Criteria & Levels

8 criteria · 30 levels

Status: the framework is settled at 8 criteria. These are the criteria used to prioritize pig diseases. Individual disease briefs are being written against them and will appear on this site as they are completed.

This page is the complete reference for the 8 criteria used to prioritize pig diseases in this Multi-Criteria Decision Analysis (MCDA) framework. Criteria do not all carry the same number of levels — some have three, some four. Example diseases are given for each level to illustrate what that level is meant to capture; they are illustrations rather than fixed assignments, and a disease named as an example under one criterion carries no implied score under any other.

The concern-based ordering below is also the order in which levels are entered into 1000minds for the PAPRIKA elicitation, so that trade-off questions read consistently across very different disease threats. A printable summary is available as a PDF cheat sheet.

Levels run from least concern (Level 1) to greatest concern (highest level).

General scoring rule. Score each criterion as it would apply if the agent is, or were to be, present in the US. Being currently exotic is not itself a reason to score high. Score what would actually happen, not the alarm the agent's "foreignness" creates. Where a criterion asks what is available in the US today — a licensed vaccine, a validated assay, etc. — score today's reality. Where an agent comprises multiple serotypes, pathotypes, strains, or clinical presentations, score the typical situation represented by the registered entry rather than the most benign or the most severe possible variant. Do not score hypothetical future variants. Example diseases illustrate the intended meaning of each level — they are illustrations, not fixed assignments.

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C1: Zoonotic potential

Likelihood of transmission from pigs to humans

Description: Likelihood that the pathogen reaches humans FROM PIGS, by any route — food chain, occupational contact, environmental exposure, aerosol, or vector. Control points are the steps at which transmission can be interrupted, and control measures are what is applied at them: slaughter inspection, processing hygiene, food handling, personal protective equipment, vector control. Score likelihood only. How severe the resulting human illness is, is scored in C2. The pig must be the source: an agent that reaches people constantly by another route, but for which the pig is a dead-end host, scores Level 1. Eric, 2026-08-26, ruling on chikungunya: "C1 means reaching humans from pigs... there is a reverse zoonosis potential from Chikungunya but evidence seems like pigs are not a risk to humans. It is different for different related viruses like JEV."

#	Level label	Example diseases
1	Highly unlikely: Human infection with the agent has never been reported, or has been reported but is not attributed to pig or pork exposure	PCV2, PRRSV, Actinobacillus pleuropneumoniae
2	Rarely occurs: Human infection from pigs is plausible but has only rarely been reported, and specific control points are not commonly implemented to prevent transmission to humans	Pseudorabies Virus, Porcine Deltacoronavirus, Sarcoptic Mange
3	Sometimes occurs: Known risk of transmission to humans (foodborne or occupational), but requires failure of one or more control points for transmission to humans	Salmonella enterica serogroup B (enteric salmonellosis), Yersinia enterocolitica, Trichinella spiralis
4	Likely to occur: Transmission from pigs can occur even when control points are intact, or is prevented only by extraordinary control measures such as respiratory protection or vector control	Influenza A Virus, Japanese encephalitis virus

C2: Zoonotic impact

Severity of human illness caused by the agent

Description: Severity of the illness this agent causes in a person. Score the clinical consequences of infection only. How likely a person is to be infected FROM PIGS is C1's job, and the two are deliberately independent: Eric, 2026-09-04, "c1 and c2 are an appropriate counterbalance. c1 is about exposure to the agent (but only from pigs) while c2 is about the agent itself, regardless of where the exposure came from. It would never make sense to say tetanus in a person who got the exposure from pigs would have any diffrent outcome than if they were exposed to the agent through soil." SCORE THE ILLNESS IN AN INDIVIDUAL, NOT THE BURDEN IN A POPULATION. How many people are affected is frequency, and frequency is C1. Trichinella is the worked case: level 3 "though annual case load is very low", so a low case count does not lower the severity score. JUDGE A TYPICAL-TO-SEVERE BOUT, NOT THE TAIL. Influenza A is level 2 because "there is always a risk of a major uptick in human severity but this remains unlikely, even in the 2009 pandemic"; West Nile virus is level 2 -- "usually mild, rarely severe" -- despite a 10-30% case fatality among the under 1% who become neuroinvasive; and Staphylococcus aureus is level 3 because "not all S.aureus are drug resistant so need to avoid the temptation to put this as l4. l3 is suitable for a more general risk rating." WHERE THE AGENT IS A GROUP AND THE FAMILY PLAINLY SICKENS PEOPLE, HEDGE UPWARD. Eric on porcine reoviruses: "we will hedge to slightly higher risk L2 based on broad view of the human evidence." A LOW C1 WITH A HIGH C2 IS A NORMAL PAIR, not an inconsistency. Rabies, tetanus, botulism, eastern equine encephalitis and Hendra are all severe in people and none of them is acquired from a pig.

