leptospirosis
Enable an agent to recognise leptospirosis, assess the evidence and severity of a suspected episode, and identify appropriate clinical and public-health actions.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
recalled by Codex without web access - no source was read
Researched by: Codex
Purpose and description
Enable an agent to recognise leptospirosis, assess the evidence and severity of a suspected episode, and identify appropriate clinical and public-health actions.
Leptospirosis is a zoonotic infection caused by pathogenic bacteria of the genus Leptospira, usually acquired through contact with infected animal urine or contaminated water or soil, with manifestations ranging from asymptomatic infection to life-threatening multiorgan disease.
It can be Assemble an exposure and illness timeline to assess compatibility with leptospirosis.; Identify missing diagnostic evidence and questions for the responsible clinician or laboratory.; Flag documented deterioration or organ involvement for clinical review.; Retrieve applicable management guidance using host, severity, jurisdiction and guideline version.; Classify surveillance eligibility separately from clinical diagnostic confidence.; Link potentially related cases for investigation while preserving uncertainty about a shared source..
Distinguishing features
Require evidence connecting illness to Leptospira; fever or a history of flood exposure alone cannot distinguish leptospirosis.
Record contact with potentially urine-contaminated water, soil or animals as exposure evidence, separately from proof of infection.
Use the combination of clinical findings, exposure history and laboratory evidence to distinguish suspected leptospirosis from alternatives such as dengue or malaria.
Distinguish severe manifestations, including renal, hepatic or pulmonary involvement, from the broader disease concept; their absence does not exclude leptospirosis.
Distinguish an antibody finding from a supported current episode by retaining specimen timing and the applicable interpretation criteria.
Scope
+ Leptospira-associated disease and host-specific applicability
+ Animal and environmental exposure pathways
+ Time-dependent laboratory evidence and diagnostic uncertainty
+ Clinical course, organ involvement and recovery
+ Disease-specific management, prevention and surveillance requirements
- The patient's complete health record
- Leptospira taxonomy and organism biology beyond disease attribution
- Independent models of animal reservoirs and contaminated environments
- Drug formularies, prescribing systems and care-encounter administration
- Other febrile diseases except as differential diagnoses
Characteristics
- Host species and clinical context
- Human or named animal species; clinical illness, asymptomatic infection or unresolved Human diagnostic and management rules must not be transferred automatically to animal hosts.
- Exposure-to-onset interval
- Days, with earliest and latest plausible exposure dates Supports assessment of temporal compatibility without inventing a precise infection date.
- Time from symptom onset to specimen collection
- Days; unknown onset explicitly permitted Leptospiral test interpretation depends on when and where material was collected.
- Diagnostic assertion
- Suspected, supported, confirmed, excluded or unresolved under a named clinical framework Makes certainty traceable to evidence rather than treating a disease label as proof.
- Laboratory evidence
- Linked specimen, assay, result, laboratory, collection date and interpretation Preserves the basis for confirming or challenging a diagnostic assertion.
- Organ involvement
- Renal, hepatic, pulmonary, neurological and other assessed involvement; absent, present or unknown Supports severity assessment and escalation without reducing the disease to jaundice alone.
- Disease course
- Acute illness, deterioration, recovery, persistent manifestations, death or unresolved Allows longitudinal assessment without assuming every episode follows the same phases.
- Terminology mapping
- Verified ICD-10, ICD-11 or SNOMED CT concept with edition, jurisdiction and mapping scope Prevents silent equivalence between codes for the disease and particular manifestations.
- Population burden
- Cases, incidence per defined population and period, or prevalence with denominator and year Separates reported disease from estimated burden and serological exposure.
Also called
Where this came from
wikidata · CC0 1.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 7 bundles · 13 layers · 21 findings · 33 questions.
Disease identity and boundaries Establish what the leptospirosis concept covers and how assertions about it are represented.
An exposure, infection, clinical diagnosis and care encounter must not become interchangeable records.
Causal and host scope
Define the disease while retaining the host context needed to interpret evidence.
Leptospira-associated disease
Leptospirosis affects people and animals; host-specific rules require explicit applicability. Reference: [CDC clinical overview](https://www.cdc.gov/leptospirosis/hcp/clinical-overview/index.html).
- What evidence attributes this illness to Leptospira, and in which host species? definition
- Does this assertion concern clinical disease, asymptomatic infection, exposure or a reservoir state? boundary
Terminology and assertions
Keep the registered disease separate from codes, manifestations and diagnostic claims.
Versioned disease mapping
Require reviewed terminology mappings and explicit relationships between leptospirosis and narrower severe presentations.
- Which ICD-10, ICD-11 and SNOMED CT identifiers apply in the selected editions and jurisdiction? provenance
- Does a label such as Weil disease denote a narrower presentation rather than the entire leptospirosis concept? boundary
Exposure and acquisition Represent plausible acquisition pathways and the strength of source attribution.
Exposure history informs suspicion, but an environmental association does not establish where infection occurred.
Animal and environment interface
Connect relevant contact events to possible animal or environmental sources.
