{"schema":"https://ver.cy/schemas/card/1.0.0","id":"vr.tr.flu-season","code":"thing-q4120645","url":"https://ver.cy/models/thing/q4120645/","name":"flu season","alternateNames":["United States flu season"],"kind":"thing","status":"published","version":"0.1.0-research.1","language":"en","classifiers":{"family":"Thing Registry","category":"Cross-cutting context","entryKind":"thing","plane":"XCT","domain":["XCT.QLT"],"industry":[],"navPath":"","tags":[],"facets":{}},"whatItIs":"A flu season is a recurring period of elevated influenza activity in a population, whose timing, duration and intensity vary with geography, circulating viruses and population susceptibility.","purpose":"Enable an agent to recognise a geographically bounded flu season, assess its progression and evidence, and identify locally justified preparedness and response options.","scope":{"in":["Geographic and population boundaries of a particular flu season","Calendar-based and surveillance-based definitions of seasonal onset and end","Influenza activity, timing, peaks and circulating virus composition","Season-level burden, severity and uneven effects across populations","Evidence linking seasonal conditions to preparedness, escalation and recovery decisions"],"out":["An individual's influenza diagnosis, treatment or recovery","Influenza virus taxonomy, molecular biology and evolution as standalone subjects","Vaccine formulation, manufacturing and individual vaccination decisions","Year-round respiratory disease surveillance system design","A discrete institutional outbreak or influenza pandemic as a separate event","Weather and climate processes except as contextual relationships"],"boundaries":[]},"distinguishingFeatures":["An instance identifies a place, population and time interval; the generic phrase 'flu season' alone does not identify a particular season.","Evidence concerns influenza specifically, or explicitly labels syndromic observations as proxies; a rise in respiratory symptoms alone does not establish influenza activity.","The boundary convention is explicit: an administrative reporting season can exist before or after surveillance-defined elevated activity.","An isolated outbreak is related to the wider season without automatically defining its regional onset, peak or end.","The model can represent multiple peaks, weak seasonality or uncertain boundaries without forcing every locality into one annual winter wave."],"structure":{"bundles":[{"id":"season-identity-and-boundaries","name":"Season identity and boundaries","description":"Establishes what qualifies as this flu season and which locality and population it describes.","layers":[{"id":"local-season-definition","name":"Local season definition","description":"Records the authority and criteria behind the season label.","findings":[{"id":"calendar-and-activity-boundaries","name":"Calendar and activity boundaries","description":"Record whether the season is a reporting interval, an observed episode of elevated influenza activity or both.","questions":[{"text":"Which organisation or analytical method defines this season, and where is that definition documented?","id":"calendar-and-activity-boundaries-q01","kind":"provenance"},{"text":"Does the definition specify calendar dates, an activity threshold, sustained elevation or another boundary rule?","id":"calendar-and-activity-boundaries-q02","kind":"definition"}]}]},{"id":"population-and-event-boundaries","name":"Population and event boundaries","description":"Separates the regional season from nearby places and related influenza events.","findings":[{"id":"season-instance-coverage","name":"Season instance coverage","description":"Identify the covered population and relate local outbreaks or exceptional waves without treating them as interchangeable with the season.","questions":[{"text":"Which territory and population define this instance, and which areas are poorly represented?","id":"season-instance-coverage-q01","kind":"boundary"},{"text":"What rule determines whether a local outbreak or an unusual influenza wave belongs within this season or requires a linked event model?","id":"season-instance-coverage-q02","kind":"boundary"}]}]}]},{"id":"influenza-surveillance-evidence","name":"Influenza surveillance evidence","description":"Establishes what the available observations reveal about influenza activity.","layers":[{"id":"activity-signal-interpretation","name":"Activity signal interpretation","description":"Distinguishes influenza-specific measurements from broader respiratory illness signals.","findings":[{"id":"indicator-specificity-and-denominators","name":"Indicator specificity and denominators","description":"Record what each indicator measures and the population or samples to which it applies.","questions":[{"text":"Which observations confirm influenza, and which measure influenza-like illness