ABSTRACT
Brucellosis is a zoonosis transmittable to humans that shows a high degree of morbidity. More than 500,000 new cases of human brucellosis are reported each year, and according to the World Health Organisation, this figure underestimates the magnitude of the problem. Owing to the heterogeneous and poorly specific clinical symptomatology of the disease, its diagnosis always requires laboratory confirmation. The conventional microbiological methods used for the diagnosis of human brucellosis have important limitations. Although blood culture provides the best results in microbiological diagnosis, its sensitivity is considerably reduced in patients with long-term clinical courses or with focal complications. Furthermore, blood cultures are time-consuming and handling of the microorganisms represents a high risk for laboratory personnel, since Brucella spp. are Class III pathogens. Serological diagnosis lacks specificity in areas where the disease is endemic and in those persons exposed professionally to Brucella. Moreover, cross-reactions with other bacteria can also occur. In order to overcome some of the limitations of these conventional techniques, assays based on the polymerase chain reaction (PCR) have been proposed as a very useful tool for the diagnosis of human of brucellosis. Our group has recently reported that PCR methods applied to blood samples provide better results than conventional culture techniques for the diagnosis of both primary infection and relapses, as well as for focal complications of the disease. In the present Chapter, we review the current status and future contribution of PCR techniques for the diagnosis and follow-up of human brucellosis.