Urine-associated exposure
Record potentially contaminated water, soil and animal contact, including flood-related exposures. Reference: [CDC clinical overview](https://www.cdc.gov/leptospirosis/hcp/clinical-overview/index.html).
- Which occupational, household or recreational contacts involved potentially contaminated water, soil or animals? provenance
- Is contamination supported by investigation or only inferred from the setting? boundary
Exposure timing and linkage
Preserve uncertainty in exposure dates and links between cases.
Plausible acquisition window
Represent candidate exposure intervals and competing source hypotheses without assigning an unsupported infection date.
- What interval separates each candidate exposure from symptom onset, including date uncertainty? measurement
- What epidemiological or laboratory evidence supports linking this episode to an animal, location or cluster? provenance
Diagnostic evidence Organise clinical suspicion and laboratory interpretation around the illness timeline.
Symptoms are nonspecific, and test results require specimen and timing context.
Clinical differentiation
Assess compatible illness while retaining competing explanations.
Compatible but nonspecific presentation
Fever, myalgia, conjunctival suffusion and jaundice may inform assessment but do not independently establish the disease. Reference: [CDC clinical overview](https://www.cdc.gov/leptospirosis/hcp/clinical-overview/index.html).
- Which compatible findings are documented, absent or not assessed? measurement
- Which locally relevant alternatives, including dengue and malaria where applicable, remain unresolved? boundary
Specimen and assay interpretation
Interpret molecular and antibody evidence using collection timing and laboratory criteria.
Time-qualified test evidence
Retain specimen type, illness day, PCR results and serological evidence; MAT is a reference serological method. Reference: [CDC Yellow Book](https://www.cdc.gov/yellow-book/hcp/travel-associated-infections-diseases/leptospirosis.html).
- Which specimen and assay were used, on what illness day, and with what result and laboratory interpretation? measurement
- Do negative, isolated antibody or discordant results require repeat sampling or reference-laboratory review under the applicable guidance? action
Course and severity Track disease evolution and manifestations that change urgency.
A positive diagnostic result does not describe current severity or subsequent recovery.
Organ involvement
Assess disease-associated dysfunction using observations and trends.
Severity-driving manifestations
Track renal, hepatic, respiratory and neurological complications with attribution confidence. Reference: [CDC clinical overview](https://www.cdc.gov/leptospirosis/hcp/clinical-overview/index.html).
- What do renal function, urine output, bilirubin, oxygenation and neurological observations show over time? measurement
- Which findings meet the applicable clinical thresholds for urgent escalation? action
Trajectory and outcome
Separate observed progression from assumed disease stages.
Episode resolution and persistence
Record deterioration, recovery and persistent manifestations without assuming discharge proves resolution.
- Which dated observations demonstrate improvement, recurrence of symptoms or persistent dysfunction? measurement
- What evidence distinguishes continuation of this episode from reinfection or another condition? boundary
Management and prevention Connect disease evidence to supervised treatment and exposure-reduction decisions.
Clinical urgency, treatment suitability and preventive interventions depend on different evidence.
Clinical management
Identify applicable treatment guidance and document the basis for action.
Treatment decision context
CDC advises early antibiotics when clinical suspicion is high; record the clinician's decision and applicable guidance. Reference: [CDC clinical overview](https://www.cdc.gov/leptospirosis/hcp/clinical-overview/index.html).
- Which guideline version governs treatment for this host, severity and clinical setting? provenance
- What antimicrobial and supportive-care decisions require clinician review given allergies, pregnancy, age and organ function? action
Exposure reduction
Match prevention decisions to the actual exposure setting.
Context-specific prevention
Record feasible exposure controls and require separate evidence for prophylaxis or vaccination policies.
- Which changes to water contact, protective equipment, sanitation or animal management address the documented pathway? action
- What host-specific and jurisdiction-specific guidance supports any proposed prophylaxis or vaccination? provenance
Surveillance and burden Support reporting, cluster assessment and interpretation of population estimates.
Surveillance classification and population burden must remain distinct from individual clinical diagnosis.
Case definition and reporting
Apply the correct surveillance framework without substituting it for clinical judgment.
Versioned surveillance classification
Surveillance definitions serve case counting rather than individual diagnosis; preserve issuing body, jurisdiction and revision. Reference: [CDC 2025 case definition](https://ndc.services.cdc.gov/case-definitions/leptospirosis/).
- Which case-definition revision applies, and which clinical, laboratory and epidemiological criteria are satisfied? provenance
- What reporting or cluster-investigation action is required by the applicable local authority? action
Population measurement
Make burden estimates comparable only when their populations and methods support comparison.
Qualified burden estimate
Require location, year, population, denominator, case definition and ascertainment method for every burden claim.
- Does this estimate measure reported cases, clinical incidence, infection prevalence, seropositivity or deaths? definition
- What population, period, uncertainty interval and adjustments for missed cases support the estimate? measurement
Evidence and external alignment What the world already says about this thing, gathered so the model can be checked against it.
A model that cannot be lined up against existing standards, identifiers and practice cannot be adopted by anyone who already uses them.
