First Detection of Hepatitis B Virus Subgenotype A5, and Characterization of Occult Infection and Hepatocellular Carcinoma-Related Mutations in Latin American and African Immigrants in Brazil.

This study aims to characterize the molecular profile of the hepatitis B virus (HBV) among socially vulnerable immigrants residing in Brazil to investigate the introduction of uncommon HBV strains into the country. Serum samples from 102 immigrants with positive serology for the HBV core antibody (anti-HBc) were tested for the presence of HBV DNA by PCR assays. Among these, 24 were also positive for the HBV surface antigen (HBsAg). The full or partial genome was sequenced to determine genotype by phylogenetic analysis. Participants were from Haiti (79.4%), Guinea-Bissau (11.8%), Venezuela (7.8%), and Colombia (1%). Of the 21 HBV DNA-positive samples, subgenotypes A1 (52.4%), A5 (28.6%), E (9.5%), F2 (4.8%), and F3 (4.8%) were identified. Among the 78 HBsAg-negative participants, four were positive for HBV DNA, resulting in an occult HBV infection rate of 5.1%. Phylogenetic analysis suggested that most strains were likely introduced to Brazil by migration. Importantly, 80% of A5 sequences had the A1762T/G1764A double mutation, linked to an increased risk of hepatocellular carcinoma development. In conclusion, this study is the first report of HBV subgenotype A5 in Brazil, shedding new light on the diversity of HBV strains circulating in the country. Understanding the genetic diversity of HBV in immigrant communities can lead to better prevention and control strategies, benefiting both immigrants and wider society.

Occult infection with HBV intergenotypic A2/G recombinant following acute hepatitis B caused by an HBV/A2 isolate.

Viral and host factors leading to occult hepatitis B virus (HBV) infection (OBI) are not fully understood. Whether HBV genotype may influence the occurrence and course of OBIs is unknown. Here, we describe the case of a patient infected with HBV genotype A2 who developed symptomatic acute hepatitis and did not seroconvert after loss of HBsAg and HBeAg. The acute phase of hepatitis B was followed by a period of more than 2 years during which the DNA of an intergenotypic HBV/A2/G recombinant was intermittently detected in serum.

Hepatitis B viral markers in banked human milk before and after Holder pasteurization.

BACKGROUND: Blood screening for hepatitis B virus (HBV) is not universally performed for donor selection in human milk banks. OBJECTIVES: To evaluate the frequency of detection of HBV surface antigen (HBsAg) and HBV-DNA in colostrum of HBV-infected nursing mothers before and after Holder pasteurization. STUDY DESIGN: Forty-two concentrated breast milk samples were obtained within two postnatal weeks from 24 HBsAg-positive women (4 HBeAg-positive and 20 HBeAg-negative, anti-HBe-positive) were tested for the presence of HBsAg and HBV-DNA before and after Holder pasteurization (30min at 62.5 degrees C). RESULTS: Before pasteurization, HBsAg and HBV-DNA were found in 14/24 (58%), and 20/24 (75%) first milk samples, respectively, obtained by 4 days after delivery. At least one marker was detected in 20/24 (83%) milk samples. Both markers were identified in milk of HBeAg-positive mothers, and most mothers with anti-HBe in blood had at least one HBV marker. Once detected, viral markers were frequently found in milk samples subsequently obtained from the same woman. Holder pasteurization did not affect the probability of detecting HBsAg (8/18, 44%), HBV-DNA (12/18, 67%), or at least one of them (15/18, 83%). CONCLUSIONS: Although the biological implications of these findings remain to be determined, considering that HBV is highly contagious and most recipients of banked human milk are preterm infants, these findings should be taken into account when donors are enlisted for human milk banks without serological screening.