Evaluation of accuracy of hepatitis B virus antigen and antibody detection and relationship between epidemiological factors using dried blood Spot

Abstract Dried blood spots (DBS) testing might increase the access for Hepatitis B virus (HBV) diagnosis, but little is known about the performance of these assays in real life conditions. This study aims to evaluate the diagnostic accuracy of HBsAg, anti-HBc and anti-HBs detection in DBS in clinical settings and field studies and to evaluate demographic and risk behaviour according the presence of HBsAg and anti-HBc. Paired sera and DBS samples were obtained from 2,309 individuals from 3 groups, defined as follows: G1: clinical setting (n = 509), G2: general population (n = 1,305) and G3: vulnerable individuals that could be more exposed to blood contact (n = 485). Sera and DBS were tested using commercial enzyme immunoassay (EIA), with some modifications added. Using DBS samples, the specificity values were above 90% for HBsAg and anti-HBc in all groups and for anti-HBs range from 58.6% to 85%. HBsAg testing had the best performance in GI (sensitivity = 84.4%) and among those samples that the paired serum also presented anti-HBc marker (sensitivity = 91.6%). High sensitivity of anti-HBc testing in DBS samples was observed in GI (80.8%) and among HBV active cases (HBsAg+/anti-HBc+) (98.4%). Testing of anti-HBs in DBS showed the highest sensitivity in GIII (65.5%), in previous HBV exposed and cured individuals and when serum titers were above 100 IU/mL (86.7%). DBS samples could be used for screening and prevalence studies for HBsAg and anti-HBc, particularly in clinical settings and among HBV active cases in field studies.