Migratory flow and hepatitis delta infection in Italy: A new challenge at the beginning of the third millennium

Prospective study of hepatitis B and D epidemiology and risk factors in Romania: A 10-year update

BACKGROUND

The global burden of hepatitis D virus (HDV) infection represents a major medical challenge and a public health crisis worldwide. However, there is a lack of accurate data on the epidemiology and risk factors for HDV. Hepatitis B virus (HBV) and HDV coinfection causes the most severe form of viral hepatitis, leading to a higher cumulative incidence of liver-related events compared with HBV monoinfection, including the need for liver transplantation and death.

AIM

To investigate the epidemiology, natural history, risk factors and clinical management of HBV and HDV coinfection in Romanian patients.

METHODS

This prospective study was conducted between January and July 2022 in six tertiary gastroenterology and hepatology referral centres in Romania. All consecutive adults admitted for any gastroenterology diagnosis who were HBV-positive were enrolled. Patients with acute hepatitis or incomplete data were excluded. Of the 25390 individuals who presented with any type of gastroenterology diagnosis during the study period, 963 met the inclusion criteria. Testing for anti-HDV antibodies and HDV RNA was performed for all participants. Demographic and risk factor data were collected by investigators using medical charts and patient questionnaires. All data were stored in an anonymized online database during the study.

RESULTS

The prevalence of HBV was 3.8%; among these patients, the prevalence of HBV/HDV coinfection was 33.1%. The median age of the study population was 54.0 years, and it consisted of 55.1% men. A higher prevalence of HBV/HDV coinfection was observed in patients 50-69 years old. Patients with HBV/HDV coinfection were significantly older than those with HBV monoinfection (P = 0.03). Multivariate multiple regression analysis identified female gender (P = 0.0006), imprisonment (P < 0.0001), older age at diagnosis (P = 0.01) and sexual contact with persons with known viral hepatitis (P = 0.0003) as significant risk factors for HDV.

CONCLUSION

This study shows that HDV infection among those with HBV remains endemic in Romania and updates our understanding of HDV epidemiology and associated risk factors. It emphasizes the need for systematic screening for HDV infection and collaborative initiatives for controlling and preventing HBV and HDV infection.

Epidemiology of hepatitis D virus infection in Europe: Is it vanishing?

Co-infection with hepatitis delta virus (HDV) is a challenging health care problem worldwide, estimated to occur in approximately 5%-10% of patients with chronic hepatitis B virus (HBV) infection. While HBV prevalence is decreasing globally, the prevalence of HDV infection is rising in some parts mainly due to injection drug use, sexual transmission and immigration from high endemicity areas. Eastern Europe and the Mediterranean are among the regions with high rates of endemicity for HDV and the immigration from high endemicity areas to Central and Western Europe has changed the HDV epidemiology. We aimed to review the prevalence of HDV infection in Europe. A paucity of publication appears in many European countries. Prevalence studies from some countries are old dated and some other countries did not report any prevalence studies. The studies are accumulated in few countries. Anti-HDV prevalence is high in Greenland, Norway, Romania, Sweden and Italy. Belgium, France, Germany, Spain, Switzerland, Turkey and United Kingdom reported decreasing prevalences. Among cirrhotic HBV patients, Germany, Italy and Turkey reported higher rates of HDV. The studies including centres across the Europe reported that HIV-HBV coinfected individuals have higher prevalence of HDV infection. The immigrants contribute the HDV infection burden in Greece, Italy, and Spain in an increasing rate. Previous studies revealed extremely high rates of HDV infection in Germany, Greece, Italy and Sweden. The studies report a remarkably high prevalence of hepatitis delta among HIV/HBV-coinfected individuals, individuals who inject drugs, immigrants and severe HBV infected patients across Europe. The HDV infection burden still appears to be significant. In the lack of an effective HDV therapy, prevention strategies and active screening of HBV/HDV appear as the most critical interventions for reducing the burden of liver disease related to HDV infection in Europe.

