Cryptogenic Hypervirulent Klebsiella pneumoniae Pyogenic Liver Abscess: A Case Report.

BACKGROUND Klebsiella pneumoniae is a gram-negative organism known to cause pyogenic liver abscesses. It is most often caused by one of the hypervirulent strains, which are capable of causing metastatic infection. This occurs most commonly in Asia in patients without hepatobiliary disease; however, it is becoming increasingly recognized in North America. CASE REPORT We report a previously healthy man in his 50s who presented to hospital with 3 weeks of fever, chills, and mild abdominal pain following a minor motor vehicle collision. Ultrasound and computed tomography of his abdomen revealed a large multi-loculated liver abscess. This was drained percutaneously and grew a hypervirulent strain of Klebsiella pneumoniae known to cause metastatic infection. His blood cultures were negative. In addition to percutaneous drainage, he was treated with 8 weeks of antimicrobial therapy. Fortunately, he did not develop evidence of metastatic infection despite the hypervirulent strain. Etiology of the abscess was not clearly identified; however, it was speculated that the motor vehicle collision could have led to its development through gut translocation. CONCLUSIONS Presentation of Klebsiella pneumoniae liver abscesses is often nonspecific, and clinicians must have a high index of suspicion in order to ensure rapid diagnosis and treatment. Delay in diagnosis is associated with increased morbidity and mortality, and thus it is an important entity for clinicians to be aware of, especially as it becomes more prevalent in North American populations. Additionally, it is important that physicians are aware of the hypervirulent strains and screen patients clinically for evidence of metastatic infection.