Search Results (2,571)

New insecticides for indoor residual spraying (IRS) are being developed to manage resistance. Chlorfenapyr (Sylando^® 240SC), a pro-insecticide, is metabolized by active mosquitoes into the toxic metabolite tralopyril. This mode of action requires adapted “free flying” bioassays (because chlorfenapyr is converted to its toxic metabolite tralopyril when mosquitoes are metabolically active). A miniature-experimental hut (MEH) assay was developed within the Ifakara Ambient Chamber Test (I-ACT) with a rabbit as a host to measure residual efficacy under controlled conditions. Sylando^® 240SC was compared with SumiShield^® 50WG (clothianidin) for 12-month residual efficacy against malaria and arbovirus vectors. Residual activity was assessed on mud, wood and concrete with two huts per substrate treated with Sylando^® 240SC, one with SumiShield^® 50WG, and one with untreated control. Five replicates of 20 mosquitoes per strain (malaria vectors: pyrethroid-susceptible Anopheles gambiae and -resistant An. arabiensis and An. funestus; culicines Aedes aegypti and Culex quinquefasciatus) were exposed overnight at one-week post spraying and monthly thereafter. Multivariable mixed-effect logistic regression with binomial errors and log link function assessed non-inferiority with a 7% margin on mosquito mortality as the primary outcome for malaria vectors. Both products induced delayed mortality, with higher effects on malaria vectors than culicines. Across all substrates and malaria species combined over the full 12 months of observation, Sylando^® 240SC was non-inferior to SumiShield^® 50WG on mortality measured at 72 h (76% vs. 67%, OR = 0.86, 95% CI: 0.77–0.97) and 168 h (89% vs. 82%, OR = 0.74, 95% CI: 0.63–0.87). Sylando^® 240SC performed comparably to SumiShield^® 50WG, supporting its use as an IRS additional option. The new I-ACT mini-experimental-hut assay provides a practical tool for evaluating pro-insecticides. The importance of free-flight evaluation methods for pro-insecticides is discussed. Full article

Background: At the end of each year, stakeholders of the Essential Immunization Programme (EPI) in the DR Congo meet to review progress made and lessons learned from the implementation of the Annual Operational Plan (AOP) and to set priorities for the following year. This paper presents a conference report that summarizes the main outcomes of the 2025 annual review meeting, which took place from 15 to 20 December 2025, and attracted 76 participants. Conference takeaways: While the 2024 WUENIC data show that the DR Congo is off-track for the 2030 Immunization agenda targets for all antigens, the administrative coverages were reported as optimal in 2025. EPI activities are planned based on administrative coverages, likely overestimated. In 2025, 47% of health zones in North-Kivu, South-Kivu and Ituri (49 out of 104) were fully or partially controlled by armed groups, leading to partial disruptions of immunization service delivery. In 2025, the DR Congo successfully launched the measles–rubella vaccine introduction preceded by a catch-up vaccination campaign in children aged from 6 months to 14 years old and continued to roll out malaria vaccines using a phased approach. Conclusions: Learning from the implementation of the 2025 AOP, the EPI stakeholders adopted a set of priority actions for the immunization programme in 2026. Full article

Background/Objectives: Next to malaria, respiratory viruses, particularly respiratory syncytial virus (RSV), are responsible for the hospitalization and death of thousands of young children each year in sub-Saharan Africa. During peak seasons, conducting separate tests is time-consuming and distressing. This underscores the need for efficient, rapid multiplexed diagnostic tools. This study aimed to evaluate the clinical performance of a lateral flow assay (LFA) based antigen combo rapid diagnostic test (ML Ag Combo RDT, manufactured by MobiLab) that detects RSV, influenza viruses A and B (Flu A/B), and SARS-CoV-2. Methods: The Allplex panel 1 rRT-qPCR assay was used as a reference assay to evaluate the clinical performance of the LFA Ag Combo RDT in pediatric hospital settings. It was performed using 470 nasopharyngeal swab (NPS) specimens from hospitalized children under two years of age with respiratory symptoms. Results: Based on the comparative analysis of the testing results for 470 NPS, the ML Ag Combo RDT demonstrated high sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 90.06%, 98.38%, 93.67, and 97.39% for RSV, and 30%, 100%, 100%, and 95.43 for Flu A/B, respectively. Agreement with the Allplex panle1 1 rRT-qPCR was strong (κ = 0.90 for RSV) and moderate (κ = 0.45 for Flu A/B), with overall accuracies of 96.63% for RSV and 95.5 for Flu A/B. This was further supported by ROC analysis for aggregated data (RSV and, Flu A/B) with an AUC value of 0.925. As expected, in samples with high viral loads (Ct < 20), the Ag Combo RDT achieved 100% sensitivity for RSV and Flu A/B. Sensitivity declined slightly at lower viral loads (Ct > 35). Conclusions: The ML Ag Combo RDT demonstrates high specificity and diagnostic accuracy for the detection of RSV and Flu A/B in pediatric hospital settings where timely diagnosis is critical. Full article

