Clinical manifestations and treatment outcomes of human brucellosis at a tertiary care center in Saudi Arabia

BACKGROUND: Brucellosis, which has profound public health and economic consequences, is endemic to Saudi Arabia. Brucella is transmitted to humans by direct contact with infected animals or by consumption of unpasteurized dairy products. Manifestations of brucellosis are protean and require a combination of drugs to prevent the emergence of resistance. The WHO recommends the use of doxycycline with rifampicin or an aminoglycoside for brucellosis, but experts in Saudi Arabia prefer to avoid the use of rifampicin and aminoglycosides to lessen the possibility of emergence of drug-resistant tuberculosis. OBJECTIVES: Compare rifampicin and doxycycline in the treatment of human brucellosis versus various combinations of doxycycline, with either trimethoprim-sulfamethoxazole (co-trimoxazole), quinolones or aminoglycosides, and describe the clinical manifestations of brucellosis. DESIGN: Retrospective medical record review. SETTING: Single tertiary care center. PATIENTS AND METHODS: Diagnosis of brucellosis was based on positive serology by standard agglutination test (SAT), or isolation by culture of Brucella species from blood, body fluid or tissue. MAIN OUTCOME MEASURES: Cure rate with the use of doxycycline in combination with either co-trimoxazole, quinolone or aminoglyco-sides in comparison to doxycycline/rifampicin and the clinical features of brucellosis. SAMPLE SIZE: 123. RESULTS: In 118 (96%) patients, the median IgG/IgM antibody titers at diagnosis and at 6 and 12 months were 1:1280/1:1280, 1:640/1:640, and 1:320/1:160, respectively. There were no differences in outcome between treatment regimens, as evidenced by a significant decrease in SAT titers and symptom resolution within six months. Five (4%) patients relapsed from non-adherence to treatment, but responded well to a second course of treatment. Blood cultures were positive in 50 patients (41%) patients. Fever, arthralgia and back pain were the most common symptoms. Good serological and clinical responses were achieved in 96% of patients. Relapse in 4% (n=5) was due to self-reported non-adherence. LIMITATIONS: Retrospective, relatively small sample size. CONCLUSIONS: Doxycycline with co-trimoxazole is as efficacious as doxycycline/rifampicin in non-focal brucellosis and is preferred in countries with a high prevalence of tuberculosis. CONFLICT OF INTEREST: None.