{ "abstract": "Background: Rapid urbanization in Brazil has shifted the epidemiological landscape of parasitic diseases, such as schistosomiasis and malaria. Although typically considered a rural infection, Schistosoma mansoni transmission persists in urban settings where sanitation and water access remain uneven. This study investigates the persistence and dynamics of urban schistosomiasis across neighborhoods of Salvador, Bahia, Brazil. Methods: Between 2011 and 2024 cross-sectional surveys were conducted to identify neighborhoods with the highest prevalence in the major metropolitan area of Salvador, Bahia. A total of 6,863 residents provided demographic information and Kato-Katz examination of at least one stool sample. We conducted demographic surveys and stool examination on 3,964 individuals who were re-examined on up to three occasions at intervals ranging from 1-5 years. Findings: The overall prevalence of initial examination was 7%. Regardless of treatment intervals, the community-wide prevalence declined by more than half and did not rebound. Apparent Incidence decreased to <0.5%/year following a second period of treatment. In nearly all communities, most infections occurred among individuals born in Salvador with no travel history outside the city. Interpretation: Overall, the study provides one of the first individual-level longitudinal assessments of schistosomiasis persistence in an urban Brazilian setting, combining repeated parasitological surveys with demographic and environmental data across multiple neighborhoods. These findings indicate that schistosomiasis transmission in Salvador is largely local rather than imported. The decline in prevalence coincides with observed community-level improvements in sanitation and reduced contact with surface water. f prevalence rates were applied across the population of Salvador, this city could be considered one of the state’s most important endemic areas. Author summary: Rapid urbanization and the lack of accompanying sanitation is urbanizing diseases previously considered rural. While sanitation in Salvador is generally good, Schistosoma mansoni infection was identified in all poor neighborhoods examined, and most evidence indicates this is a result of active transmission. Studies in urban environments pose difficulties not experienced or experienced to a lesser degree in most rural areas. Participation in research is lower, and violence is generally higher. Urban areas also offer opportunities for effective intervention due to the greater impact of infrastructure modifications and population density. Interventions tend to more easily affect a greater number of people. The prevalence of infection and the size of the city make urban infection an important focus for management. The Brazilian setting may provide a preview of schistosomiasis transmission as endemic areas become increasingly urbanized.", "abstract_shown": true, "affiliations": [ "Laboratory for Pathology and Molecular Biology, Gonçalo Moniz Institute, Oswaldo Cruz Foundation, Salvador, Bahia, Brazil", "Laboratory of Clinical Parasitology, Bahiana School of Medicine and Public Health, Salvador, Bahia, Brazil", "Health Surveillance Directorate, Municipal Health Secretariat of Salvador, Salvador, Bahia, Brazil", "Health Sciences Institute, Federal University of Bahia, Salvador, Bahia, Brazil", "Epidemiology of Microbial Diseases, Yale University, New Haven, Connecticut, United States of America", "Department of Tropical Medicine and Infectious Disease, Tulane Celia Scott Weatherhead School of Public Health and Tropical Medicine, New Orleans, Louisiana, United States of America" ], "article_type": "Research Article", "arxiv": null, "author_total": 18, "authors": [ { "affs": [ 0 ], "name": "Pedro Santos-Muccillo" }, { "affs": [ 0 ], "name": "Fernanda Mac-Allister Cedraz" }, { "affs": [ 0 ], "name": "Luciano K. Silva" }, { "affs": [ 1 ], "name": "Lúcio M. Barbosa" }, { "affs": [ 0 ], "name": "Vanessa T. Moretto" }, { "affs": [ 0 ], "name": "Vanessa S. Zanardi" }, { "affs": [ 0 ], "name": "Camila F. Chaves" }, { "affs": [ 0 ], "name": "João R. P. Cruz-Filho" }, { "affs": [ 0 ], "name": "Lee S. A. Andrade" }, { "affs": [ 0 ], "name": "Cláudio R. A. Santos" }, { "affs": [ 0 ], "name": "Eliana A. G. Reis" }, { "affs": [ 0, 2 ], "name": "Cristiane W. Cardoso" }, { "affs": [ 2 ], "name": "Rogerio S. Teixeira" }, { "affs": [ 2 ], "name": "Fabiano M. Simões" }, { "affs": [ 3 ], "name": "Roberto J. M. Nascimento" }, { "affs": [ 0 ], "name": "Jackson M. L. Costa" }, { "affs": [ 0, 3, 4 ], "name": "Mitermayer G. Reis" }, { "affs": [ 