{
  "schema_version": "2.0.0",
  "id": "colombo-dengue",
  "name": "Colombo Dengue Study (CDS)",
  "aliases": [
    "CDS"
  ],
  "outbreak_event": null,
  "pathogen_id": "dengue-virus",
  "pathogen_class": "virus",
  "exposure_ascertainment": "mixed",
  "design": "prospective_non_inception",
  "denominator_defined": "yes",
  "denominator_method": "Adults presenting with acute febrile illness (<3 days) clinically suspected as dengue; dengue confirmed vs non-dengue by laboratory testing.",
  "recruitment_source": "hospital",
  "time_zero_definition": "Onset of acute febrile illness",
  "time_zero_precision": "week",
  "control_group": "other_disease",
  "control_matching_variables": [],
  "n_source_population": null,
  "n_enrolled": 260,
  "n_analysed": 260,
  "followups": [
    {
      "months": 2,
      "n_assessed": 260,
      "n_lost": null
    }
  ],
  "max_followup_months": 2,
  "instruments": [
    "chalder-fatigue-scale"
  ],
  "case_definition": "author_defined",
  "pem_assessed": "no",
  "objective_measures": [
    "lab_panel"
  ],
  "specimens_collected": true,
  "specimen_types": [
    "serum",
    "plasma"
  ],
  "acute_phase_specimens": "yes",
  "storage": null,
  "biobank_status": "unknown",
  "consent_future_use": "unknown",
  "external_access": "unknown",
  "contact": null,
  "registration_id": null,
  "funders": [],
  "conflicts": null,
  "data_availability": null,
  "notes": "Prospective cohort with a same-setting non-dengue febrile comparator, enabling a relative-risk estimate for post-infection fatigue. Short (2-month) follow-up captures early convalescence only.",
  "publications": [
    {
      "id": "sigera-2021",
      "title": "Dengue and post-infection fatigue: findings from a prospective cohort—the Colombo Dengue Study",
      "authors": "Sigera PC, Rajapakse S, Weeratunga P, et al.",
      "year": 2021,
      "journal": "Transactions of the Royal Society of Tropical Medicine and Hygiene",
      "doi": "10.1093/trstmh/traa110",
      "pmid": "33099653",
      "url": "https://pubmed.ncbi.nlm.nih.gov/33099653/",
      "open_access": false,
      "is_primary_cohort_paper": true
    }
  ],
  "symptom_inventory_scope": "single_domain",
  "n_symptoms_queried": null,
  "symptom_instrument_note": null,
  "related_cohorts": [],
  "last_verified": "2026-07-20",
  "verified_by": "OSMF research-tracker (web-verified against source)",
  "harmonisation_ruleset": "pais-harmony-v1",
  "observations": [
    {
      "id": "cds-fatigue-2mo",
      "cohort_id": "colombo-dengue",
      "publication_id": "sigera-2021",
      "schema_version": "2.0.0",
      "measure_id": "sym:fatigue",
      "measure_verbatim": "fatigue at 2 months post-infection",
      "population": {
        "scope": "whole_cohort",
        "stratum": null,
        "denominator_basis": "assessed_at_timepoint",
        "n_assessed": 158
      },
      "timing": {
        "timepoint_months": 2,
        "timepoint_band": "0-3mo",
        "reference_period": "not_reported",
        "is_cumulative": false
      },
      "method": {
        "ascertainment": "unclear",
        "instrument_id": "chalder-fatigue-scale",
        "severity_threshold": null,
        "blinded_assessment": "not_reported"
      },
      "value": {
        "type": "proportion",
        "numerator": 51,
        "denominator": 158,
        "percent": 32,
        "ci": null,
        "precision": "exact"
      },
      "comparator": {
        "group": "none",
        "value": {
          "status": "not_applicable"
        },
        "effect": null
      },
      "harmonised": null,
      "provenance": {
        "source_locator": "Results/Abstract (51/158 dengue patients; RR 4.93, 95% CI 2.3–10.4 vs non-dengue)",
        "extracted_by": null,
        "extracted_on": null,
        "verified_by": "OSMF research-tracker (web-verified against source)",
        "verified_on": "2026-07-20",
        "extraction_method": "manual"
      }
    }
  ]
}