by King-Thom Chung, Department of Biology, The University of Memphis

"We are all children of one Father. The advance of knowledge in the causation and prevention of disease is not for the benefit of any one country, but for all----" David Bruce (1855-1931)

David Bruce was well known for his study of Malta fever (brucellosis) and sleeping sickness (trypanosomiasis). He identified Micrococcus (Brucella) melitensis as the etiological agent of brucellosis in cattle; and proved that a Trypanosoma brucei was the agent causing sleeping sickness and tsetse fly (Glossina morsitans) was the vector transitions the disease. He was a great physician, and a pioneer of veterinary microbiology.

David Bruce was born on May 29, 1855 in Melbourne, Australia. His father was also called David, and his mother was Jane Hamilton. They originally lived in Edinburgh, Scotland, and migrated to Australia during the gold rush of the early 1850. When David was five years old, they decided to return to Scotland and settled in Stirling. He attended high school till the age of 14 when he decided to work for a warehouse firm in Manchester. He dreamed to be a professional athlete. But his dream was not realized because he had a terrible pneumonia at the age of 17. He decided to go back to school. In 1876, he gained admission to the University of Edinburgh.

David was interested in natural history, particularly animals. He loved birds. He took courses in zoology. But he was persuaded by a physician to study medicine and he graduated in 1881 with M.B. C.M. degree. As he was working as an assistant to a doctor in Reigate, where he met Mary Elizabeth Steele, daughter of a previous owner of the practice. Mary was 6 years older than David, and they were married in 1883. Although they never had any children, they had a very successful marriage. Mary was an indispensable helpmate at home and social occasions for David. And above all, Mary helped David’s scientific research, which made him a great scientific pioneer.

Dr. Bruce was not fond of general practice. In August of 1883, he was commissioned as a surgeon captain in the Royal Army Medical Corps. The following year, he was sent to Malta, stationed in the Valetta Hospital. Despite no facility for research at the hospital, Dr. Bruce was impressed by Dr. Robert Koch’s (1843-1910) recent discovery of the tubercle bacillus, he began to do some investigations on a disease called Malta fever, which was quite common among soldiers in the British garrison in Malta. He purchased a microscope and observed an enormous number of micrococci in the spleen of a fatally ill patient. He isolated the micrococci following the method of Robert Koch and reported his observations in 1887. He continued to study the properties of this organism and proposed the name of Micrococcus melitensis. This organism was renamed as Brucella melitensis by Feusier and Meyer in 1920, because that the organisms was not a Micrococcus. The epidemiology of Malta fever was not clear until 1905 when T. Zammit, one of the Maltese member of the Commission for the Investigation of Mediterranean Fever headed by Bruce, found that goat milk was the disseminating vehicle. When goat’s milk was eliminated from the diet of the Malta garrison, the disease disappeared. This disease is now called brucellosis. The names "Malta fever" or other names such as "Mediterranean fever" or "undulant fever" are no longer used.

Bruce left Malta in 1889. Following a stage in Dr. Robert Koch’s laboratory in Germany where David and Mary learned the latest techniques in microscopy, staining and media making, etc. Dr. Bruce taught pathology at the Army Medical School at Netley where he introduced the most advanced knowledge and experimental procedures of Louis Pasteur (1822-1895), Joseph

L. Lister ( 1827-1912) and Robert Koch to his students. In 1894, Bruce was posted to Natal. The Governor of Natal whom he knew while he was in Malta asked him to investigate a disease called nagana—a sleeping illness affecting cattle in the Northern Zululand.

The Bruces went to Ubombo by an oxen wagon. It took them five weeks. It must be an extraordinary experience for them. They lived in a creede hut for two months, and used a veranda as a laboratory. Time after time they examined the specimen and the animals affected with this nagana. Initially the bacteriological examinations of affected oxen proven negative, but extensive microscopic study of blood specimens revealed a motile, vibrating hematozoon. Bruce inoculated the blood from the infected cattle into healthy horses and dogs; they became acutely ill, and the blood swarmed with hematozoa. The hematozoon was confirmed to be a trypanosome. The Bruces discovered that the mode of transmission of the disease was the tsetse fly. Bruce proved that nagana was identical with the tsetse fly disease described by David Livingstone (1813-1873) in 1858. Bruce stayed at the Zululand bush for almost two years except some temporary recalled to Natal. He published his observations entitled Preliminary Report in 1895 and followed by Further Report in 1897. These were the classic documents which described the hematozoa of nagana, established the tsetse fly, Glossina morsitans, as the vector, and also implicated regional wild animals such as antelope and buffalo as the trypanosomal reservoirs.

In 1899, Bruce was elected as a fellow of the Royal Society of London, the highest scientific honor in England. Bradford and Plimmer published a paper naming the trypanosome as Trypanosoma brucei.

During the Boer War (1880-1902) Dr. Bruce was a director of a hospital at Ladysmith, and he successfully performed many surgeries. Mary Bruce worked as a nurse in her husband’s operating theater, she received the Royal Red Cross. They returned home in October, 1901 when the Boer War was almost over.