Background: Cholangiocarcinoma (CCA) is a highly heterogeneous malignancy in which numerous biomarker candidates have been reported, yet few progress to clinical use. Beyond biological complexity, this low translational yield reflects the lack of systematic criteria for prioritizing biomarkers during the discovery stage. In particular, tumor-derived signals identified in tissue often fail to persist in clinically accessible biofluids, as cross-compartment signal behavior is rarely evaluated explicitly. Methods: We developed an extracellular vesicle (EV)-guided, multi-compartment proof-of-concept framework to assess biomarker robustness and translatability early in discovery. EV proteomes from three biologically distinct CCA cell lines and a normal cholangiocyte were analyzed using multivariate and machine-learning-assisted approaches to identify conserved EV-associated features. These were integrated with public transcriptomic, epigenetic, copy-number, promoter usage, and miRNA regulatory data. Tissue relevance was assessed using TCGA/GTEx RNA-seq datasets, and exploratory signal behavior was examined in pooled serum- and urine-derived EVs from CCA patients and controls. Results: EV proteomics revealed marked molecular heterogeneity across CCA models but identified a small subset of conserved EV-associated proteins. SERPINF2 was used as a representative example, showing consistently reduced EV-associated abundance across all CCA models with coordinated regulation across multiple molecular layers. SERPINF2 expression was independent of patient sex and tumor stage and clearly distinguished tumor from normal bile duct tissue. Exploratory biofluid analyses demonstrated compartment-dependent signal behavior, with SERPINF2 depletion detectable in urine-derived EVs but not in serum-derived EVs. Conclusions: Rather than validating a single biomarker, this study presents an EV-guided, multi-compartment framework for prioritizing biomarker candidates at the discovery stage. By explicitly accounting for tumor heterogeneity and compartment-specific signal preservation, this proof-of-concept approach provides a practical decision-support strategy for identifying biomarkers with greater translational potential in heterogeneous cancers such as CCA. Full article

This study demonstrates the feasibility of using a T7 phage display platform to deliver a library of tick antigens as a vaccine to disrupt tick feeding in cattle. Cattle were vaccinated at three-week intervals via intradermal and intramuscular routes with a cocktail of male and female Amblyomma americanum T7 phage display cDNA libraries, with and without adjuvant. ELISA and Western blot analyses confirmed that vaccinated cattle mounted immune responses directed against phage-displayed tick proteins rather than the T7 phage backbone. Vaccine-induced antibodies recognized both native tick salivary gland proteins and selected recombinant salivary proteins, indicating effective antigen presentation and biologically relevant immunity with binding to native tick saliva proteins. The adjuvanted formulation elicited significantly stronger immune responses than phage-only immunization. Immunized cattle exhibited robust immune memory, evidenced by a pronounced anamnestic response following tick infestation. This immunity translated into measurable anti-tick effects, including reduced tick feeding efficiency and blood ingestion. Tick reproductive success was severely compromised, with larval hatching declining from 54% in ticks fed on control cattle to 4% in ticks fed on immunized cattle. This study establishes a practical and scalable T7 phage-displayed whole-tick antigen platform capable of inducing durable anti-tick immunity in cattle. Full article

The identification of species complexes in freshwater snails remains challenging due to limited diagnostic morphological characters and incomplete taxonomic knowledge in many taxa. Within the family Bithyniidae, species have traditionally been classified using shell morphology and genital anatomy to distinguish intraspecific variation from interspecific differences. However, extensive morphological plasticity has hindered reliable species delimitation, and the presence of cryptic diversity further complicates taxonomy. Recent DNA barcoding studies of Hydrobioides have provided evidence of such cryptic diversity, highlighting the need for taxonomic reassessment within the genus. In the present study, we examined morphological variation in Hydrobioides nassa from Thailand in conjunction with mitochondrial DNA sequence data. Molecular phylogenetic analyses based on cytochrome c oxidase subunit I (cox1) sequences revealed three well-supported genetic lineages within H. nassa, accompanied by high levels of pairwise genetic divergence. Morphological comparisons of shell, operculum, and radular characters further supported differentiation among these lineages, although some characters showed overlap. While Hydrobioides has previously been regarded as comprising a single morphologically defined species, our results demonstrate that H. nassa represents a complex of genetically distinct lineages with subtle but consistent morphological differences. This study highlights the importance of integrating molecular approaches with traditional morphological analyses to improve taxonomic resolution and to better understand biodiversity within freshwater snail groups exhibiting cryptic diversity. Full article