or other nonspecific respiratory symptoms?","id":"indicator-specificity-and-denominators-q01","kind":"measurement"},{"text":"What numerator, denominator, case definition and sampling process underpin each indicator?","id":"indicator-specificity-and-denominators-q02","kind":"measurement"}]}]},{"id":"coverage-and-revisions","name":"Coverage and revisions","description":"Preserves limitations that could change the interpretation of seasonal trends.","findings":[{"id":"surveillance-comparability","name":"Surveillance comparability","description":"Record reporting delays, missing coverage and methodological changes before interpreting differences as changes in influenza activity.","questions":[{"text":"Which reporting weeks remain incomplete, and how are revisions incorporated into the season assessment?","id":"surveillance-comparability-q01","kind":"provenance"},{"text":"Have testing practices, participating sites or case definitions changed enough to limit comparison with earlier weeks or seasons?","id":"surveillance-comparability-q02","kind":"boundary"}]}]}]},{"id":"seasonal-progression-and-composition","name":"Seasonal progression and composition","description":"Describes the evolving shape of the season and the influenza viruses represented in observations.","layers":[{"id":"onset-peaks-and-end","name":"Onset, peaks and end","description":"Tracks phase estimates using an explicit indicator and boundary method.","findings":[{"id":"seasonal-trajectory","name":"Seasonal trajectory","description":"Represent onset, one or more peaks and decline as estimates that may differ between indicators and subregions.","questions":[{"text":"Which indicator and persistence rule establish onset and end, and how uncertain are those estimates?","id":"seasonal-trajectory-q01","kind":"measurement"},{"text":"Does the evidence support one peak, multiple waves or an unresolved trajectory, and does that assessment vary by subregion?","id":"seasonal-trajectory-q02","kind":"measurement"}]}]},{"id":"circulating-virus-patterns","name":"Circulating virus patterns","description":"Relates observed influenza composition to the season's temporal and geographic pattern.","findings":[{"id":"virus-composition-over-time","name":"Virus composition over time","description":"Record reported type, subtype or lineage composition without assuming sampled proportions represent all infections.","questions":[{"text":"Which influenza groups are identified in each period, and what share of samples remains uncharacterised?","id":"virus-composition-over-time-q01","kind":"measurement"},{"text":"How were samples selected for characterisation, and which populations or locations do they represent?","id":"virus-composition-over-time-q02","kind":"provenance"}]}]}]},{"id":"seasonal-burden-and-severity","name":"Seasonal burden and severity","description":"Assesses outcomes and disruption attributable to the season.","layers":[{"id":"outcomes-and-attribution","name":"Outcomes and attribution","description":"Separates measured influenza outcomes from estimates and broader seasonal effects.","findings":[{"id":"influenza-associated-burden","name":"Influenza-associated burden","description":"Record consultations, admissions, deaths or other outcomes with their attribution method and uncertainty.","questions":[{"text":"Which outcomes are laboratory-confirmed, clinically assigned or statistically estimated as influenza-associated?","id":"influenza-associated-burden-q01","kind":"measurement"},{"text":"What comparator and method support the severity assessment, and how are overlapping respiratory infections handled?","id":"influenza-associated-burden-q02","kind":"provenance"}]}]},{"id":"uneven-burden-and-service-pressure","name":"Uneven burden and service pressure","description":"Examines differences hidden by season-wide totals.","findings":[{"id":"population-and-capacity-differences","name":"Population and capacity differences","description":"Relate disaggregated outcomes and service indicators to their denominators and available capacity.","questions":[{"text":"How do outcome rates vary by age group, location or setting, and where are estimates too sparse to interpret?","id":"population-and-capacity-differences-q01","kind":"measurement"},{"text":"What evidence distinguishes influenza-related service pressure from pressure caused by other concurrent demands?","id":"population-and-capacity-differences-q02","kind":"boundary"}]}]}]},{"id":"season-linked-preparedness-and-response","name":"Season-linked preparedness and response","description":"Connects seasonal evidence to locally authorised operational decisions.","layers":[{"id":"preparedness-and-escalation","name":"Preparedness and escalation","description":"Links anticipated or observed seasonal activity to documented planning and response criteria.","findings":[{"id":"local-seasonal-action-criteria","name":"Local