{
  "schema_version": "2.0.0",
  "id": "morroy-netherlands-qfever",
  "name": "Netherlands Q-fever outbreak cohort (Morroy)",
  "aliases": [
    "Dutch Q-fever fatigue cohort"
  ],
  "outbreak_event": "Netherlands Q-fever outbreak 2007-2010",
  "pathogen_id": "coxiella-burnetii",
  "pathogen_class": "bacterium",
  "exposure_ascertainment": "serology",
  "design": "cross_sectional",
  "denominator_defined": "yes",
  "denominator_method": "Notified acute Q-fever patients from the 2007-2008 Dutch outbreaks, surveyed by postal questionnaire 12-26 months after illness onset; health status compared with Dutch reference norms.",
  "recruitment_source": "population_registry",
  "time_zero_definition": "Onset of notified acute Q-fever illness",
  "time_zero_precision": "month",
  "control_group": "none",
  "control_matching_variables": [],
  "n_source_population": null,
  "n_enrolled": 870,
  "n_analysed": null,
  "followups": [
    {
      "months": 18,
      "n_assessed": null,
      "n_lost": null
    }
  ],
  "max_followup_months": 26,
  "instruments": [
    "somatic-symptom-self-report"
  ],
  "case_definition": "author_defined",
  "pem_assessed": "no",
  "objective_measures": [
    "none"
  ],
  "specimens_collected": false,
  "specimen_types": [],
  "acute_phase_specimens": "no",
  "storage": null,
  "biobank_status": "not_applicable",
  "consent_future_use": "not_applicable",
  "external_access": "not_applicable",
  "contact": null,
  "registration_id": null,
  "funders": [
    "Netherlands National Institute for Public Health and the Environment (RIVM)"
  ],
  "conflicts": null,
  "data_availability": null,
  "notes": "Large registry-based survey following the world's largest documented Q-fever outbreak, measuring long-term fatigue and quality of life 1-2 years after acute illness with the Nijmegen Clinical Screening Instrument. A denominator-defined bacterial (non-viral) post-infectious fatigue cohort. Cross-sectional postal survey design; compared with population norms rather than a concurrent unexposed control.",
  "publications": [
    {
      "id": "morroy-2011",
      "title": "The health status of Q-fever patients after long-term follow-up",
      "authors": "Morroy G, Peters JB, van Nieuwenhof M, et al.",
      "year": 2011,
      "journal": "BMC Infectious Diseases",
      "doi": "10.1186/1471-2334-11-97",
      "pmid": "21501483",
      "url": "https://pubmed.ncbi.nlm.nih.gov/21501483/",
      "open_access": true,
      "is_primary_cohort_paper": true
    }
  ],
  "symptom_inventory_scope": "targeted_panel",
  "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": "qfever-fatigue-longterm",
      "cohort_id": "morroy-netherlands-qfever",
      "publication_id": "morroy-2011",
      "schema_version": "2.0.0",
      "measure_id": "sym:fatigue",
      "measure_verbatim": "severely affected by fatigue 12-26 months after acute Q-fever",
      "population": {
        "scope": "whole_cohort",
        "stratum": null,
        "denominator_basis": "unclear",
        "n_assessed": {
          "status": "measured_not_reported"
        }
      },
      "timing": {
        "timepoint_months": 18,
        "timepoint_band": "12-24mo",
        "reference_period": "not_reported",
        "is_cumulative": false
      },
      "method": {
        "ascertainment": "unclear",
        "instrument_id": "somatic-symptom-self-report",
        "severity_threshold": null,
        "blinded_assessment": "not_reported"
      },
      "value": {
        "type": "proportion",
        "numerator": {
          "status": "measured_not_reported"
        },
        "denominator": {
          "status": "measured_not_reported"
        },
        "percent": 43.5,
        "ci": null,
        "precision": "approximate"
      },
      "comparator": {
        "group": "none",
        "value": {
          "status": "not_applicable"
        },
        "effect": null
      },
      "harmonised": null,
      "provenance": {
        "source_locator": "Results/Abstract (fatigue severely affected 43.5%)",
        "extracted_by": null,
        "extracted_on": null,
        "verified_by": "OSMF research-tracker (web-verified against source)",
        "verified_on": "2026-07-20",
        "extraction_method": "manual"
      }
    },
    {
      "id": "qfever-qol-longterm",
      "cohort_id": "morroy-netherlands-qfever",
      "publication_id": "morroy-2011",
      "schema_version": "2.0.0",
      "measure_id": "func:qol-impairment",
      "measure_verbatim": "severely affected general quality of life 12-26 months after acute Q-fever",
      "population": {
        "scope": "whole_cohort",
        "stratum": null,
        "denominator_basis": "unclear",
        "n_assessed": {
          "status": "measured_not_reported"
        }
      },
      "timing": {
        "timepoint_months": 18,
        "timepoint_band": "12-24mo",
        "reference_period": "not_reported",
        "is_cumulative": false
      },
      "method": {
        "ascertainment": "unclear",
        "instrument_id": "somatic-symptom-self-report",
        "severity_threshold": null,
        "blinded_assessment": "not_reported"
      },
      "value": {
        "type": "proportion",
        "numerator": {
          "status": "measured_not_reported"
        },
        "denominator": {
          "status": "measured_not_reported"
        },
        "percent": 44.9,
        "ci": null,
        "precision": "approximate"
      },
      "comparator": {
        "group": "none",
        "value": {
          "status": "not_applicable"
        },
        "effect": null
      },
      "harmonised": null,
      "provenance": {
        "source_locator": "Results/Abstract (general quality of life severely affected 44.9%)",
        "extracted_by": null,
        "extracted_on": null,
        "verified_by": "OSMF research-tracker (web-verified against source)",
        "verified_on": "2026-07-20",
        "extraction_method": "manual"
      }
    }
  ]
}