Human Brucellosis Diagnosed by Blood Culture from a Tertiary Care Center in Western Rajasthan, India: Clinical Profile and Time to Detection

Human brucellosis is an important zoonotic infection in India, although most published data continue to rely on serological diagnosis. Reports of culture-confirmed disease remain limited. We reviewed all cases of blood culture-confirmed brucellosis diagnosed at a tertiary care center in western Rajasthan between January 2019 and February 2026. During the study period, 110,687 blood cultures were processed, of which 96 (0.1%) yielded Brucella spp., representing 62 patients. The cohort was predominantly male (n = 51/62; 82%), with a mean age of 36.2 ± 20.8 years old. Most patients were from livestock-rearing districts of western Rajasthan. Raw milk consumption (87%) and direct animal contact (57%) were the most frequent exposures, and farmers and agricultural workers comprised the largest occupational group. Fever was present in all patients, with a median duration of 30 days, and arthralgia was reported in 65%. Hepatic involvement was documented in 24.2% of patients, and osteoarticular disease was documented in 12.9% of patients. Elevated transaminases were observed in 77% of cases. Among 96 positive blood culture bottles, median time to detection was 65.8 hours (interquartile range: 60.3-78.5), and 95% flagged positive within 96 hours. Fifty-seven patients (92%) recovered; however, two patients experienced relapse, and two patients died of comorbid illnesses. This study highlights the clinical and microbiological profile of culture-confirmed brucellosis in an endemic region of western Rajasthan. Most isolates were detected within 4 days by the automated blood culture system, indicating that routine incubation periods are sufficient for Brucella recovery in the majority of acute cases.