Bacteraemia with Hepatic Abscess Due to Actinomyces Odontolyticus Associated with Gastrointestinal Foreign Body

Hepatic actinomycosis is a rare intra-abdominal infection, particularly caused by Actinomyces odontolyticus. Liver abscess due to a perforating gastrointestinal foreign body is also extremely rare. We report the first case of bacteraemia with a liver abscess caused by A. odontolyticus, as evidenced by both positive blood culture and abscess fluid culture, associated with a perforating foreign body from a fish bone.

An 86-year-old male with dementia was admitted with a high fever of 39.5°C and right upper quadrant abdominal pain. Abdominal ultrasound revealed a right liver abscess. Both blood culture and abscess fluid culture identified A. odontolyticus by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. After percutaneous drainage, the patient's abdominal pain increased. Contrast-enhanced computed tomography scan revealed a fish bone foreign body penetrating from the duodenum into the liver. The patient underwent laparoscopic surgery for foreign body removal and abscess drainage, followed by treatment with intravenous piperacillin/tazobactam for 21 days, then oral amoxicillin/clavulanate for 3 weeks. The patient was discharged in stable condition.

This case emphasizes the importance of computed tomography scan when a liver abscess does not respond to conventional treatment, especially in elderly patients with dementia at risk of foreign body ingestion. Actinomyces spp. should be considered in cases of liver abscess of unknown aetiology.

Always consider gastrointestinal foreign bodies: In elderly patients with dementia presenting with liver abscesses that do not respond to conventional treatment, foreign body perforation should be suspected and actively investigated using a contrast-enhanced computed tomography scan.Actinomyces spp. should be considered: In cases of liver abscess of unknown aetiology, Actinomyces spp. should be considered - a slow-growing anaerobic bacterium requiring matrix-assisted laser desorption/ionization matrix-assisted laser desorption/Ionization time-of-flight mass spectrometry for accurate species identification and targeted antibiotic therapy guidance.Combined treatment is the key to success: Optimal management requires a combination of three elements - surgical removal of the foreign body, thorough abscess drainage, and prolonged beta-lactam antibiotics to prevent recurrence.