Prevalence And Molecular Characterization Of Hepatitis Delta Virus Infection Among Hepatitis B Virus Surface Antigen Positive Students And Pregnant Women In N’djamena, Chad.

Abstract

Objectives: This study sought to determine the prevalence of hepatitis B virus (HBV)-hepatitis D virus (HDV) co-infection and to characterize isolates of both viruses in a Chadian population of HBV surface antigen (HBsAg)- positive pregnant women and students. Methods: This was a cross-sectional retrospective study using archived samples from pregnant women and stu dents in N’djamena who had been systematically screened for HBsAg between April and August 2021. HBsAg positive samples were tested for the presence of HDV antibodies (Ab) and were screened for the presence of both HBV and HDV (in anti-HDV Ab-positive samples) viral load estimations. Genome sequencing of the viruses was used for both genotyping and phylogenetic analysis. Results: A total of 94 participants were included in this study. The mean age was 24 ± 4.89 years (range: 18-42 years). Anti-HDV Ab were found in 9.57% (9/94) of the participants. The prevalence of anti-HDV Ab positivity among students (6.45% [4/62]) was lower than the 15.63% (5/32) observed among pregnant women. HDV-RNA was detected in 7/9 (77.77%) confirmed anti-HDV-positive participants. Most HDV-RN-positive participants had very low HBV DNA viral loads. All HBV sequences belonged to genotype E and all HDV sequences to genotype 1. Conclusions: Hepatitis D is a potential public health challenge in Chad, which requires active surveillance and public education in the country for proper control. This surveillance should be supported with mass immunization against HBV.