Successful azithromycin treatment of Chlamydia psittaci pneumonia in second-trimester pregnancy resulting in term delivery: a case report

Psittacosis pneumonia is a zoonotic infection caused by Chlamydia psittaci (C. psittaci), primarily transmitted via contact with infected avian species. Diagnostic challenges arise from the inherent difficulties of pathogen culture and serological testing, frequently resulting in misdiagnosis or underdiagnosis. Gestational psittacosis, in particular, is a rare but life-threatening condition, with delayed diagnosis conferring risk of severe maternal and fetal complications. We present a case of C. psittaci pneumonia in a 24-week pregnant woman, with the diagnosis confirmed by metagenomic next-generation sequencing (mNGS). Empirical intravenous azithromycin (0.5 g daily) was promptly initiated for 3 days, leading to rapid symptomatic resolution. After a 2-day interruption, targeted oral azithromycin (0.5 g daily) was restarted for an additional 3 days following pathogen confirmation via mNGS. The patient was successfully discharged after a 10-day hospital stay under multidisciplinary management. She finally gave birth to a healthy baby girl at 40 weeks and 3 days of gestation, with favorable maternal and neonatal outcomes. To our knowledge, this represents one of the few reported cases of full-term delivery following azithromycin monotherapy for gestational psittacosis. It provides valuable insights into the diagnosis and management of gestational psittacosis, emphasising the importance of multidisciplinary involvement in preserving maternal and fetal safety.