Standard numerical methods such as Runge–Kutta and Euler methods have been widely used to approximate solutions to nonlinear systems. These methods converge to the solution only for small step sizes; for larger time steps, they generally generate spurious or chaotic solutions. In this paper, we consider a malaria propagation model with control for which we construct a second-order nonstandard finite difference scheme that preserves the important mathematical properties of the continuous model, which are positivity, boundedness, and stability of solutions irrespective of the step size. Moreover, we show that the equilibrium points of the discrete model are the same as those of the continuous model. By applying the double mesh principle, we provide evidence that the second-order NSFD scheme approximates the true solution with small errors. Theoretical assertions and numerical results show the advantages of the developed second-order nonstandard finite difference method. Full article

Malaria is a major global health concern caused by Plasmodium parasites, among which Plasmodium falciparum is responsible for the most severe and fatal cases. The emergence of drug resistance to existing antimalarial therapies necessitates the discovery of novel molecular targets and chemically distinct inhibitors. Current study employed an integrated in silico drug discovery pipeline combining high-throughput structure-based virtual screening of 1549 deep-sea marine microbial metabolites with MM-GBSA binding free-energy estimation, QikProp-based ADME/Tox profiling, and 100 ns molecular dynamics (MD) simulations to link rapid screening with dynamic verification of binding stability. Molecular docking against Plasmodium falciparum dihydroorotate dehydrogenase (PfDHODH; PDB ID: 7KZ4) yielded five top-ranked compounds with Glide scores ranging from −12.02 to −10.61 kcal·mol⁻¹, which is higher than the Primaquine (−6.920 kcal·mol⁻¹; a clinically approved antimalarial reference compound). MM-GBSA analysis further refined hit selection, producing binding free energies (ΔG_bind) between −63.28 and −31.37 kcal·mol⁻¹. The selected lead compounds included (±)-puniceusine P, aspergilol F, tersaphilone C, 4-carbglyceryl-3,3′-dihydroxy-5,5′-dimethyldiphenyl ether, and 15-O-methyl ML-236A. The top hits were subjected to 100 ns MD simulations in Desmond, demonstrating stable protein–ligand complexes, particularly for (±)-puniceusine P and 15-O-methyl ML-236A (protein backbone root mean square deviation (RMSD; ~0.8–1.0 Å). ADME profiling indicated acceptable predicted physicochemical and pharmacokinetic properties. Overall, these in silico findings highlight deep-sea marine microbial metabolites as promising PfDHODH inhibitor candidates requiring experimental validation. Full article

Malaria remains a major global health challenge, driven in part by widespread antimalarial drug resistance in Plasmodium parasites. Artemisinin-based combination therapies (ACTs) are currently the first-line treatment; however, resistance has also emerged. Artemisinin damages parasite proteins, promoting their ubiquitination and subsequent proteasomal degradation. Because inhibitors of the Plasmodium 26S proteasome synergize with artemisinin, the proteasome has emerged as a promising drug target, yet tools to monitor its function in live parasites remain limited. Here, we generated a P. falciparum line expressing green fluorescent protein fused to a destabilization domain (GFP-DD) to assess proteasome activity and combined it with MitoTracker^TM staining. In the absence of the stabilizing ligand Shield-1, the GFP-DD reporter is rapidly degraded by the proteasome. Using fluorescence microscopy and flow cytometry, we show that GFP-DD fluorescence provides a quantitative, inverse readout of proteasomal activity, increasing upon ligand-mediated stabilization or pharmacological inhibition with MG132. Shield-1 titration identified an optimal stabilization range, and MG132 induced a dose-dependent fluorescence increase. This work establishes a practical live-cell platform to probe ubiquitin–proteasome system function, with potential applications in future phenotypic screening and antimalarial resistance studies. Full article

