Dr Thoon Koh Cheng obtained his postgraduate Specialist Paediatrics qualifications from RCPCH as well as NUS in 2004. He trained in Paediatric Infectious Diseases at the Hospital for Sick Children in Toronto in 2007, and was appointed as Head of Infectious Disease Service at KKH from June 2010 to May 2022. He is also a Clinical Professor at the Duke-NUS Graduate Medical School, an Adjunct Associate Professor at the YLL School of Medicine, NUS, and the LKC School of Medicine, Nanyang Technological University.
He is currently Chairman of the Division of Medicine, Chairman of the Hospital Infection Control Committee, and Academic Chair in KKH. He is also the current Chairman of the National Verification Committee for Measles Elimination, and was previous Chairman of the National Paediatrics ICU-ID Subcommittee, Vice-Chairperson of the National Antimicrobial Resistance Control Committee in the Ministry of Health (MOH), Chairman of the Singhealth Hand Hygiene Event Committee, and also previous Head of Infectious Disease Service and Director (MOH designate) of the Antimicrobial Stewardship Program at KKH. In addition, he sits as a Member on multiple Departmental and Hospital committees including the Medical Board and Senior Management Committees, as well as Singhealth and MOH Committees including the Expert Committee on Immunisation. He was instrumental in developing the KKH Infectious Disease System, the KKH Vaccine Pocketbook (and subsequently the Vaccine Calculator and eBook App), and piloted the 1st National Inpatient Active Vaccine Safety surveillance in collaboration with Health Science Authority (HSA).
In 2018, he was awarded the Public Sector Transformation Star Service Individual Award by the Singapore Civil Service for championing the prevention and therapy of childhood infectious diseases, and in 2024, the Singhealth Excellence Awards for Distinguished Champion of Change Leader.
He has authored or co-authored more than 150 peer-reviewed articles, letters, editorials, books and book chapters, and his research interests include epidemiology of vaccine-preventable diseases (particularly invasive pneumococcal and Haemophilus influenzae disease) and respiratory viral diseases, antimicrobial stewardship, infection control, adverse events following immunization, mycobacterial infections (including TB and NTM), severe invasive bacterial and viral diseases, HIV and dengue.