[3] He served in the Mediterranean and in Egypt, in hospital ships and troop transports, and then in Mesopotamia, where he succeeded Hugh W. Acton as pathologist.
[4] Kala-azar was his main sphere of work for fifteen years, and his reputation became world wide, for he made important contributions to knowledge of epidemiology, ætiology, transmission, diagnosis, treatment and in fact to every branch of the subject.
It was, however, a fitting crown to his work that shortly before he left India, the scientific proof was completed by men who had been his co-workers.
[4] In 1943 he went to New York City's Columbia University as a visiting professor and while there completed his 1946 textbook Principles and Practice of Tropical Medicine.
[1] Soon after Napier returned to England he was appointed specialist in tropical diseases to the Ministry of Pensions and consultant to Queen Mary's Hospital, Roehampton.