Comparative performance of Kato-Katz and spontaneous sedimentation methods for schistosomiasis mansoni diagnosis in endemic areas of Northeastern Brazil T.L.H. Ferreira, V.T.C. Campos, R.E.S. Ramos, C. Graeff-Teixeira, F.A. Brayner, et al. Journal of Helminthology, 2026 Schistosomiasis mansoni, caused by the trematode Schistosoma mansoni , is a major public health issue in Northeastern Brazil. This study compares the diagnostic performance of Kato-Katz (KK) and spontaneous sedimentation (Lutz) techniques in detecting S. mansoni infections in three areas of Sergipe, Northeastern Brazil, each with varying degrees of schistosomiasis endemicity. We compared the performance of Kato-Katz (KK) and spontaneous sedimentation (SSM) in three localities of Sergipe and Alagoas with different endemicity levels. Stool samples were examined by both methods, and individuals were considered positive if at least one test was positive. KK showed higher sensitivity across all sites (88.5%–100%), while SSM performed better in moderately endemic areas (up to 61.5%). These complementary performance profiles suggest that using both methods in combination could yield a measurable increase in case detection – potentially improving prevalence estimates, guiding more accurate treatment interventions, and strengthening surveillance strategies in areas with heterogeneous transmission intensities.
Comparison Between Phenotypic Profile and Functional Aspects of IL-9-Producing Lymphocytes, Th17 and Tfh of Individuals From Endemic and Non-Endemic Areas for Hookworm Infection Yvanna Louise Di Christine Oliveira, Marcelo Eduardo Cardozo, Luisa Mourão Dias Magalhães, Carlos Thailan de Jesus Santos, Ramayana Morais de Medeiros Brito, et al. Parasite Immunology, 2026 Hookworm infections remain a major public health concern in endemic areas, modulating both the adaptive and innate immune systems. While the type 2 response is well‐characterised, the roles of T follicular helper (Tfh), Th17, and IL‐9‐producing lymphocytes remain poorly defined. Here, we characterised these T cell subsets in individuals naturally infected with hookworms. From 1500 faecal samples screened, 60 were positive for hookworms, and peripheral blood was collected from 10 uninfected controls from endemic (NEG END) and non‐endemic (NEG NE) areas, as well as from 7 infected individuals before (HKW BT) and after (HKW PT) treatment. Infected individuals displayed haematological alterations, including anaemia ( n = 2), eosinophilia ( n = 1), monocytosis ( n = 4), and lymphocytosis ( n = 3), along with an expansion of PBMCs, particularly Tfh cells, during infection. Expression of IL‐9 and IL‐10 by Tfh cells was markedly elevated after treatment. In contrast, individuals from non‐endemic areas displayed a distinct baseline profile with higher Tfh activation (CD69) expression, suggesting immune adaptation in endemic settings. While IL‐10‐producing Tfh expanded during infection, IL‐9‐producing cells and Th17 cells expanded mainly after treatment. These findings suggest that individuals living in endemic areas, regardless of infection status, exhibit signs of persistent antigenic stimulation that promote a more tolerogenic and regulated immune profile. Moreover, hookworm infection and subsequent treatment reshape the immune landscape, highlighting the contribution of Tfh‐ and Th17‐associated pathways, as well as IL‐9 and IL‐10 production, in modulating host–parasite interactions.
