Title:
Prevalence and Clinical Characteristics of Hepatitis Delta Virus (HDV) Infected Individuals in British Columbia

Background:
Globally, HDV is reported in 4.5-13% of chronic hepatitis B (CHB) patients. HDV and HBV co-infection is associated with progression to cirrhosis and higher risk of hepatocellular carcinoma (HCC). HDV prevalence in Canada is not fully elucidated. The purpose of the study was to describe the prevalence and clinical characteristics of HDV infection in CHB patients in a tertiary care centre.

Methods:
Retrospective study of HBsAg-positive patients >18 years of age tested for HDV Ab between April 2013 and October 2022. Data collected included HDV Ab status, patient demographics, comorbidities, alcohol use, fibrosis stage, and therapies utilized.

Results:
Amongst 663 HBsAg-positive patients tested for HDV Ab, 10/663 (1.5%, 95% CI 0.58-2.44) were HDV-Ab (+), with 8/10 (80%, 95% CI 0.55-1.05) of those confirmed HDV RNA (+). Average age of HDV patients was 57.8 (95% CI 52.7- 62.9) years, similar to HBV patients. Compared to HBV mono-infected patients, HBV-HDV co-infected patients were more likely to be male (90.0% vs 57.6%; p=0.04), have decompensated liver disease (30.0% vs 1.4%; <0.0001) and less likely to be Asian (50.0% vs 80.9%; p =0.014). One HBV-HDV co-infected patient was also HIV/HCV co-infected, and two had cleared HCV. One HDV patient had a known history of IVDU (10%, 95% CI 0.09 – 0.28). Mean ALT in HDV patients was 55.9, vs. 34.3 in HBV mono group (p=0.0508). 50% of HDV patients consumed any lifetime alcohol compared to 31.9% of HBV mono-infected patients (p=0.22). HDV patients were more likely to have liver stiffness measurements (>9.0 kPa 30% vs 8.9%, p=0.02), and equally likely to have HCC 10% vs 2.5% (p=0.13). One HDV patient received a liver transplant, and one HDV patient passed away.

Conclusion:
The prevalence of HDV positivity in CHB patients in this tertiary care centre was 1.5%, lower than reported 4.8% across Canada, although, our study looked at all-comers vs a selected population. Persons with HDV were more likely to be male, and less likely to be Asian than those with HBV mono-infection. Persons with HDV were more likely to have advanced disease, including cirrhosis, higher fibrosis, and decompensation. Further studies to understand the burden of disease in other regions are needed.