#	Level label	Example diseases
1	No human illness: Agent does not cause illness in people	PRRSV, PCV2, Actinobacillus pleuropneumoniae
2	Mild: Human illness is usually mild and self-limiting, and serious disease occurs only rarely	Erysipelothrix rhusiopathiae, Balantioides coli, Influenza A Virus
3	Moderate: Clinically important illness is common and may require medical treatment or hospitalization, but death or permanent disability is uncommon	Salmonella enterica serogroup B (enteric salmonellosis), Campylobacter spp., Trichinella spiralis
4	Severe: Infection carries a substantial risk of life-threatening illness, death, or permanent disability, even if human infections are uncommon	Streptococcus suis, Brucella suis, Nipah virus

C3: Herd introduction risk

Effort required to keep the agent out of the herd

Description: How hard the agent is to keep out of a herd. Score the effort required to exclude it, not the consequences if it gets in. The four levels are four tiers of one biosecurity programme: nothing to prevent because it is already there, housing alone, a routine programme, and extraordinary measures that may still fail. THE RESERVOIR IS NOT THE QUESTION. Eric, 2026-09-03: "C3 is about exclusion, not reservoirs per se... In some respects, the response is 'who cares about reservoirs'? Reservoirs really don't matter as long as you keep domestic pigs from becoming infected through biosecurity implementation. The problem is feral pigs as an example could be considered a reservoir for virtually any pig pathogen." That last clause is the argument: a reservoir test cannot discriminate, because feral swine are a reservoir for almost everything. THE OPERATIVE TEST. Housing closes the route when the route is the ground the pig stands on or the animals it grazes among -- soil, pasture, cats, sheep, cattle, carnivore faeces, human effluent. It does nothing when the route is other pigs, pig products, or something that flies. That is why anthrax is level 2 and pseudorabies is level 4: feral swine do not enter a barn either, but PRV arrives in a truck. LEVEL 2 SITS BELOW LEVEL 3 because the reference production system is modern US indoor confinement, the same reference C5 uses. A barn costs more than a quarantine protocol, but the barn already exists for the overwhelming majority of US pigs, so level 2 asks nothing beyond the status quo. Level 3 requires a programme that runs continuously and can fail. Level 2 is where the outdoor herd, and only the outdoor herd, stays exposed. Species separation belongs to level 2, not level 3 -- Eric: "species separation is done by moving pigs inside." DO NOT ARGUE ABOUT THE ADJECTIVES, READ THE LISTS. "Routine" means quarantine of incoming stock, transport and fomite control, cleaning and disinfection, and the usual monitoring. "Extraordinary" means air filtration, thermally treated feed and bedding, or repeated costly testing to find carriers. A practice is in one tier or the other because it is named, not because a scorer judged it typical. C3 ASKS HOW THE AGENT REACHES A CLEAN HERD, not how it moves within an infected one. A cycle that runs inside the building is not a soil cycle. Where more than one level applies, assign the highest. THERE IS NO "CANNOT BE EXCLUDED" LEVEL, deliberately. One existed for two days and was deleted on 2026-09-03: level 4 already ends "and may still fail", and nothing survives unlimited biosecurity. The cost, accepted openly, is that ASF and PRRSV score the same here and the permanence of a feral reservoir has no home in any of the eight criteria -- permanence shows up as consequence, in C5 and C6, and PAPRIKA adds the criteria, so a second home would give it double weight invisibly.

#	Level label	Example diseases
1	Already in the herd: Present in most herds, or carried by pigs themselves, so there is no introduction event to prevent	Streptococcus suis, Glaesserella parasuis, Escherichia coli (neonatal colibacillosis)
2	Housing alone keeps it out: Raising pigs indoors and off soil breaks the cycle, so no ongoing biosecurity program is needed and only outdoor herds stay exposed	Ascaris suum, Trichuris suis, Stephanurus dentatus
3	Routine biosecurity keeps it out: Quarantine of incoming stock, transport and fomite control, cleaning and disinfection, and the usual monitoring reliably exclude it	Salmonella Choleraesuis, Brachyspira hyodysenteriae, Progressive atrophic rhinitis (PAR)
4	Extraordinary biosecurity required: Exclusion needs measures beyond the routine, such as air filtration, thermally treated feed and bedding, or repeated costly testing to find carriers, and may still fail	PRRSV, porcine epidemic diarrhea virus, African swine fever virus