Feasibility of a phase 3 partially randomised clinical trial to assess the safety and efficacy of paediatric praziquantel for schistosomiasis treatment in children aged 3 months to 6 years in endemic regions of Brazil: a pilot study Camilla Almeida Menezes, Ane Caroline Casaes, Brenda Rodrigues Brito Cunha Silva, Maria Gabriella Brito dos Santos, Caio Daroz Martins, et al. BMJ Open, 2026 Objective This study assessed the feasibility of implementing a phase 3 field-based clinical trial protocol to evaluate paediatric praziquantel (PED-PZQ) for the treatment of Schistosoma mansoni infection in children aged 3 months to 6 years in endemic areas of Brazil, focusing on operational aspects such as recruitment logistics, documentation management, investigational product handling and protocol adherence. Design Pilot and feasibility study for a phase 3 clinical trial, comprising two components: a randomised, open-label, parallel-group, two-arm trial and a single-arm trial. Setting Conde, Bahia, Brazil, from December 2024 to January 2025. Participants Two trials aim to screen 5774 participants from three rural areas in Bahia and three in Sergipe, states in northeastern Brazil, and enrol 403 children eligible for either randomisation or allocation. Trial 1 will randomise (1:1 ratio) 240 children aged 4–6 years into the PED-PZQ treatment arm or the standard praziquantel (PZQ) 1. Trial 2 will enrol 163 children aged 3 months to 3 years, all receiving PED-PZQ. Both trials are open label. Eligible participants shall meet age criteria, test positive for S. mansoni and fulfil other inclusion criteria. In the first recruiting centre, Conde (Bahia), it was estimated that 650 participants would need to be screened for trial 1 and 552 for trial 2, assuming schistosomiasis prevalence of 5% and 4%, respectively. This pilot study reports on the first 60 participants enrolled. Primary and secondary outcome measures The primary outcome of this pilot study is the feasibility of implementing the research protocol in a real-world field setting, focusing on key aspects such as study documentation challenges, participant safety, investigational medicinal product custody chain and protocol adherence. In addition to providing preliminary data on the parasitological cure rate, secondary outcomes include the prevalence of S. mansoni infection and the reduction in S. mansoni egg count (Kato-Katz method). Furthermore, the occurrence and severity of drug-related adverse events are monitored from drug administration to day 21 post-treatment, alongside changes in renal, hepatic and cardiac functions assessed through biochemical markers. Results A total of 60 participants were recruited, and 55 provided stool samples for screening. The pilot phase demonstrated the feasibility of implementing the clinical protocol under field conditions, with successful completion of all planned procedures and minimal protocol deviations. Operational challenges were identified mainly in documentation processes, participant recruitment and investigational product management and were addressed through preventive and corrective quality assurance actions. The experience also highlighted logistical and infrastructural barriers typical of field-based trials in remote endemic areas, which informed adjustments for the subsequent phase 3 study. Preliminary parasitological results indicated an overall S. mansoni prevalence of 9.1% (5/55), with 21% in trial 1 and 2.8% in trial 2. All infected participants met the eligibility criteria, received treatment and completed follow-up. Four achieved a parasitological cure, and one case of treatment failure was observed (trial 1, PZQ group). Two mild adverse events (diarrhoea) were reported, with no serious complications or clinically significant changes in biochemical parameters. Conclusions This pilot study demonstrated the feasibility of implementing a field-based phase 3 clinical trial protocol for PED-PZQ in endemic areas of Brazil. The findings confirm that the protocol can be successfully applied in primary care settings, despite operational challenges related to recruitment, logistics and documentation. The study also provided preliminary evidence supporting the safety and effectiveness of the paediatric formulation and highlighted the need to revise prevalence assumptions to improve future screening strategies. Overall, the experience offers valuable insights to guide the large-scale phase 3 trial and supports the incorporation of PED-PZQ into national schistosomiasis control policies. Trial registration number Brazilian Clinical Trials Registry; RBR-86kcy37.
Whole-Genome Characterization Reveals High Prevalence of Human Papillomavirus Type 18 Sublineage A1 With Novel Functional Polymorphisms Among Women in Northeastern Brazil Anny Beatriz de Oliveira Gama, Sérgio Nolasco dos Santos, Iracy Menezes de Souza Barbosa, Anne Caroline Santos Ramos, Silvio Santana Dolabella, et al. International Journal of Microbiology, 2026 Few studies have characterized the complete genome of HPV18. Although incipient, its variant lineages and sublineages have been shown to have a set of polymorphisms associated with distinct risks for the development of high‐grade lesions and cervical cancer. Thus, this study aimed to characterize the complete genomic sequences of HPV18 from the state of Sergipe, Northeastern Brazil. Sequencing of 25 HPV18 genomes from women in Sergipe was performed using the Illumina platform. After bioinformatics analysis, genetic polymorphisms were characterized, and a phylogenetic analysis was performed. In total, approximately 45 unprecedented variable sites were identified, with 82.92% of the mutations being nonsynonymous and mapped to the functional domains of the viral proteins. In LCR, the identified mutations were associated with transcription factor binding sites, such as C/EBPα, YY1, and AP‐1. Phylogenetic analysis showed that all HPV18 isolates belonged to lineage A, sublineage A1. Clinically, 20.83% of patients had preinvasive lesions. These results show a relatively high incidence of HPV18 sublineage A1, presenting novel mutations in structural and functional domains of the proteins, which could potentially affect viral carcinogenesis. In this context, the importance of genomic surveillance of HPV18 variants worldwide is highlighted.
