Occult and active hepatitis B virus detection in donated blood in São Paulo, Brazil

Abstract

Background The present study determined the HBV antigen, antibody, and DNA status in blood donations deemed to be HBV positive. Individuals with an occult HBV infection (OBI), defined as being positive for HBV DNA but negative for HBV surface antigen (HBsAg), as well as those with active infection (HBsAg‐positive), were identified and characterized. Study Design and Methods From a total pool if 198,363 blood donations, we evaluated in a cross‐sectional study, 1106 samples that were positive in screening tests for antibody to HBV core antigen (HBcAb), HBsAg, and/or HBV DNA by nucleic acid testing (NAT‐HBV). The presence of genetic variants in the HBV pol/S gene in individuals with an active HBV infection was also determined. Results OBIs were detected in six of 976 samples (0.6%) that were positive only for HBcAb. The rate of HBV active infection was 0.024% (48/198,363) and there was a predominance of HBV sub‐genotype A1 (62.2%, 28/45), followed by D3 (17.8%, 8/45). Mutations in the S gene were found in 57.8% (26/45) and immune escape mutations in 37.8% (17/45) of active HBV‐infected donors. Among them, T123N, G145A, and D144G high‐impact immune escape mutations were identified. Conclusion Highly sensitive molecular tests improve the capacity to detect OBIs. When NAT is performed in pooled samples, HBcAb test has value in the detection of donors with OBI and improves transfusion safety. Mutations in the S gene are frequent in HBsAg‐positive blood, including those associated with diagnostic failure and vaccine escape mutations.

Hepatitis B Virus Infection among Japanese Immigrants and Descendants: The Need to Strengthen Preventive and Control Measures

“…The prevalence found for OBI was 6.1%; this is considered high in comparison to another study conducted among blood donors performed in São Paulo in which the prevalence was 0.6% [ 37 ]. It has been shown in many studies that rates for OBI vary in different populations according to the endemicity of HBV infection.…”

Evaluating the cost-effectiveness of low-level HBV DNA screening in occult hepatitis B infection donors: A study from Shandong Blood Center, China

“…According to a WHO report, countries around the world employ three main strategies for screening blood donors for HBV: (a) 56% (98/176) of countries employ HBsAg testing; (b) 17.6% (31/176) of countries employ both HBsAg and anti -HBc testing (with 5 countries, including selective anti -HBc testing); (c) Another 8 countries implemented a 3-testing strategy that included selective anti -HBc testing [ 19 ]. In São Paulo, Brazil, 0.6% (6/976) of anti -HBc positive blood donors who were negative for HBsAg and 6 MP-NAT were positive for single-sample HBV DNA testing [ 20 ]. This rate is half as low as that found in Shandong Province, China, where 1.2% (2/164) of donors were positive for HBV DNA testing.…”

Donated Blood Screening for HIV, HCV and HBV by ID-NAT and the Residual Risk of Iatrogenic Transmission in a Tertiary Care Hospital Blood Bank in Puebla, Mexico

“…Regarding OBI, we only detected one case in 52,574 donations using ID-NAT-HBV ( Table 3 ). Recently, González-Santos et al detected 1 in 66,137 in Mexico City [ 10 ] ( Table 6 ), Dodd et al, in the USA, detected 1 in 67,974 [ 36 ] and Nishiya et al reported 1 in 33,121 donations in Brazil [ 37 ].…”