Epidemiology Unit, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla 90110, Thailand;
Department of Hepatology, Third Municipal People's Hospital of Kunming, Kunming 650041, Yunnan Province, China;
Department of Infectious Diseases, First Affiliated Hospital of Kunming Medical University, Kunming 650032, Yunnan Province, China;
Department of Infectious Diseases, Yunnan General Hospital of the Chinese People's Armed Police Forces, Kunming 650111, Yunnan Province, China;