Duke attended Gonville and Caius College, Cambridge and later Guy's Hospital, in all he attained an MD, MA, ScD, MB, BChir and a diploma in Tropical medicine.
In 1975 Duke joined WHO as head of Filariasis infectious unit, his earlier research enabling the clinical trials of Ivermectin to go smoothly.
Duke is also credited with pressuring Merck to supply Invermectin free to all sufferers of River Blindness, which led to the creation of the Mectizan Donation Programme.
He was a distinguished scientist at the Armed Forces Institute of Pathology (AFIP) where he developed invaluable teaching materials on Helminithic Diseases.
He worked closely with Aileen Marty in developing various infectious disease conferences and in identifying unusual effects caused in the female Onchocerca by Ivermectin.