Epidemiology, Clinical and Laboratory Manifestations, and Outcomes of Brucellosis Among 104 Patients in Referral Hospitals of Tehran, Iran

Background: Brucellosis is the most common zoonotic disease in Iran, imposing a significant financial burden on the healthcare system. The diversity of non-specific clinical manifestations of this disease can lead to misdiagnosis or delayed diagnosis. Therefore, it is important to pay attention to other aspects of this disease. Objectives: This study aimed to determine the epidemiology, clinical and laboratory manifestations, and outcomes of brucellosis. Methods: In this cross-sectional study, brucellosis patients, admitted to three hospitals, affiliated to Shahid Beheshti University of Medical Sciences (Tehran, Iran) from April 2015 to September 2020, were examined. The patients' medical records were reviewed for epidemiological, clinical, and laboratory findings. The outcomes of the disease were evaluated by phone calls. Results: Of the 104 patients included in this study, 53.8% were male, and 46.2% were female. The mean age of the patients was 43.07 +/- 18.521 years. Unpasteurized dairy consumption and contact with livestock were reported in 60.6 and 27.9% of the patients, respectively. Also, 23.1% of the patients had high-risk occupations. The most common symptoms included fever (80.8%), chills (58.7%), backache (55.8%), and sweating (51%). The most common complication was osteoarticular involvement (21.2%), followed by neurobrucellosis (6.7%). Elevated alkaline phosphatase (89.7%), anemia (67.3%), increased C-reactive protein (57.7%), and increased erythrocyte sedimentation rate (48.1%) were common laboratory findings. The rates of improvement, treatment failure, and relapse were 86.9, 9.1, and 4%, respectively. There was no significant relationship between the rate of improvement and the antibiotic regimen. However, the most common cause of treatment failure was the patient's poor compliance with treatment. Conclusions: The diversity of non-specific clinical manifestations of brucellosis is a diagnostic challenge. Therefore, physicians must request laboratory tests to evaluate brucellosis after taking a precise epidemiological and clinical history of suspected cases.