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Community-Based Cohort Study of Hidden Malaria Infections, Diagnostic Gaps, & Mosquito Vector Dynamics in Odisha, India (CSCMi3)

10. august 2026 oppdatert av: Sam Wassmer, London School of Hygiene and Tropical Medicine

The Center for the Study of Complex Malaria in India (CSCMi 3.0): Hidden Plasmodium Infections: Reservoirs, Impact, and Biomarker Discovery

The goal of this prospective cohort study is to understand the factors responsible for the persistence of malaria transmission in some areas despite intensive control efforts. The study will measure the prevalence and incidence of asymptomatic and sub-patent Plasmodium infections and examine the factors that contribute to persistent transmission among residents of malaria-endemic areas of Odisha, India.

The main questions the study aims to answer are: Do asymptomatic and sub-patent Plasmodium infections contribute to persistent malaria transmission in endemic areas of Odisha? What is the frequency of false-negative results and incorrect species identification when microscopy and rapid diagnostic tests (RDTs) are compared with PCR? How is malaria epidemiology changing over time across areas with different transmission patterns, including shifts in Plasmodium species? What is the prevalence of asymptomatic gametocyte carriers, and how might they contribute to ongoing transmission? What are the characteristics and distribution of mosquito vectors in and around households, and how do they relate to transmission patterns? Can novel host- and parasite-derived biomarkers improve the detection of malaria infections, including asymptomatic cases?

Participants will provide blood samples for malaria testing by microscopy, RDT and PCR. A subset will provide additional samples for biomarker analysis as part of a nested sub-study. Participants will be followed over time to measure malaria infection prevalence, incidence and changes in transmission patterns. They will also take part in household-level assessments, including surveys and mosquito vector monitoring around their homes.

Studieoversikt

Status

Rekruttering

Forhold

Detaljert beskrivelse

Malaria transmission has declined in many parts of India as a result of expanded control efforts. However, persistent transmission continues in several regions despite high intervention coverage. Increasing evidence suggests that asymptomatic and subpatent Plasmodium infections may form an important hidden reservoir that sustains transmission and complicates malaria elimination. These infections are often missed by routine diagnostic methods such as microscopy and rapid diagnostic tests (RDTs), particularly in low-transmission or pre-elimination settings.

Local mosquito vector dynamics, including species composition, density and behaviour, are also likely to play a critical role in sustaining residual transmission, but remain insufficiently characterised in these settings.

This study is part of the Center for the Study of Complex Malaria in India 3 (CSCMi-3) and aims to characterise the epidemiology and biological determinants of hidden malaria infections in Odisha, India. It will also examine how vector, human and parasite factors interact to sustain transmission. The study is a prospective, community-based cohort conducted in selected rural villages across three endemic districts, representing different malaria transmission settings. Participants will be enrolled through household-based community surveys and followed longitudinally to monitor malaria infection dynamics over time.

The parent cohort study will enrol approximately 3,000 individuals, who will be followed through repeated visits to estimate the prevalence and incidence of asymptomatic malaria infections. The study will also assess the frequency of false-negative results and species misclassification by comparing routine diagnostic methods with molecular detection. In addition, it will evaluate Pfhrp2/Pfhrp3 gene deletions and explore potential shifts in Plasmodium species composition over time. Blood samples collected during study visits will be used for parasitological testing and laboratory analyses to better understand the persistence of malaria transmission.

Concurrent entomological surveys will be conducted in and around participant households to characterise mosquito vector species, density and seasonal patterns, and to examine their relationship with household-level infection patterns and ongoing transmission.

A nested biomarker sub-cohort will include a subset of participants who will undergo more frequent sampling to investigate circulating host- and parasite-derived biomarkers associated with malaria infection and transmission. These data will support the identification of biological indicators that may improve the detection of hidden infections and inform malaria surveillance strategies in elimination settings.

In parallel with the active community-based cohort, routinely collected malaria surveillance data from the Government of Odisha will be obtained for the study villages throughout the study period. These data will be used to characterise temporal trends in routine malaria surveillance, compare passive and active malaria case detection, and generate evidence to inform malaria surveillance and elimination strategies.

Together, the study will generate longitudinal epidemiological, diagnostic, biomarker and entomological data to improve understanding of residual malaria transmission and support evidence-based malaria surveillance, control and elimination strategies in India.

Studietype

Observasjonsmessig

Registrering (Antatt)

3000

Kontakter og plasseringer

Denne delen inneholder kontaktinformasjon for de som utfører studien, og informasjon om hvor denne studien blir utført.

