A Case of Neurobrucellosis Mimicking Brucellosis and Acute Q Fever: Diagnostic Challenges

Abstract

Brucellosis and Q fever are zoonotic bacterial infections with overlapping epidemiological exposure risks, nonspecific clinical manifestations, and potential diagnostic challenges, particularly in endemic regions. Neurological involvement in brucellosis is uncommon but may raise suspicion of neurobrucellosis in patients presenting with persistent neurological symptoms. We report a 25-year-old male shepherd with occupational exposure to farm animals and a history of unpasteurized dairy consumption who was initially diagnosed with brucellosis and received appropriate antimicrobial treatment at an external center. Despite therapy, he continued to experience persistent headache, dizziness, fatigue, syncope, tinnitus, arthralgia, and generalized body pain, prompting referral for further evaluation with suspected neurobrucellosis. Neurological examination, cranial magnetic resonance imaging, computed tomography, and cerebrospinal fluid analysis were unremarkable, excluding central nervous system involvement. Brucella serology remained positive, while additional serological investigation for persistent symptoms demonstrated Coxiella burnetii Phase I IgG of 1:128 and Phase II IgG of 1:256. Follow-up testing four weeks later revealed seroconversion with disappearance of Phase I IgG and a marked rise in Phase II IgG to 1:1280, strongly supporting acute Q fever. The patient received streptomycin, doxycycline, and rifampicin, resulting in complete clinical recovery and declining serological titers during follow-up. This case highlights the importance of considering concomitant zoonotic infections and carefully interpreting serological dynamics in patients with persistent symptoms despite adequate brucellosis treatment.