Mycoplasma pneumoniae and Chlamydia spp. Infection in Community-Acquired Pneumonia, Germany, 2011–2012

Mycoplasma pneumoniae and Chlamydia spp., which are associated with community-acquired pneumonia (CAP), are difficult to propagate, and can cause clinically indistinguishable disease patterns. During 2011–2012, we used molecular methods to test adult patients in Germany with confirmed CAP for infection with these 2 pathogens. Overall, 12.3% (96/783) of samples were positive for M. pneumoniae and 3.9% (31/794) were positive for Chlamydia spp.; C. psittaci (2.1%) was detected more frequently than C. pneumoniae (1.4%). M. pneumoniae P1 type 1 predominated, and levels of macrolide resistance were low (3.1%). Quarterly rates of M. pneumoniae–positive samples ranged from 1.5% to 27.3%, showing a strong epidemic peak for these infections, but of Chlamydia spp. detection was consistent throughout the year. M. pneumoniae–positive patients were younger and more frequently female, had fewer co-occurring conditions, and experienced milder disease than did patients who tested negative. Clinicians should be aware of the epidemiology of these pathogens in CAP.