In 1903, Bruce was appointed with another mission. He was chosen to head the Royal

Society’s Sleeping Sickness Commission to Uganda. As a matter of fact, a similar commission was formed in 1902 on behalf of the Foreign Office and at Patrick Manson’s urging. But the mission of 1902 had not been successfully directed, and its two members had returned home. The Bruces reached Entebbe (captial of Uganda) in March, 1903. Along with him were Dr. David Nabarro and a sergeant technician. A young very productive Italian bacteriologist, Dr. Aldo Castellani (1879-1971) who was on the previous mission, remained.

Sometimes earlier, Patrick Manson had suggested that Filaria perstans was the etiological agent of sleeping sickness. But it was soon proved not to be the case. Castellani observed trypanosomes in the cerebrospinal fluid taken from five victims of sleeping sickness. He had also previously cultured streptococci from cerebrospinal fluid and heart blood from more than thirty patients who died of sleeping sickness. He was well aware of the potential significance of the trypanosomes. He was further unhappy about the arriving of Dr. David Nobarro who was a little older than him and who was due to replace him. Castellani imparted his observations to Bruce, asked permission to temporarily continue working on this disease, and also to publish his finding as the sole author. Dr. Bruce agreed to his request. Thus Dr. Castellani continued to make observations, and demonstrated trypanosomes in twenty additional cases. He also taught Dr. Bruce techniques of lumbar puncture and examinination of cerebrospinal fluid for trypanosomes.

At first, Dr. Bruce was skeptical that trypanosomes caused human sleeping sickness, because Dr. Dutton in 1902 had reported that Trypanosoma gambiense in the blood of a febrile Englishman in Gambia, and in 1903, Dr. Baker had diagnosed similar cases of trypanosome fever in Uganda. Their reports showed no connection between these conditions and human sleeping sickness. However, soon after the departure of Castellani, Bruce and Nabarro accumulated an ample evidence that human sleeping sickness was caused by T. gambiense. Dr. Bruce returned to England in August 1903. The progress report by Bruce and Nabarro did acknolwedge the discovery made by Castellani. But the following report written by Bruce, Nabarro and E. D. W. Greig betrayed a changed attitude. The later report encouraged Bruce’s supporters, particularly Ray Lankester (1847-1929) to minimize Castellani’s contribution. This caused a controversy carefully reviewed by Jack N. P. Davies (1915-) in his articles published in 1962 and also in1968.

Dr. Bruce rejoined the Royal Society’s Continuing Commission in Uganda between 1908-1910. He was then in charge of research concerning the conditions affecting the transmissibility of T. gambiense by Glossina palpalis . They also found that cattles and other animals were potential reservoirs of the parasites. In 1911, he was appointed director of another Sleeping Sickness Commission in Nyasaland ( now Malawi) to study trypanosomiasis. Between 1912-1913, they identified T. rhodesiense as the main regional pathogen and Glossina morsitans as the vector. They also characterized other trypanosomal species pathogenic to domestic animals. The Commission concluded that T. rhodesiense and T. brucei were identical species. But this view did not hold because later studies by German group proved that they were different.

From 1914 to 1919, Bruce was commander of the Royal Army Medical College. He was was the chairman of a committee responsible for scientific research of tetanus and trench fever which were quite common during the war time. His administrative abilities were fully utilized. He retired in 1919. In his last years of life, he suffered recurrent lung infections, and had to stay in Madeira (in Portugal) in winter. He died on November 27, 1931. His beloved wife, Mary, died four days before him. Mary stayed with him all these years, accompanied him in all adventurous trips, worked self-effacingly beside him as a technician, microscopist, and draft woman. Bruce requested that her outstanding assistance should always be emphasized in any biographical account of him. Wherever there was a story about a successful man, there was always a great woman behind him. Mary Bruce was a typical example of this kind of woman.

Dr. Bruce received many awards and honors in his life. He was elected member of the Royal Society and the Royal College of Physicians of London. He received honorary doctorates from the universities of Glasgow, Liverpool, Dublin, and Toronto. He was also a honorary member in several foreign academies and societies, and received numerous medals of honor. He was appointed C.B. in 1905, knighted in 1908, and made K.C.B. in 1918.

Some accounts mentioned that Dr. Bruce had an abrupt manner and egotistical personality, and that he often made blunt speeches. But he unselfishly dedicated his great energies and talents to mankind’s health and welfare. He lived in humble conditions and died not wealthy. He cared about future of humanity and had great compassion as expressed in his presidential speech "Prevention of Disease" delivered to the British Association meeting at Toronto in1924. He said: "We are all children of one Father. The advance of knowledge in the causation and prevention of disease is not for the benefit of any one country, but for all–---for the lonely African native, deserted by his tribe, dying in the jungle of sleeping sickness, or the Indian or Chinese coolie dying miserably of beri beri, just as much as for citizens of our own towns."