Which parasites are mosquitoes capable of transmitting as vectors?

• A. Tapeworms
• B. Heartworms
• C. Pinworms
• D. Strongyles

Answer: (B)

Mosquitoes can act as vectors for parasites that have a life cycle requiring an intermediate host to reach an infectious stage. In veterinary medicine, heartworms are the classic example. The parasite Dirofilaria immitis circulates as microfilariae in an infected animal’s blood. A mosquito bites the animal and ingests these microfilariae, which develop into infective larvae inside the mosquito. When the same mosquito bites another animal, it transmits the larvae, which then mature into adult heartworms in the heart and pulmonary arteries. This transmission route specifically involves the mosquito as a vector.

Tapeworms, pinworms, and strongyles have transmission methods that do not involve mosquitoes. Tapeworms are spread through fleas or by ingesting intermediate hosts; pinworms spread via contact with contaminated bedding or environment; strongyles are typically acquired by ingesting larvae or eggs from contaminated soil or feed.