What is the mode of transmission for pinworms?

The correct answer is the mode of transmission for pinworms is the ingestion of eggs. Pinworms, specifically Enterobius vermicularis, are transmitted primarily when their microscopic eggs are ingested. This typically occurs when a person unintentionally swallows eggs from contaminated surfaces, such as hands that have touched the anal area after scratching, or through contaminated clothing, bedding, or household items. The eggs can survive for extended periods on surfaces, making it easy for them to be transferred to the mouth, especially in children.

The other modes of transmission listed in the choices do not apply to pinworm infections. Contaminated water is a common mode of transmission for other types of parasites but not pinworms. Inhalation is not a route of transmission for pinworms, as they are not spread through respiratory means. Lastly, a bite from an infected insect is characteristic of certain other parasites, like those that cause malaria or Lyme disease, but it is not how pinworms are transmitted. Therefore, the ingestion of eggs is the definitive route by which pinworms infect an individual.