bovine spongiform encephalopathy
Enable an agent to recognise suspected bovine spongiform encephalopathy, assess diagnostic and exposure evidence, and identify justified surveillance and control 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 suspected bovine spongiform encephalopathy, assess diagnostic and exposure evidence, and identify justified surveillance and control actions.
Bovine spongiform encephalopathy (BSE) is a fatal, transmissible neurodegenerative disease of cattle associated with abnormal prion protein accumulation and characteristic spongiform changes in the brain.
It can be Assemble a BSE suspicion record for veterinary assessment while preserving alternative diagnoses.; Identify missing specimen, assay or reference-laboratory evidence needed to resolve diagnosis and typing.; Trace plausible feed exposures and shared-exposure cohorts with explicit confidence levels.; Identify applicable reporting, movement and material-disposition requirements for competent-authority review.; Check whether surveillance findings support a stated population-level conclusion.; Link potential human exposure to the appropriate public-health investigation without diagnosing vCJD..
Distinguishing features
Require evidence of a bovine prion disease; neurological behaviour alone does not establish BSE. [WOAH diagnostic manual](https://www.woah.org/app/uploads/2021/03/3-04-05-bse-1.pdf)
Distinguish C-type from H-type and L-type using laboratory characterisation, rather than age or feed history alone. [WOAH diagnostic manual](https://www.woah.org/app/uploads/2021/03/3-04-05-bse-1.pdf)
Separate classical BSE's contaminated-feed association from atypical BSE's presumed spontaneous occurrence; do not assign an individual case's origin solely from that general distinction. [WOAH BSE overview](https://www.woah.org/en/disease/bovine-spongiform-encephalopathy/)
Keep human vCJD as a related disease, not a synonym or bovine case subtype. [FDA BSE questions and answers](https://www.fda.gov/vaccines-blood-biologics/safety-availability-biologics/bovine-spongiform-encephalopathy-bse-questions-and-answers)
Scope
+ Classical C-type and atypical H-type and L-type BSE, including unresolved typing
+ Bovine clinical suspicion, progression and laboratory-supported case classification
+ Feed exposure histories and epidemiologically relevant animal cohorts
+ BSE-specific tissue, carcass and food-chain control decisions
+ Surveillance interpretation and links to dated official BSE risk assessments
- Human variant Creutzfeldt-Jakob disease diagnosis and management
- Scrapie, chronic wasting disease and other distinct animal prion diseases
- General cattle husbandry and complete lifetime animal records
- Prion molecular biology beyond evidence needed to identify and distinguish BSE
- Complete feed-production, food-recall and international trade models
Characteristics
- BSE diagnostic standing
- suspected; screening-reactive; confirmed; inconclusive; not detected in tested specimen; excluded under cited criteria Prevents suspicion, screening reactivity and confirmed disease from being treated as equivalent.
- BSE type
- classical C-type; atypical H-type; atypical L-type; unresolved; not assessed Supports type-specific interpretation without forcing a classification before laboratory evidence exists.
- Age at clinical onset or detection
- months, with event date and age-estimation uncertainty Allows age-pattern assessment while keeping onset distinct from surveillance detection.
- Neurological presentation
- dated observations of behaviour, sensory responses, gait and ability to rise; absent; present; unobserved Captures the presentation supporting veterinary suspicion and its progression.
- Diagnostic specimen and result
- animal linked to tissue, anatomical site, collection date, sample condition, assay, laboratory and report Makes diagnostic conclusions traceable to the actual material examined.
- Potential feed exposure
- dated links to feed batches, suppliers and shared-feed cohorts; documented, suspected or unknown Supports source investigation without treating missing feed records as absence of exposure.
- Food and feed chain disposition
- unknown; held; excluded; disposal pending; disposal verified; possible distribution under investigation Shows whether affected material has been accounted for and whether further tracing is needed.
- Applicable BSE authority
- jurisdiction, competent authority, instrument version, effective date and applicable disease type Anchors reporting and control decisions to the correct rules.
Where this came from
wikidata · CC0 1.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 6 bundles · 11 layers · 18 findings · 28 questions.
BSE identity and type Establish the disease boundary and the evidence supporting its classical or atypical classification.
BSE must remain distinct from both nonspecific bovine neurological illness and neighbouring prion diseases.
Bovine disease boundary
Identify what qualifies as an instance of this registered disease.
Bovine prion disease identity
BSE is a fatal neurological prion disease of bovines; the model must distinguish its disease identity from a reporting case definition. [WOAH BSE chapter](https://www.woah.org/fileadmin/Home/eng/Health_standards/tahc/2024/en_chapitre_bse.htm)
- What bovine host and disease evidence place this record within BSE? definition
- Does the record describe disease, exposure, a clinical suspect or an administrative case classification? boundary
Classical and atypical classification
Preserve the distinction among C-type, H-type and L-type and unresolved results.
