Criteria & Levels
This page provides a complete reference for the 11 evaluation criteria used in this Multi-Criteria Decision Analysis (MCDA) framework for prioritizing pig diseases.
Overview
Each disease is systematically evaluated across 11 standardized criteria. All criteria follow a harm-based framework, where levels progress from least harm to greatest harm. This consistent structure enables meaningful comparisons across diverse disease threats.
The 11 Criteria
1. Foodborne Zoonotic Transmission Potential
What it measures: Risk of human infection through consumption or handling of pork products.
Why it matters: Evaluates whether the pathogen can transmit from pigs to humans via the food chain, regardless of frequency.
Levels (least → greatest harm):
- No evidence of transmission
- Rare transmission (control failures)
- Transmission under some conditions
- Transmission despite controls
2. Non-Foodborne Zoonotic Transmission Potential
What it measures: Risk of human infection through routes other than food consumption, including occupational exposure, aerosol transmission, environmental contamination, or direct contact with infected pigs.
Why it matters: Identifies diseases that pose occupational health risks to farm workers, veterinarians, and others who work with pigs.
Levels (least → greatest harm):
- No evidence of transmission
- Rare transmission events
- Occupational/contact transmission
- Common transmission routes
3. Disease Spread Beyond Farm Biosecurity Control
What it measures: Transmission pathways that operate independently of pig-to-pig contact and undermine farm-level biosecurity.
Key principle: All diseases can spread pig-to-pig through direct/indirect contact (assumed baseline). This criterion focuses specifically on: wildlife reservoirs, insect vectors, aerosol spread beyond farm boundaries, long-term environmental persistence, and contaminated feed.
Why it matters: These pathways fundamentally limit what farms can control through biosecurity measures.
Levels (least → greatest harm):
- Farm biosecurity effective
- Some bypass of biosecurity
- Biosecurity largely ineffective
Note: Transmission via trucks, boots, clothing, equipment, and personnel is considered part of pig-to-pig transmission under imperfect biosecurity and is NOT scored under this criterion.
4. Difficulty of Detecting and Confirming Infection
What it measures: The challenge of recognizing and confirming the disease, combining both clinical recognition and diagnostic capability.
Why it matters: Reflects how quickly and reliably the disease can be identified in the field, which affects response speed and containment effectiveness.
Levels (least → greatest harm):
- Easy: distinct signs and rapid tests
- Moderate: confirmation once suspected
- Difficult: poor recognition and diagnostics
5. Financial Impact on Cost of Production
What it measures: Direct financial losses from the disease itself, including mortality, morbidity, reduced growth rates, treatment costs, and lost productivity.
Important: This does NOT include market or trade impacts (covered separately in Criterion 6).
Why it matters: Quantifies the on-farm economic burden of disease.
Levels (least → greatest harm):
- No measurable losses
- Limited losses (few pigs)
- Manageable chronic losses
- Substantial ongoing losses
- Rapid widespread losses
6. Effect on Domestic or Export Markets
What it measures: Impact on market access, prices, consumer confidence, and trade relationships resulting from disease detection.
Why it matters: Includes export restrictions, domestic movement controls, market closures, price impacts, and regulatory trade responses.
Levels (least → greatest harm):
- Little market disruption
- Temporary disruption
- Significant time-limited disruption
- Major prolonged losses
7. Pathogen's Ability to Develop and Spread Resistance
What it measures: The pathogen's biological capacity to acquire, carry, and transmit antimicrobial resistance genes to other bacteria.
Key distinction: This is about the organism's inherent characteristics, NOT about how much antimicrobial use the disease drives (that's Criterion 8).
Why it matters: Identifies pathogens that contribute to the broader AMR crisis through horizontal gene transfer.
Levels (least → greatest harm):
- Low resistance risk
- Moderate resistance risk
- High resistance risk
Note: Viruses score "Low resistance risk" because they don't carry or transmit antimicrobial resistance.
8. AMR Development Driven by Disease Management
What it measures: The extent to which controlling or treating this disease drives antimicrobial use in pig populations, creating selection pressure for resistance.
Key distinction: This is about usage patterns, NOT pathogen characteristics (that's Criterion 7).
Why it matters: More antimicrobial use creates more opportunities for resistance to develop across all bacteria on farms.
Levels (least → greatest harm):
- Minimal: Rare or short-course individual treatments
- Moderate: Common treatment or prophylactic use
- High: Frequent or large-scale antimicrobial use
9. Availability of Effective Treatment Options
What it measures: The existence and effectiveness of therapeutic interventions that can alter disease outcomes in infected animals.
Why it matters: Considers both availability and actual efficacy in field conditions.
Levels (least → greatest harm):
- Multiple effective treatments
- Effective in some situations
- Limited effectiveness
- No effective treatments
10. Availability of Effective Vaccines or Bacterins
What it measures: The existence and effectiveness of preventive vaccination options.
Why it matters: Considers vaccine efficacy, practical availability, breadth of protection, and whether vaccines are part of standard disease control programs.
Levels (least → greatest harm):
- Highly effective vaccines widely available
- Effective vaccines available but with limitations
- Vaccines exist but inconsistent protection
- No effective vaccine or bacterin available
11. Can This Disease Be Eradicated from the US?
What it measures: The biological and practical feasibility of completely eliminating the disease from domestic US pig populations using available tools and foreseeable resources.
Why it matters: Considers both technical feasibility and realistic implementation, helping prioritize diseases where eradication is achievable.
Levels (least → greatest harm):
- Can be eradicated using existing tools and knowledge
- Feasible but requires major investment of time and/or money
- Extremely difficult and with uncertain success rate
- Not feasible or extremely unlikely
- Feasibility of eradication not known
Note: The "not known" level is used for emerging diseases where eradication feasibility is genuinely uncertain.
How to Use This Framework
When evaluating a disease:
- Read the criterion description to understand what is being measured
- Review all level definitions for that criterion
- Select the level that best matches the disease characteristics
- Use the "Level Guidance" (in the detailed CSV) if uncertain between levels
- Document your rationale in the disease brief
All disease assessments should be evidence-based and draw from peer-reviewed literature, surveillance data, and expert consensus.
Key Principles
- Harm-based framing: All criteria progress from least harm → greatest harm
- Consistent application: Level definitions must be applied consistently across all diseases
- Evidence-based: Assessments should be justified with scientific evidence
- Transparent: Rationale for each level assignment is documented in disease briefs
For detailed level descriptions and usage guidance, see the complete criteria_levels.csv file in the project repository.