A survey of cryptosporidiosis among 2,541 residents of 25 coastal islands in Jeollanam-Do (Province), Republic of Korea

In order to determine the distribution and prevalence of human cryptosporidiosis on western and southern coastal islands of Jeollanam-do (Province), fecal samples were collected from 2,541 people residing on 25 islands, 13 in the western coasts and 12 in the southern coasts, during July and August 2000. Fecal smears were prepared following formalin-ether sedimentation of the samples and stained by a modified acid-fast procedure. The presence of Cryptosporidium oocysts was determined by light microscopy. Cryptosporidium oocysts were detected in 38 specimens (1.5%). The oocyst positive rate varied (0-6.0%) according to island; the highest was detected on Oenarodo (6.0%), followed by Naenarodo (5.6%) and Nakwoldo (5.4%). The majority (35 persons, 94.6%) of Cryptosporidium-infected individuals were older than 50 years of age. Men (22/1,159; 1.9%) were infected at a higher rate than women (16/1,382; 1.2%). The results of the present survey indicate that human Cryptosporidium infections (due to Cryptosporidium hominis and/or C. parvum) are maintained at a relatively low prevalence on coastal islands of Jeollanam-do, Republic of Korea.