New epidemiology of hepatitis delta

Abstract

Hepatitis D virus (HDV) is a defective pathogen that needs hepatitis B virus (HBV) for infection. Co‐infection of HBsAg‐positive individuals with HDV is commonly associated with a more rapid progression to cirrhosis, a higher incidence of hepatocellular carcinoma (HCC) and increased mortality. Initial studies have shown that about 5% of chronic HBV carriers worldwide (15‐20 millions) were also infected with HDV. However, recent studies suggest that the prevalence of HDV is at least two‐ to three‐fold higher than previous estimations. Improved diagnostic techniques have shown that HDV infection remains endemic in certain areas of the world. Injection drug users, individuals with high‐risk sexual behaviour and patients co‐infected with human immunodeficiency virus (HIV) represent the major reservoir of the disease in the Western world. Although the burden of HDV infection significantly decreased in Europe in the nineties, there has been no further decrease in the last decade, probably because of migration from HDV endemic countries. Until new and more effective therapies are available, public health measures should be reinforced by increasing prophylactic HBV vaccination programs, preventing transmission of the virus among parenteral drug users and implementing universal HDV screening of all HBV‐infected individuals.

Demographics and outcomes of hepatitis B and D: A 10-year retrospective analysis in a Swiss tertiary referral center

“…By comparison, in a prospective cohort of 4673 patients with CHB, the anti-HDV testing rates ranged from 57% before 2003 to 35% thereafter [21]. The lack of HDV screening and the fact that serological tests were less accurate in the past may explain why the epidemiology of CHD is still not fully understood and the real global prevalence remains unknown [29].…”

Is hepatitis delta underestimated?

“…Significant improvements in public health, modifications in sexual behaviours as a result of infection with the human immunodeficiency virus (HIV), the introduction of universal HBV vaccination at an early age and the widespread availability of single‐use syringes resulted in a decrease in the incidence of HBV and HDV rates as well. Data from Italy during this period showed that the seroprevalence of HDV was more than three times lower in 1997 than in 1983 with similar trends in Turkey and other Eastern European countries 8 . On the basis of the decreasing rates at the end of 1990s, the complete eradication of HDV infection was expected sooner rather than later.…”

“…Possible differences in the transmission routes of HDV and HBV may also contribute to occasional deviant rates of prevalence for these two infections. While parenteral transmission has clearly been shown for HDV in animal studies, evidence of transmission in men who have sex with men and mother‐to‐child vertical transmission has not been confirmed 6,8 …”

In Vivo Models of HDV Infection: Is Humanizing NTCP Enough?

“…The hepatitis delta virus (HDV) was discovered in Italy in 1977 [1] and still causes at least 15-20 million chronic infections worldwide [2]. Recent metanalyses estimated the HDV infection prevalence even at 62-72 million [2][3][4].…”

“…The hepatitis delta virus (HDV) was discovered in Italy in 1977 [1] and still causes at least 15-20 million chronic infections worldwide [2]. Recent metanalyses estimated the HDV infection prevalence even at 62-72 million [2][3][4]. HDV is not only the smallest RNA pathogen known to interact with a human host, but it is also a satellite virus which needs the expression of the envelope proteins of the hepatitis B virus (HBV) for the release of HDV particles and propagation among hepatocytes.…”