Which factor is a plausible introduction route for CSF into the United Kingdom?

• A. Exposure to contaminated food discarded by people on a footpath adjacent to a pig farm
• B. Import of an infected animal/animals
• C. Contaminated vaccines
• D. Transmission from an infected insect vector

Answer: (A)

Classical swine fever (CSF) can be introduced into a new area through contaminated meat or meat products and related waste that ends up with pigs. The virus can survive in pork products and on contaminated waste long enough to reach a pig population, especially if humans discard food near a farm and pigs access or contact that material. That makes contaminated human food waste an accessible, plausible introduction route for CSF.

While importing infected animals is another possible route, the scenario focuses on a pathway driven by environmental contamination near a farm, not movement of live animals. Contaminated vaccines are unlikely to introduce CSF in this context, and CSF is not transmitted by insect vectors, so that route isn’t considered plausible.