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Author Spotlight: Advancements and Challenges in Hepatitis B Virus Detection
Published on: December 15, 2023
Molecular epidemiology and clinical characteristics of hepatitis D virus infection in Canada
Carla Osiowy1,2, Ken Swidinsky1, Sarah Haylock-Jacobs3
1National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB, Canada.
Insights
Approximately 5% of Canadian chronic hepatitis B patients are co-infected with Hepatitis D Virus (HDV). HDV infection is linked to higher rates of severe liver disease, emphasizing the need for increased screening in Canada.
Area of Science:
- Hepatology
- Infectious Diseases
- Virology
Background:
- Hepatitis D Virus (HDV) co-infection impacts 4.5-13% of global chronic hepatitis B (CHB) patients.
- The prevalence and characteristics of HDV in Canada remain largely uncharacterized.
Purpose of the Study:
- To determine the prevalence, genotypes, demographics, and clinical features of HDV infection among CHB patients in Canada.
- To compare clinical outcomes between HDV-positive and HBV mono-infected patients.
Main Methods:
- Retrospective analysis of HDV antibody and RNA positivity in referred specimens (2012-2019).
- Cross-sectional study comparing 135 HDV-positive patients with 5,132 HBV mono-infected patients from the Canadian HBV Network.
- Clinical data included risk factors, demographics, comorbidities, and liver disease severity.
Main Results:
- HDV seropositivity was found in 4.8% of referred Canadian CHB patients, with 64.8% being RNA-positive.
- HDV-positive patients were more likely to be White, Black/African/Caribbean, born in Canada, and report high-risk behaviors.
- Cirrhosis, end-stage liver disease complications, and liver transplantation were significantly more frequent in the HDV-positive cohort.
Conclusions:
- Nearly 5% of the Canadian HBV referral population exhibits HDV seropositivity.
- HDV infection is associated with increased risk behaviors and progressive liver disease.
- Enhanced screening and surveillance for HDV in Canada are crucial.
Background & Aims:
HDV affects 4.5-13% of chronic hepatitis B (CHB) patients globally, yet the prevalence of HDV infection in Canada is unknown. To investigate the prevalence, genotype, demographics, and clinical characteristics of HDV in Canada, we conducted a retrospective analysis of (1) HDV antibody and RNA positivity among referred specimens, and (2) a cross-sectional subset study of 135 HDV seropositive +/-RNA (HDV+) patients compared with 5,132 HBV mono-infected patients in the Canadian HBV Network.
Methods:
Anti-HDV IgG-positive specimens collected between 2012 and 2019 were RNA tested and the genotype determined. Patients enrolled in the Canadian HBV Network were >18 years of age and HBsAg-positive. Clinical data collected included risk factors, demographics, comorbidities, treatment, fibrosis assessment, and hepatic complications.
Results:
Of the referred patients, 338/7,080 (4.8%, 95% CI 4.3-5.3) were HDV seropositive, with 219/338 RNA-positive (64.8%, 95% CI 59.6-69.7). The HDV+ cohort were more likely to be born in Canada, to be White or Black/African/Caribbean than Asian, and reporting high-risk behaviours, compared with HBV mono-infected patients. Cirrhosis, complications of end-stage liver disease, and liver transplantation were significantly more frequent in the HDV+ cohort. HDV viraemia was significantly associated with elevated liver transaminases and cirrhosis. Five HDV genotypes were observed among referred patients but no association between genotype and clinical outcome was detected within the HDV+ cohort.
Conclusions:
Nearly 5% of the Canadian HBV referral population is HDV seropositive. HDV infection is highly associated with risk behaviours and both domestic and foreign-born patients with CHB. HDV was significantly associated with progressive liver disease highlighting the need for increased screening and surveillance of HDV in Canada.
Lay Summary:
Evidence of HDV infection was observed in approximately 5% of Canadians who were infected with HBV referred to medical specialists. HDV-positive patients were more likely to be male, born in Canada, or White or Black/African/Caribbean compared to Asian, and to have reported high-risk activities such as injection or intranasal drug use or high-risk sexual contact compared with patients infected with only HBV. Patients infected with HDV were also more likely to suffer severe liver disease, including liver cancer, compared with HBV mono-infected patients.
