AFRICAN SWINE FEVER (ASF)
LEVELS: Highly unlikely: No controls necessary; Highly unlikely: No evidence of non-foodborne zoonotic transmission; Unlikely to be effective: One or more pathways of farm-to-farm transmission exist that cannot be controlled by on-farm biosecurity; Moderate: Clinical signs not unique but existing tests available at local/regional laboratory(s); Substantial: Unsustainable acute or chronic losses related to severe clinical signs in a high prevalence of animals; Prolonged disruption: Measureable negative effect on demand for more than 6 months when disease occurs on one or more farms; Minimal risk: Agent inherently unlikely to develop clinically important resistance to antibacterial or antiviral treatments; Minimal risk: Antibacterial or antiviral treatments rarely occur, or are typically limited to short-course individual animal therapy; No availability: Effective treatments not currently available in the US (or have not been developed); No availability: Effective vaccines not currently available in the US (or have not been developed); Difficult and uncertain: Extremely difficult and with uncertain success rate, few global examples of success even at farm level
OVERVIEW
African swine fever (ASF) is a highly consequential viral disease of domestic pigs and wild suids that can cause severe hemorrhagic disease with very high mortality, depending on strain. It is not a human health (zoonotic) threat, but it is a major transboundary animal disease because it spreads efficiently through direct contact, contaminated pork products, and contaminated fomites (including trucks, equipment, clothing), and can be sustained by wild boar populations in many settings. The virus is resilient in organic material (blood, tissues, carcasses, some pork products), which supports persistence and indirect spread. Control typically relies on rapid detection, movement controls, stamping out, and intensive biosecurity; effective, widely deployable vaccines and treatments are not available for routine use.
FOODBORNE ZOONOTIC TRANSMISSION POTENTIAL
Level: Highly unlikely: No controls necessary
ASF virus does not infect humans. There is no evidence that people become infected via consuming or handling pork or pork products. "Foodborne" relevance for ASF is instead about pigs: contaminated pork products can introduce virus to pigs (e.g., swill/food waste), but that is not zoonosis.
NON-FOODBORNE ZOONOTIC TRANSMISSION POTENTIAL
Level: Highly unlikely: No evidence of non-foodborne zoonotic transmission
ASF is not transmitted from pigs to humans through occupational exposure, aerosols, or contact with pigs/pig environments. People can mechanically move the virus between pig populations on contaminated clothing/equipment, but this is not human infection.
EFFECTIVENESS OF ON-FARM BIOSECURITY IN PREVENTING FARM-TO-FARM TRANSMISSION
Level: Unlikely to be effective: One or more pathways of farm-to-farm transmission exist that cannot be controlled by on-farm biosecurity
External pathways can strongly amplify ASF spread and persistence beyond straightforward pig-to-pig contact. Key amplifiers include (1) wildlife reservoirs (wild boar) that can maintain transmission and seed reinfections, (2) environmental persistence in carcasses and contaminated organic material, and (3) pig exposure to contaminated pork products or feed-like materials (e.g., swill/food waste pathways). In some regions, soft ticks (Ornithodoros spp.) can maintain virus long-term (important globally even if less relevant to many US production contexts). The practical implication is that ASF spread is not solely governed by pig movements—persistence and reintroduction can occur via wildlife/environment/product pathways that are hard to fully control with farm-only measures.
DIFFICULTY OF DETECTING AND CONFIRMING INFECTION
Level: Moderate: Clinical signs not unique but existing tests available at local/regional laboratory(s)
ASF clinical presentation can be highly suspicious (high fever, depression, hemorrhagic signs, sudden death), but these signs are not uniquely diagnostic because they overlap with other severe systemic diseases (e.g., classical swine fever and other septicemic conditions). Confirmation therefore depends on laboratory testing. The good news is that confirmatory diagnostics (e.g., PCR) are well-established and can be deployed rapidly through competent labs once ASF is suspected. Overall, ASF is not "easy to recognise on signs alone," but it is "confirmable once suspicion is raised," which fits Moderate.
FINANCIAL IMPACT ON FARM'S COST OF PRODUCTION
Level: Substantial: Unsustainable acute or chronic losses related to severe clinical signs in a high prevalence of animals
Where virulent strains are involved, ASF can cause rapid, high mortality and abrupt loss of production capacity at affected sites. Even beyond direct mortality, the response requirements (quarantine, depopulation, disposal, cleaning/disinfection, downtime) and movement controls can make normal production untenable for affected premises and create major disruption for associated production flows. From a cost-of-production perspective, this is among the most severe disease scenarios.
EFFECT ON DOMESTIC OR EXPORT MARKETS
Level: Prolonged disruption: Measureable negative effect on demand for more than 6 months when disease occurs on one or more farms
ASF detection typically triggers immediate and significant trade consequences (loss of export market access, regionalisation negotiations, and prolonged recovery timelines). Domestic supply chains can also be heavily disrupted by movement restrictions, depopulation activities, and downstream market reactions. For an exporting industry, ASF is a classic "market shock" disease and is expected to sit at the severe end of this scale.
PATHOGEN'S ABILITY TO DEVELOP AND SPREAD RESISTANCE
Level: Minimal risk: Agent inherently unlikely to develop clinically important resistance to antibacterial or antiviral treatments
ASF is caused by a virus, so it does not itself acquire, carry, or disseminate antimicrobial resistance determinants of clinical relevance.
AMR DEVELOPMENT DRIVEN BY DISEASE MANAGEMENT
Level: Minimal risk: Antibacterial or antiviral treatments rarely occur, or are typically limited to short-course individual animal therapy
Because ASF has no effective antimicrobial therapy, ASF management does not inherently drive antimicrobial use for controlling the causal agent. (Secondary bacterial issues may be treated case-by-case, but ASF control is not antimicrobial-driven.)
AVAILABILITY OF EFFECTIVE TREATMENT OPTIONS
Level: No availability: Effective treatments not currently available in the US (or have not been developed)
There is no effective treatment that meaningfully alters ASF outcome once animals are infected. Response is based on containment and eradication measures (biosecurity, movement control, stamping out, cleaning/disinfection), not therapeutic cure.
AVAILABILITY OF EFFECTIVE VACCINES OR BACTERINS
Level: No availability: Effective vaccines not currently available in the US (or have not been developed)
There is no widely available, routinely deployable, highly effective ASF vaccine/bacterin used as a standard control tool (particularly in the US context). While vaccine research and limited-use products may exist in some settings, the practical availability of broadly applicable, validated vaccination options for routine prevention and control remains absent for the purposes of this scoring scale.
FEASIBILITY OF ERADICATING THE DISEASE FROM THE US
Level: Difficult and uncertain: Extremely difficult and with uncertain success rate, few global examples of success even at farm level
Eradication can be feasible if ASF is detected early and eliminated before it becomes established in wildlife reservoirs or widely disseminated networks. However, once ASF becomes entrenched—especially with wild boar involvement and environmental persistence—eradication becomes extremely difficult and prolonged. Given the realistic risk of establishment outside commercial herds in many outbreak scenarios, ASF sits in the "eradication extremely difficult" category rather than "not feasible in all circumstances."