Seroprevalence of Epstein-Barr Virus in North-Eastern Bulgaria

Epstein-Barr Virus (EBV) is a widely spread member of the Herpesviridae family. Data show that in more than 90% of the adult population, specific anti-EBV can be found. In different Bulgarian studies the seroprevalence was set between 60% and 80%. The primary infection early in life is often asymptomatic or with nonspecific clinical symptoms, while in teenagers infectious mononucleosis develops. EBV is a proven agent of malignant, autoimmune and lymphoproliferative diseases, especially in immunocompromised patients. Tracking and analyzing the seroepidemiological status of the population in every region is of utmost importance. In our study, 5016 single serum samples from patients referred for EBV testing for various reasons were analyzed for the period 2010-2015. People aged between 1 month and 89 years old were divided into sixteen age groups. The samples were tested using indirect enzyme-linked immunosorbent assay (ELISA) for detection of anti-EBV (VCA) IgM and IgG. The proportion of EBV seropositive individuals and their corresponding confidence intervals (CI), chi-squared distributions and p-values were calculated. Our data indicated high, age-dependent EBV (VCA) IgG dissemination with 90% seroprevalence after age 26. Primary infections detected by anti-EBV (VCA) IgM occur in a bimodal model with peaks in age groups 1 – 5 and 11 - 20 years old.