Clinical Features and Treatment Strategies of Q Fever Spinal Infection: A Pooled Analysis of 39 Cases and Narrative Review of the Literature.

Background: The incidence of spinal infections is increasing; However, pathogen identification remains challenging. Although Q fever spinal infection is reported infrequently, its accrual incidence is likely underestimated. The causative agent, Methods: We present a case of Q fever spinal infection and conducted literature searches in PubMed and the Chinese core journals of the Wanfang Database using keywords including "Q fever," " Results: A total of 39 adult patients were enrolled (mean age: 67.82 ± 10.51 years, male: 34,87.2%), Eleven cases reported potential pathogen exposure. Thirty-three cases presented with early-onset of lower back pain, and 13 developed fever during the disease course. Thirty-four cases involved the lumbar spine, exhibiting continuous lesions of 1-3 vertebral bodies, with imaging features of vertebral osteomyelitis, discitis, paravertebral soft-tissue swelling, and/or adjacent aneurysmal changes. Among 21 cases with routine blood tests, 2 showed elevated leukocyte counts, 5 had mild anemia, and the remainder were normal. Serological testing was performed in 34 cases, with 29 testing positive on the first time; PCR testing was conducted in 25 cases, with 23 cases detecting positive specimens; and rapid diagnosis confirmed in all 3 cases via metagenomic next-generation sequencing (mNGS). Inflammatory reactions were identified in all 21 biopsied cases, with inflammatory granulomas reported in 7 and explicitly excluded in 4. There were 24 cases complicated with aneurysm and 15 cases with isolated spinal infection. A significant difference in CRP elevation rate was observed between the two groups (14/15, 93.33% vs 4/8, 50.00%, Conclusions: This study systematically summarizes the clinical characteristics of Q fever spinal infection and, for the first time, reports features associated with its distinct clinical subtypes. Q fever should be considered in case of chronic spinal infections-especially those complicated with vascular lesions. Based on clinical history evaluation, rapid diagnosis may be achieved through mNGS of specimens from local lesions. Combined with early initiation of doxycycline-based regimens, timely debridement of necrotic tissues and purulent material may improve treatment outcomes. Further investigations are needed to identify reliable biomarkers for monitoring therapeutic efficacy and to establish optimal treatment strategies for subtypes of Q fever spinal infection.