C4: Detection difficulty

Difficulty of recognizing and confirming infection

Description: How readily the disease is recognized in the field and confirmed by laboratory testing. This combines whether a practitioner would suspect the disease from clinical signs, history and epidemiology in normal practice, and whether confirmation is available without referral. The working assumption is that NVSL and FADDL can essentially test for anything, with standardized tests or with sequencing, so this criterion is about what can be recognized in routine practice and confirmed at local or regional level. "Local/regional laboratory" is applied generally across the US — one exceptional facility does not make a test locally available. Access to a NAHLN laboratory does not count as local availability for high-consequence diseases, because access is uneven, not every NAHLN laboratory runs every assay, and confirmation goes to a national laboratory in any case. Identification of a macroparasite by gross examination or necropsy counts as a routinely available test. THE AXIS IS WHETHER A VALIDATED ASSAY EXISTS AND WHERE IT CAN BE RUN. Levels 1 and 2 both require an assay of known reliability available at local or regional level. Level 3 is for one that exists but only at a reference or research laboratory. Level 4 is for no assay of known reliability anywhere. WHAT COUNTS AS VALIDATED. Not merely published. A primer set appearing in a paper means one group used it and believed the result -- it is not evidence that anyone checked it. The standard is critical evaluation: validation by a regulator, or independent evaluation by more than one laboratory, or a laboratory's own documented internal validation. Eric, 2026-08-31: "'published' likely means at least one lab has evaluated them but what we are looking for is validation by a regulator, or by multiple labs or something to that effect." VALIDATION IS THE TEST, NOT COMMERCIAL AVAILABILITY. A laboratory's own in-house primers, internally validated, count fully -- for PRRSV several laboratories deliberately use their own rather than a commercial kit, having found them to perform better, because manufacturers will not bear the cost of relicensing updated primers. Conversely, a published primer set that no laboratory has evaluated is NOT a validated assay, however easy it would be to synthesize. PCR is available everywhere and a competent laboratory can stand up a test from the literature, but an assay of unknown accuracy does not make a disease confirmable -- it makes it Level 4. This matters because diagnostic laboratories test for what is requested and what the history and lesions suggest, so agents like the minor enteric picornaviruses are never tested for at all unless the routine panel comes back negative.

#	Level label	Example diseases
1	Routine: The disease would be suspected from clinical signs, history and epidemiology in normal practice, and confirmed by tests that local or regional laboratories run routinely	Erysipelothrix rhusiopathiae, Actinobacillus pleuropneumoniae, sarcoptic mange
2	Laboratory-dependent: The presentation does not point to this disease specifically, but local or regional laboratories can confirm it with a validated assay once it is suspected	Influenza A Virus, PRRSV, Porcine Parvovirus 1
3	Reference or research laboratory required: A validated assay exists, but only at a national reference or research laboratory rather than at local or regional level	Foot-and-mouth disease (FMD), African swine fever, Hepatitis E Virus
4	No validated assay: No pathogen-specific test of known reliability exists anywhere, and identification depends on sequencing or on primers that have not been critically evaluated	Porcine norovirus, porcine sapovirus, porcine astrovirus

C5: Production cost

Financial impact on the infected farm's cost of production

Description: Direct financial losses borne by the infected farm itself, including mortality, morbidity, reduced growth rates, treatment costs, and lost productivity. Scope is limited to costs stood by a farm because it is infected. Score the magnitude of the financial effect, whether it arises from acute, chronic, or endemic disease. Follow-on consequences of one or more farms becoming infected — effects on the supply of, and demand for, pork and live pigs — belong to C6 and must not be scored here.

