bWe report a case of Campylobacter volucris bacteremia in an immunocompromised patient with polycythemia vera and alcoholic liver cirrhosis. To our knowledge, this is the first case report in which this organism has been isolated from a human clinical specimen. CASE REPORTA 75-year-old male patient visited the Chung-Ang University Hospital with a chief complaint of abdominal discomfort due to accumulation of ascites fluid. The abdomen was diffusely distended without tenderness or rebound tenderness. The patient had a medical history of polycythemia vera with splenomegaly and alcoholic liver cirrhosis classified as Child-Pugh score B. The patient was taking medication for liver cirrhosis, including diuretics and ursodeoxycholic acid but was receiving no treatment for polycythemia vera. He had no travel history within 1 year and was not currently employed. Laboratory results revealed anemia (hemoglobin level of 5.0 g/dl), and vital signs were stable. The patient was admitted to the gastrointestinal department for management of abdominal distension, and a paracentesis was performed.On the next day, the patient complained (subjectively) of feeling febrile, and at that time the vital signs were as follows: body temperature, 38.3°C; pulse rate, 86/min; respiration rate, 20 breaths/min; and blood pressure, 100/60 mm Hg. A complete blood count (CBC) at the time of the fever revealed a white blood cell (WBC) count of 4,670/l, hemoglobin level of 6.8g/dl, and platelet count of 106,000/l. A peripheral blood smear showed a left shift in the maturation of WBCs. Chemistry results showed increased values of total bilirubin/direct bilirubin of 4.3/2.1 mg/ dl, lactate dehydrogenase of 382 IU/liter, and blood urea nitrogen/ creatinine of 77/1.81 mg/dl and decreased values of total protein/ albumin of 4.9/2.7 g/dl. The estimated glomerular filtration rate was decreased to 36.83 ml/min, and the C-reactive protein level was 51.3 mg/liter. Ascites analysis results revealed that specific gravity, pH, red blood cell (RBC), and WBC counts were within normal ranges, and no bacteria were observed on a Gram stain. Urinalysis results showed an increased WBC count (Ͼ100/highpower field) with proteinuria (1ϩ), hematuria (1ϩ), and nitrites (ϩ). Therefore, the patient was diagnosed with acute kidney injury due to a urinary tract infection, and empirical treatment with ceftriaxone (1 g/day) was administered intravenously. To determine the source of fever and the causative pathogen, urine, ascites, and blood cultures were performed. Ascites culture resulted in no growth for any microorganisms after 72 h of incubation. Urine culture resulted in the growth of an extended-spectrum ␤-lactamase-producing Klebsiella pneumoniae isolate (Ͼ100,000 CFU/ ml) after 24 h of incubation. The clinician changed the antibiotic to meropenem (1 g/day).Blood culture results were positive for growth after 72 h of incubation in 35°C by the BacT/Alert 3D blood culture system (bioMérieux, Inc., Durham, NC). Positive signals were detected from both sets of anaerobic (BacT...