seasonal action criteria","description":"Record current criteria for seasonal communications, prevention programmes and service readiness, with responsible decision-makers.","questions":[{"text":"Which current local guidance links flu-season timing or indicators to preparedness and escalation actions?","id":"local-seasonal-action-criteria-q01","kind":"provenance"},{"text":"Which criteria are met, what lead time is needed, and who is authorised to decide the corresponding action?","id":"local-seasonal-action-criteria-q02","kind":"action"}]}]},{"id":"de-escalation-and-season-review","name":"De-escalation and season review","description":"Supports ending seasonal measures and learning from the completed season.","findings":[{"id":"closure-and-retrospective-assessment","name":"Closure and retrospective assessment","description":"Distinguish operational stand-down from the final retrospective account of a season.","questions":[{"text":"What local criteria permit seasonal measures to end, and how is the possibility of another wave addressed?","id":"closure-and-retrospective-assessment-q01","kind":"action"},{"text":"Which conclusions remain provisional until delayed reporting and retrospective burden estimates are available?","id":"closure-and-retrospective-assessment-q02","kind":"boundary"}]}]}]},{"id":"evidence-and-external-alignment","name":"Evidence and external alignment","description":"What the world already says about this thing, gathered so the model can be checked against it.","layers":[{"id":"reported-evidence","name":"Reported evidence","description":"Findings from the breadth pass, kept separate from the structural claims.","findings":[{"id":"evidence-confidence-notes","name":"Check these first","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these check these first hold for the sense of flu season this model covers, and on what evidence?","id":"evidence-confidence-notes-q01","kind":"provenance"}]},{"id":"evidence-kinds","name":"Kinds and varieties","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these kinds and varieties hold for the sense of flu season this model covers, and on what evidence?","id":"evidence-kinds-q01","kind":"provenance"}]},{"id":"evidence-standards-and-regulation","name":"Standards and regulation","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these standards and regulation hold for the sense of flu season this model covers, and on what evidence?","id":"evidence-standards-and-regulation-q01","kind":"provenance"}]},{"id":"evidence-real-world-use","name":"Real-world use","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these real-world use hold for the sense of flu season this model covers, and on what evidence?","id":"evidence-real-world-use-q01","kind":"provenance"}]},{"id":"evidence-measurements","name":"Typical measurements","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these typical measurements hold for the sense of flu season this model covers, and on what evidence?","id":"evidence-measurements-q01","kind":"provenance"}]},{"id":"evidence-failure-modes-and-hazards","name":"Failure modes and hazards","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these failure modes and hazards hold for the sense of flu season this model covers, and on what evidence?","id":"evidence-failure-modes-and-hazards-q01","kind":"provenance"}]},{"id":"evidence-regional-variation","name":"Regional variation","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these regional variation hold for the sense of flu season this model covers, and on what evidence?","id":"evidence-regional-variation-q01","kind":"provenance"}]},{"id":"evidence-neighbours","name":"Neighbouring kinds and how to tell them apart","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these neighbouring kinds and how to tell them apart hold for the sense of flu season this model covers, and on what evidence?","id":"evidence-neighbours-q01","kind":"provenance"}]}]}]}]},"agentConduct":{"may":["Report flu activity, timing and vaccine advice from public health sources with their date and region.","Remind users of vaccination and hygiene advice published by health authorities."],"mustNot":["Declare that the flu season has started or peaked in a region without data from health authorities.","Spread unverified claims about vaccines or treatments.","Diagnose influenza in a person without a clinician.","Use health data from surveillance to identify individuals."],"requiresHuman":["Advising a high-risk person on treatment or whether to seek urgent care."]