5 ], "name": "Ronald E. Blanton", "orcid": "0000-0001-6655-7336" } ], "bibtex": "https://research.draconitic.com/paper/9vjhq75zfdg1a.bib", "cited_by": 0, "doi": "10.1371/journal.pntd.0013418", "fulltext_url": "https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0013418", "id": "9vjhq75zfdg1a", "issns": [ "1935-2735", "1935-2727" ], "landing_url": "https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0013418", "language": "en", "licence": "CC-BY-4.0", "licence_label": "CC BY 4.0", "licence_source": "article", "licence_url": "https://creativecommons.org/licenses/by/4.0/", "metadata_licence": null, "native_subjects": [ [ "heading", "Animals" ], [ "heading", "Biology and Life Sciences" ], [ "heading", "Brazil" ], [ "heading", "Earth Sciences" ], [ "heading", "Ecology and Environmental Sciences" ], [ "heading", "Environmental Health" ], [ "heading", "Eukaryota" ], [ "heading", "Geographical locations" ], [ "heading", "Geography" ], [ "heading", "Health Care" ], [ "heading", "Helminth Infections" ], [ "heading", "Helminths" ], [ "heading", "Human Geography" ], [ "heading", "Hydrology" ], [ "heading", "Invertebrates" ], [ "heading", "Medical Conditions" ], [ "heading", "Medicine and Health Sciences" ], [ "heading", "Neglected Tropical Diseases" ], [ "heading", "Neighborhoods" ], [ "heading", "Organisms" ], [ "heading", "Parasitic Diseases" ], [ "heading", "People and places" ], [ "heading", "Public and Occupational Health" ], [ "heading", "Research Article" ], [ "heading", "Sanitation" ], [ "heading", "Schistosoma" ], [ "heading", "Schistosoma Mansoni" ], [ "heading", "Schistosomiasis" ], [ "heading", "Social Geography" ], [ "heading", "Social Sciences" ], [ "heading", "South America" ], [ "heading", "Surface Water" ], [ "heading", "Terrestrial Environments" ], [ "heading", "Tropical Diseases" ], [ "heading", "Urban Environments" ], [ "heading", "Urban Geography" ], [ "heading", "Urbanization" ], [ "heading", "Zoology" ], [ "openalex", "2405|Parasites and Host Interactions" ], [ "plos", "/Biology and life sciences/Organisms/Eukaryota/Animals/Invertebrates/Helminths/Schistosoma/Schistosoma mansoni" ], [ "plos", "/Biology and life sciences/Zoology/Animals/Invertebrates/Helminths/Schistosoma/Schistosoma mansoni" ], [ "plos", "/Earth sciences/Geography/Human geography/Social geography/Neighborhoods" ], [ "plos", "/Earth sciences/Geography/Human geography/Urban geography/Urbanization" ], [ "plos", "/Earth sciences/Hydrology/Surface water" ], [ "plos", "/Ecology and environmental sciences/Terrestrial environments/Urban environments" ], [ "plos", "/Medicine and health sciences/Health care/Environmental health/Sanitation" ], [ "plos", "/Medicine and health sciences/Medical conditions/Parasitic diseases/Helminth infections/Schistosomiasis" ], [ "plos", "/Medicine and health sciences/Medical conditions/Tropical diseases/Neglected tropical diseases/Schistosomiasis" ], [ "plos", "/Medicine and health sciences/Public and occupational health/Environmental health/Sanitation" ], [ "plos", "/People and places/Geographical locations/South America/Brazil" ], [ "plos", "/Social sciences/Human geography/Social geography/Neighborhoods" ], [ "plos", "/Social sciences/Human geography/Urban geography/Urbanization" ] ], "openalex": "W7223367943", "pdf_url": "https://journals.plos.org/plosntds/article/file?id=10.1371/journal.pntd.0013418&type=printable", "pmcid": "PMC13734582", "pmid": "42912825", "published": "2026-10-23", "publisher": "Public Library of Science", "ris": "https://research.draconitic.com/paper/9vjhq75zfdg1a.ris", "sources": [ { "first_seen": "2026-10-30T12:17:17Z", "native_id": "10.1371/journal.pntd.0013418", "source": "plos", "url": "https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0013418" }, { "first_seen": "2026-11-08T12:24:01Z", "native_id": "PMC13734582", "source": "pmc", "url": "https://doi.org/10.1371/journal.pntd.0013418" } ], "subjects": [ { "field": "biology", "origin": "plos:zoology", "subfield": "zoology-behaviour" }, { "field": "earth", "origin": "plos:hydrology", "subfield": "hydrology-soils" }, { "field": "medicine", "origin": "plos:public and occupational health", "subfield": "epidemiology-public-health" } ], "title": "Schistosomiasis as an urban disease: 13 years of studies in the neighborhoods of Salvador, BA, Brazil", "title_text": "Schistosomiasis as an urban disease: 13 years of studies in the neighborhoods of Salvador, BA, Brazil", "type": "peer-reviewed", "updated_at": "2026-11-08T12:24:01Z", "url": "https://research.draconitic.com/paper/9vjhq75zfdg1a", "venue": "PLOS Neglected Tropical Diseases", "versions": [] }