1. Department of Parasitology, College of Medicine, Chung-Ang University, Seoul 156-756, Korea.
2. Department of Parasitology, Gyeongsang National University College of Medicine, Jinju 660-751, Korea.
3. Ryujaehwa Internal Medicine Clinic, Bangu-dong 446, Chung-gu, Ulsan 681-261, Korea.