[1] In 1903, he with David Bruce, Aldo Castellani and Cuthbert Christy established that sleeping sickness was caused by the blood parasite, Trypanosoma, and that it was transmitted by tsetse fly.
He entered Dame Alice Owen's School in Herdfordshire for secondary education and completed matriculation in 1890.
Before long he was appointed pathologist at the Great Ormond Street Hospital for Children, where he worked till his retirement in 1939.
But Nabarro, on concern that he was not senior to the other members in age and service, asked the Royal Society to make someone else as the head.
[2] The Commission successfully investigated the etiology of the disease as an infection with the protozoan parasite known as Trypanosoma gambiense.
[16] By August 1903, Bruce and his team established that the disease was transmitted by the tsetse fly, Glossina palpalis.