Brucella bacteraemia: Clinical and laboratory observations in 160 patients

Objectives: To describe the clinical, serological, and prognostic features of bacteraemic brucellosis in an endemic region. Methods: Retrospective case series of 160 patients admitted from 1983 to 19 95 to a hospital providing secondary and tertiary level medical care in Sau di Arabia. All patients had positive blood cultures for Brucella species, p redominantly Brucella melitensis. Results: Bacteraemia was documented in 38% of 545 cases of brucellosis admi tted to our institution during the study period. The main clinical syndrome s were febrile illness alone (44%) or fever with arthritis (42%). Of 68 iso lates that were speciated, 93% were Brucella melitensis. Initial agglutinat ing antibody titre was greater than or equal to 1:320 in 96% of the patient s. Antimicrobial resistance of B.melitensis isolates was: co-trimoxazole, 2 9%; rifampicin, 3.5%; streptomycin, 0.6%; and tetracycline, 0.6%. No increa se in resistance was noted over the 13-year study period. Commonly used ant imicrobial regimens consisted of streptomycin plus tetracycline or rifampic in plus doxycycline given for 6 weeks. Seven patients (5%) had relapse of t heir symptoms after antimicrobial therapy Three of these had infective endo carditis with repeated bacteraemia, These patients required aortic valve re placement and recovered after surgery. The remaining four patients responde d to a second course of therapy. Conclusions: Brucella bacteraemia is an acute febrile disease often associa ted with rheumatologic complaints. Most patients have an agglutinating anti body titre greater than or equal to 1:320 and respond well to standard chem otherapy regimens with low mortality. (C) 2000 The British Infection Societ y.