Osteoarticular Involvement and Inadequate Treatment of Brucellosis Are Related with Relapse

The goal of treatment in brucellosis is to control symptoms for preventing the development of complications and relapse of infection. Aim of this study was to evaluate the risk factors for relapse in brucellosis patients, including those with complications. Materials and Methods: Our study was performed retrospectively with data from three centers. The complication of brucellosis was defined as the involvement of specific anatomical regions by the disease. Recurrence of symptoms and signs of brucellosis 6 months after termination of treatment and increased standard tube agglutination titer under treatment or isolation of Brucella spp. in sterile body fluids was defined as relapse. Inadequate treatment duration was defined as treatment duration of less than 8 weeks in patients with osteoarticular complications and less than 6 weeks in other brucellosis involvement.. A multivariate logistic regression model was built with the variables determined to be effective in relapse development. Logistic regression model included gender, presence of osteoarticular complications, inadequate treatment duration, treatment combinations and leukocyte count. SPSS 20 statistical package program was used for statistical analysis. Results: A total of 1296 patients were enrolled in the study whose median age was 42 (31-54) years and 631 (48.7%) were female. One or more complications were detected in 448 (34.6%) cases. A 2-drug antibiotic combination was given to 1125 (86.8%) patients and 171 (13.2%) were treated with a 3-drug antibiotic combination regimen. Three hundred sixteen (24.4%) of the patients were treated with combination therapies that included an aminoglycoside. Relapse occurred in 110 (8.5%) patients and treatment was inadequate for 105 (8.1%) of all cases.. Osteoarticular complications were more frequent in patients with relapse than in those without relapse (33.6% vs 18.5%, p<0.001). The presence of osteoarticular complications (odds ratio [OR]=2.413, 95% confidence interval [CI]: 1.550-3.756) and inadequate treatment duration (OR=2.861, 95% CI: 1.645-4.974) were associated with higher rate of brucellosis relapse, while combination therapies including an aminoglycoside (OR=0.432, 95% CI: 0.249-0.752) was associated with lower rate. Conclusion: Our results indicate that in patients with osteoarticular complications, treatment should be administered for the recommended optimal duration and combination therapies including aminoglycosides should be chosen preferentially in order to prevent the relapse of infection.