Adjusted estimate of the prevalence of hepatitis delta virus in 25 countries and territories

BACKGROUND & AIMS

Hepatitis delta virus (HDV) is a satellite RNA virus that requires the hepatitis B virus (HBV) for assembly and propagation. Individuals infected with HDV progress to advanced liver disease faster than HBV-monoinfected individuals. Recent studies have estimated the global prevalence of anti-HDV antibodies among the HBV-infected population to be 5-15%. This study aimed to better understand HDV prevalence at the population level in 25 countries/territories.

METHODS

We conducted a literature review to determine the prevalence of anti-HDV and HDV RNA in hepatitis B surface antigen (HBsAg)-positive individuals in 25 countries/territories. Virtual meetings were held with experts from each setting to discuss the findings and collect unpublished data. Data were weighted for patient segments and regional heterogeneity to estimate the prevalence in the HBV-infected population. The findings were then combined with The Polaris Observatory HBV data to estimate the anti-HDV and HDV RNA prevalence in each country/territory at the population level.

RESULTS

After adjusting for geographical distribution, disease stage and special populations, the anti-HDV prevalence among the HBsAg+ population changed from the literature estimate in 19 countries. The highest anti-HDV prevalence was 60.1% in Mongolia. Once adjusted for the size of the HBsAg+ population and HDV RNA positivity rate, China had the highest absolute number of HDV RNA+ cases.

CONCLUSIONS

We found substantially lower HDV prevalence than previously reported, as prior meta-analyses primarily focused on studies conducted in groups/regions that have a higher probability of HBV infection: tertiary care centers, specific risk groups or geographical regions. There is large uncertainty in HDV prevalence estimates. The implementation of reflex testing would improve estimates, while also allowing earlier linkage to care for HDV RNA+ individuals. The logistical and economic burden of reflex testing on the health system would be limited, as only HBsAg+ cases would be screened.

IMPACT AND IMPLICATIONS

There is a great deal of uncertainty surrounding the prevalence of hepatitis delta virus among people living with hepatitis B virus at the population level. In this study, we aimed to better understand the burden in 25 countries and territories, to refine techniques that can be used in future analyses. We found a lower prevalence in the majority of places studied than had been previously reported. These data can help inform policy makers on the need to screen people living with hepatitis B virus to find those coinfected with hepatitis delta virus and at high risk of progression, while also highlighting the pitfalls that other researchers have often fallen into.

Anti-HDV reflex testing in HBsAg-positive subjects: An efficacious strategy to identify HDV infection

BACKGROUND AND AIMS

The prevalence of HDV infection in HBsAg carriers is about 9.9% in Italy. However, the real prevalence is underestimated because the anti-HDV test is not performed routinely in all HBsAg carriers. The aim of this study was to compare the prevalence and the absolute number of HDV infection identified in HBsAg-positive subjects tested at University Hospital Federico II before and after the introduction of anti-HDV reflex testing.

METHODS

From January to December 2022, reflex test for the detection of total HDV antibodies was performed in all HBsAg-positive subjects tested at University Hospital Federico II. The control group consisted of all the HBsAg-positive subjects tested at the same laboratory in 2019, before the implementation of anti-HDV reflex testing. Sera were evaluated with ADVIA Centaur HBsAgII Qualitative, Liaison Murex HBsAg Quantitative and Liaison Murex Total Anti-HDV Qualitative.

RESULTS

Before reflex testing, anti-HDV had been tested in 16.4% (84/512) of HBsAg-positive subjects, while after its implementation, 100% (484/484) of HBsAg-positive patients was tested for anti-HDV. The anti-HDV positive prevalence was lower than before the introduction of reflex test (10.7% vs. 16.6%) but the absolute number of anti-HDV positive patients increased (14 vs. 52 subjects). HDV-RNA was detectable in 26 (53%) of 49 tested subjects.

