1. Joint Research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto, Japan;
2. AIDS Clinical Center, National Center for Global Health and Medicine, Tokyo, Japan;
3. Department of Gastroenterology, Dokkyo Medical University, Tochigi, Japan;
4. Department of Tropical Medicine and Parasitology, Dokkyo Medical University, Tochigi, Japan;
5. Department of Parasitology, National Institutes of Infectious Diseases, Tokyo, Japan;
6. Department of Infection Control and Clinical Laboratory Medicine, Dokkyo Medical University, Tochigi, Japan;
7. Graduate School of Medicine, The University of Tokyo, Tokyo, Japan