Evaluation of serological methods in the diagnosis of Chlamydia pneumoniae pneumonia during an epidemic in Finland.

Abstract

A complement fixation (CF) test, a micro-immunofluorescence (micro-IF) test and an enzyme immunoassay (EIA) using Re-lipopolysaccharide as antigen were compared in the diagnosis of chlamydial infection in 136 mainly elderly patients hospitalized with community-acquired pneumonia during a Chlamydia pneumoniae epidemic in Finland in 1986-1987. Chlamydial pneumonia was diagnosed in 58 (42.6%) of the 136 pneumonia patients; 44 (75.9%) of them could be shown by micro-IF to be caused by Chlamydia pneumoniae, three by Chlamydia psittaci and four by Chlamydia spp. Only 5 (11.4%) of 44 patients with Chlamydia pneumoniae pneumonia were IgM-positive, indicating that the majority of cases were reinfections. In this population of mainly elderly patients the CF test was insensitive, being positive in only 6 (10.3%) of 58 cases of chlamydial pneumonia. The EIA detected 72.4% of cases and micro-IF 87.9% of cases (including infections with Chlamydia pneumoniae, Chlamydia psittaci and Chlamydia spp.). In the EIA 77% of positive cases were positive in serum samples taken a week apart, whereas the corresponding figure for micro-IF was 50%. In micro-IF the measurement of IgA antibody levels is recommended and IgM-positive sera should be retested after removal of IgG antibody to avoid false-positive findings due to presence of rheumatoid factor. The collection of a third serum sample, for instance one month after onset, is also recommended, since half of the patients showed a diagnostic response in the micro-IF only in the sera taken one month apart.

• Authors: M R Ekman, M Leinonen, H Syrjälä, E Linnanmäki, P Kujala, P Saikku
• Journal: European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology (Eur J Clin Microbiol Infect Dis) Vol. 12 Issue 10 Pg. 756-60 (Oct 1993) ISSN: 0934-9723 [Print] Germany
• PMID: 8307044 (Publication Type: Journal Article)

Chemical References

• Antibodies, Bacterial

Topics

• Adolescent
• Adult
• Aged
• Aged, 80 and over
• Antibodies, Bacterial (blood)
• Chlamydia Infections (diagnosis, epidemiology)
• Chlamydophila pneumoniae (immunology, isolation & purification)
• Complement Fixation Tests
• Female
• Finland (epidemiology)
• Fluorescent Antibody Technique
• Humans
• Immunoenzyme Techniques
• Male
• Middle Aged
• Pneumonia (diagnosis)
• Serologic Tests