Shedding of oocysts of Cryptosporidium in immunocompetent patients.

Forty nine patients (19 adults and 30 children) with oocysts of Cryptosporidium in their faeces had repeated stool specimens taken until oocysts could no longer be identified. They were found in the stools up to 35 days after the onset of symptoms in one patient, but most had stopped shedding them by 20 days. In 25 of the 49 patients in whom symptoms could be compared with the shedding of oocysts, 19 (76%) had symptoms corresponding to the shedding period while symptoms persisted in four (16%) after shedding had stopped.