Professor Denis Mitchison, who has died aged 98, will be remembered for his outstanding contribution to the field of tuberculosis research.

‘Denny’ as he was known, was Emeritus Professor in the Institute for Infection and Immunity at St George’s, and only formally retired from academic life in 2015.

As a pathologist in the 1940s, at the Brompton Hospital in London, Denis Mitchison carried out the first randomized controlled clinical trial which involved tuberculosis. He and his colleagues investigated the antibiotic streptomycin, comparing its efficacy with the then standard treatment, bed rest. He pioneered drug combinations to address antibiotic resistance which was already on the rise.

Later, as Director of the Medical Research Council Unit for Research on Drug Sensitivity in Tuberculosis, he turned his attention to the problem of TB in the developing world. He devised a pioneering set of trials in India that compared inpatient and outpatient treatment of TB. These showed that home care was just as effective as being held in a sanatorium for months and led to a new WHO plan to get treatment out to those who needed it.

His research on drug combinations led to the reduction of treatment periods, and he was at the forefront of developing so called ‘short-course’ regimes. These short course regimens remain the basis of today’s current standard TB therapy.

His enormous body of work was recorded in more than 250 publications and recognised with prestigious awards.

Even after his first ‘retirement’ in 1985 he continued to innovate in the field, developing new techniques to measure early bactericidal activity of drugs and establishing new approaches to accelerate phase II clinical studies for TB drugs.

We extend our warmest sympathies to his family.