Abstract
The aim of our study was to compare different laboratory methods of the CAP etiological factor identification.
30 patients (20 male and 10 female) with non-severe CAP were enrolled in the study (50,5±3,4 years). We have performed: microbiological test and polymerase chain reaction (PCR)-based study of induced sputum and peripheral blood samples, serologic tests to evaluate the level of IgM and IgG antibodies to C.pneumoniae and M.pneumoniae in peripheral blood.
Results: With all laboratory tests the etiologic agents were determined in 76,7 % of cases, mostly of S.pneumoniae. In sputum there were 30 positive results in PCR and 19 - in microbiological study. PCR study of sputum revealed in 10 patients monobacterial flora, 5 - bacterial mixture, 4 - virus-bacterial mixture while in microbiological study in all 19 patients there was monobacterial flora. The frequency of S.pneumoniae was comparable both in the PCR study, and in microbiological studies (46.6%). Frequency of K.pneumoniae and H.influenzae identification was the highest in the PCR study of sputum (13.3 and 26,7%). In PCR study of sputum M.pneumoniae was detected in 6,7%, C.pneumoniae was not found. Serological tests have revealed IgM antibodies to M.pneumoniae in 20% of patients, C.pneumoniae in 13.3% of patients. Conclusion: PCR study is the most efficient method of etiological diagnostics of the CAP, and reflects the complex etiological picture compared to microbiological study. Serological tests with specific IgM detection are the efficient methods of etiologic diagnosis in CAP caused by atypical pathogens. Thus the combination of different methods of etiologic diagnostics is the most appropriate way for non-severe CAP.
- © 2012 ERS
