ANALYSIS OF COMORBID CONDITIONS IN PATIENTS WITH QUESTIONABLE RESULTS DURING SCREENING BY ENZYME IMMUNOASSAY (ELISA) FOR ANTIBODIES TO HUMAN IMMUNODEFICIENCY VIRUS

As part of the implementation of the State Strategy for Countering the Spread of HIV Infection in the Russian Federation, one of the five targets is the coverage of medical examinations of the population with an annual increase from 29 % to 39 % over the ten-year period until 2030 [2]. The number of surveyed citizens has increased by almost 30 % over the five–year period alone, while the number of foreign citizens has more than doubled (+125 %), which is also due to the inclusion of new regions in the state and the intensification of migration processes. The trend line shows a significant increase in the volume of research, which indicates the need to use diagnostic tests with extremely high levels of specificity and sensitivity. The use of modern test systems (IV generation), which have a high detection capability during diagnosis, nevertheless does not exclude the possibility of contradictory results (doubtful, false positive, false negative) and the analysis of these cases as part of the quality control of screening. High viral variability and heterogeneity in the structure of subtypes affect differences in the antigenic structure, which, together with the presence of comorbid pathology, can affect the incorrect recognition of antibodies by tests and complicate the work of diagnostic systems.