanolic extract. A further antiproliferative evaluation is warranted to confirm the contribution of ursolic acid to the effect of the ethyl acetate extract. Additional fractionations may uncover more phytoconstituents of diverse pharmaceutical interests. Full article