It is with deep sadness to learn that David has passed away. When I entered the field of infectious tropical diseases and malaria in particular over 20 years ago I became to know David. He acted as mentor, providing advice and guidance in me finding my way in this field of research. I much enjoyed talking with him, and will always remember his interest in cockroaches, how intelligent they can look!  Will keep the happy memories. Dr. Henk Schallig, Academic Medical Centre at the University of Amsterdam