Epidemiology and clinical outcomes of hepatitis delta (D) virus infection in Queensland, Australia.

OBJECTIVES

To investigate the epidemiology, clinical characteristics and outcomes of those with hepatitis delta virus (HDV) infection in Queensland, Australia.

DESIGN

Retrospective cohort study of individuals tested for HDV between 1997 and 2016 in the public healthcare system in Queensland.

RESULTS

179 individuals recorded positive HDV serology between 1997 and 2016, with a total of 4407 individuals undergoing testing (seroprevalence 4.1%). The majority of HDV positive individuals were male and were born overseas. Those born in Africa had a higher risk ratio (RR) for HDV infection (RR, 1.55; 95% CI, 1.14-2.09); being born in Asia was associated with a relatively lower risk of HDV infection (RR, 0.36; 95% CI, 0.27-0.58). Positive hepatitis C virus (HCV) serology was significantly associated with positive HDV serology (RR, 2.98; 95% CI, 2.36-3.78). Of the HDV positive individuals born in Australia, the majority were HCV positive (69.8%). HDV positive individuals were less likely to be Hepatitis B e antigen (HBeAg) positive (RR, 0.64; 95% CI, 0.45-0.93) and recorded lower hepatitis B virus (HBV) viral loads. Positive HDV serology was associated with increased risk of liver cirrhosis (RR, 2.3; 95% CI 1.73-3.07) and liver transplantation (RR, 1.93; CI 1.31-2.85). Only 8% of HDV positive individuals underwent HDV treatment.

CONCLUSIONS

In Queensland, HDV seropositivity is associated with overseas birth, particularly in Africa. HDV infection is associated with decreased HBV viraemia and more advanced liver disease.