1. Department of Parasitology, Seoul National University College of Medicine and Institute of Endemic Diseases, SNUMRC, Seoul 110-799, Korea.
2. Department of Parasitology, Catholic University of Korea, Seoul 137-701, Korea.
3. Department of Parasitology, Seonam University College of Medicine, Namwon, Chonbuk 590-170, Korea.
4. Department of Pediatrics, Hallym University College of Medicine, Seoul 150-020, Korea.
5. Department of Pediatrics, Seoul National University College of Medicine, Seoul 110-799, Korea.