1. Department of Parasitology and Tropical Medicine, Seoul National University College of Medicine, and Institute of Endemic Diseases, Seoul National University Medical Research Center, Seoul 110-799, Korea.
2. Seoul National University Bundang Hospital, Seongnam 463-707, Korea.
3. Department of Internal Medicine, Seoul National University Hospital, Gangnam Health Care Center, Seoul 135-984, Korea.
4. Laboratory Center, Wenzhou Medical College-Affiliated Taizhou Hospital of Zhejiang Province, Linhai, Zhejiang Province, P. R. China.
5. Department of Parasitology, Hanyang University College of Medicine, Seoul 133-791, Korea.