New endemic foci of Gymnophalloides seoi and heterophyid Fluke infections with surveys on the intensity of infection among the inhabitants in the Republic of Korea

초록

Three new endemic foci of Gymnophalloides seoi were found in Haenam-gun (Kaegok-myon), Yongam-gun (Haksan-myon and Seo-myon), and Shinan-gun (Aphae-myon), Chollanam-do, Korea. The former two areas (Haenam-gun and Yongam-gun) were surveyed from September to November 2003, and the third was on June 2004. Fecal samples were collected and examined by Kato-Katz thick smear and formalin-ether sedimentation techniques. Adult flukes were recovered after treatment with praziquantel (10 mg/kg) and purgation. Out of 58 samples from Haenam-gun, 17 (29.3%) were positive for helminth eggs; G. seoi (13 persons; 22.4%), heterophyids (5; 6.9%), Clonorchis sinensis (4; 8.6%), and unidentified (1; 1.7%). Adult flukes of G. seoi (28-17,231 worms/person), H. nocens (4-16), Pygidiopsis summa (2), Heterophyopsis continua (7), Enterobius vermicularis (2), and unidentified worms (1) were found from 12 examined persons. Out of 118 samples from Yongam-gun, 33 (28.0%) were positive for helminth eggs; G. seoi (11 persons; 9.3%), heterophyids (17; 14.4%), C. sinensis (10; 8.5%). Adult flukes of G. seoi (2-1,503 worms/person), H. nocens (9-146), P. summa (1), Stictodora fuscata (1-9), Acanthotrema sp. (1), E. vermicularis (4), and unidentified worms (2) were found from 11 examined persons. A total of 37 persons (64.9%) from Aphae-myon, Shinan-gun were egg positive; G. seoi (33; 57.9%), H. nocens (13; 22.8%), P. summa (4; 7%), C. sinensis (1; 1.7%), Trichuris trichiura (1; 1.7%). A total of 86,591 specimens of G. seoi and 1,068 of H. nocens were collected from 13 persons. Other intestinal parasites including P. summa (35 worms), H. continua (4), Stellanchasmus falcatus (1), S. fuscata (471), E. vermicularis (31). were also collected. Based on these results, the surveyed areas were verified as new endemic areas of G. seoi and heterophyid flukes.