CONCLUSIONS

Our data showed that the implementation of anti-HDV reflex testing increased the diagnoses of HDV infection. In this setting, due to the approval of specific anti-HDV drugs, a reflex test for anti-HDV should be implemented to early identify patients with HBV/HDV infection.

Prevalence of hepatitis D virus infection in Central Italy has remained stable across the last 2 decades with dominance of subgenotypes 1 and characterized by elevated viral replication

OBJECTIVES

Here we investigate Hepatitis D virus (HDV)-prevalence in Italy and its fluctuations over time and we provide an extensive characterization of HDV-infected patients.

METHODS

The rate of HDV seroprevalence and HDV chronicity was assessed in 1579 hepatitis B surface antigen (HBsAg)+ patients collected from 2005 to 2022 in Central Italy.

RESULTS

In total, 45.3% of HBsAg+ patients received HDV screening with an increasing temporal trend: 15.6% (2005-2010), 45.0% (2011-2014), 49.4% (2015-2018), 71.8% (2019-2022). By multivariable model, factors correlated with the lack of HDV screening were alanine-aminotransferase (ALT) less than two times of upper limit of normality (<2ULN) and previous time windows (P <0.002). Furthermore, 13.4% of HDV-screened patients resulted anti-HDV+ with a stable temporal trend. Among them, 80.8% had detectable HDV-ribonucleic acid (RNA) (median [IQR]:4.6 [3.6-5.6] log copies/ml) with altered ALT in 89.3% (median [IQR]:92 [62-177] U/L). Anti-HDV+ patients from Eastern/South-eastern Europe were younger than Italians (44 [37-54] vs 53 [47-62] years, P <0.0001), less frequently nucleos(t)ide analogs (NUC)-treated (58.5% vs 80%, P = 0.026) with higher HDV-RNA (4.8 [3.6-5.8] vs 3.9 [1.4-4.9] log copies/ml, P = 0.016) and HBsAg (9461 [4159-24,532] vs 4447 [737-13,336] IU/ml, P = 0.032). Phylogenetic analysis revealed the circulation of HDV subgenotype 1e (47.4%) and -1c (52.6%). Notably, subgenotype 1e correlated with higher ALT than 1c (168 [89-190] vs 58 [54-88] U/l, P = 0.015) despite comparable HDV-RNA.

CONCLUSIONS

HDV-screening awareness is increasing over time even if some gaps persist to achieve HDV screening in all HBsAg+ patients. HDV prevalence in tertiary care centers tend to scarcely decline in native/non-native patients. Detection of subgenotypes, triggering variable inflammatory stimuli, supports the need to expand HDV molecular characterization.

Apulian infectious diseases network: survey on the prevalence of delta infection among chronic HBV carriers in Apulia

Background

The current prevalence and clinical burden of Hepatitis Delta Virus (HDV) infection in Apulia are unknown. This study aimed to define the current epidemiological scenario of delta infection and to detect difficulties in the diagnosis and clinical management of HDV patients in Apulia.

Methods

From May to September 2022, a fact-finding survey was conducted at eight Infectious Diseases Units of the Apulian region; each Unit was asked to complete a questionnaire on screening and diagnosis of HDV infection and demographic, virological, and clinical characteristics of HDV patients.

Results

A total of 1,461 HBsAg-positive subjects were followed up on an outpatient basis. Screening for HDV ranged from 30 to 90% of HBsAg + carriers in a single center. Overall, 952 HBsAg ± subjects (65%) were tested for HDV, and 80/952 (8.4%) were anti-HDV positive. Serum HDV RNA was detected only in 15/80 (19%) anti-HDV-positive subjects, and 12/15 patients (80%) were viremic. Sixty-five anti-HDV-positive subjects (81%) were from Italy; risk factors for HDV acquisition included the presence of HDV infection in the family (29/80 = 36%), drug addiction (12/80 = 15%), and co-infection with HCV or HIV (7/80 = 9%). Liver cirrhosis and hepatocellular carcinoma were diagnosed in 41 (51%) and 4 (5%) patients, respectively. Fifty-seven patients (71%) received nucleos(t)ide analog treatment.

