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

Abstract

This cross-sectional study aimed to investigate the prevalence and risk factors of Hepatitis B virus infection among Japanese immigrants and their descendants from São Paulo (SP), and to verify the occurrence of occult hepatitis B and coinfection with HCV, Delta, and HTLV. All samples (n = 2.127) were tested for HBV serological markers by electrochemiluminescence. HBsAg and/or total anti-HBc positive samples were tested for HBV DNA by real-time PCR, and genotyped by sequencing using the Sanger methodology. The prevalence rate of HBV exposure was 13.4% (CI 95%: 11.9–14.9%), and 22 (1.1%) were HBsAg positive. A high rate of susceptibility to HBV infection was found (67.4%; CI 95%: 65.4–69.4%). In contrast, only 19.2% (CI 95%: 17.6–20.9%) presented a serological profile analogous to that elicited by Hepatitis B vaccination. HBV isolates (n = 8) were classified as genotypes HBV/B1 (62.5%), HBV/C2 (12.5%), HBV/F1b (12.5%), and HBV/A1 (12.5%). Hepatitis B vaccination strategies and educational measures to control this infection should be considered.

Global prevalence and molecular characteristics of three clades within hepatitis B virus subgenotype C2: Predominance of the C2(3) clade in South Korea

“…HBV subgenotype C2 is responsible for most genotype C infections in three nations of East Asia, namely, China, Japan and South Korea, which are major HBV endemic areas ( Cho et al, 2009 ; Wang et al, 2010 ; Demarchi et al, 2022 ). Subgenotype C2 is reported to have unique virological and clinical traits distinct from other genotypes and subgenotypes, including higher virulence, higher BCP or preC/C mutation frequency, and lower response to IFN-I therapy ( Lin and Kao, 2011 ; Ito et al, 2018 ; Tang et al, 2018 ).…”

“…The frequency of HBV mutations between three clades. Wang et al, 2010;Demarchi et al, 2022). Subgenotype C2 is reported to have unique virological and clinical traits distinct from other genotypes and subgenotypes, including higher virulence, higher BCP or preC/C mutation frequency, and lower response to IFN-I therapy (Lin and Kao, 2011;Ito et al, 2018;Tang et al, 2018).…”