Leidiane Barbosa Ribeiro

The Amazon Basin was historically hyperendemic for HBV and HDV, associated with severe outcomes like fulminant hepatitis. Brazil initiated its hepatitis B vaccination in 1989. This study assessed the current prevalence in this endemic region to evaluate the impact of vaccination. A cross-sectional population-based survey enrolled 1100 urban and rural residents. HBsAg prevalence was 1.5%, with no cases in individuals under 20 years, demonstrating interrupted vertical and horizontal transmission. Anti-HBc positivity (30.9%) indicated past exposure, predominantly in those over 30 years. Isolated anti-HBc (10.3%) included two occult HBV infections. HDV coinfection occurred in 25% of HBsAg-positive cases, with HDV RNA detected in two. Anti-HDV positivity was exclusive to adults over 30. Vaccination coverage was poorly documented, but 23.7% had protective anti-HBs titers. HBV vaccination has reduced HBsAg prevalence from high to low endemicity in the region, eliminating chronic infections in younger generations. Persistent HDV in older age groups underscores the need for targeted screening. Despite vaccination record gaps, the findings highlight the program’s success in interrupting transmission and support continued efforts toward HBV/HDV elimination.

The hepatitis E virus (HEV) is an important causative agent of acute hepatitis (AH). Despite reports of human infection in Brazil, the investigation is not routinely conducted, even in cases of elevated liver enzymes. This study evaluated two groups: group 1—patients with acute hepatitis A ( n = 44); group 2—patients with nonA‐C AH ( n = 47). They were tested by enzyme immunoassay for anti‐HEV IgM/IgG and real‐time PCR for HEV RNA detection. The positive sample for HEV RNA was submitted for sequencing. The seroprevalence of anti‐HEV IgM and IgG in group 1 was 4% (2/44) and 14.5% (7/44), respectively. Viral RNA was not detected in any sample. In group 2, the anti‐HEV IgM positivity was 4.3% (2/47), and IgG 14.9% (7/47). RNA was detectable in one case, which presented a viral load of 222.4 IU/μL and positive anti‐HEV IgM/IgG. In the phylogenetic analysis, the genotype identified was HEV‐3f. These results indicate that HEV infection should be considered a possible diagnosis in cases of non‐A–C AH. The patient identified with acute hepatitis E had recently traveled to the Northeast region of Brazil (Garanhuns city in Pernambuco state), where there are reports of high HEV seroprevalence among pigs. The close phylogenetic relationship observed between the sequence characterized in this study and strains isolated from pigs in nearby cities where the patient went suggested a possible zoonotic transmission in this region. This study highlights the importance of expanding studies and improving surveillance to understand better and manage HEV infections nationwide.