Case Presentation: A 57-year-old woman with a history of morbid obesity, cholecystectomy, and prior choledocholithiasis with placement of biliary stents presented with nausea, vomiting, rigors, and fever with epigastric pain radiating to her back. Cardiopulmonary, neurological, and skin exams were unremarkable. Initial laboratory studies showed a white blood cell count of 10.7 x 10^3/µL, AST of 356 U/L, and ALT of 307 U/L. MRCP showed common bile duct dilatation with multiple stones in the distal biliary stent. She was admitted for sepsis secondary to choledocholithiasis with evolving Grade I cholangitis per the Tokyo 2018 guidelines. Empiric antibiotics were initiated and interventional gastroenterology was consulted. ERCP showed pus, sludge, and stones consistent with cholangitis and her biliary stents were replaced. Brushings from a common hepatic duct stricture were negative for atypia. In the interim, blood cultures taken at admission were positive for penicillin-resistant Streptococcus pneumoniae (S. pneumoniae). Chest X-ray did not show evidence of pneumonia and transthoracic echocardiogram (TTE) did not demonstrate any valvular vegetations, although the pulmonic valve was not well-visualized. Urinalysis and respiratory viral panel were negative. Infectious Disease was consulted and recommended transesophageal echocardiogram (TEE) to further evaluate the pulmonic valve. The study was negative and thus, given the unrevealing work-up, recommended treating for uncomplicated S. pneumoniae bacteremia with presumed source to be the biliary tree. The patient received IV antibiotics and recovered without complication.
Discussion: S. pneumoniae is an extremely rare cause for cholangitis. It is typically found in the nasopharynx and does not normally colonize the biliary tree due to its autolysis in bile. To our knowledge, pneumococcal biliary tract infections have not been described in the US literature but have been found in some international case reports to be associated with extrahepatic obstructive cholestasis and placement of biliary drainage devices (1-3). In this case, the patient had an extensive history of biliary disease and instrumentation from numerous prior ERCPs and stent placements and her examination, imaging studies, and infectious workup from this admission all failed to indicate a clear source of the S. pneumoniae bacteremia. Additionally, the ERCP findings were consistent with cholangitis, lending credibility to the hypothesis that the bacteremia originated from a biliary source given the negative cardiac and pulmonary workup. Thus, pneumococcal biliary tract infections may be underreported in patients with a history of biliary tract disease and/or device placement. However, given the costs and resources associated with definitive diagnosis of pneumococcal biliary tract infections (e.g., bile culture, studies like TEE to rule out alternative etiologies), culture confirmation of S. pneumoniae in bile may not be clinically necessary and physicians should consider treating S. pneumoniae bacteremia without definitive source identification.
Conclusions: In patients with S. pneumoniae bacteremia of unclear origin, a biliary source should be suspected in those with a history of biliary disease and device placement. From a clinical and high-value care perspective, the obtainment of a bile culture or other further diagnostic studies may not be necessary and should not preclude prompt treatment of the bacteremia and underlying cause.