His interests have been in general medicine and infectious diseases, with a research emphasis on severe (life-threatening) malaria. His special concerns have been making research relevant to clinical practice and promoting the local training of clinicians and scientists in Africa. He has been Editor of 'Tropical Doctor', 'Malawi Medical Journal' and its forerunner ‘Medical Quarterly’; and has served on committees of the Malaria Control Programme in Malawi, the World Health Organization, and various components of GSK’s candidate malaria vaccine RTS,S. He is also the Ombudsman for The Lancet. He and his wife Liz, a consultant paediatrician, were both awarded the OBE by the Queen in 2006. They moved from Malawi to live in Liverpool, UK, in December 2015, but continue to support and collaborate in research and training in Malawi and other low-income countries.