{
  "abstract": "Background: The co-circulation of Leishmania (Leishmania) infantum strains carrying a naturally occurring 12 kb genomic deletion (DEL) and the wild-type (NonDEL) parasites in the Americas raises important challenges for epidemiological surveillance, molecular diagnostics, and the interpretation of infection dynamics in visceral leishmaniasis (VL). In this study, we aimed to develop and apply a robust molecular approach to discriminate and quantify DEL and NonDEL genotypes and to assess their distribution, frequency, and patterns of co-infection across endemic regions.\n\nMethods: We established a qPCR-based genotyping strategy combining a constitutive genomic target, present in all Leishmania (L.) infantum strains, with a NonDEL-specific target, enabling simultaneous genotype discrimination and parasite quantification.\n\nResults: After validation using cultured parasites, the assay was applied to a large and diverse panel of strains isolates from humans and dogs preserved in a biobank, as well as clinical samples from dogs, cats, coatis, and sand flies across South and Central America. DEL parasites predominated (69.8%) and showed a wide geographic distribution in both strains and clinical samples, indicating their major contribution to transmission cycles. No significant association was observed between host type (human vs. canine) and genotype frequency. Notably, mixed-genotype infections were frequently detected, revealing within-host complexity not captured by conventional diagnostic methods. Quantification based on the constitutive target strongly correlated with kDNA-based parasite load estimates, supporting its simultaneous use for genotyping and quantification of L. (L.) infantum variants directly from clinical material.\n\nConclusions: This approach thus provides new insights into parasite population structure and infection dynamics and supports improved molecular surveillance and interpretation of diagnostic and epidemiological data in VL.\n\nGraphical Abstract:\n\nSupplementary Information: The online version contains supplementary material available at https://doi.org/10.1186/s13071-026-07571-2.",
  "abstract_shown": true,
  "affiliations": [
    "Laboratório de Pesquisa em Leishmanioses, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Fiocruz, Rio de Janeiro, RJ Brazil",
    "Communicable Diseases and Environmental Determinants of Health (CDE), Neglected, Tropical and Vector Borne Diseases (VT), Pan American Health Organization, World Health Organization (PAHO/WHO), Rio de Janeiro, Brazil",
    "Laboratório de Pesquisa Clínica em Dermatozoonoses em Animais Domésticos-Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Fiocruz, Rio de Janeiro, RJ Brazil",
    "Laboratório de Biologia de Tripanosomatídeos, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Fiocruz, Rio de Janeiro, RJ Brazil",
    "Universidade Católica Dom Bosco, Campo Grande, MS Brazil",
    "Instituto Gonçalo Moniz, Fundação Oswaldo Cruz, Fiocruz, Salvador, BA Brazil",
    "Escola de Medicina Veterinária e Zootecnia, Universidade Federal da Bahia, Salvador, BA Brazil",
    "Departamento de Patologia, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, SP Brazil",
    "Centro de Parasitologia e Micologia, Instituto Adolfo Lutz, São Paulo, SP Brazil",
    "Laboratory of Pathology of Infectious Diseases, Medical School, São Paulo University, São Paulo, SP Brazil",
    "Laboratorio de Interacciones Hospedero-Patógeno-UBM, Institut Pasteur de Montevideo, Montevideo, Uruguay",
    "Laboratory of Molecular Virology and Parasitology, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Fiocruz, Rio de Janeiro, Brazil"
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 21,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Marne Coimbra das Chagas"
    },
    {
      "affs": [
        1
      ],
      "name": "Ana Nilce Silveira Elkhoury"
    },
    {
      "affs": [
        1
      ],
      "name": "Samantha Valadas"
    },
    {
      "affs": [
        0
      ],
      "name": "Bruna Dias das Chagas"
    },
    {
      "affs": [
        0
      ],
      "name": "Camilly Enes"
    },
    {
      "affs": [
        2
      ],
      "name": "Artur Augusto Velho Mendes Junior"
    },
    {
      "affs": [
        2
      ],
      "name": "Sandro Antonio Pereira"
    },
    {
      "affs": [
        3,
        4
      ],
      "name": "Gabriel Carvalho de Macedo"
    },
    {
      "affs": [
        3
      ],
      "name": "André Luiz Rodrigues Roque"
    },
    {
      "affs": [
        5,
        6
      ],
      "name": "Manuela da Silva Solcà"
    },
    {
      "affs": [
        5
      ],
      "name": "Claudia Brodskyn"
    },
    {
      "affs": [
        5,
        6
      ],
      "name": "Deborah Bittencourt Mothé"
    },
    {
      "affs": [
        7
      ],
      "name": "Juliana Mariotti Guerra"
    },
    {
      "affs": [
        8
      ],
      "name": "José Eduardo Tolezano"
    },
    {
      "affs": [
        9
      ],
      "name": "Luiz Fabio Batista"
    },
    {
      "affs": [
        9
      ],
      "name": "Marcia Dalastra Laurenti"
    },
    {
      "affs": [
        10
      ],
      "name": "Lisvane Paes-Vieira"
    },
    {
      "affs": [
        10
      ],
      "name": "Carlos Robello"
    },
    {
      "affs": [
        11
      ],
      "name": "Otacilio C. Moreira"
    },
    {
      "affs": [
        0
      ],
      "name": "Elisa Cupolillo"
    },
    {
      "affs": [
        0
      ],
      "name": "Mariana Côrtes Boité"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/ad4v6b6dthz2t.bib",
  "cited_by": 0,
  "doi": "10.1186/s13071-026-07571-2",
  "fulltext_url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC13746658/",
  "id": "ad4v6b6dthz2t",
  "issns": [
    "1756-3305"
  ],
  "landing_url": "https://doi.org/10.1186/s13071-026-07571-2",
  "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",
      "Research"
    ],
    [
      "openalex",
      "2739|Research on Leishmaniasis Studies"
    ]
  ],
  "openalex": "W7202162667",
  "pdf_url": null,
  "pmcid": "PMC13746658",
  "pmid": "43000398",
  "published": "2026-08-11",
  "publisher": "BMC",
  "ris": "https://research.draconitic.com/paper/ad4v6b6dthz2t.ris",
  "sources": [
    {
      "first_seen": "2026-11-11T12:24:00Z",
      "native_id": "PMC13746658",
      "source": "pmc",
      "url": "https://doi.org/10.1186/s13071-026-07571-2"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "openalex:2739|Research on Leishmaniasis Studies",
      "subfield": "epidemiology-public-health"
    }
  ],
  "title": "Tracking the spread of a naturally occurring Leishmania (L.) infantum mutant: a qPCR-based investigation in strains and clinical samples",
  "title_text": "Tracking the spread of a naturally occurring Leishmania (L.) infantum mutant: a qPCR-based investigation in strains and clinical samples",
  "type": "peer-reviewed",
  "updated_at": "2026-11-13T12:23:12Z",
  "url": "https://research.draconitic.com/paper/ad4v6b6dthz2t",
  "venue": "Parasites & Vectors",
  "versions": []
}