[Etiologic diagnosis of pneumoccocal pneumonia by counterimmunoelectrophoresis (author's transl)]. / Diagnóstico etiológico de la neumonía neumocócica por contrainmunoelectroforesis.

The antigenic composition of the pneumoccocal capsule and its easy detection by counterimmunoelectrophoresis led us to carry out a comparative study of this method and the results obtained from cultures. A series of 159 patientes with suspected bacterial pneumonia were included in the study. Blood cultures were prepared for all of the patients; sputum cultures were practiced on 35 and cultures of pleural fluid on 32. Serum from all of the patients, urine from 104, sputum from 34, and pleural fluid from 16 were analyzed by counterimmunoelectrophoresis for pneumoccocal antigen. This method was particularly useful for detecting the germ in sputum and pleural fluid. Furthermore, a higher number of positive indexes in serum were obtained by counterimmunoelectrophoresis than by blood cultures (p less than 0.01). This was also true for tests with sputum and pleural fluid. Urine tests resulted in an even greater number of detections. Counterimmunoelectrophoresis is thus a simple, quick method for detecting pneumococcus and is especially useful when accompanied by cultures tests, since they are complementary. We were able to discover a positive indication of penumoccocus in bacterial pneumonia in 39.6 percent of cases with this technique, as opposed to 15 percent using cultures alone.