[Controversies, difficulties and changes in serological confirmatory testing]

The significance of the diagnosis and the specificity of the screening assays might both justify the confirmatory testing of primary results. The widespread distribution of recombinant antigen-based assays, the availability of molecular testing and the sero-epidemiological trends of the pathogens resulted in significant changes of the testing algorythms in recent years. The characteristics of the commercially available assays, the common practice of indicating laboratory testing as well as the expectations toward the tests were not completely able to keep pace with the changes, which resulted in difficulties in the clinician-laboratory dialog. The aim of our present work is to review the changes, capabilities, limitations and appropriate application of confirmatory tests for four infections (hepatitis B virus, Hepacivirus hominis, human immunodeficiency virus, Borrelia burgdorferi sensu lato), in which controversies regarding the optimal testing algorythm and the interpretation of the results are common in our practice. Orv Hetil. 2023; 164(52): 2065–2073.