Assessment of polymerase chain reaction and serology for detection of chlamydia pneumoniae in patients with acute respiratory tract infection.

OBJECTIVE

To study Chlamydia pneumoniae (C. pneumoniae) infection in 110 patients with respiratory tract infection admitted to our hospital from January to December 1995 in Nanjing.

METHODS

Sputum and throat swab specimens were taken and C. pneumoniae DNA was detected by using polymerase chain reaction (PCR) with the HM-1-HR-1 primer pair. At the same time, serum samples were taken and immunoglobulin G and M (IgG and IgM) fractions of antibodies to C. pneumoniae were studied by microimmunofluorescence test.

RESULTS

Prevalence of specific IgG was 70% in patients with respiratory tract infection. Seventeen patients (15.5%) were serologically diagnosed as having recent C. pneumoniae infections and 12 patients (10.9%) had positive PCR in sputum and/or swab specimens. The total positive rate was 22.7% (25/110) detected by PCR combined with serological tests. Acute infection of C. pneumoniae was common in patients with asthma (57.1%), pneumonia (35.0%), COPD (25.9%) and bronchitis (25.0%). Clinical features between C. pneumoniae infection and non-C. pneumonia infection showed no significant differences.

CONCLUSIONS

Chlamydia pneumoniae is an important pathogen that causes infection of the human respiratory tract and attention should be drawn to this special illness.