Genome-guided antimicrobial potential of Bacillus stercoris from coastal sand with activity against multidrug-resistant bacteria, including MRSA Camilla Andrade Silva Valença, Bruno Andrade, Marcus Viana, Ana Andrea Teixeira Barbosa, Silvio Santana Dolabella, et al. International Microbiology, 2026 Coastal beach environments harbor diverse bacterial communities, yet their antimicrobial potential remains largely unexplored. This study evaluates the antimicrobial potential of a bacterial isolate 2AT10 from Brazilian beach sand through in vitro , in silico , and ex vivo assays. Isolate 2AT10, a rod-shaped Gram-positive bacterium, exhibited broad-spectrum antimicrobial activity, with its culture supernatants showing greater efficacy against Gram-positive bacteria, including multidrug-resistant strains such as methicillin-resistant Staphylococcus aureus (MRSA). Antimicrobial activity from two differently processed supernatants decreased after heat treatment, enzymatic digestion, and pH changes, suggesting similar proteolytic profiles. Fourier-transform infrared spectroscopy (FTIR) revealed peaks corresponding to C = O and NO₂ groups, indicating the presence of amide functional groups. Importantly, the supernatants did not cause irritation in the ex vivo chorioallantoic membrane assay. Genomic analysis identified isolate 2AT10 as Bacillus stercoris , harboring genes encoding subtilosin A, bacilysin, bacillibactin, bacillaene and lactococcin-like bacteriocins, all associated with antimicrobial activity. A mutation in the sboA gene, involved in subtilosin A biosynthesis and previously linked to in vitro hemolytic activity and enhanced activity against Gram-positive bacteria, was also detected. Molecular docking and dynamics analyses suggested a possible interaction between lactococcin-like bacteriocin and a membrane component of the S. aureus phosphotransferase system transporter, possibly increasing membrane permeability. Graphical Abstract
Novel Antischistosomal Drug Targets: Identification of Alkaloid Inhibitors of SmTGR via Integrated In Silico Methods Valéria V. M. Paixão, Yria J. A. Santos, Adriana O. Fernandes, Elaine S. Conceição, Ricardo P. Rodrigues, et al. Pathogens, 2025 Schistosomiasis mansoni is a neglected tropical disease caused by the parasite Schistosoma mansoni, affecting approximately 200 million people annually. Currently, treatment relies primarily on a single drug, praziquantel (PZQ), which shows limited efficacy against the parasite’s immature forms. As a result, Thioredoxin Glutathione Reductase from S. mansoni (SmTGR) has emerged as a promising target for novel drug development. This study presents the development of integrated in silico methods to identify alkaloids from medicinal plants with potential activity against S. mansoni. Fourteen alkaloids were identified, with predicted activity ranging from 61.3 to 85.2%. Among these, lindoldhamine and daibucarboline A demonstrated, for the first time, potential SmTGR inhibition, with probabilities of 85.2% and 75.8%, respectively. These findings highlight the potential of these alkaloids as promising candidates for the development of new therapies against schistosomiasis.
DNA-ICM as an adjuvant method applied on oral cytological specimens Mariana Goveia Melo Ribeiro, Silvio Santana Dolabella, Cleverson Luciano Trento, Juliana da Silva Barros, Valéria Souza Freitas, et al. Oral Surgery Oral Medicine Oral Pathology and Oral Radiology, 2023
Trypanocidal essential oils: A review Mayara Castro de Morais, Jucieudo Virgulino de Souza, Carlos da Silva Maia Bezerra Filho, Silvio Santana Dolabella, Damião Pergentino de Sousa Molecules, 2020
Human amebiasis: Breaking the paradigm? Cecilia Ximénez, Rene Cerritos, Liliana Rojas, Silvio Dolabella, Patricia Morán, et al. International Journal of Environmental Research and Public Health, 2010
