Researchers tested 217 patients who developed diarrhea in a hospital in Isfahan, Iran to see if a parasite called Cryptosporidium was responsible. Using advanced DNA testing, they found the parasite in only 2 out of 217 patients (less than 1%). This suggests that while this parasite can spread in hospitals, it is not a major cause of diarrhea in this particular hospital, which likely has good hygiene practices.