Fred Neufeld, German physician and bacteriologist, began his professional career in 1894. His thesis, submitted at Heidelberg and dealing with the causes of congenital cranial swelling, was published in Tuebingen the next year. In 1899 he published a paper on the cultivation of the bacillus of Typhoid fever and the techniques of bacteriological investigations of the blood, followed the next year by another on the specific bacteriological functioning of bile. Later he found the first reliable evidence for the diversity of pneumococcal strains (the bacteria that cause pneumonia), and around 1902 devised a method of typing them on the basis of their capsular swelling. This and related work was reported in a substantial number of scientific papers over a period of more than two decades. In 1904 he described and named different bacteriotropins (substances in blood serum that render bacteria more subject to the action of anitoxin).
From 1894 Neufeld worked at the Institute for Infectious Diseases (generally known as Koch's Institute) in Berlin. He and Dr F.K. Kleine* came to southern Africa as assistants to Dr Robert Koch*, to investigate the cattle disease that came to be known as East Coast fever, on behalf of the British South Africa Company. They landed at Beira, Mozambique, in January 1903. When they arrived in Bulawayo, Zimbabwe, the next month it was too late in the season to properly study the disease, but Koch none the less recognised it as a distinct disease, different from redwater, and named it African coast fever. He and his team wrongly identified the carrier of the causative parasite as the blue tick, were unsuccessful in producing the disease with injections of blood of diseased animals, and also unsuccessful in producing effective immunisation against it. Neufeld returned to Germany in January 1904.
In 1914 Neufeld published a manual for medical practitioners and students on the causes and treatment of contagious diseases. He became director of Koch's Institute in 1917 and remained in charge until 1933, when he retired at the age of 64 after a severe attack of pneumonia.