Studiekontakt

Studiesteder

  • India
    • Odisha
      • Bhubaneswar, Odisha, India, 751023
        • Rekruttering
        • ICMR-National Institute of Health Research
        • Ta kontakt med:
        • Hovedetterforsker:
          • Sanghamitra Pati, MD MPH PhD
        • Hovedetterforsker:
          • Madhusmita Bal, PhD
      • Raurkela, Odisha, India, 769042
        • Rekruttering
        • Community Welfare Society Hospital (CWSH)
        • Ta kontakt med:
        • Hovedetterforsker:
          • Sanjib Mohanty, MBBS MD
        • Hovedetterforsker:
          • Praveen Kishore Sahu, PhD

Deltakelseskriterier

Forskere ser etter personer som passer til en bestemt beskrivelse, kalt kvalifikasjonskriterier. Noen eksempler på disse kriteriene er en persons generelle helsetilstand eller tidligere behandlinger.

Kvalifikasjonskriterier

Alder som er kvalifisert for studier

  • Barn
  • Voksen
  • Eldre voksen

Tar imot friske frivillige

Ja

Prøvetakingsmetode

Sannsynlighetsprøve

Studiepopulasjon

Community residents living in selected rural villages in three districts of Odisha, India (Keonjhar, Boudh, and Malkangiri), representing different malaria transmission settings. Participants include males and females aged 12 months to 69 years who are enrolled through household-based community surveys and followed longitudinally to assess malaria infection, transmission dynamics, and biomarkers of infection. There are no restrictions based on residency duration, pregnancy status, social class, or underlying health conditions. For participants with severe anemia, study procedures are limited to finger-prick blood sampling in accordance with the study protocol.

Beskrivelse

Inclusion Criteria:

  • Individuals 12 months to 69 years, all social classes, and all types of health status will be enrolled

Exclusion Criteria:

  • Individuals unable or unwilling to provide informed consent (or parental consent/assent for minors) Individuals unable to comply with study procedures or follow-up visits according to investigator judgement

Studieplan

Denne delen gir detaljer om studieplanen, inkludert hvordan studien er utformet og hva studien måler.

Hvordan er studiet utformet?

Designdetaljer

Kohorter og intervensjoner

Gruppe / Kohort
Project 1
This prospective, community-based cohort will enrol approximately 3,000 participants from 15 villages across three districts of Odisha, India: Keonjhar, Boudh and Malkangiri, with five villages selected from each district. Participants aged 12 months to 69 years will be followed for four years, with study visits every six months before and after the monsoon season. At each visit, participants will undergo clinical assessment and finger-prick blood collection for malaria testing by rapid diagnostic test (RDT), microscopy and PCR. Samples will also be used for haemoglobin measurement and for the collection of plasma and erythrocytes for molecular and serological analyses, to monitor malaria epidemiology and transmission dynamics.
Project 2

This nested prospective sub-cohort will enroll approximately 1,000 participants selected from the parent cohort across six villages, with two villages selected from each district. Participants will be recruited from three villages, one per district, beginning at the 12-month visit of the parent study in Year 2, and from the remaining three villages, one per district, in Year 3.

Participants will undergo more frequent longitudinal sampling to characterise malaria transmission and infection dynamics using sero-epidemiology and circulating host- and parasite-derived biomarkers. Finger-prick blood samples will be collected for rapid diagnostic testing (RDT), microscopy, PCR-based detection of Plasmodium infection, and bead-based assays measuring anti-Plasmodium antibodies and other infection biomarkers.

Concurrent entomological assessments conducted as part of the parent cohort will provide context on vector dynamics in relation to observed infection patterns and transmission.

Hva måler studien?

