The results of fecal examination for helminth eggs and protozoan cysts in Seoul Paik Hospital during 1984-1992 are reported. Fecal specimens of a total of 52,552 out- or inpatients were examined by formalin-ether sedimentation and/or direct smear method. The overall egg positive rate of helminths was 6.5% and the cyst positive rate of protozoa 2.5%. The egg positive rate (number of positive cases) for each species of helminth was; Clonorchis sinensis 3.2% (1,667), Trichuris trichiura 2.0% (1,089), Metagonimus yokogawai 1.2% (613), Ascaris lumbricoides 0.2% (100), Trichostrongylus orientalis 0.1% (34), Taenia spp. 0.05% (28), Hymenolepis nana 0.03% (18), hookworms 0.03% (17), Paragonimus westermani 0.02% (12), Echinostoma spp. 0.03% (12), Enterobius vermicularis 0.02% (10), Strongyloides stercoralis (larvae) 0.01% (6), and Diphyllobothrium latum 0.004% (2). The cyst positive rate (number of positive cases) for each protozoan was; Entamoeba coli 1.1% (588), Endolimax nana 0.8% (402), Giardia lamblia 0.3% (173), Entamoeba histolytica 0.3% (164), and Trichomonas hominis (trophozoites) 0.004% (2). Viewing from the data of 9 years, it was evident that the prevalence of soil-transmitted helminths such as A. lumbricoides and T. trichiura has been decreasing remarkably, while that of snail-transmitted helminths such as C. sinensis and intestinal protozoans has not.

Nine cases of human infection with Strongyloides stercoralis are reported among patients admitted to the Seoul Paik and Sang-Kye Paik Hospitals, Inje University, from April 1990 to January 1992. The patients, 7 males and 2 females aged between 50 and 70, either had the history of long term use of steroids for management of arthritis, or were complicated with other chronic diseases such as hypertension, liver diseases, psychotic disorders, and gastrointestinal problems. All of the nine patients revealed rhabditoid larvae of S. stercoralis in fecal examination. A 57-year-old woman who complained of arthritis and abdominal discomfort, was treated with albendazole and mebendazole, and on the 4th and 5th treatment day 220 parasitic adult females were collected from the diarrheal stool. The patient had a long history of administration of steroids for treatment of arthritis, and seems to have suffered from hyperinfection syndrome due to autoinfection with S. stercoralis. This is the 3rd report on the recovery of parasitic adult females of S. stercoralis in Korea.