Re-emerging interest in hepatitis delta: New insights into the dynamic interplay between HBV and HDV

Delta hepatitis is still a major global health problem affecting 15–20 million individuals world-wide [1,2]. The implementation of vaccine programs against hepatitis B was initially associated with a decline in hepatitis D virus (HDV) infections in Southern Europe during the 1980s and 1990s [3,4]. However, several studies published over the last few years have shown that the prevalence of hepatitis delta remains rather high in Europe – in particular in immigrant populations. Between 8% and 12% of HBsAg-positive individuals tested anti-HDV positive in France [5], Germany [6,7], Italy [8–10], the United Kingdom [11], and Turkey [4].