Professor Dick Hilson, who has died aged 83, was a pioneer in the study of leprosy and tuberculosis. From 1974 to 1985, he was head of the department of medical microbiology at St George's hospital medical school, London, where, in 1961, he had single-handedly started the bacterial research unit. He was also consultant medical microbiologist at St George's hospital.
The organism that causes leprosy is notoriously difficult to cultivate, so that successfully arguing the case for such a unit was, in itself, a great achievement. The organism would not grow in normal laboratory conditions, and more sophisticated techniques had to be developed.
Similarly, the tubercle bacillus is not an easy organism to work with, although it will grow slowly in a laboratory medium. The research thus required great patience, a quality that Hilson had in abundance. The work was very important, as the disease was still rampant in India and other developing countries in the 1950s, and the growth in world travel increased the risk of it spreading to Europe and elsewhere.
During a year-long sabbatical at the communicable diseases centre, Atlanta, in 1963, Hilson worked with Charles Shepard, internationally renowned for the development of new techniques for research in experimental leprosy. On returning to St George's, he established a research team to introduce these techniques in his laboratory, in order to study new drugs for the treatment of experimental leprosy.
The research results from here and elsewhere established the basis of the modern treatment of the disease, and, in 1981, the World Health Organisation (WHO) proposed an effective treatment regimen, which is now being implemented throughout the world. When Hilson became involved, there were an estimated 16m people afflicted with leprosy in the under-developed and developing world. Since the WHO initiative, the total has now fallen to less than 1m globally. It is to Hilson's great credit that the unit he founded is still of international excellence. He was also, in 1954, a founder member of the Acid Fast Club, which specialises in the clinical and experimental aspects of mycobacterial research - the field that includes the study of the tubercle bacillus - and, in 1963, a founder member of the Royal College of Pathologists; he became a fellow in 1966. This was in addition to being a sub-editor of the Journal of Medical Microbiology.
Born in Chester le Street, County Durham, Hilson spent his early years in India, where his father was director of agriculture in the then Madras presidency. He went to Carlisle grammar school, Edward VI school, Norwich, and to St George's hospital medical school, University of London, where he gained a medical degree in 1943, and completed his training.
Apart from war service in India and Burma, from 1944 to 1945, and the Atlanta sabbatical, he remained at St George's for his entire career, and was one of the first research directors to have a laboratory on the site in Tooting, south London, to which the hospital moved in the 1970s, from its earlier base at Hyde Park Corner.
Hilson's rigorous intellect stood out prominently during conversations with him. One had to get used to his frequent pauses, but soon realised that his mind was at work analysing the subject of discussion, down to basic principles. This always resulted in a logical answer that could not be bettered, with no wasting of words. Not only PhD students benefited from his guidance; many qualified researchers sought his opinion on papers before submitting them to journals.
In his younger days, his hobby was to relax on his boat on the Hamble. He is survived by his wife Helen, two daughters and a son.
· George Richard Forsyth 'Dick' Hilson, microbiologist, born June 19 1919; died September 3 2002
