A 22-year-old woman with fulminant Chlamydia pneumoniae pneumonia.

Chlamydia pneumoniae (C. pneumoniae) is a common pathogen of community-acquired pneumonia. The clinical features of infection caused by C. pneumoniae are usually mild and it does not progress into respiratory failure in young people. We describe a healthy, immunologically intact, 22-year-old woman with severe respiratory failure caused by C. pneumoniae accompanied by aspergillosis. The infection rapidly progressed and required mechanical ventilation. C. pneumoniae infection should be taken into account when treating patients with rapidly progressive pneumonia even in immunocompetent young adults.