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

Characteristics and outcome of anti-hepatitis D virus positive patients with hepatocellular carcinoma

BACKGROUND & AIMS

Chronic hepatitis D virus (HDV) often leads to end-stage liver disease and hepatocellular carcinoma (HCC). Comprehensive data pertaining to large populations with HDV and HCC are missing, therefore we sought to assess the characteristics, management, and outcome of these patients, comparing them to patients with hepatitis B virus (HBV) infection.

METHODS

We analysed the Italian Liver Cancer database focusing on patients with positivity for HBV surface antigen and anti-HDV antibodies (HBV/HDV, n = 107) and patients with HBV infection alone (n = 588). Clinical and oncological characteristics, treatment, and survival were compared in the two groups.

RESULTS

Patients with HBV/HDV had worse liver function [Model for End-stage Liver Disease score: 11 vs. 9, p < .0001; Child-Turcotte-Pugh score: 7 vs. 5, p < .0001] than patients with HBV. HCC was more frequently diagnosed during surveillance (72.9% vs. 52.4%, p = .0002), and the oncological stage was more frequently Milan-in (67.3% vs. 52.7%, p = .005) in patients with HBV/HDV. Liver transplantation was more frequently performed in HBV/HDV than in HBV patients (36.4% vs. 9.5%), while the opposite was observed for resection (8.4% vs. 20.1%, p < .0001), and in a competing risk analysis, HBV/HDV patients had a higher probability of receiving transplantation, independently of liver function and oncological stage. A trend towards longer survival was observed in patients with HBV/HDV (50.4 vs. 44.4 months, p = .106).

CONCLUSIONS

In patients with HBV/HDV, HCC is diagnosed more frequently during surveillance, resulting in a less advanced cancer stage in patients with more deranged liver function than HBV alone. Patients with HBV/HDV have a heightened benefit from liver transplantation, positively influencing survival.

Impact of the COVID-19 pandemic on the Italian national viral hepatitis surveillance: an interrupted time series analysis, 2006-2022

OBJECTIVES

This study aimed to assess the impact of the COVID-19 pandemic on national surveillance of viral hepatitis in Italy.

STUDY DESIGN

Interrupted time series analysis.

METHODS

Using an interrupted time series analysis with a customised AutoRegressive Integrated Moving Average model on hepatitis cases reported to the Integrated Epidemiological System of Acute Viral Hepatitis from 2006 to 2022, we examined trends in incidence, time to diagnosis and time to epidemiological investigations for hepatitis A, hepatitis B and hepatitis C.

RESULTS

The quarterly incidence of hepatitis B (-0.251, P = 0.05) and hepatitis C (-0.243, P = 0.003) significantly decreased with the onset of the pandemic. Surveillance times for hepatitis B (5.496, P < 0.001) and hepatitis C (35.723, P < 0.001), measured as days lost per quarter, significantly increased 12 and 24 months after the pandemic's start. This aligns with a notable rise in quarterly incidence at 36 months for both (0.032, P = 0.030 for hepatitis B; 0.040, P < 0.001 for hepatitis C).

CONCLUSIONS

The decrease in reported cases could be due to an increase in infection prevention control and containment measures put in place in a pandemic context. However, a delay in the initiation of epidemiological investigations was observed, which could lead to a further increase in incidence in the future.

Hepatitis B Vaccine: Four Decades on

Hepatitis B virus is a substantial contributor to cirrhosis and hepatocellular carcinoma (HCC) globally. Vaccination is the most effective method for prevention of hepatitis B and its associated morbidity and mortality, and the only method to prevent infection with hepatitis D virus. The hepatitis B vaccine has been used worldwide for more than four decades; it is available in a single- or triple-antigen form and in combination with vaccines against other infections. Introduction of the vaccine and administration at birth led to sustained decline in mother-to-child transmission, chronic hepatitis B, and HCC, however, global birth dose coverage remains suboptimal. In this review we will discuss different hepatitis B vaccine formulations and schedules, vaccination guidelines, durability of the response, and vaccine escape mutants, as well as the clinical and economic benefits of vaccination.

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.

