Our Leadership Team

Executive Team

Ms. Joyce Lau, President
Ms. Joyce Lau, President

Joyce Lau graduated with a Bachelor of Science in economics and mathematics from National University of Singapore. She completed her Masters in Management Science in Public Policy from Peking University in 2017. Joyce joined MSI Professional Services in 2001 and has served in Sichuan and Yunnan provinces in various roles, including English teacher, site manager, office manager and Chief Representative of MSI Yunnan. She assumed the role of Chief Representative of MSI Sichuan on1 November 2018.

Ms. Ellise Koehorst, Vice President
Ms. Ellise Koehorst, Vice President

Ellise Koehorst is a graduate of Hogeschool Holland, a university of Applied Sciences in the Netherlands, where she received training in nursing. She specialized as an oncology nurse and worked for a number of years at an academic hospital (university medical centre) in Amsterdam. She served as a Nurse Trainer in a Hospice Project in Kyrgyzstan in 2008. Ellise received further training in Intercultural Studies (UK) as well as International Public Health (NL), and has lived in mainland China where she studied Chinese language and culture. Ellise has been involved in Intercultural Education and Training in Asia since 2014 and joined MSI in 2023.

Dr. David Leung, Executive Director for International Mobilisation
Dr. David Leung, Executive Director for International Mobilisation

Dr. David Leung graduated from the Medical College of Ohio, and completed his Family Medicine residency in California. He is a Fellow of the American Academy of Family Physicians. He and his wife Vivian served in Shanxi from 1996 until 2014, where he was involved in clinical medicine, rural health, urban community health, and Family Medicine training. He served as President of MSI Professional Services during 2015 to April 2020.

Dr. Cedric Cheung, Chief Representative of Sichuan Province
Dr. Cedric Cheung, Chief Representative of Sichuan Province

Dr. Cedric Cheung graduated from The Johns Hopkins University (Maryland, USA) with a Bachelors of Arts in Natural Sciences and went on to study medicine at Albert Einstein College of Medicine (New York, USA). After an internal medicine residency at New York University (New York, USA), Cedric returned to Albert Einstein College of Medicine for his fellowship in infectious disease. In 2009 he joined MSI Professional Services and studied Chinese for 3 years at Sichuan University in Chengdu after which he served as a consultant in HIV medicine at Zhaojue County Hospital in Liangshan Prefecture in Sichuan province for 7 years. Cedric assumed the role of MSI’s Sichuan Provincial Chief Representative since 2023.

Mr. Paulo Leung Kwok Sing, Chief Representative of Yunnan Province
Mr. Paulo Leung Kwok Sing, Chief Representative of Yunnan Province

Mr. Paulo Leung Kwok Sing worked in the University of Hong Kong for close to 21 years, whereby his last position was medical technologist. During this period, he obtained the relevant Ordinary and Higher Diplomas, and graduated from Edinburgh Napier University/Hong Kong University School of Professional and Continuing Education with a Bachelor’s Degree in Applied Biological Sciences in 1995.  He also later obtained the Diploma in Occupational Safety and Health from The Open University of Hong Kong Li Ka-shing School of Professional and Continuing Education.  Paulo with his wife Amy joined MSI in 2003 and served in Zhaojue County and Mianyang City in Sichuan Province. Paulo assumes the role of Chief Representative of Yunnan in January 2024.

Directors and

Senior Consultants

Dr. Eugene Choi
Dr. Eugene Choi

Dr. Eugene Choi graduated from the University of Hong Kong, followed by specialized training in paediatrics and allergy/immunology at McGill University, the National Asthma Center and Columbia University. He is emeritus Clinical Associate Professor of Pediatrics at the University of California and also the past president of Northern California Association of Allergists.

Dr. Matthew Koh
Dr. Matthew Koh

Dr. Matthew Koh has served in MSI since 1994. He was MSI’s director of medical services until 2004, when he succeeded Dr. James Taylor. He has been serving as President of MSI Professional Services since 2004. Trained as a surgeon, he went on to obtain his surgical specialisations through fellowships in Edinburgh, Glasgow, Singapore and Hong Kong. He is a member of the Hong Kong Academy of Surgeons, fellow of the Royal College of Surgeons and Physicians of Edinburgh, and honorary Associate Professor of Surgery at Chinese University of Hong Kong. He also has a Master in Marketplace Theology from Regent College, and a D. Min from the Asbury Theological Seminary.

Dr. Edward Sitt, Director
Dr. Edward Sitt, Director

Dr. Edward Sitt graduated from the University of Hong Kong, Faculty of Medicine in 1984 and received training in cardiology. He is a member of the Royal Colleges of Physicians of the United Kingdom, fellow of Hong Kong College of Cardiology and Hong Kong College of Physicians. He received a Bachelor of Divinity at the University of London, Bachelor of Theology at the University of Oxford, Master of Public Health at the University of Hong Kong and Master of Christian Marriage and Family Therapy at Bethel Bible Seminary. He participated in many MSI short term service trips to China since 1995. Currently, he is practising as a specialist in cardiology in Hong Kong.