Conclusions

The results of this survey show that HDV screening is variable and insufficient, thus real prevalence data on delta infection are lacking in Apulia. Moreover, the HDV RNA test is not available in most laboratories and is not provided by the national health system. These results underline the need for an organizational model to optimize the management of HDV patients throughout the Apulian region.

Phylogenetic and Phylodynamic Analysis of Delta Strains Circulating in Italy

The hepatitis delta virus (HDV) exhibits high genetic and evolutionary variability and is classified into eight genotypes (HDV-1 to -8). HDV-1 is the most widespread genotype worldwide and includes several subtypes. It predominates mainly in Europe, the Middle East, North America, and Northern Africa, and is associated with both severe and mild forms of liver disease. In this study, we performed phylogenetic and phylodynamic analyses of HDV strains circulating in Regione Lazio, Italy, to understand when these strains were introduced into the Lazio region and to define their genetic variability in Italy. Fifty HDV RNA positive patient samples were amplified using a nested RT-PCR approach targeting the HDV R0 region and sequenced. A phylogenetic tree of patient-derived sequences and reference sequences representing HDV-1 to -8 was constructed using the GTRGAMMA model in RAxML v8. The results indicated that HDV-1 was the predominant genotype with HDV-1d being the most frequently inferred subtype. HDV-1 sequences clustering with subtypes 1b and 1e were also identified. A phylodynamic analysis of HDV-1 sequences employing a Bayesian birth-death model inferred a clock rate of 3.04 × 10-4 substitutions per site per million years, with a 95% Highest Posterior Density (HPD) interval of 3.45 × 10-5 to 5.72 × 10-4. A Bayesian birth-death analysis with tree calibration based on a sample dating approach indicated multiple original sources of infection (from the late 1950s to late 1980s). Overall, these results suggest that HDV sequences from the native Italian and non-Italian patients analyzed in this study represent multiple lineages introduced across a wide period. A common ancestral origin should be excluded.

HDV RNA Levels and Progression of Hepatitis Delta Infection: A 14 Year Follow Up Experience in Italy

BACKGROUND

Identification of outcome predictors is one of the unmet needs in chronic HDV infection. Until recently, no reliable quantitative assays for HDV RNA were available.

AIMS

To evaluate the impact of baseline viremia on natural history of HDV infection in a cohort of patients whose serum samples were stored at their first visit 15 years ago.

METHODS

Quantitative HBsAg, HBeAg, HBeAb, HBV DNA, HDV RNA, genotypes, and liver disease severity were assessed at baseline. Patients who were no longer on active follow-up were recalled and re-evaluated in August 2022.

RESULTS

The majority of patients were male (64.9%); the median age was 50.1 years; and all patients were Italian, with only three born in Romania. All were HBeAg negative with HBV genotype D infection. Patients were subdivided three groups: 23 were in active follow-up (Group 1), 21 were recalled due to no longer being in follow-up (Group 2), and 11 died (Group 3). Liver cirrhosis was diagnosed in 28 subjects at the first visit; 39.3% of diagnosed patients were in Group 3, 32.1% were in Group 1 and 28.6% were in Group 2 (p = 0.001). Baseline HBV DNA IU/mL Log10 were 1.6 (1.0-5.9) in Group 1, 1.3 (1.0-4.5) in Group 2, and 4.1 (1.5-4.5) in Group 3; median baseline HDV RNA Log10 levels were 4.1 (0.7-6.7) in Group 1, 3.2 (0.7-6.2) in Group 2, and 5.2 (0.7-6.7) in Group 3, resulting significantly higher rates among patients in Group 3 compared to the other groups (p = 0.038). Eighteen patients in Group 2, as compared to 7 in Group 1, had undetectable HDV RNA at the follow-up evaluation (p = 0.001).

