[Evaluation of specificity of pneumococcal antigen detection in clinical samples by using the polymerase chain reaction as reference method].

BACKGROUND

Sensitivity and specificity of latex agglutination test on samples obtained by transthoracic needle aspiration was evaluated for diagnosis of pneumococcal pneumonia by using the polymerase chain reaction as reference method.

METHODS

Samples from 29 patients with community acquired pneumonia were processed for culture, antigen detection and polymerase chain reaction. The latex agglutination test was performed with a reagents kit (Slidex méningite kit, BioMérieux, France) using the procedure recommended by the manufacturer. The polymerase chain reaction was carried out by using two primers: Pn2x up and Pn2x down that amplify the PBP2x gene of Streptococcus pneumoniae.

RESULTS

Culture was positive in 5 patients, antigen detection in 15 and polymerase chain reaction in 14 patients. The specificity of latex agglutination test was 93% compared with polymerase chain reaction as reference method.

CONCLUSION

The pneumococcal antigen detection by latex agglutination test is as sensitive as the polymerase chain reaction, it seems to be highly specific, and it is rapid and easy to perform.