Vaccination Campaign against Hepatitis B Virus in Italy: A History of Successful Achievements

In Italy, the vaccination campaign against hepatitis B virus has been characterized by two phases. In the first phase (1984-1991), vaccination with plasma-derived vaccines was first recommended for the high-risk group. In the second phase (1991-nowadays), recombinant vaccine targeted, by law, infants 2 months old and teenagers 12 years old (limited to the first 12 years of campaign); screening for HBsAg became compulsory for all pregnant women during the third trimester of pregnancy. Successful achievements have been attained: No acute HBV case has been observed in the age group targeted by vaccination, the pool of chronic HBsAg carriers is strongly reduced, perinatal HBV transmission is under control, and acute delta virus hepatitis cases are nearly eliminated. The key point of this success has been the peculiar vaccination policy adopted. The combined vaccination of teenagers has generated an early immune cohort of youths, who are no longer at risk of acquiring HBV infection by sources of exposure (i.e., drug use and unsafe sex practices) typical of the young adults. Vaccination of household contacts with HBsAg-positive subjects represents an area of improvement; providing migrants and refugees access to healthcare services is also a focal point. In 2020, Italy became the first country in Europe to achieve the WHO's regional hepatitis targets.

Cellular Factors Involved in the Hepatitis D Virus Life Cycle

Hepatitis D virus (HDV) is a defective RNA virus with a negative-strand RNA genome encompassing less than 1700 nucleotides. The HDV genome encodes only for one protein, the hepatitis delta antigen (HDAg), which exists in two forms acting as nucleoproteins. HDV depends on the envelope proteins of the hepatitis B virus as a helper virus for packaging its ribonucleoprotein complex (RNP). HDV is considered the causative agent for the most severe form of viral hepatitis leading to liver fibrosis/cirrhosis and hepatocellular carcinoma. Many steps of the life cycle of HDV are still enigmatic. This review gives an overview of the complete life cycle of HDV and identifies gaps in knowledge. The focus is on the description of cellular factors being involved in the life cycle of HDV and the deregulation of cellular pathways by HDV with respect to their relevance for viral replication, morphogenesis and HDV-associated pathogenesis. Moreover, recent progress in antiviral strategies targeting cellular structures is summarized in this article.

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.

Hepatitis delta infection among persons living with HIV in Europe

BACKGROUND AND AIMS

A high prevalence of hepatitis delta virus (HDV) infection, the most severe form of viral hepatitis, has been reported among persons living with HIV (PLWH) in Europe. We analysed data from a large HIV cohort collaboration to characterize HDV epidemiological trends across Europe, as well as its impact on clinical outcomes.

METHODS

All PLWH with a positive hepatitis B surface antigen (HBsAg) in the Swiss HIV Cohort Study and EuroSIDA between 1988 and 2019 were tested for anti-HDV antibodies and, if positive, for HDV RNA. Demographic and clinical characteristics at initiation of antiretroviral therapy were compared between HDV-positive and HDV-negative individuals using descriptive statistics. The associations between HDV infection and overall mortality, liver-related mortality as well as hepatocellular carcinoma (HCC) were assessed using cumulative incidence plots and cause-specific multivariable Cox regression.

RESULTS

Of 2793 HBsAg-positive participants, 1556 (56%) had stored serum available and were included. The prevalence of HDV coinfection was 15.2% (237/1556, 95% confidence interval [CI]: 13.5%-17.1%) and 66% (132/200) of HDV-positive individuals had active HDV replication. Among persons who inject drugs (PWID), the prevalence of HDV coinfection was 50.5% (182/360, 95% CI: 45.3%-55.7%), with similar estimates across Europe, compared to 4.7% (52/1109, 95% CI: 3.5%-5.9%) among other participants. During a median follow-up of 10.8 years (interquartile range 5.6-17.8), 82 (34.6%) HDV-positive and 265 (20.1%) HDV-negative individuals died. 41.5% (34/82) of deaths were liver-related in HDV-positive individuals compared to 17.7% (47/265) in HDV-negative individuals. HDV infection was associated with overall mortality (adjusted hazard ratio 1.6; 95% CI 1.2-2.1), liver-related death (2.9, 1.6-5.0) and HCC (6.3, 2.5-16.0).

