Prof Gage has over 45 years’ experience as a Medical Practitioner. He holds M.D University of Tubingen {West} Germany, D.T.P.H in Public Health from London University, M.Sc. in Medical Sciences/Epidemiology at McMaster University, Canada. He is a fellow of the West African College of Physician {FWACP}.

Nationally, Prof Gage has served as Medical Officer, Connaught Hospital, District Medical Officer, Kenema, Provincial Medical Officer and Head Endemic Diseases Control unit in Bo, Deputy Chief Medical Officer Ministry of Health. He was Head of Department of Community Health and Vice Principal College of Medicine & Allied Health Sciences. Served as National Consultant to the Global Fund Supported HIV/AIDS and Malaria Programmes. He was appointed Registrar Sierra Leone Medical and Dental Council.  

Internationally, Prof Gage has worked as External Assessor and Advisor Midterm review of HIV/AIDS Control Programme in Ghana, Health Management Advisor in Ethiopia, and Epidemiologist- Consultant to the Government on the prevention and control of communicable disease and primary Health Care in the Kingdom of Lesotho. Consultant Epidemiologist, Onchocerciasis Control Programme in Nigeria.