Genotypic characterization of cryptosporidium oocysts isolated from healthy people in three different counties of Korea.

To investigate Cryptosporidium infection among healthy people, we collected stool samples from 150 healthy individuals in Gokseong, Muan, and Imshil Counties, southwest Korea, where neighbors on both an animal farm and a river respectively. In 12 of 150 samples, Cryptosporidium oocysts were detected by means of modified acid-fast staining. The bovine genotype, Cryptosporidium parvum, was identified by PCR/RFLP and 18S rRNA sequencing. C. parvum existed endemically in these areas, and the residents showed a relatively higher infection rate for C. parvum than that for C. hominis. Our results indicate that countermeasures against Cryptosporidium infection must be taken in these areas to ensure human health.