CONCLUSION

We found a very high prevalence of hepatitis delta among PWID across Europe. Among PLWH who do not inject drugs, the prevalence was similar to that reported from populations without HIV. HDV coinfection was associated with liver-related mortality and HCC incidence.

Silent HDV epidemics culminates in high levels of liver cirrhosis in endemic region despite 20 years of HBV vaccination

The hepatitis delta virus (HDV) is believed to be a vanishing infection in countries with successful hepatitis B virus (HBV) vaccination programs. We assessed the current status of HDV infection in Tuva, a region of the Russia that has been highly endemic for HBV. The proportion of HDV-infected patients among HBsAg-positive patients in the regional registry in 2020 was 32.7% (786/2401). An analysis of the medical records of 514 HDV patients demonstrated that 37.5% (193/514) had liver cirrhosis at the first doctor's visit, and 7.4% of patients lived in families where another family member had HDV. All HDV patients were infected with genotype HDV-1, 94.5% had HBV genotype D, and 5.5% had genotype A. A serosurvey conducted among 1170 healthy volunteers showed that the average detection rate of HBsAg with anti-HDV was 1.0% (95% CI: 0.57-1.81%). No anti-HDV positive samples were detected in participants aged under 30 years. The HBsAg/anti-HDV positivity rate peaked at 7.4% in patients aged 50-59 years, which was significantly higher than in a similar age cohort surveyed in 2008 (1.6%, p < .0001). A Bayesian analysis showed that HDV circulation in Tuva resulted from two waves of introduction, the first in the 1810s (95% HPD: 1741-1834) from Central Asia, and the second in the 1960s (95% HPD: 1953-1979) from Russia. HBV has a much longer history of circulation in Tuva with the MRCA for the predominant genotype HBV-D dated to 972 (95% HPD: 535-1253) for subtype D1, 1274 (95% HPD: 936-1384) for D2, and 1173 (95% HPD: 1005-1618) for D3. A SkyGrid reconstruction of population dynamics showed an increase in the intensity of HDV spread in recent decades. This situation shows the need for HDV screening and prevention measures among people living with HBV.

Epidemiology and Risk Factors for Acute Viral Hepatitis in Bangladesh: An Overview

Viral infections by hepatotropic viruses can cause both acute and chronic infections in the liver, resulting in morbidity and mortality in humans. Hepatotropic viruses, including hepatitis A virus (HAV), hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis D virus (HDV), and hepatitis E virus (HEV), are the major pathogens that cause acute and chronic infections in humans. Although all of these viruses can cause acute hepatitis in humans, HAV and HEV are the predominant causative agents in Bangladesh, where the occurrence is sporadic throughout the year. In this review, we provide an overview of the epidemiology of hepatotropic viruses that are responsible for acute hepatitis in Bangladesh. Additionally, we focus on the transmission modes of these viruses and the control and prevention of infections.

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.

Hepatitis B Vaccination: A Historical Overview with a Focus on the Italian Achievements

Vaccination is the most effective way to control and prevent acute and chronic hepatitis B, including cirrhosis and HCC, on a global scale. According to WHO recommendations, 190 countries in the world have introduced hepatitis B vaccination into their national childhood immunization programs with an excellent profile of safety, immunogenicity, and effectiveness. Following vaccination, seroprotection rates are close to 100% in healthy children and over 95% in healthy adults. Persistence of anti-HBs is related to the antibody peak achieved after vaccination. The peak is higher the longer the antibody duration is. Loss of anti-HBs does not necessarily mean loss of immunity since most vaccinated individuals retain immune memory for HBsAg and rapidly develop strong anamnestic responses when boosted. Evidence indicates that the duration of protection can persist for at least 35 years after priming. Hence, booster doses of vaccines are currently not recommended to sustain long-term immunity in healthy vaccinated individuals. In Italy, vaccination against hepatitis B is met with success. In 2020, Italy became one of the first countries in Europe to be validated for achieving the WHO regional hepatitis B control targets.