#	Level label	Example diseases
1	Negligible: No measurable effect on cost of production	Torque teno sus viruses, Balantioides coli
2	Minor: Small and generally short-lived losses with little effect on overall cost of production	Escherichia coli (neonatal colibacillosis), Escherichia coli (postweaning colibacillosis), Actinobaculum suis
3	Moderate: Losses measurably increase cost of production but remain manageable within normal farm operations, whether acute, chronic, or associated with endemic disease	PRRSV, PCV2, Progressive atrophic rhinitis (PAR)
4	Substantial: Severe losses cause a major and potentially unsustainable increase in cost of production	African swine fever, Porcine Epidemic Diarrhea Virus

C6: Market impact

Duration of material disruption to pork and pig markets

Description: Follow-on consequences when one or more farms become infected: effects on the supply of, and demand for, pork and live pigs, and therefore on their value. Includes export restrictions, domestic movement controls and standstills, market closures, price impacts, consumer confidence, and regulatory trade responses. A disruption is material if it produces a discernible effect on market access, price, or the ability to move pigs or pork — trivial or purely technical fluctuations do not start the clock, however long they persist. The total duration should include both the period of active farm infection and, where applicable, the additional period from cleanup of the last infected farm until normal market and trade conditions are restored. Costs borne only by the infected farm itself are C5 and must not be scored here.

#	Level label	Example diseases
1	Negligible: Little or no material disruption to supply or demand when disease occurs on one or more farms	Mycoplasma hyopneumoniae, Actinobacillus pleuropneumoniae, Pseudorabies Virus
2	Temporary disruption: Material negative effect on supply or demand lasting less than a month when disease occurs on one or more farms	Seneca Valley Virus, Swine Brucellosis
3	Significant disruption: Material negative effect on supply or demand lasting 1 to 6 months when disease occurs on one or more farms	Japanese encephalitis virus, Vesicular Stomatitis Virus, Swine Vesicular Disease Virus
4	Prolonged disruption: Material negative effect on supply or demand lasting more than 6 months when disease occurs on one or more farms	Foot-and-mouth disease (FMD), African swine fever

C7: Treatment potential

Potential for treatment to improve outcomes

Description: How much better outcomes could be if effective treatment existed. Treatment means any pathogen-directed intervention — antimicrobial, antiviral, antiparasitic, herbal or other. Score the size of the opportunity, not whether a product happens to exist today: an agent with no antiviral scores high because one could be developed, not low because none is available. Adjunctive treatment such as antipyretic or anti-inflammatory therapy does not constitute pathogen-directed treatment and should not be considered here.

#	Level label	Example diseases
1	Little: Effective pathogen-directed treatment is available and works, or animals recover acceptably without it	Escherichia coli (neonatal colibacillosis), porcine rotaviruses, Foot-and-mouth disease (FMD)
2	Some: Treatment exists but is inconsistent, requires extralabel use, or works only in some circumstances	Actinobacillus pleuropneumoniae, Mycoplasma hyopneumoniae, Staphylococcus hyicus
3	Substantial: No effective treatment (antimicrobial, antiviral, antiparasitic, herbal or other) is available, but outcomes would meaningfully improve if one existed	PEDV, PRRSV

C8: Vaccine availability

Availability of effective vaccines or bacterins

Description: Existence and effectiveness of preventive vaccination options, SCORED AGAINST WHETHER A VACCINE IS WARRANTED. Considers vaccine efficacy, practical availability in the United States, breadth of protection, and whether vaccines are part of standard disease control programs, including national response arrangements where relevant. A vaccine counts as secured for national response if it is held in a national vaccine bank, or held by a manufacturer under standing contract to USDA, or obtainable under an emergency import permit or equivalent authorization. It need not be licensed for routine commercial sale in the US, and it need not sit in a government warehouse. Release under these arrangements requires APHIS authorization rather than a veterinarian's prescription — that is a constraint on how the vaccine is used, not on whether it exists and can be got. THE ABSENCE OF A VACCINE IS ONLY A CONCERN WHERE ONE IS WARRANTED. Level 1 therefore holds two different situations that are alike in the only respect this criterion measures: a vaccine exists and works, or the disease does not justify one. An agent that is rare, subclinical, or trivial in its production impact is scored level 1 even though no product exists, because there is no unmet need to record. Level 3 is reserved for a genuine gap — no vaccine, and a disease that would warrant one. Judge "warranted" on the agent's own clinical and economic weight, not on whether a manufacturer has chosen to build a product.

#	Level label	Example diseases
1	Available, or not needed: Effective vaccines are widely available in the US or secured for national outbreak response, or the disease does not clinically or economically justify vaccinating	Escherichia coli (neonatal colibacillosis), Foot-and-mouth disease (FMD), Campylobacter spp.
2	Available but inconsistent: Commercial or autogenous vaccines exist in the US but protection may be inconsistent	PRRSV, Influenza A Virus, Clostridium perfringens type A
3	Needed but not available: No effective vaccine is available in the US or has been developed, and the disease would justify vaccinating if one existed	African swine fever, Japanese encephalitis virus