How is Enterobius vermicularis reliably diagnosed in school-aged children, and what preventive measures reduce transmission?

• A. Stool examination for eggs; vaccine administration to households.
• B. Blood antibody testing; avoid contact with infected individuals.
• C. Perianal cellophane/adhesive tape test; hygiene, handwashing, nail trimming, laundering bedding.
• D. Urine antigen testing; isolation of infected children in hospitals

Answer: (C)

The key idea is that pinworm infection is most reliably diagnosed by collecting eggs from the skin around the anus using a sticky adhesive tape or cellophane tape, usually done first thing in the morning before bathing. The tape is pressed to the perianal area and then examined under a microscope for the distinctive eggs; this method works well because the female worms lay eggs around the anus at night, and eggs are shed there more consistently than in stool. Stool tests often miss infection since eggs are not always present in stool, and blood or urine tests aren’t used for pinworms.

Preventing transmission relies on interrupting the cycle of spread. Good personal hygiene is essential: frequent handwashing, especially after using the toilet and before meals; keeping nails short and clean to prevent egg ingestion after scratching; avoiding scratching the perianal area. Environmental cleaning helps as well: laundering bedding, underwear, and nightclothes in hot water to kill eggs, daily washing of the perianal area, and regular cleaning of living areas to remove any eggs that may have fallen off. These measures together reduce environmental contamination and reinfection risk, which is especially important in households with several children.