EN
In the action undertaken for evaluating of the reliability of serological tests for M. pneumoniae infection 33 laboratories of the Sanitary Epidemiological Stations participated. Every laboratory had to determine twice at an interval of 2-4 weeks the level of mycoplasma antibodies by the complement fixation test in serum samples divided into 4 groups: sera not containing these antibodies-titre < 5, or containing them in titres of 60, 120 and 320. The correct results of the determinations were obtained in 27 laboratories (81.8%) for samples without M. pneumoniae antibodies, and in 22 (66.6%) and 14 (42.4%) for samples with titres of 60 and 120, and 320 respectively. Only 4 laboratories (12.1%) obtained correct results of these determinations for every sample and in both testing series. In these series considered separately correct results were obtained in 9 (27.3%) and 8 (24.2%) laboratories. Faulty results in all samples in both testing series were reported from 2 (6.1%) laboratories. In the individual series all false results were obtained in 4 (12.1%) and 3 (9.1%) laboratories. The study showed that for raising of the quality and reliability level of serological investigations for M. pneumoniae infection a permanent practice should be periodic training of laboratory workers and frequently repeated interlaboratory controls of the reliability of test results.