Analysis of epidemiological, clinical, laboratory and radiological findings of patients with brucellosis and review of the literature

Aim: Brucellosis is one of the most common zoonotic diseases worldwide and continues to be a significant public health concern. In this study, we aimed to evaluate the demographic and clinical characteristics, complications, laboratory and radiological findings, and treatment regimens of patients who were diagnosed with brucellosis and followed up in the Department of Infectious Diseases and Clinical Microbiology at Harran University Faculty of Medicine. The findings were discussed in the context of the current literature. Material and Methods: In this study, the medical records of 223 patients diagnosed with brucellosis and followed up at the Department of Infectious Diseases and Clinical Microbiology, Harran University Faculty of Medicine between January 2018 and December 2024 were retrospectively reviewed. The patients' demographic and clinical characteristics, laboratory findings, diagnostic methods, treatment modalities, and post-treatment evaluations were analyzed. Results: Among the 223 patients included in the study, 107 (%48) were female and 116 (%52) were male. The mean age of the patients was 42 (18-80) years. A total of %58,7 of the patients resided in urban areas, while %41,3 lived in rural regions. The most common route of transmission was via the digestive system; %79,4 of the patients had a history of consuming unpasteurized fresh cheese. Additionally, %34,5 of the patients were engaged in livestock farming. When categorized according to the time of admission, %55,6 (n=124) of the patients were classified as having acute brucellosis. The most frequently reported symptoms at presentation were widespread body pain in %82,5 (n=184), fatigue in %76,7 (n=171) and sweating in %66,4 (n=148). The most common physical examination finding at presentation was tenderness in bones and joints, observed in %40,3 of the patients. Complications (focal involvement) were detected in %47,1% of the cases, involving either a single region or multiple sites. Among the complicated cases, the most frequent complication was osteoarticular involvement (n=67, %37). No statistically significant relationship was found between the stage of brucellosis and the presence of chronic diseases (p=0,656). However, comparison based on the stage of disease revealed that patients in the acute phase more frequently presented with epididymo-orchitis (p=0,005). At presentation, the mean erythrocyte sedimentation rate (ESR) was 25,3 mm/hour, and the mean C-reactive protein (CRP) level was 3,1 mg/dL. When evaluated across clinical stages, the mean CRP levels were 4,1 mg/dL in acute brucellosis, 2,3 mg/dL in subacute cases, 1,7 mg/dL in chronic cases, and 1,7 mg/dL in relapse cases (p=0,005). Mean ESR values were 30,1 mm/hour in acute brucellosis, 27 mm/hour in subacute, 20 mm/hour in chronic, and 14,9 mm/hour in relapse cases (p=0,002). The Rose Bengal test was positive in 165 patients (%74) and negative in 58 (%26). The serum agglutination test (SAT) showed titers of 1/160 or higher in all patients. Among those with a titer of 1/160, Rose Bengal test positivity was %51,6, while positivity increased to %96,4 in patients with a titer of 1/5120 (p=0.001). 10 Among 220 patients who underwent ultrasonographic imaging, hepatosplenomegaly was observed in 26 (%11,8), epididymo-orchitis in 21 (%9,4), hepatomegaly in 10 (%4,5), splenomegaly in 5 (%2,3), and breast masses in 2 (%0,9). Among 103 patients who underwent magnetic resonance imaging (MRI), spondylodiscitis was detected in 35 (%34), arthritis in 23 (%22,3), sacroiliitis in 19 (%18,4), and meningitis findings in 4 (%3,9). The most commonly preferred treatment regimen was a combination of streptomycin, doxycycline, and rifampicin, used in %63,7 of the cases. Conclusion: Brucellosis is a zoonotic disease that continues to cause serious complications and significant economic losses. In our study, when patients were categorized based on the time of admission, it was found that %55,6 presented during the acute phase. The rate of complicated brucellosis was %47,1, with osteoarticular involvement being the most common complication (%37). In young patients with acute brucellosis, the presence of epididymo-orchitis as a complication was found to be statistically significant. From a laboratory perspective, the mean erythrocyte sedimentation rate at admission was 25,3 mm/hour, and the mean C-reactive protein level was 3,1 mg/dL. A statistically significant increase in Rose Bengal test positivity was observed as the serum agglutination test titer exceeded 1/160. Given that the region is endemic for brucellosis, it is crucial to consider the disease in the differential diagnosis in order to initiate early treatment and prevent complications. Therefore, increasing awareness of brucellosis among both healthcare professionals at all levels and the local population living in endemic areas should be a key public health goal. Keywords: Brucellosis, Rose Bengal, Complication, Epididymoorchitis, Osteoarticular