Understanding Biosecurity Risk Levels
Swine biosecurity operates at three levels that must be addressed in an integrated program.
External biosecurity (preventing pathogen introduction):
- Source of animals — purchase from high-health-status, PRRS-negative or -stable herds when possible
- Quarantine and testing of all new introductions
- Personnel downtime requirements (typically 24–48 hours after visiting other swine farms)
- Vehicle and equipment disinfection protocols
- Rodent and bird control (fomite vectors for PCV2, Salmonella, and potentially ASF)
Internal biosecurity (preventing pathogen spread within the facility):
- All-in/all-out production flow (prevents age-group commingling and pathogen recycling)
- Dedicated tools, boots, and clothing for each room or barn section
- Traffic flow patterns — move from youngest to oldest animals
- Prompt removal and proper disposal of dead animals
- Separate manure-handling equipment from animal-contact equipment
External biosecurity for the community (neighborhood biosecurity):
- Coordination with neighboring farms on movement schedules
- Avoiding purchasing animals through sale barns or livestock auctions (highest-risk source)
- Participating in area disease surveillance programs
- Reporting suspected FAD signs immediately (African Swine Fever, Foot-and-Mouth Disease)
Risk tiers by entry route:
1. Live animal introductions — highest risk
2. People (personnel, visitors, service technicians) — high risk
3. Vehicles and equipment — moderate to high risk
4. Feed and water — low to moderate risk
5. Air (aerosol transmission) — variable, range-dependent (PRRS: up to 9 km under optimal conditions)
African Swine Fever (ASF) Preparedness
African Swine Fever is a priority foreign animal disease for the North American swine industry. As of 2026, ASF has not been confirmed in the continental U.S., but the proximity of confirmed cases in the Caribbean (Dominican Republic, 2021; Haiti, 2021) and its rapid global spread make preparedness planning mandatory.
Key ASF facts for biosecurity planning:
- Caused by a large DNA arbovirus; no vaccine is commercially available in the U.S.
- Highly lethal (up to 100% mortality in naive herds with virulent strains)
- Stable in the environment: survives months in frozen pork products, weeks in carcasses, and days on fomites
- Not a human health concern — does not affect people
- Transmitted by direct animal contact, contaminated pork products (fed to pigs), infected fomites (vehicles, boots, clothing), and the Ornithodoros soft tick (in areas where the tick is established)
Biosecurity actions specific to ASF risk:
- NEVER feed garbage or table scraps to swine (illegal in most U.S. states; major ASF introduction risk from imported pork products)
- Control access to facilities housing international travelers who may have recently visited ASF-affected countries
- Implement premises identification (USAHERDS or your state system) to enable rapid trace-forward/trace-back
- Know how to recognize ASF clinical signs: sudden death, high fever (104–107°F), reddening/purple discoloration of skin (ears, snout, abdomen), vomiting, diarrhea, incoordination
- Report any suspected FAD to your state veterinarian or USDA APHIS immediately (do not wait for a diagnosis)
- Enroll in USDA Secure Pork Supply Plan to ensure continued operation during a regional outbreak
USDA APHIS Emergency contact: 1-866-536-7593
