1. Divison of Infectious Diseases, Department of Internal Medicine, College of Medicine, Dankook Unverisity, Cheonan 330-714, Korea.
2. Department of Parasitology and Tropical Medicine, and Institute of Infectious Diseases, Seoul National University College of Medicine, Seoul 110-799, Korea.
3. Department of Parasitology, College of Medicine, Dankook Unverisity, Cheonan 330-714, Korea.
4. Division of Gastroenterology, Department of Internal Medicine, College of Medicine, Dankook University, Cheonan 330-714, Korea.