EN
The porcine respiratory and reproductive syndrome is a relatively new swine disease first described in the USA in 1987, and in Europe in 1990. Serodiagnosis of the disease can be performed by using an immunoperoxidase mono- layer assay (IPMA), To evaluate this test, the following materials were used to perform the assay: Hesse strain of PRRSV, MARC-145 cells, 42 sera obtained from PRRS suspected herd, 60 sera from herds free from PRRS, and positive reference anti-PRRSV serum. In order to test the sera for the presence of antibodies to PRRSV, 50 pi of successive, 2-fold serum dilutions (from undiluted to diluted 1:256) were distributed in triplicate on the prepared 96-well microplate. The serum samples were considered as positive if brownish-red precipitates were found in the cell cytoplasm of at least one of the tested serum dilutions. The presence of antibodies to PRRSV was found in 23 out 42 examined sera from a suspected farm. In 10 out of 23 positive serum samples the titre was >1:256. No antibodies to PRRSV were detected in the sera that came from swine herds free from PRRS. Taking into account our results, the IPMA can be applied for routine serodiagnosis of PRRS in Poland.