CONCLUSIONS

HDV chronic infection is a heterogeneous disease. It may not only progress but also improve over time in patients, who eventually become HDV RNA-undetectable. HDV RNA levels may help identify the subgroup of patients with less progressive liver disease.

Epidemiology Pattern, Prevalent Genotype Distribution, Fighting Stigma and Control Options for Hepatitis D in Bulgaria and Other European Countries

Hepatitis D virus (HDV) is a satellite virus that causes the most aggressive form of all viral hepatitis in individuals already infected with HBV (hepatitis B virus). In recent years, there has been a negative trend towards an increase in the prevalence of chronic hepatitis D in Europe, especially among immigrant populations coming from regions endemic for the virus. The aim of this review is to analyse the current epidemiology of chronic HDV, routes of transmission, prevalent genotype, its management, prevention, fighting stigma and options for viral control in European countries, such as Bulgaria.

Hepatitis D virus infection in a large cohort of immigrants in southern Italy: a multicenter, prospective study

Background

Since few data are available in the literature on the prevalence of anti-Delta-positive subjects in immigrant populations, the aim of the present study was to evaluate the demographic and virological characteristics of HDV infection in a large cohort of immigrants living in southern Italy.

Methods

Between January 2012 and February 2020 all immigrants attending one of the 5 first- level centers were enrolled and screened for HBsAg, the HBsAg-positive for anti-Delta and if positive, for HDV-RNA and HDV genotype.

Results

Of the 3521 immigrants observed in the study period, 3417 (97.0%) agreed to be screened; they were mainly males (61%), with a median age of 27 years (IQR 8–74) and came prevalently (58%) from sub-Saharan Africa.

Of the 3417 patients enrolled, 319 (9%) subjects were HBsAg-positive, and of those, 8 (2.5%) were anti-Delta-positive. No difference in the demographic and epidemiological characteristics was observed between the anti-Delta-negative vs -positive. Of the 8 anti-Delta-positive subjects, only one was HDV-RNA-positive (viral load: 7050 IU/mL), genotype 1, with clinical signs of cirrhosis.

Conclusions

the present study showed a prevalence of HDV of 2.5% in a large cohort of asymptomatic immigrants, suggesting the need for screening campaigns for viral infections including delta hepatitis in this population.

Supplementary Information

The online version contains supplementary material available at 10.1007/s15010-022-01938-0.

A Review of HDV Infection

Hepatitis D is the most severe viral hepatitis. Hepatitis D virus (HDV) has a very small RNA genome with unique biological properties. It requires for infection the presence of hepatitis B virus (HBV) and is transmitted parenterally, mainly by superinfection of HBsAg carriers who then develop chronic hepatitis D. HDV has been brought under control in high-income countries by the implementation of HBV vaccination, and the clinical pattern has changed to a chronic hepatitis D seen in ageing patients with advanced fibrotic disease; the disease remains a major health concern in developing countries of Africa and Asia. Every HBsAg-positive subject should be tested for HDV serum markers by reflex testing, independently of clinical status. Vaccination against HBV provides the best prophylaxis against hepatitis D. The only therapy available so far has been the poorly performing Interferon alfa; however, several new and promising therapeutic approaches are under study.