Reported evidence
Findings from the breadth pass, kept separate from the structural claims.
Check these first
Recalled without web access and unsourced; every item is a lead to verify.
- This is recalled knowledge, not a researched or source-verified account; confirm current guidance, surveillance definitions and terminology identifiers.
- Clinical categories overlap and are not a mutually exclusive formal classification; diagnostic thresholds depend on the assay and issuing authority.
- No population-specific incidence or prevalence estimate is supplied; any estimate needs a location, observation period and case-ascertainment method.
- Which of these check these first hold for the sense of leptospirosis this model covers, and on what evidence? provenance
Kinds and varieties
Recalled without web access and unsourced; every item is a lead to verify.
- Asymptomatic infection
- Anicteric leptospirosis
- Icteric leptospirosis, including Weil disease
- Leptospirosis with severe pulmonary haemorrhage
- Which of these kinds and varieties hold for the sense of leptospirosis this model covers, and on what evidence? provenance
Identifiers and schemes
Recalled without web access and unsourced; every item is a lead to verify.
- WHO ICD-10 - A27 - Category for leptospirosis; subcodes distinguish specified forms. Record the ICD revision and any national modification.
- SNOMED CT - Numeric concept identifier - The exact disease concept identifier and terminology edition require verification.
- Which of these identifiers and schemes hold for the sense of leptospirosis this model covers, and on what evidence? provenance
Standards and regulation
Recalled without web access and unsourced; every item is a lead to verify.
- World Health Organization: Human leptospirosis: guidance for diagnosis, surveillance and control.
- US Council of State and Territorial Epidemiologists and CDC: leptospirosis surveillance case definitions; the applicable revision must accompany their use, and surveillance definitions are not individual clinical diagnostic rules.
- Which of these standards and regulation hold for the sense of leptospirosis this model covers, and on what evidence? provenance
Real-world use
Recalled without web access and unsourced; every item is a lead to verify.
- Clinical recognition of a febrile illness associated with animal, freshwater, floodwater or occupational exposure.
- Laboratory investigation using molecular detection, serology and, less commonly, culture.
- Public-health surveillance and investigation of outbreaks after flooding or shared environmental exposure.
- Occupational and recreational exposure prevention.
- Coordinated human, animal and environmental disease control.
- Which of these real-world use hold for the sense of leptospirosis this model covers, and on what evidence? provenance
Typical measurements
Recalled without web access and unsourced; every item is a lead to verify.
- Incubation period - Usually 5-14; reported range approximately 2-30 - days
- Which of these typical measurements hold for the sense of leptospirosis this model covers, and on what evidence? provenance
Failure modes and hazards
Recalled without web access and unsourced; every item is a lead to verify.
- Nonspecific early symptoms can delay recognition or lead to confusion with other febrile diseases.
- Early serology can be negative; test interpretation depends on illness timing, specimen type and local epidemiology.
- Severe infection can cause acute kidney injury, jaundice, haemorrhage and circulatory failure.
- Pulmonary haemorrhage can be rapidly fatal and may occur without the classic jaundiced presentation.
- Animal reservoirs and contaminated environments can sustain exposure after individual cases are treated.
- Which of these failure modes and hazards hold for the sense of leptospirosis this model covers, and on what evidence? provenance
Regional variation
Recalled without web access and unsourced; every item is a lead to verify.
- Transmission occurs worldwide but is especially associated with tropical settings, heavy rainfall, flooding and inadequate sanitation.
- Reservoir animals and circulating pathogenic species and serovars vary geographically.
- Notification requirements, laboratory access and surveillance practices differ between jurisdictions, limiting direct comparisons of reported incidence.
- Which of these regional variation hold for the sense of leptospirosis this model covers, and on what evidence? provenance
Neighbouring kinds and how to tell them apart
Recalled without web access and unsourced; every item is a lead to verify.
- Weil disease - A severe manifestation of leptospirosis classically involving jaundice and renal impairment, often with haemorrhage; it does not encompass all leptospirosis.
- Dengue - A mosquito-borne viral infection; overlapping clinical features require pathogen-specific testing and exposure assessment to distinguish it from leptospirosis.
- Hantavirus infection - A viral infection associated with rodent exposure that can also cause renal or pulmonary disease; laboratory identification separates the causes.
- Leptospira - The bacterial genus contains the causative organisms; leptospirosis is the infection, not the organism, patient, diagnostic label or episode of care.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of leptospirosis this model covers, and on what evidence? provenance
What the second pass must settle
- Does an existing Vercy world model already own this disease concept, requiring a registry link rather than a separate publication?
- Which exact ICD-10, ICD-11 and SNOMED CT mappings are valid for the selected editions, including narrower severe presentations?
- Which host-specific clinical and laboratory criteria should be supported, and how should human and veterinary guidance be separated within this single registry entry?
- Which regional assay interpretation rules, management guidance and prevention policies are sufficiently evidenced and current?
- Which population- and year-specific burden estimates and follow-up evidence adequately distinguish clinical illness, asymptomatic infection and persistent manifestations?