Enterobius vermicularis infection is usually diagnosed by detecting eggs in which sample?

Enterobius vermicularis infection is usually diagnosed by detecting eggs in which sample?

• A. Larvae in feces
• B. Larvae in perianal specimens
• C. Eggs in perianal specimens
• D. Eggs in the feces

Answer: (C)

Pinworm diagnosis hinges on finding eggs deposited around the anus, not on stool. After mating, female Enterobius vermicularis migrate to the perianal skin at night to lay eggs, which makes the perianal area the most reliable source for detection. A simple perianal specimen—typically collected with clear tape or swab in the morning before washing—picks up these sticky eggs, and examining the sample under a microscope confirms infection. Stool samples are frequently negative because eggs are not shed into feces in large, consistent numbers, so eggs in perianal specimens provide the best diagnostic yield. Multiple consecutive mornings can improve sensitivity.

Pinworm diagnosis hinges on finding eggs deposited around the anus, not on stool. After mating, female Enterobius vermicularis migrate to the perianal skin at night to lay eggs, which makes the perianal area the most reliable source for detection. A simple perianal specimen—typically collected with clear tape or swab in the morning before washing—picks up these sticky eggs, and examining the sample under a microscope confirms infection. Stool samples are frequently negative because eggs are not shed into feces in large, consistent numbers, so eggs in perianal specimens provide the best diagnostic yield. Multiple consecutive mornings can improve sensitivity.