Post coital pin-worm infection.

In Ibadan, Nigeria, an Enterobius vermicularis worm was found in the urine of a soldier complaining of urethral irritation that had started 4 hours after coitus. After his first post-coital micturition, which yielded the worm, the irritation stopped. There was convincing evidence that the worm had entered the soldier's urethra from his partner's perianal region (rear-entry coital position, no ejaculation because of partner's complaint of painful coitus, the partner was a school girl of 15, enterobiasis is common in young school girls in the city, etc.).