An asymptomatic pulmonary arteriovenous fistula presenting with a Campylobacter rectus brain abscess as the initial manifestation: a case report

Background Brain abscess is a severe infectious disease of the central nervous system associated with high rates of mortality and morbidity. Pulmonary arteriovenous fistula (PAVF) is a rare but important cause of cryptogenic brain abscesses. The pathogens associated with PAVF-related brain abscesses are typically oral anaerobes or facultative anaerobes, most commonly non-hemolytic streptococci and Streptococcus intermedius . To our knowledge, no case of a monomicrobial Campylobacter rectus (C. rectus) brain abscess in a patient with asymptomatic PAVF has been reported. Case presentation Herein, we report the case of a 57-year-old man with a C. rectus brain abscess in association with an asymptomatic PAVF. The patient presented to our hospital with fever and headache. Magnetic resonance (MR) imaging revealed a 5 × 2 cm brain abscess in the right temporal and occipital lobes, surrounded by extensive edema. Enhanced computed tomography (CT) scanning of the lungs revealed both nodules and PAVF. Blood culture and cardiac ultrasound failed to detect any abnormalities. Piperacillin-tazobactam and meropenem were administered for anti-infection, although the headache persisted. He was subsequently transferred to neurosurgery to resect the abscess by craniotomy; postoperative pus culture confirmed the presence of C. rectus . Conclusions For brain abscesses caused by oral anaerobes such as C. rectus , screening for right-to-left shunting diseases such as PAVF may be considered when no other source is identified.