Acute lower respiratory tract infection associated with Chlamydia pneumoniae in Germany.

Serum specimens from 223 patients with acute lower respiratory tract infection were examined for antibodies to Chlamydia pneumoniae using the microimmunofluorescence test. Antibodies to Chlamydia pneumoniae were detected in 18 (20%) of 91 children and 64 (48%) of 132 adults. Among those individuals, 4 (4%) children and 15 (11%) adults had elevated IgG antibody titres indicating acute or recent infection. Specific IgM antibodies were observed in two patients. These results suggest that a significant proportion of lower respiratory tract infections in Germany is caused by Chlamydia pneumoniae.