Multiloculated Liver Abscess Caused by Fusobacterium: Role of Karius Testing in Diagnosis

Pyogenic liver abscess can be a major diagnostic and therapeutic challenge despite advances in cutting edge technologies. A patient presented with fever, right upper quadrant pain and diarrhea. CT revealed multiple hypodensities in both lobes of liver. The largest lesion was in the left lobe of liver and was multiloculated with thick septations. The causative organism was identified to be Fusobacterium nucleatum by Karius testing. The patient was discharged on six weeks of ertapenem therapy, which resulted in complete resolution. This is the first case of liver abscess where Karius testing was used to identify microorganism. It also highlights that multiloculated and difficult to drain liver abscesses caused by highly sensitive organisms can potentially be treated by intravenous antibiotics alone in immunocompetent patients.