Enterobius vermicularis infection in a children's ward.

Following the discovery that two patients on a children's orthopaedic ward were excreting Enterobius, all patients and staff on the ward were screened for the presence of pinworms. None of the staff was infected but 11 (55%) of 20 patients either had Enterobius ova on the anal margin or excreted worms following piperazine treatment. Epidemiological investigations indicated that this was unlikely to be a ward outbreak because four of the infected children had been on the ward for under 3 days, i.e., less than the prepatent period for Enterobius. Although none of the children was symptomatic, all children and staff on the ward were treated with piperazine. Faecal samples were collected from nine children and the majority of their worm load was shed within 32 h of starting therapy. Microscopic examination of the adult male worms showed that each patient was excreting both Enterobius vermicularis and E. gregorii.