Q fever with biliary dilatation following contact with muntjac deer: a case report.

Q fever is a zoonosis caused by Coxiella burnetii. Classic presentations include atypical pneumonia and hepatitis, but bile duct dilation on imaging is rarely described. We report a case of acute Q fever in an urban resident of Chengdu, Sichuan Province, Southwestern China, who presented with cholestatic liver injury and intra- and extrahepatic bile duct dilation, highlighting an unusual manifestation that mimicked biliary tract disease. A 53-year-old man was admitted with persistent high fever (up to 41.8 °C), headache, chills, and right upper quadrant pain. Laboratory tests showed cholestatic hepatitis (AST 132 U/L, ALT 110 U/L, ALP 221 U/L, GGT 231 U/L), with normal total and direct bilirubin. Magnetic resonance cholangiopancreatography (MRCP) revealed mild intra- and extrahepatic bile duct dilation without obstruction. The patient had no livestock contact but had been exposed to wild muntjac deer from informal sources. Empiric doxycycline combined with piperacillin-tazobactam led to rapid defervescence and symptom improvement. The diagnosis of acute Q fever was supported by metagenomic next-generation sequencing (mNGS) of peripheral blood, in the absence of confirmatory seroconversion. In this case, bile duct dilation without jaundice was a notable manifestation of the infection. For febrile patients with unexplained cholestasis and bile duct dilation, especially those with a history of contact with wild animals, Q fever should be considered in the differential diagnosis.