Misdiagnosed acute Q fever due to Coxiella burnetii in Guangxi China: A case report and literature review.

Coxiella burnetii (C. burnetii), a Gram-negative obligate intracellular bacterium, is the etiological agent of Q fever. Timely diagnosis and initiation of appropriate therapy are critical for favorable clinical outcomes, particularly in cases of acute Q fever. This report describes a case of C. burnetii infection in a 35-year-old male electrical grid engineer who presented with a 4-day history of febrile illness, peaking at 40.0 °C. Associated symptoms included night sweats, chills, anorexia, nausea, non-productive cough, and chest tightness. During hospitalization, the patient also developed headache and vomiting. Metagenomic next-generation sequencing (mNGS) of peripheral blood identified C. burnetii as the causative pathogen. The patient was treated with oral doxycycline (100 mg twice daily) for 14 days and levofloxacin (500 mg once daily) for 5 days. Following antimicrobial therapy, the patient's symptoms resolved rapidly, with no clinical evidence of relapse or progression to chronic Q fever during follow-up. This report describes a case of Q fever diagnosed by mNGS. The case highlights the diagnostic value of mNGS in patients presenting with febrile illness of unknown origin. It also serves as a reminder to clinicians that, even in regions where Q fever is enzootic in animals but no human cases have been reported, the possibility of human infection should not be overlooked.