Prevalence and molecular characterization of occult hepatitis B virus in pregnant women from Gondar, Ethiopia

Vanessa Meier-Stephenson; Tekalign Deressa; Meaza Genetu; Debasu Damtie; Sheila Braun; Kevin Fonseca; Mark G Swain; Guido van Marle; Carla S Coffin

doi:10.3138/canlivj-2019-0031

Prevalence and molecular characterization of occult hepatitis B virus in pregnant women from Gondar, Ethiopia

Can Liver J. 2020 Nov 17;3(4):323-333. doi: 10.3138/canlivj-2019-0031. eCollection 2020 Fall.

Authors

Vanessa Meier-Stephenson¹, Tekalign Deressa^{2

3}, Meaza Genetu², Debasu Damtie², Sheila Braun⁴, Kevin Fonseca^{1

4}, Mark G Swain⁵, Guido van Marle¹, Carla S Coffin^{1

5}

Affiliations

¹ Department of Microbiology, Immunology and Infectious Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.
² Department of Immunology and Molecular Biology, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia.
³ Ethiopian Public Health Institute, Addis Ababa, Ethiopia.
⁴ Provincial Laboratory for Public Health, Alberta Health Services, Calgary, Alberta, Canada.
⁵ Division of Gastroenterology and Hepatology, Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.

Abstract

Background: The greatest risk of chronic hepatitis B (CHB) is from mother-to-child transmission. Approximately 20% of individuals in sub-Saharan Africa are hepatitis B virus (HBV) surface antigen-positive (HBsAg+), but the prevalence of occult hepatitis B (OHB) is unknown. Aim: This study investigated CHB and OHB prevalence and viral variants in a cohort of pregnant women in Gondor, Ethiopia.

Methods: Patients were prospectively recruited from the University of Gondar Hospital (N = 200; median age 27 [inter-quartile range] 8.3y) from March through June 2016. Data were collected using an investigator-administered questionnaire. Plasma was tested for HBsAg and HBV core antibody (anti-HBc), and HBV genotype and presence of HBV variants (ie, vaccine escape mutants [VEMs]) were determined by polymerase chain reaction, Sanger sequencing, and phylogenetic analysis.

Results: Of women tested, 1% (2/200) were HBsAg+; 26.8% (47/182) of HBsAg-negative patients were anti-HBc+, of whom 37/47 (78.7%) had detectable HBV DNA. The overall rate of OHB was 20.3%. Both HBsAg+ cases were HBV genotype D, and 36/37 (97.3%) of OHB individuals were genotype D. None carried VEM, but both HBsAg+ cases and 32/37 (86.5%) of the OHB cases showed lamivudine-resistant mutations.

Conclusions: Twenty-seven percent of pregnant women in this cohort showed evidence of CHB or prior HBV exposure (ie, HBsAg+ or anti-HBc+) and clinically relevant HBV variants. Data from this single-centre study suggests high HBV prevalence, reinforcing the World Health Organization's recommendation for universal prenatal HBV screening and infant vaccination.

Keywords: hepatitis B virus; infant vaccination; occult hepatitis B; pregnancy; prenatal screening; sub-Saharan Africa.

Grants and funding

Funding: CSC and TD have received research funding from a Cumming School of Medicine Clinical Research Fund Pilot Grant. TD was funded through the University of Gondar. MG has received funding from the Cal Wenzel Hepatology Chair (MGS). VMS has fellowship salary support through the Canadian Hepatitis C Network.