},"ethics":{"considerations":["Flu seasons kill many older people and those with chronic illness each year.","Health messages must reach people with less access to care, not just the well informed."],"affectedParties":["Older people","People with chronic illness","Health workers"]},"owners":{"steward":"Nobody owns it; public health authorities monitor and declare seasonal activity.","roles":[],"masterSystems":["National influenza surveillance systems"]},"relations":[{"target":"Q107387897","type":"parent","note":"registry parent class"}],"interaction":{"identity":{"applicability":"required","items":["Vercy registry: vr.tr.flu-season","Wikidata: Q4120645 (https://www.wikidata.org/wiki/Q4120645)"]},"properties":{"applicability":"not-applicable","items":["Season reference and naming convention: Jurisdiction-specific season label, reporting year or cross-year interval","Geographic and population coverage: Defined territory, surveillance catchment and included population","Boundary basis: Calendar convention, surveillance criterion, authority declaration, mixed or unresolved","Onset and end estimates: Dates or epidemiological weeks, with uncertainty and criterion","Current seasonal phase: Not yet elevated, rising, near peak, declining, between waves, ended or indeterminate","Influenza activity indicators: Indicator-specific counts, rates or percentages with denominators, reporting intervals and coverage","Circulating influenza composition: Reported type, subtype or lineage shares among characterised samples, including unclassified shares","Seasonal burden and severity assessment: Locally defined assessment with supporting outcomes, comparator and uncertainty"]},"recognition":{"applicability":"not-applicable","items":[]},"capabilities":{"applicability":"required","items":["Identify the applicable local flu season and explain how its boundaries were chosen.","Track progression and revise provisional onset, peak and end estimates.","Compare seasons where surveillance methods, populations and reporting intervals support comparison.","Identify populations or places whose seasonal burden differs from the aggregate.","Connect observed seasonal conditions to current local preparedness and response criteria.","Produce a season summary that preserves evidence gaps, revisions and unresolved attribution."]},"hazards":{"applicability":"required","items":["Hospital and clinic capacity can be overwhelmed at the peak.","Mismatch between vaccine and circulating strains reduces protection."]},"interfaces":{"applicability":"required","items":["International Health Regulations (2005), World Health Organization."]},"context":{"applicability":"required","items":["Flu season is a population-level time period used in influenza surveillance and health service planning.","It provides context for interpreting changes in reported infections, laboratory detections and demand for care within a particular region.","Its timing varies geographically, so a seasonal label requires a location and supporting surveillance evidence."]}},"sources":[{"title":"Wikidata item Q4120645: flu season","url":"https://www.wikidata.org/wiki/Q4120645","note":"identity and sense of the item"},{"title":"Wikipedia: Flu season","url":"https://en.wikipedia.org/wiki/Flu_season","note":"general description of the item"}],"openQuestions":["Which reference definitions should anchor the generic concept when jurisdictions use different calendar and surveillance conventions?","How should season instances be represented in places with persistent influenza circulation or multiple recurring periods of elevated activity?","Which onset, end and severity methods permit defensible comparisons across surveillance systems?","What criteria should distinguish an exceptional seasonal wave from an event requiring a separate pandemic or outbreak model?","Which current local sources establish response criteria, and how often must those sources be rechecked?"],"resources":{"spec":"/models/things/publications/thing-q4120645/spec.json"},"provenance":{"origin":"thing registry research (pass 2)","builtFrom":["models/things/publications/thing-q4120645/spec.json"],"providers":["Codex"],"researchStatus":"unreviewed","generatedAt":"2026-09-12T09:45:52Z","builder":"tools/build_cards.py@1.0.0"},"completeness":{"sections":{"classifiers":"filled","whatItIs":"filled","purpose":"filled","distinguishingFeatures":"filled","structure":"filled","agentConduct":"filled","ethics":"filled","owners":"filled","relations":"filled","interaction.identity":"filled","interaction.properties":"not-applicable","interaction.recognition":"not-applicable","interaction.capabilities":"filled","interaction.hazards":"filled","interaction.interfaces":"filled","interaction.context":"filled","sources":"filled"},"notes":{"_gate":"Published through the thing publication gate 1.0 on 2026-10-07T10:10:30+00:00: completeness 1.00; sense: Wikidata description; 2 live sources; review by codex: pass","interaction.properties":"Plane XCT: no invented physical properties.","interaction.recognition":"Flu season is inferred from population surveillance over time and cannot be identified through visual inspection."},"score":1.0}}