The global hepatitis delta virus (HDV) epidemic: what gaps to address in order to mount a public health response?

Abstract

Background Co-infection between hepatitis B virus (HBV) and hepatitis delta virus (HDV) causes the severest chronic hepatitis and is associated with a high risk of cirrhosis and hepatocellular carcinoma (HCC). The Global Health Sector Strategy on Viral Hepatitis called for the elimination of hepatitis (− 65% mortality and − 90% incidence) by 2030. Our aims were to summarize key points of knowledge and to identify the gaps that need to be addressed to mount a public health response to HDV. Methods We performed a current literature review in terms of epidemiology by WHO regions, genotypes distribution and their pathogenicity, factors associated with HDV infection, mortality due to HDV infection, testing strategies and treatment. Results Prevalence of infection and genotypes are heterogeneous distributed, with highest prevalence in foci around the Mediterranean, in the Middle East, and in Central, Northern Asia and Eastern Asia. Persons who inject drugs (PWID) and migrants from highly endemic areas are highly affected. While antibody detection tests are available, HDV RNA tests of current infection are not standardized nor widely available. The few therapeutic options, including lofartinib, are not widely available; however several new and promising agents have entered clinical trials. Conclusion HDV infection is an poorly known cause of chronic liver disease. To mount a public health response, we need a better description of the HDV epidemic, standardized testing strategies and better treatment options.

A changing landscape: Tracking and analysis of the international HDV epidemiology 1999–2020

“…The dataset from the United States, utilizing the CDC’s NHANES dataset, detected HDV in >50% of HBV-positive subjects tested (2013–2016). This may indicate widespread occurrence of HDV in asymptomatic HBV carriers and in patients that may not fit recommended testing guidelines [ 52 , 53 ]. The significant increase in newly reported HDV cases among HBV-positive subjects suggests that the current HDV testing guidelines need to be reassessed.…”

Low prevalence of hepatitis delta infection in Cuban HBsAg carriers: Prospect for elimination

“…Consistent global data on the prevalence of HDV are lacking because of different reasons such as lack of testing of HBsAg carriers for HDV infection or non-availability of high quality anti-HDV antibody assays and there are considerable geographical variations (3,19,20). Countries in Asia have reported prevalence rates between 4.4 and 60% (21)(22)(23), while in sub-Saharan Africa HDV prevalence ranged from 0 to 50% in relation to the clinical picture of the patients (12).…”

Delta hepatitis epidemiology and the global burden of disease

“…5 Similarly, IDU was reported as a prevalent risk factor for HDV in other parts of the world including United Kingdom and Iran, and migration from endemic regions has been identified as a prevalent risk factor among HDV-infected individuals living in Western Europe. 6 Studies evaluating risk factors for HDV infection in lower-income countries have additionally cited HIV infection, intra-household transmission, sexual transmission and cultural practices such as tattoos and circumcision as important risk factors, despite HDV being considered a predominantly healthcare-associated infection. 7,8 The distribution of risk factors has also evolved over time, particularly in response to the HBV vaccination programmes.…”

“…For instance, in an evaluation of a North American cohort, most common risk factors included having a history of injection drug use (IDU; adjusted OR 25.2) and being from an HDV endemic country of origin (adjusted OR 5.8) 5 . Similarly, IDU was reported as a prevalent risk factor for HDV in other parts of the world including United Kingdom and Iran, and migration from endemic regions has been identified as a prevalent risk factor among HDV‐infected individuals living in Western Europe 6 . Studies evaluating risk factors for HDV infection in lower‐income countries have additionally cited HIV infection, intra‐household transmission, sexual transmission and cultural practices such as tattoos and circumcision as important risk factors, despite HDV being considered a predominantly healthcare‐associated infection 7,8 …”