Acute Delta Hepatitis in Italy spanning three decades (1991-2019): Evidence for the effectiveness of the hepatitis B vaccination campaign

Updated incidence data of acute Delta virus hepatitis (HDV) are lacking worldwide. Our aim was to evaluate incidence of and risk factors for acute HDV in Italy after the introduction of the compulsory vaccination against hepatitis B virus (HBV) in 1991. Data were obtained from the National Surveillance System of acute viral hepatitis (SEIEVA). Independent predictors of HDV were assessed by logistic-regression analysis. The incidence of acute HDV per 1-million population declined from 3.2 cases in 1987 to 0.04 in 2019, parallel to that of acute HBV per 100,000 from 10.0 to 0.39 cases during the same period. The median age of cases increased from 27 years in the decade 1991-1999 to 44 years in the decade 2010-2019 (p < .001). Over the same period, the male/female ratio decreased from 3.8 to 2.1, the proportion of coinfections increased from 55% to 75% (p = .003) and that of HBsAg positive acute hepatitis tested for by IgM anti-HDV linearly decreased from 50.1% to 34.1% (p < .001). People born abroad accounted for 24.6% of cases in 2004-2010 and 32.1% in 2011-2019. In the period 2010-2019, risky sexual behaviour (O.R. 4.2; 95%CI: 1.4-12.8) was the sole independent predictor of acute HDV; conversely intravenous drug use was no longer associated (O.R. 1.25; 95%CI: 0.15-10.22) with this. In conclusion, HBV vaccination was an effective measure to control acute HDV. Intravenous drug use is no longer an efficient mode of HDV spread. Testing for IgM-anti HDV is a grey area requiring alert. Acute HDV in foreigners should be monitored in the years to come.

Hepatitis delta in patients hospitalized in Spain (1997-2018)

BACKGROUND

Hepatitis delta is the most aggressive form of chronic viral hepatitis. We examined the clinical burden, epidemiological features and time trends for hepatitis delta patients hospitalized in Spain during the last two decades.

METHODS

Retrospective, observational study using the Spanish National Registry of Hospital Discharges. Information was retrieved since 1997 to 2018.

RESULTS

From a total of 79 647 783 nationwide hospital admissions recorded during the study period, 5179 included hepatitis delta as diagnosis. The overall hospitalization rate because of hepatitis delta was 6.5/105, without significant yearly changes. In-hospital death occurred in 335 (6.6%) patients. Acute hepatitis and cirrhosis were recorded in 46.5 and 33.5% of hepatitis delta hospitalizations, respectively. Acute hepatitis delta predominated until 2007 (55.9%) whereas cirrhosis increased since then (39.4%). Hepatic decompensation events and liver cancer accounted on average for 16 and 8% of hospitalizations, increasing significantly over time. Coinfection with HIV and hepatitis C virus (HCV) were recognized in 24 and 31.2% of hepatitis delta patients, respectively. All hepatitis C, HIV and injection drug use declined significantly since 2008.

CONCLUSION

The rate of hepatitis delta in patients hospitalized in Spain is low and has remained stable over two decades. However, hepatitis delta-related decompensation events and liver cancer are on the rise. The association of hepatitis delta with injection drug use, HIV and HCV has declined among recently hospitalized hepatitis delta patients.

The hepatitis D virus in Italy. A vanishing infection, not yet a vanished disease

Introduction

Hepatitis D Virus (HDV) infection is vanishing in Italy. It is therefore believed that hepatitis D is no longer a medical problem in the domestic population of the country but remains of concern only in migrants from HDV-endemic areas.

Objectives

To report the clinical features and the medical impact of the residual domestic HDV infections in Italy.

Methods

From 2010 to 2019, one hundred ninety-three first-time patients with chronic HDV liver disease attended gastroenterology units in Torino and San Giovanni Rotondo (Apulia); 121 were native Italians and 72 were immigrants born abroad. For this study, we considered the 121 native Italians in order to determine their clinical features and the impact of HDV disease in liver transplant programs.

Results

At the last observation the median age of the 121 native Italians was 58 years. At the end of the follow-up, the median liver stiffness was 12.0 kPa (95% CI 11.2-17.4), 86 patients (71.1%) had a diagnosis of cirrhosis; 80 patients (66.1%) remained HDV viremic. The ratio of HDV to total HBsAg transplants varied from 38.5% (139/361) in 2000-2009 to 50.2% (130/259) in 2010-2019, indicating a disproportionate role of hepatitis D in liver transplants compared to the minor prevalence of HDV infections in the current scenario of HBsAg-positive liver disorders in Italy.

