Choe, Ju-Song , Department of Dermatology, Hospital of Chongjin College of Medical Sciences, Chongjin, Democratic People’s Republic of Korea. Choe , Su Hyang, Pyongyang University of Medical Sciences Choe, Sun-Yong , Department of Dental Caries and Oral Medicine Research, Faculty of Dentistry, Pyongyang University of Medical Sciences, Pyongyang, Democratic People’s Republic of Korea. Choe, Tong Il , Institute for Infection Control, Faculty of Hygiene, Pyongyang University of Medical Sciences, Democratic People’s Republic of Korea.