Laboratory-supported type
Classical and atypical phenotypes are distinguished through laboratory characterisation, including Western immunoblot patterns. [WOAH diagnostic manual](https://www.woah.org/app/uploads/2021/03/3-04-05-bse-1.pdf)
- Which laboratory report supports C-type, H-type or L-type classification? provenance
- What uncertainty or conflicting result requires the type to remain unresolved? boundary
Clinical course and confirmation Connect observed neurological changes to appropriately qualified diagnostic conclusions.
An agent must recognise suspicion without mistaking clinical appearance for confirmation.
Neurological presentation
Capture onset, progression and competing explanations for observed signs.
Progressive signs with differentials
Incoordination, difficulty rising and behavioural changes can accompany BSE; record their chronology and veterinary interpretation. [FDA BSE overview](https://www.fda.gov/animal-veterinary/animal-health-literacy/all-about-bse-mad-cow-disease)
- Which neurological changes were observed, by whom, and how did they progress? measurement
- Which alternative explanations have been assessed, and what remains unresolved? boundary
Postmortem diagnostic evidence
Track specimens and testing from initial result to final interpretation.
Specimen-dependent confirmation
Confirmation relies on detecting disease-associated prion protein in brain tissue; clinical assessment of a living animal does not provide equivalent confirmation. [WOAH diagnostic manual](https://www.woah.org/app/uploads/2021/03/3-04-05-bse-1.pdf)
- What brain region, specimen condition, assay and laboratory support the result? provenance
- Does the evidence support confirmation, further testing or only a qualified negative result? action
Origin and exposure investigation Reconstruct plausible acquisition pathways and epidemiological links without overstating causation.
Classical and atypical BSE require different origin interpretations, while both require accountable case investigation.
Feed pathway reconstruction
Connect classical BSE investigations to historical feeding and supply records.
Contaminated feed hypothesis
Classical BSE is associated with ingestion of prion-contaminated feed; a case-specific source attribution still requires evidence. [WOAH BSE overview](https://www.woah.org/en/disease/bovine-spongiform-encephalopathy/)
- Which feed batches, ingredients, suppliers and feeding dates can be reconstructed? provenance
- What evidence separates a plausible feed pathway from a demonstrated exposure link? boundary
Atypical origin and cohort links
Keep presumed origin separate from observed animal relationships.
Origin uncertainty
Atypical BSE is believed to arise spontaneously; that population-level interpretation does not establish the cause of an individual case. [WOAH BSE overview](https://www.woah.org/en/disease/bovine-spongiform-encephalopathy/)
- What supports the proposed origin, and which alternative explanations remain open? provenance
- Which animals share relevant feed or rearing histories, rather than merely current location? boundary
Surveillance and risk interpretation Interpret detected cases and negative surveillance within their sampling and administrative context.
A tested animal, a herd investigation and an official population risk designation answer different questions.
Surveillance detection context
Record how an animal entered testing and what the programme could detect.
Sampling frame and detection
Record the tested population, selection criteria and diagnostic coverage before drawing conclusions from case counts.
- Was the animal tested because of neurological suspicion, fallen-stock surveillance or another defined pathway? provenance
- What denominator, age distribution, period and testing coverage accompany the reported detections? measurement
Official risk status context
Link population assessments to their issuer, territorial scope and effective period.
Dated status and case definition
Official BSE risk recognition is an authority-issued population assessment; retain its date and criteria separately from individual diagnosis. [WOAH BSE overview](https://www.woah.org/en/disease/bovine-spongiform-encephalopathy/)
- Which official decision establishes the claimed status, for what territory and date? provenance
- How does the applicable framework treat classical and atypical detections? boundary
Case control and exposure prevention Connect case evidence to authorised action and accountable management of potentially affected material.
The operational value of recognising BSE is preventing further exposure while preserving evidence and authority.
Veterinary authority response
Track escalation, decisions and completion under the applicable BSE response framework.
Case response authority
BSE has no available treatment or preventive vaccine; response records therefore need explicit veterinary decisions and control responsibilities. [FDA BSE overview](https://www.fda.gov/animal-veterinary/animal-health-literacy/all-about-bse-mad-cow-disease)
- Which current jurisdictional rule determines notification and response for this case classification? provenance
- Which competent authority owns the next action, and what evidence will establish its completion? action
Material disposition and human interface
Account for potentially affected tissues and connect exposure concerns to the appropriate investigation.
