Comparison of different treatments and treatment durations in patients with brucellosis: a prospective randomized study

Objective: Various treatment options and durations can be chosen in the treatment of brucellosis. The clinical condition of the patients and the physician's preference are decisive in the decision to choose the treatment. However, well-planned randomized controlled studies demonstrating which of these treatments are superior to one another are scarce in the literature. This thesis aims to evaluate the outcomes of different treatment combinations in patients diagnosed with brucellosis and to assess whether serological and nonspecific tests used in diagnosis can be utilized in treatment follow-up. Material–Methods: The study was conducted prospectively, observationally, and without intervention on newly diagnosed brucellosis patients at the Department of Infectious Diseases and Clinical Microbiology, Afyonkarahisar Health Sciences University, between July 2022 and February 2024. Two different combinations of doxycycline with gentamicin and rifampicin were applied to the patients included in the study over treatment durations of 4 and 6 weeks. Standard Tube Agglutination (STA), Brucellacapt, Brucella IgM, and IgG levels were investigated in the patients before treatment, at the 2nd week of treatment, at the end of treatment, and during follow-ups at the 3rd and 6th months post-treatment. The effectiveness of the 4 and 6-week treatments of both treatment combinations was compared with each other. The potential use of the serological tests in treatment follow-up was statistically evaluated. Results: A total of 60 uncomplicated brucellosis patients were included in the study, with 15 patients in each group. When the patients who received brucellosis treatment were evaluated in terms of treatment response and relapse, only one patient in the doxycycline + rifampicin 6-week group was considered unresponsive to treatment. The relapse rates in the patient groups were found to be 21.4% for doxycycline + rifampicin 6-week, 13.3% for doxycycline + rifampicin 4-week, 6.6% for doxycycline + gentamicin 6-week, and 13.3% for doxycycline + gentamicin 4-week. In treatment-responsive patients, a gradual decrease in STA values was observed at the end of treatment, and during the 3rd and 6th months post-treatment follow-up. Brucellacapt values at the 3rd and 6th months post-treatment were found to be lower than those before treatment, after treatment, and at the 2nd week of treatment. In treatment-responsive patients, Brucella IgG values at the 6th month post-treatment were found to be lower than before treatment, at the 2nd week of treatment, and at the end of treatment; Brucella IgM values at the 3rd and 6th months post-treatment were found to be lower than before treatment and at the 2nd week of treatment. Conclusion: In our study, it was observed that there is no superiority between the gentamicin + doxycycline treatment combination and the rifampicin + doxycycline treatment combination. When patients were evaluated in terms of treatment duration, it was found that a 6-week treatment duration is not superior to a 4-week treatment duration for brucellosis patients. It was concluded that monitoring STA, Brucellacapt, and Brucella IgM titers could be significant in the follow-up of treatment response and that monitoring STA, Brucellacapt, Brucella IgM, and IgG could be significant in predicting relapse. Our study suggests that a 4-week combination of rifampicin + doxycycline or gentamicin + doxycycline may be sufficient for uncomplicated brucellosis patients. Keywords: brucellosis, treatment, serological diagnosis, follow-up