New developments in the diagnostic procedures for zoonotic brucellosis in humans

At present, laboratory diagnosis of human brucellosis is based on isolation of the bacteria from clinical samples followed by standard microbiological tube testing, detection of anti-Brucella antibodies using various serological tests, and the use of molecular methods for the detection of Brucella DNA. None of these diagnostic tools can be used on its own to reliably detect the causative agent. Cultures give a low yield and subsequent phenotypic characterisation is time consuming, meaning that the initiation of adequate antibiotic therapy is frequently delayed. Serological tests seem to be more effective but are not internationally standardised. Moreover, antibodies can remain detectable despite successful therapy, cross-reacting antibodies may occur, and variable cut-offs for different levels of endemicity are lacking. Molecular assays may reduce diagnostic delays in clinical laboratories, but diagnostic criteria for active infection have not yet been defined. This article reviews the latest microbiological methods for the diagnosis of human brucellosis and outlines developments for the future.