Cryptosporidiosis in hospital personnel. Evidence for person-to-person transmission

An intern responsible for the care of a patient with chronic cryptosporidiosis developed acute diarrhea and serologic evidence of cryptosporidium infection. Sera from 26 hospital personnel exposed to the patient and 18 personnel with no exposure were examined with an indirect immunofluorescent antibody procedure for the presence of antibodies to Cryptosporidium. Eight (31%) exposed personnel - 5 nurses, 2 house officers, and 1 student - had positive antibody titers (1:10 or more). The frequency of positivity in the nurse-housestaff-student group (8 of 18, 45%) was significantly greater (p < 0.05) than that in the attending physicians and respiratory therapists (0 of 8). The former group had significantly more exposure to the patient's feces than did the latter group (p < 0.01). Three of eighteen control personnel (17%) had positive cryptosporidium antibody titers. These findings suggest that Cryptosporidium may be transmitted from person to person in the hospital environment and that serologic evidence of infection is common among hospital personnel.