Severe Chlamydia psittaci pneumonia complicated by deep vein thrombosis: a case report and literature review.

Psittacosis is a zoonotic disease caused by Chlamydia psittaci, primarily transmitted through the respiratory tract. In humans, the most frequently associated condition is atypical pneumonia, while Chlamydia psittaci remains a relatively uncommon pathogen in cases of community-acquired pneumonia. Historically, reports of pneumonia due to Chlamydia psittaci have been limited, largely due to challenges in diagnosis. However, recent advancements in technologies such as next-generation sequencing (NGS) have led to an annual increase in reported cases of Chlamydia psittaci infection. Despite this, many hospitals still possess limited knowledge regarding Chlamydia psittaci, particularly in the context of diagnosing and treating critically ill patients. This report presents a case of severe Chlamydia psittaci pneumonia complicated by deep vein thrombosis in a 50-year-old male patient. The diagnosis was confirmed through polymerase chain reaction (PCR), and the patient was successfully treated with omadacycline. By analyzing 55 cases, this paper aims to summarize the etiology, clinical manifestations, diagnostic approaches, and treatment strategies for severe Chlamydia psittaci pneumonia, thereby enhancing clinicians' understanding of this disease.