Institution: | 1. Microbiology unit, Department of Laboratory Medicine, Jigme Dorji Wangchuck National Referral Hospital, , Thimphu, Bhutan;2. Department of Surgery, Jigme Dorji Wangchuck National Referral Hospital, , Thimphu, Bhutan;3. Department of Medicine, Baylor College of Medicine, , Houston, TX, USA;4. Massachusetts General Hospital, Harvard Medical School, MGH Gastroenterology Associates, Harvard University, , Boston, MA, USA |