1. Department of Internal Medicine; Seoul National University Bundang Hospital; Seongnam; Republic of Korea
2. Department of Internal Medicine; Soonchunhyang University Bucheon Hospital; Bucheon; Republic of Korea
3. Department of Internal Medicine; The Catholic University of Korea; Seoul; Republic of Korea
4. Department of Internal Medicine; Inje University Busan Paik Hospital; Busan; Republic of Korea
5. Department of Internal Medicine; Asan Medical Center; Seoul; Republic of Korea
6. Division of Enteric and Hepatitis Viruses; Korea Centers for Disease Control and Prevention; Osong; Republic of Korea