RPD Cooke 1 , MM Rothburn 1 , NJ Beeching 2

1. Neurobrucellosis in the UK RPD Cooke1,MM Rothburn1, NJ Beeching2 Brucella Reference Unit, Aintree Hospitals NHS Foundation Trust, Liverpool1 and Liverpool School of Tropical Medicine, Liverpool2, UK Introduction Methods • Involvement of the nervous system in brucellosis is rare (<2% of cases)1. • A variety of neurological syndromes have been described of which meningitis (acute or chronic) is most common. • Due to the diverse presentations of neurobrucellosis, it is often considered in the differential diagnosis of unexplained neurological disorders. • Brucellae are rarely isolated from cerebrospinal fluid (CSF) so antibody detection in serum and CSF often provides the only positive laboratory findings. • The Brucella Reference Unit at Aintree Hospitals NHS Foundation Trust offer a national sero-diagnosis service for England, Wales, Eire and Northern Ireland. A review of our experience with Brucella CSF examination is presented. • Over an 8 year review period (2001-2008), the results of all Brucella CSF antibody tests were analysed and compared with corresponding serum samples. • All samples were examined by a combination of in-house (micro-agglutination, complement fixation) and commercial tests (Brucellacapt and specific IgG and IgM assays (Vircell)) as previously described.2 • Clinical details of CSF positive cases were obtained through the referring laboratories. • Contact was also made with Health Protection Scotland to determine if any of their reported cases of brucellosis had neurological involvement. Results Table: Brucella antibody profiles of 3 cases of neurobrucellosis identified in the UK between 2001-2008 • 30 CSF samples, from 29 patients were examined for Brucella antibodies (0.1% of total Brucella antibody workload). • In 12 cases (41%), an additional serum sample was not sent. • Only 3 patients were CSF antibody positive. All were male, from the Middle East and aged, 40,48 and 71 years. Serum Brucella antibody titres were also positive. Their antibody profiles are presented in the Table, the results being consistent with diagnosies of chronic brucellosis. • There were no positive serum samples from the patients whose CSF Brucella antibody tests were negative. • No cases of neurobrucellosis were identified in Scotland. MAG = Micro-agglutination CFT = Complement fixation test Discussion • It is already known that the UK has a very low prevelance of Brucella infection. This study confirms the view that neurobrucellosis remains an extremely rare complication. • As all 3 cases of neurobrucellosis had previously lived in a Brucella endemic area, unnecessary CSF examination can be avoided by taking a detailed travel history. • CSF Brucella antibody production follows on from systemic infection, the findings of Brucella specific antibodies in the CSF always being indicative of CNS infection. It is therefore essential that reference laboratories receive both CSF and serum samples whenever a diagnosis of neurobrucellosis is considered. References • 1. Young EJ: An overview of human brucellosis. Clin Infect Dis 1994; 21:283-90. • 2. Sharma R; Chisnall C; Cooke RPD: Evaluation of in-house and commercial immunoassays for the sero-diagnosis of brucellosis in a non-endemic low prevalence population. J Infect 2008; 56:108-113.