INFECÇÃO PELO VÍRUS DA HEPATITE B EM IMIGRANTES JAPONESES E SEUS DESCENDENTES

Abstract

Hepatitis B is a serious public health problem in Brazil and worldwide. The present study aimed to: investigate the prevalence of infection caused by hepatitis B virus (HBV) and predictive factors associated with this infection among Japanese immigrants and their descendants living in Sao Paulo - SP, verify the situation of immunization against hepatitis B and the occurrence of occult hepatitis B and co-infection by HTLV, hepatitis C and Delta viruses, as well as identify the main circulating HBV genotypes / subtypes in this population. This cross-sectional study with a quantitative approach used database and biological sample bank from previous studies that were conducted in São Paulo (SP – Southeast region) from the period of July 2017 and December 2018. All samples from the population of São Paulo (n = 2,127) were subjected to detection of serological markers of HBV infection (HBsAg, total anti-HBc and anti-HBs) using electrochemiluminescence (ECLIA). All HBsAg positive samples were subjected to detection of HBeAg / anti-HBe, anti-HBc, anti-HCV, total anti-HD antibodies and anti-HTLV. All HBsAg and / or total anti-HBc positive samples were performed to detect HBV DNA by real-time PCR (qPCR) and then genotyped by sequencing using the Sanger methodology. Analyzes of 2127 samples from the studied population residing in Sao Paulo - SP demonstrate that the majority of the population was of the female sex (59.8%), descended from Okinawa (87.54%), with age varying from 6 to 92 years (median of 56 years). The prevalence rate of HBV exposure was 13.4% (CI 95%: 11.9% - 14.9%) and 22 (1.1%) participants were HBsAg positive. A high rate of susceptibility to HBV infection (absence of infection marker and vaccine response) 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 similar to the vaccine response against HBV. Among positive samples for HBsAg (n=22), 68.2% were reactive for anti-HBeAg (15/22) and no one was positive for HBeAg or anti-HBc IgM. Of the 22 HBsAg positive individuals, 8 were genotyped, with the B1 subgenotype being the most frequent (62.5%), followed by the C2 (12.5%), F1b (12.5%) and A1 (12.5%) subgenotypes. Despite the low prevalence rate of active HBV infection observed in the studied population group, the high rate of susceptibility to HBV infection added to the low rate of positivity for the serological marker of vaccine immunity emphasizes that hepatitis B vaccination strategies and educational measures to control this infection should be considered in this population group.

Keywords: Hepatitis B, Epidemiology, Seroprevalence, Genotype