The increasing prevalence of hepatitis delta virus (HDV) infection in South London.

On the basis of historical studies, hepatitis delta virus (HDV) infection is considered uncommon in the United Kingdom (UK) and mainly confined to intravenous drug users. In order to assess the current prevalence of HDV co-infection in patients with chronic hepatitis B (HBV), a retrospective analysis was performed of 962 consecutive HBV-infected adult patients referred to King's College Hospital between January 1st 2000 and March 31st 2006. The 82 subjects positive for HDV antibody (8.5%) had a similar age to those without HDV (median 36 years, interquartile range 30-47, vs. 35 years, 29-43). Excluding non-UK residents, the prevalence of HDV Antibody was 7.1%. Most HDV-infected subjects were born in regions where HDV is endemic, for example, Southern or Eastern Europe (28.1%), Africa (26.8%) or Middle-East (7.3%). Forty one (50%) were considered to have acquired HDV infection via intra-familial transmission but intravenous drug use was still a common route of transmission (24.4%). Comparing HBV/HDV co-infected to HBV mono-infected patients, a higher proportion were hepatitis C antibody positive (25.6% versus 3.8%; odds ratio 8.89, 95% confidence interval 4.4-17.9; P < 0.00001) and more had cirrhosis (26.8% vs. 12.9%; odds ratio 2.64, 95% confidence interval 1.55-4.49; P < 0.0001) but, despite this, the risk of hepatocellular carcinoma was similar (odds ratio 1.34, 95% confidence interval 0.62-2.91). Although HDV infection is reportedly declining in some endemic regions, our data demonstrate a high prevalence in South London. HDV co-infection is associated with increased morbidity and patients with HBV should be tested for HDV infection.