Preliminary results suggesting that real time PCR assay may become the standard method for diagnosing neurological complications of brucellosis represent an important breakthrough for avoiding lasting damage to patients. It means that antibiotic treatment can be started within hours, rather than days or months it can take to reach a diagnosis by conventional means.

The other big advantage is the assay’s closed, automated system, which limits the chances of cross contamination and makes it suitable for handling large numbers of specimens in a clinical laboratory—and without having to handle a class III pathogen directly.

Six patients with neurobrucellosis confirmed conventionally by a combination of clinical signs and symptoms and isolation of Brucella abortus or detection of specific agglutinins, or both, all showed specific B abortus sequences in CSF with the assay. Only four samples (66%) were positive by seroagglutination and two (33%) by direct culture. Symptoms had lasted on average 90 (range 5–365) days before diagnosis. All patients were Spanish: only one had no obvious exposure to B abortus.

Each CSF sample was tested for B abortus by culturing on isolation media, by testing for specific antibodies and testing for B abortus DNA by LightCycler real time PCR assay.

Brucellosis is endemic around the Mediterranean, in India, Mexico, Central and South America. Almost 20–40% of infections cause complications, albeit only 1–2% in the CNS, but these can be serious. Low antibiotic titres in the CSF and the low yield of culture make diagnosis difficult.