Case Report: The First Case of Bloodstream Infection Complicated with Psoas Abscess and Pulmonary Infection Caused by Aggregatibacter aphrophilus in China.

Aggregatibacter aphrophilus is part of the normal flora in the oropharynx and upper respiratory tract, which causes invasive bacteremia in rare cases. However, the culture and identification of Aggregatibacter aphrophilus are challenging, hence easily misdiagnosed or undetected in clinical practice. In this case, a 73-year-old male patient was admitted to the hospital with a fever and right hip pain. Routine blood and C-reactive protein tests showed abnormal inflammatory markers. Positive blood culture revealed the presence of Aggregatibacter aphrophilus through mass spectrometry. The computed tomography examination further revealed the presence of psoas abscess, pulmonary infection, and pleural effusion, which was relieved by ceftriaxone combined with levofloxacin therapy, the drainage of psoas abscess and pleural effusion. Therefore, since multiple anatomic sites infection, including bloodstream, psoas abscess and pulmonary infection caused by Aggregatibacter aphrophilus, is rare, sufficient attention should be paid to its clinical diagnosis and treatment.