Human African Trypanosomiasis (HAT) and Malaria are serious infectious diseases endemic in tropical regions, caused by protozoan parasites, and necessitating an urgent development of new antiprotozoal drugs. As part of our ongoing search for new antiprotozoal steroidal alkaloids from plants, we investigated the methanolic stem bark extract of Holarrhena pubescens (Apocynaceae). H. pubescens is a tropical tree that some Kenyan coastal communities have long used to treat various ailments, including fever and stomach pain. The crude extract, alkaloid fraction, and 16 subfractions acquired through centrifugal partition chromatography (CPC) displayed promising in vitro antiprotozoal activity against Trypanosoma brucei rhodesiense (Tbr) and Plasmodium falciparum (Pf). Partial least squares (PLS) regression modeling of UHPLC/+ESI QqTOF-MS data and the antiprotozoal activity data of the crude extract and its fractions was performed to predict compounds that may be responsible for the observed antiplasmodial activity. Chromatographic separation of the alkaloid fraction afforded one new steroidal alkaloid (5), along with 18 known compounds (1, 2, 4, 6–20), and one artifact (3) that was presumably formed during the acid–base extraction process. The structural characterization of the isolated compounds was accomplished using UHPLC/+ESI-QqTOF-MS/MS and NMR spectroscopy. The isolated compounds were tested for their in vitro antiprotozoal properties against the two aforementioned pathogens, as well as for their cytotoxicity against mammalian cells (L6 cell line). Compounds 2 and 16 (IC₅₀ = 0.2 μmol/L) demonstrated the highest antitrypanosomal activity, with compound 2 showing the highest selectivity (SI = 127). The new compound 5 exhibited the strongest antiplasmodial activity and selectivity against Pf (IC₅₀ = 0.7 μmol/L, SI = 43). Our findings provide further promising antiprotozoal leads for HAT and Malaria. Full article

Malaria in pregnancy remains a major driver of poor maternal and neonatal health outcomes in sub-Saharan Africa. For decades, intermittent preventive treatment in pregnancy (IPTp), with sulphadoxine-pyrimethamine (SP), has mitigated malaria-associated health risks, but concerns have been raised regarding accumulated Plasmodium falciparum dihydrofolate reductase (dhfr) and dihydropteroate synthase (dhps) mutations on the efficacy of SP. Western Kenya, including Busia County, is a high malaria transmission setting where molecular surveillance of dhfr and dhps mutations remains limited. This study assessed the prevalence and haplotype structure of dhfr and dhps mutations in P. falciparum isolates from Busia County, Kenya. A total of 66 samples of P. falciparum isolates collected from patients attending Matayos Sub-County Hospital between November 2024 and January 2025 were analysed. PCR amplification and Sanger sequencing targeted dhfr codons C50R, N51I, C59R, S108N/T, I164L, and dhps codons I431V, S436A/F, A437G, K540E, A581G, and A613S/T to determine mutation frequencies, haplotypes, and combined dhps and dhfr haplotype profiles. High frequencies of dhfr and dhps mutations were observed across the parasite isolates. The most common dhfr substitutions included N51I (85.2%) and C59R (75.4%), while S108N (32.8%) and S108T (19.7%) were detected at lower frequencies. Dhfr haplotypes identified included N51I + C59R, N51I + C59R + S108N, and a N51I + C59R + S108T + I164L variant. The I164L mutation was detected at a frequency of 18.0% and was observed exclusively on a non-canonical S108T background (19.7%). Dhps haplotypes were dominated by A437G (92.3%), K540E (40%) alone, and the A437G + K540E double mutant. Combined dhfr and dhps haplotype analyses revealed circulation of classical dhfr triple-mutant (N51I + C59R + S108N) backgrounds with dhps A437G. Quintuple haplotypes (dhfr N51I + C59R + S108T + I164L with dhps A437G) and rare complex haplotypes incorporating both I164L and K540E or I164L and S436F were also detected. These findings indicate the persistence and circulation of both canonical and non-canonical dhfr and dhps haplotypes in P. falciparum isolates from Busia County. This study highlights the need for continuous molecular and phenotypic surveillance to clarify the functional and epidemiological significance of parasites carrying S108T and I164L mutations, and to inform IPT policy. Full article

Melioidosis is increasingly recognised in tropical and subtropical regions worldwide as a serious and potentially fatal bacterial infection affecting humans and animals, acquired from the environment. Until now, human cases of melioidosis had not been reported in Southern Africa. Over a four-year period, we identified three human and two animal cases of melioidosis in South Africa and Namibia. Burkholderia pseudomallei isolates were investigated by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) and whole-genome sequencing (WGS). Phylogenetic analysis demonstrated substantial diversity, suggesting long-term cryptic persistence of the bacterium in the Southern African region. Limited awareness of the disease and inadequate diagnostic capacity likely contribute to its apparent rarity in the region. These findings underscore the urgent need for increased surveillance, improved diagnostics, and greater awareness of melioidosis in Southern Africa to better understand its true epidemiological burden and prevent future cases. Full article

