Nicolle , Charles Jules Henri

(1866–1936) French bacteriologist

Nicolle, the son of a physician, was born at Rouen in France and educated there and in Paris, where he obtained his MD in 1893. He returned to Rouen to join the faculty of the medical school but in 1902 moved to Tunis, where he served as director of the Pasteur Institute until his death.

In 1909 Nicolle revolutionized the study and treatment of typhus. He noticed that typhus patients outside the hospital transmitted the disease to their families, to the doctors who visited them, to the staff admitting them into hospital, to the personnel responsible for taking their clothes and linen, and to hospital laundry staff. But once admitted to the ward the typhus patients did not contaminate any of the other patients, the nurses, or the doctors. Since all newly admitted patients were stripped, washed, and changed, Nicolle concluded that the disease carrier was attached to the patient's skin and clothing and could be removed by washing. The obvious carrier was the louse.

Nicolle lost no time in providing experimental evidence for his reasoning. He transmitted typhus to a monkey by injecting it with blood from an infected chimpanzee. A louse was allowed to feed on the monkey and when transferred to another monkey succeeded in infecting it by its bite alone. It was for this work that Nicolle was awarded the Nobel Prize for physiology or medicine in 1928.

Nicolle actually considered his discovery of ‘apyretic typhus’ the most important of his achievements. He found guinea pigs to be susceptible to typhus but that some of them, with blood capable of infecting other animals, showed no symptoms of the disease at all. He had in fact discovered the carrier state, which was to have significance for the emerging science of immunology.

Nicolle also attempted to develop vaccines against typhus and other infections. He was mildly successful in using serum from patients recovering from typhus and measles to induce a short-lasting passive immunity on those at risk.