Brucella possesses unique historical, epidemiological, phylogenetic and pathogenetic characteristics that constantly reinforce the pathogen's place at the epicentre of scientific interest. One such unique characteristic is the significance of bacteraemia in the course of the disease. Bacteraemia in brucellosis may be periodically present, of limited practical diagnostic importance, and of doubtful significance as an index of bacteriological cure. On the other hand, recognition of bacteraemia augments prognosis, typing and biotyping (and thus further research). Recent advances in molecular diagnosis with the help of real time polymerase chain reaction (rtPCR) have shown that bacteraemia in brucellosis may persist, at culture non-detectable levels, for protracted periods even after apparent clinical cure. This raises important issues for future research, implying that the pathogen may actually be non-eradicable.