Primære resultatmål

Resultatmål
Tiltaksbeskrivelse
Tidsramme
Prevalence and incidence of Plasmodium infection - Project 1
Tidsramme: Nine time points between Years 1 and 5, including one baseline visit and eight follow-up visits conducted every six months.
Prevalence and incidence of Plasmodium infection among study participants, determined by polymerase chain reaction (PCR)-based detection of Plasmodium species in finger-prick blood samples collected during longitudinal community surveys. The study will estimate the prevalence, incidence and persistence of asymptomatic, subpatent and submicroscopic infections, together with species-specific infections.
Nine time points between Years 1 and 5, including one baseline visit and eight follow-up visits conducted every six months.
Diagnostic performance of malaria microscopy and rapid diagnostic tests compared with PCR - Project 1
Tidsramme: Baseline and follow-up visits conducted every six months over five years.
Diagnostic performance of malaria microscopy and rapid diagnostic tests (RDTs) compared with PCR, assessed by false-negative and false-positive results, positive and negative predictive values, and species concordance for Plasmodium detection.
Baseline and follow-up visits conducted every six months over five years.
Novel circulating infection biomarkers of host and parasite origin - Biomarker Sub-study, Project 2
Tidsramme: Sixteen time points between Years 1 and 5, with eight time points each for Groups A and B.
Identification and quantification of circulating host- and parasite-derived biomarkers associated with malaria infection, using multiplex and molecular assays in longitudinal blood samples collected from the biomarker sub-cohort
Sixteen time points between Years 1 and 5, with eight time points each for Groups A and B.

Samarbeidspartnere og etterforskere

Det er her du vil finne personer og organisasjoner som er involvert i denne studien.

Sponsor

London School of Hygiene and Tropical Medicine

Samarbeidspartnere

National Institute of Allergy and Infectious Diseases (NIAID)
Community Welfare Society Hospital (CWSH), Rourkela, Odisha, India
ICMR-National Institute of Health Research, Bhubaneswar, Odisha, India

Etterforskere

  • Hovedetterforsker: Samuel Wassmer, PhD, London School of Hygiene & Tropical Medicine, London
  • Hovedetterforsker: Sanjib Mohanty, MBBS MD, Community Welfare Society Hospital, Odisha, India

Publikasjoner og nyttige lenker

Den som er ansvarlig for å legge inn informasjon om studien leverer frivillig disse publikasjonene. Disse kan handle om alt relatert til studiet.

Generelle publikasjoner

Hjelpsomme linker

Studierekorddatoer

Disse datoene sporer fremdriften for innsending av studieposter og sammendragsresultater til ClinicalTrials.gov. Studieposter og rapporterte resultater gjennomgås av National Library of Medicine (NLM) for å sikre at de oppfyller spesifikke kvalitetskontrollstandarder før de legges ut på det offentlige nettstedet.

Studer hoveddatoer

Studiestart (Faktiske)

2. mai 2025

Primær fullføring (Antatt)

31. mai 2029

Studiet fullført (Antatt)

31. mai 2029

Datoer for studieregistrering

Først innsendt

10. august 2026

Først innsendt som oppfylte QC-kriteriene

10. august 2026

Først lagt ut (Faktiske)

18. august 2026

Oppdateringer av studieposter

Sist oppdatering lagt ut (Faktiske)

18. august 2026

Siste oppdatering sendt inn som oppfylte QC-kriteriene

10. august 2026

Sist bekreftet

1. august 2026

Mer informasjon

Begreper knyttet til denne studien

Ytterligere relevante MeSH-vilkår

Andre studie-ID-numre

  • 30518
  • U19AI181587 (U.S. NIH-stipend/kontrakt)

Plan for individuelle deltakerdata (IPD)

Planlegger du å dele individuelle deltakerdata (IPD)?

JA

IPD-planbeskrivelse

De-identified individual participant data underlying the results reported in publications will be shared. This includes demographic data, clinical and laboratory measurements, malaria diagnostic results (RDT, microscopy, PCR), serological measurements, and selected entomological indicators collected during the study. Direct identifiers will be removed prior to data sharing.

IPD-delingstidsramme

De-identified individual participant data and supporting documents will be available beginning after publication of the primary study results. Data will remain available for up to 5 years following publication, subject to institutional data governance and data sharing policies.

Tilgangskriterier for IPD-deling

De-identified individual participant data and supporting documents, including the study protocol, statistical analysis plan, informed consent forms and analytic code, will be made available to qualified researchers who submit a methodologically sound research proposal. Requests will be reviewed and approved by the study investigators and participating institutions. Access will be provided through a controlled data-sharing mechanism and may require a data-use agreement to ensure appropriate use of the data and protection of participant confidentiality. Only the data necessary to address the approved research question will be shared.

IPD-deling Støtteinformasjonstype

  • STUDY_PROTOCOL
  • SEVJE
  • ICF

Legemiddel- og utstyrsinformasjon, studiedokumenter

Studerer et amerikansk FDA-regulert medikamentprodukt

Nei

Studerer et amerikansk FDA-regulert enhetsprodukt

Nei

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