The English military physician Major General Sir David Bruce (1855–1931) (Fig. 1) in 1895 showed that a disease of cattle – called Nagana by the native population – was caused by Trypanosoma specimens transmitted by the so-called tsetse fly. This latter name is also of African origin and refers to the flight sound of the Glossina flies. Before this discovery Bruce had already described the agent of the so-called brucellosis which he isolated in Malta from the spleen of a soldier that had died from this “Malta-fever.” This bacterium was later called Brucella melitensis being transmitted via milk from ruminants (especially goat, sheep, and cattle). Brucellosis is found worldwide as was first shown by the Danish veterinarian Bernhard Lauritz Frederik Bang (1848–1893) and is intensely correlated with the death of cow’s fetus. It was the American physician Alice Cathrine Evans (1881–1975) who showed the close relation between Bang’s and Bruce’s agents and described Bang’s agent as Bacterium...