The persistent emergence of infectious diseases has underscored the critical demand for next-generation vaccine technologies that are safe, effective, and scalable. This review explores virus biomimetic delivery systems, focusing on virus-like particles (VLPs) and virosomes as promising platforms for vaccine and therapeutic development. VLPs are self-assembled nanostructures composed of viral structural proteins that mimic native virions without carrying genetic material, while virosomes are reconstituted viral envelopes that retain functional glycoproteins but lack a nucleocapsid. Both systems provide strong immunogenicity and safety by mimicking viral architecture while eliminating the risk of replication. The paper examines various expression platforms for VLP production, including bacterial, yeast, insect, mammalian, and plant-based systems, highlighting their respective advantages, challenges, and optimization strategies. Mechanistic insights into antigen presentation, immune activation, and cellular uptake pathways are discussed to explain their superior performance in eliciting humoral and cellular immune responses. Furthermore, current applications of VLPs and virosomes in vaccines against major pathogens such as SARS-CoV-2, influenza, Newcastle disease virus, malaria, hepatitis, and respiratory syncytial virus are reviewed, demonstrating their versatility and clinical potential. By integrating molecular engineering, nanotechnology, and biofabrication strategies, virus biomimetic systems represent a transformative frontier in vaccinology, immunotherapy, and targeted drug delivery. Full article

Background: Albendazole, mebendazole, and ivermectin are effective against adult Trichinella spiralis but show limited efficacy against encapsulated muscle stage larvae. This limitation highlights the need for improved experimental approaches to evaluate anthelmintic activity at this stage and to identify alternative therapeutic candidates. Methods: Seven antiparasitic drugs, albendazole (ABZ), miltefosine (MLT), ivermectin (IVM), tribendimidine (TBD), praziquantel (PZQ), artesunate (ART), and mefloquine (MEQ), were evaluated for in vitro activity against T. spiralis muscle larvae. Larval viability was quantified using a tetrazolium salt XTT assay to determine IC₅₀ values and compare with microscopic assessments. Based on in vitro activity, TBD was selected for in vivo evaluation in a mouse model, where efficacy was assessed by muscle larval burden and histopathological changes. Results: TBD, MEQ, IVM, and ABZ exhibited measurable in vitro efficacies against T. spiralis larvae, with TBD showing the lowest IC₅₀ value at 135.2 μM. XTT formazan absorbance correlated strongly with larval number and incubation time. In vivo, TBD treatment significantly reduced larval burdens in diaphragm and gastrocnemius muscles and was associated with reduced collagen capsule thickness, inflammation, and fibrosis compared with ABZ-treated controls. Conclusions: This study validated an assay for quantitative evaluation of T. spiralis muscle larvae and demonstrates robust in vitro and in vivo activity of TBD against this stage. Full article

The emergence of drug-resistant strains of Plasmodium falciparum continues to challenge global malaria control efforts, underscoring the urgent need for novel therapeutic strategies. In this study, we present an integrative computational framework that combines ensemble machine learning, molecular docking, and molecular dynamics simulations to predict and characterize the antimalarial activity of compounds from the Malaria Box database. Initially, topographical and quantum mechanical descriptors were used to construct regression models for predicting pEC₅₀ values, but due to the limited predictive performance in the global regression, a classification strategy was adopted, categorizing compounds into “active” and “very active” classes. The best ensemble classifier achieved robust performance (Acc₁₀-fold = 0.738, Acc_ext = 0.675), with good sensitivity and specificity over individual models. Subsequent regression modeling within each class yielded high predictive accuracy, with ensemble models reaching Q²10-fold values of 0.810 and 0.793 for the very active and active classes, respectively. To explore potential mechanisms of action, molecular docking was performed against P. falciparum Cytochrome B, revealing strong binding affinities for most compounds, particularly those forming π–π stacking and hydrogen bonds with Glu272. Molecular dynamics simulations over 200 ns confirmed the stability of several ligand–protein complexes, including unexpected behavior from compound M31, which demonstrated stable binding despite poor docking scores, suggesting a possible competitive inhibition mechanism. Binding free energy calculations further validated these findings, highlighting several promising candidates for future experimental evaluation. This integrative approach offers a powerful platform for accelerating antimalarial drug discovery by combining predictive modeling with mechanistic insights. Full article