Food and feed exposure accountability
The link between the classical BSE agent and human vCJD makes food-chain exposure relevant, while human disease assessment remains outside this model. [WOAH diagnostic manual](https://www.woah.org/app/uploads/2021/03/3-04-05-bse-1.pdf)
- Where are the carcass and derived materials, and what records verify their hold, exclusion or disposal? provenance
- Does possible distribution require an authority-led feed, food or public-health investigation? action
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 a recall-based account; no sources were consulted.
- Check current regulatory texts and WOAH country risk designations before operational use.
- Atypical BSE is generally considered sporadic, but its origins and relationship to classical BSE warrant careful qualification.
- Which of these check these first hold for the sense of bovine spongiform encephalopathy this model covers, and on what evidence? provenance
Kinds and varieties
Recalled without web access and unsourced; every item is a lead to verify.
- Classical BSE, associated with exposure to prion-contaminated feed
- Atypical H-type BSE, distinguished by a higher apparent molecular mass of the unglycosylated protease-resistant prion protein fragment
- Atypical L-type BSE, distinguished by a lower apparent molecular mass of that fragment
- Which of these kinds and varieties hold for the sense of bovine spongiform encephalopathy 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 Organisation for Animal Health (WOAH) Terrestrial Animal Health Code: provisions for BSE surveillance, risk status and international trade.
- WOAH Manual of Diagnostic Tests and Vaccines for Terrestrial Animals: diagnostic standards for BSE.
- European Parliament and Council Regulation (EC) No 999/2001: rules for preventing, controlling and eradicating certain transmissible spongiform encephalopathies.
- United States Food and Drug Administration feed rules: restrictions on specified mammalian proteins and cattle materials in animal feed.
- Which of these standards and regulation hold for the sense of bovine spongiform encephalopathy this model covers, and on what evidence? provenance
Real-world use
Recalled without web access and unsourced; every item is a lead to verify.
- Veterinary differential diagnosis of progressive neurological disease in cattle.
- Surveillance and laboratory testing supporting national BSE risk assessments.
- Design of feed controls that prevent recycling infectious cattle material.
- Identification and removal of specified risk materials from food and feed chains.
- Assessment of animal and animal-product import conditions.
- Which of these real-world use hold for the sense of bovine spongiform encephalopathy 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 of classical BSE - Usually several years, commonly approximately 4-5; varies with exposure and dose - years
- Apparent molecular mass of the unglycosylated protease-resistant prion protein fragment - Higher in H-type and lower in L-type than in classical BSE under comparable test conditions - kDa
- Which of these typical measurements hold for the sense of bovine spongiform encephalopathy 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.
- Classical BSE exposure through contaminated food is causally linked to variant Creutzfeldt-Jakob disease in humans.
- Recycling infected tissues into cattle feed can amplify transmission.
- Long incubation permits infected cattle to appear healthy for years.
- Prions resist many routine disinfection and food-processing conditions.
- Clinical signs are not specific, and confirmation generally requires postmortem brain-tissue testing.
- Which of these failure modes and hazards hold for the sense of bovine spongiform encephalopathy this model covers, and on what evidence? provenance
Regional variation
Recalled without web access and unsourced; every item is a lead to verify.
- The historical classical BSE epidemic was concentrated in the United Kingdom, with cases also detected elsewhere.
- Surveillance systems, specified-risk-material definitions and trade conditions differ among jurisdictions.
- Atypical BSE has been detected in several countries, predominantly in older cattle.
- Which of these regional variation hold for the sense of bovine spongiform encephalopathy 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.
- Transmissible spongiform encephalopathy - The broader disease family; BSE is its cattle-associated member.
- Scrapie - A distinct prion disease principally affecting sheep and goats.
- Chronic wasting disease - A distinct prion disease affecting cervids such as deer and elk.
- Variant Creutzfeldt-Jakob disease - A human prion disease linked to the classical BSE agent, rather than the disease of cattle itself.
- Bovine spongiform encephalopathy prion - The infectious agent; BSE denotes the disease it causes.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of bovine spongiform encephalopathy this model covers, and on what evidence? provenance
What the second pass must settle
- Which current reference-laboratory algorithms and specimen requirements should govern confirmation and C/H/L discrimination in the intended jurisdiction?
- How should emerging evidence about atypical BSE origins, including possible genetic contributions, change individual-case attribution?
- What type-specific evidence is sufficient to characterise atypical BSE zoonotic risk without transferring conclusions from classical BSE?
- Which surveillance sensitivity criteria justify population-level conclusions when detections are rare and historical feed records are incomplete?
- Which current local rules govern reporting, cohort investigation, specified risk material and disposal for each BSE classification?