Charles has been involved with filarial diseases all his professional career. After completing his PhD at Sydney University he moved to London and following three years in the Department of Parasitology at the MRC labs in Mill Hill he took up a position at the London School of Hygiene and Tropical Medicine as head of the Wilson Tropical Pathology Unit.
As a pathologist his interests have always been oriented towards the pathogenesis and clinical presentation of lymphatic filariasis and onchocerciasis. As part of his postdoctoral work at the MRC in London he worked in Cameroon studying the immuno-pathology of onchodermatitis and understanding, and classifying, the clinical spectrum of this important skin disease. This set him on firm path of being an active fieldworker in these two major infections which he still maintains to this day. As part of the Moorfields' Eye Hospital team/LSTMH studying the chemotherapy of onchocerciasis in Sudan the 1980s, Charles established a close relationship with this country and has published over 40 papers on work with Sudanese colleagues and still maintains this link to this day.
In 1999 as the global program for lymphatic filariasis elimination began Charles joined the Mectizan Donation Program in Atlanta to assist in the rollout of this new NTD program in Africa. After helping to initiate the first 5 African countries to begin mass treatment for lymphatic filariasis, he formed a strong association with the first of these countries to start treatment,Tanzania. Charles worked as the Special Adviser to the Tanzanian Government for Lymphatic Filariasis since 1980, and working with Tanzania and colleagues helped instigate and manage this very successful program that covering both drug distribution and patient care for those affected with lymphatic filariasis. He has also assisted other countries to develop their LF programs and their LF patient care activities in Africa, Latina America and Asia.
Charles’ focus on fieldwork has always been balanced by a continuing laboratory research program both in London at LSTMH, and when he moved to the United States in 1988 as Head of Pathology at the medical schools at Michigan State University. His research interests have included understanding the damage that filarial infections can cause, the effects of chemotherapy on the disease, and also developing new chemotherapeutic agents for the treatment of these infections. This work has resulted in understanding, for example, the mechanisms of action of ivermectin, defining the pathogenic events that occur in the serious Loa loa encephalopathy that has plagued filarial programs in Africa, and describing the fundamental changes that cause the lymphoedema in about elephantiasis.
Charles has served as a member of various committees in the filariasis, onchocerciasis and NTD communities: a member of Mectizan Expert Committee since 1999, Chair of DMDI group of NNN since 2015 and chaired the advisory committee on LF Patient Care for the World Health Organization that produce the documentation for LF morbidity management. He also assisted the Liverpool School of Tropical Medicine in 2014-2016 to developing a LF patient care program for UK government supported DFID Program in lymphatic filariasis. He received the Order of Australia in 2012 for his work in tropical medicine.
He is a strong believer in the vital role that endemic countries play in global success that is being achieved against lymphatic filariasis, and in the importance of empowering those at the community level to continue to carry out this extraordinary work. The many people that make up the field level teams - the distributors, the healthcare workers and the patients themselves, he believes, deserve the majority of the credit for the successes that have been achieved to date in this amazing public health program - they are the fundamental component of GAELF.