Severe pneumonia caused by Chlamydia abortus complicated by hemophagocytic syndrome: a case report

<i>Chlamydia abortus</i> infection can result in severe acute respiratory distress syndrome (ARDS), necessitating prompt diagnosis and active clinical intervention. This case is unique due to the rare occurrence of HLH following <i>Chlamydia abortus</i> infection, a pathogen not commonly associated with this condition. Metagenomic next-generation sequencing (mNGS) offers a distinct advantage in rapidly and accurately identifying rare pathogen infections, while extracorporeal membrane oxygenation (ECMO) can be an effective treatment for severe pneumonia caused by <i>Chlamydia abortus</i>. It highlights the importance of early recognition and management of HLH in patients with severe, unexplained infections, particularly in those with unusual pathogens. Additionally, <i>Chlamydia abortus</i> infection may be complicated by HLH. Clinicians should remain vigilant for patients presenting with unexplained high fever, hepatosplenomegaly, and pancytopenia, and HLH screening should be initiated promptly. Early intervention can significantly improve patient survival rates.