Conclusion

Though HDV is vanishing in Italy, a legacy of ageing native-Italian patients with advanced HDV liver disease still represents an important medical issue and maintains an impact on liver transplantation.

Differences in Incidence of Acute Viral Hepatitis between Foreigners and Autochthonous Population in Italy

Background: In European countries, the prevalence of HBV and HCV in refugees and migrants tends to reflect the prevalence in their countries of origin. The aim of this study is to analyse acute viral hepatitis cases diagnosed in Italy among foreign citizens and to compare incidence rates in foreigners and Italians. Methods: We analysed the cases of each viral hepatitis type among foreigners. Standardised incidence rates were compared between natives and foreigners. Results: Between 2004 and 2019, 15,872 cases of acute viral hepatitis were notified by 10 Italian regions, 14.8% among foreign citizens. Until 2012, the percentage increased gradually, while a fluctuating trend set in from 2013 onwards; in 2019, 23.9% of cases were foreigners. Data from the SEIEVA surveillance show higher standardised incidence rates of hepatitis A and B among foreign citizens; no significant difference emerged between Italians and foreigners in terms of their hepatitis C incidence. Conclusions: foreign citizens have an increased incidence of hepatitis A and B. Regarding hepatitis A, vaccination is strongly recommended to foreigners travelling to their countries of origin. Screening tests for hepatitis B and C infection should be offered to newly arrived migrants from high prevalence countries, or having specific risk factors.

The changing context of hepatitis D

The global epidemiology of hepatitis D is changing with the widespread implementation of vaccination against hepatitis B. In high-income countries that achieved optimal control of HBV, the epidemiology of hepatitis D is dual, consisting of an ageing cohort of domestic patients with advanced liver fibrosis who represent the end stage of the natural history of HDV, and of a younger generation of immigrants from endemic countries who account for the majority of new infections. As observed in Europe in the 1980s, the distinctive clinical characteristic of chronic hepatitis D in endemic countries is the accelerated progression to cirrhosis and hepatocellular carcinoma. Despite some recent progress, the therapeutic management of HDV remains unsatisfactory, as most patients are not cured of HDV with currently available medicines. This review article describes the current epidemiology and clinical features of chronic hepatitis D, based on the literature published in the last 10 years.

Forty-Five Years after the Discovery of the Hepatitis D Virus: Where Do We Stand?

The discovery of the Australia Antigen in the mid-1960s led, in a few years, to the identification of the virus of Hepatitis B [...].

HBV/HDV Co-Infection: Epidemiological and Clinical Changes, Recent Knowledge and Future Challenges

Several investigations have been published on Hepatitis Delta Virus (HDV) infection in recent years, from which we have drawn the salient data to provide readers with useful information to improve their knowledge on the subject. HDV genotypes 5–8 have been recently imported to Western countries from central Africa, whose clinical relevance deserves further investigation. Ongoing HDV replication has been identified as an independent predictor of progression to cirrhosis and HCC for patients with HDV chronic hepatitis (HDV-CH). Long-term treatments of HDV-CH with standard or pegylated interferon alfa (peg-IFN-α) have all been unsatisfactory, leading to a sustained virological response (SVR) only in 20–30% of patients treated, faced with a poor tolerability and frequent serious adverse reactions; the addition of HBV nucleo(s)tide analogues to peg-IFN- α did not improve the rate of SVR. The improved knowledge of the HDV life cycle has allowed the development of direct acting agents towards key-points of the HDV life cycle, namely bulevirtide, lonafarnib and nucleic acid polymers. Preliminary data have shown that these drugs are more effective than interferon-based therapies, but adverse reactions are also common, which however seem toned down in combination therapy with other antivirals.