Doctor of Medicine, University Nairobi, Kenya, 1985. Master in Internal Medicine, University Nairobi, Kenya, 1992. Diploma in Thoracic Medicine, University London, 1995.
Medical officer Ministry Health, Nairobi, 1985—1992, head national Tuberculosis control programme, 2003—2006. Research officer Kenya Medical Research Institute, since 1992. Part time lecturer University Nairobi, Kenya, since 1992.
Part time lecturer, chest physician Aga Khan University Hospital, Nairobi, since 2000. Chair Directly Observed Treatment Short-Course Expansion Working Group, Stop Tuberculosis Partnership, Geneva, since 2005. Vice chair Stop Tuberculosis Partnership Coordinating Board, Geneva, since 2007.
Chair Strategic and Technology Advisory Group-Tuberculosis, World Health Organization, Geneva, since 2008.
Coordinator Association Kinango Professionals, Nairobi, since 2008. Member of Kenya Association Prevention Tuberculosis and Lung Disease (secretary 1997—2009).
Married Joyce Muthoni Gachiri. Children: Muhwa Chakaya, Mbeyu Chakaya, Nyamvula Chakaya.