Veterinary Technician Practice Exam 2025 – 400 Free Practice Questions to Pass the Exam

The correct answer, indicating that transmission occurs when an animal ingests a paratenic host, is not considered a direct mode of parasite transmission because it involves an intermediate host in the transmission process. In this scenario, the paratenic host harbors the parasite without being part of its lifecycle, allowing the parasite to remain viable and be transferred to the final host when ingested.

Direct modes of transmission, on the other hand, generally involve immediate contact or interaction between the infected host and the susceptible new host. For example, transmission from mother to offspring occurs via direct contact during gestation or via nursing, direct contact involves physical interaction that allows for parasites to transfer, and bites involve the transfer of parasites through the saliva of an insect vector directly into the bloodstream of the host. In contrast, ingestion of a paratenic host represents an indirect method because it requires an additional organism to facilitate the parasite's transfer.