Which option reflects one of the identified risks for introduction of classical swine fever to the United States?

• A. Infected non-clinical pigs and contaminated meat from an infected pig
• B. Ticks on feral swine and dogs entering the United States from abroad
• C. Hitchhiker mosquitoes from an infected country
• D. Importation of breeding stock from Canada

Answer: (A)

Classical swine fever spreads mainly through direct contact with infected pigs and via contaminated pig products. Infected pigs can shed the virus even when they look clinically normal, so seemingly healthy animals can introduce the disease if moved or sold. Contaminated pork products pose a similar risk because the virus can persist in meat and other products and infect pigs that come into contact with them or are fed them. The option describing infected non-clinical pigs and contaminated meat captures this primary risk pathway. In contrast, vectors like ticks or mosquitoes are not recognized routes for CSF transmission, and importing breeding stock from a country with CSF controls is less likely to represent an identified risk under proper biosecurity and regulatory conditions.