Having been trained at the London School of Hygiene and Tropical Medicine, I am a tropical medicine man in the tradition of Sir Patrick Manson, that is, a parasitologist. In his address inaugurating the London School of Tropical Medicine in 1899, entitled The Need for Special Training in Tropical Medicine, Manson stated that ‘the peculiar dis tribution of a large class of tropical diseases depends, in the first place, on the fact that they are entozoal diseases, in the second place, that the entozoa concerned require intermediate and definitive hosts, and, in the third, that one or other of these hosts requires a high atmospheric temperature, in other words are native to warm climates.’ He went on, ‘today the protozoan and the helminth, as regards tropical pathology, are in the ascendant.’ This belief still holds sway, as the great British and American tropical medical journals remain largely devoted to parasitic infections.