The Changing Demographics of Hepatitis B Virus Infection

Global, regional, and national burdens of vaccine-preventable infectious diseases with high incidence among middle-aged and older adults aged 55-89 years from 1990 to 2021: Results from the global burden of disease study 2021

OBJECTIVE

To evaluate the global, regional, and national burden of four vaccine preventable infectious diseases (VPDs) among adults aged 55-89 years from 1990 to 2021, in the context of an aging population.

METHODS

Data from the Global Burden of Disease Study 2021 on acute hepatitis A, B, E, and varicella and herpes zoster were analysed for incidence rates and disability-adjusted life years (DALYs), stratified by sex, age, Social Development Index (SDI), and region. Joinpoint regression analysis was used to assess trends.

RESULTS

In 2021, the global incidence of four VPDs among adults aged 55-89 years was 1698.8 cases per 100,000 population, with a total of 25,243,776 (95 % UI 17301929-34,959,277) new cases and 719,888 (95 % UI 534782-992,800) DALYs. From 1990 to 2021, the incidence rates of acute hepatitis A and acute hepatitis B consistently declined, whereas those of acute hepatitis E, varicella and herpes zoster moderately increased, with EAPCs of 0.13 (95 % UI 0.12-0.15) and 0.14 (95 % UI 0.09-0.19), respectively. In 2021, sub-Saharan Africa had the highest overall burden of the four diseases, whereas high-income Asia Pacific (945.7 per 100,000 population) and Western Europe (840.7 per 100,000 population) had the highest incidence rates of varicella and herpes zoster. Acute hepatitis A and acute hepatitis B were more prevalent in low- and middle-SDI regions, whereas increasing trends for acute hepatitis E and varicella and herpes zoster were observed in higher-SDI regions. The incidence rates of acute hepatitis A and acute hepatitis B were higher in males than in females and decreased with age.

CONCLUSIONS

Despite overall declines in VPDs among older adults, disparities remain. Public health efforts must focus on improving vaccine access and targeting at-risk populations, especially older adults, to address the burden of VPDs.

Current prevalence of hepatitis delta diagnosis in Valencia, Spain

Hepatitis delta virus (HDV) is the most aggressive form of chronic viral hepatitis, yet substantial knowledge gaps exist regarding its epidemiology and optimal diagnostic workflows. From February 2019 to March 2022, an HBV screening project was conducted across various healthcare settings in Valencia, Spain. This included twenty-six primary care centers, six sexual and reproductive health centers, three mental health centers, three addiction treatment centers, selected hospital departments, outpatient clinics, and a penitentiary center. A retrospective analysis of HDV diagnostic and prevalence (2007-2020) was followed by prospective HDV screening using reflex testing from April to October 2022. Of 31,995 patients screened, 141 were HBsAg-positive (0.44% seroprevalence). Previously unknown HBV infection prevalence was 0.36%. Among HBsAg-positive patients, 5.15% had HDV IgG/IgM antibodies, and 2% had HDV RNA. Reflex single-step HDV testing increased HDV diagnosis coverage from 24 to 99.4%. This study highlights the effectiveness of reflex HDV testing, which significantly increased diagnostic coverage and simplified the screening process. Reflex testing provides a cost-effective and efficient approach, particularly benefiting high-risk populations such as migrants, who accounted for 77.8% of HBsAg-positive cases. Its implementation is crucial for improving patient outcomes and addressing gaps in HDV diagnosis and management.

Hepatitis B Prevalence and Referral Rates in Vulnerable Populations Undergoing Community-Based Screening-Results from the LIVE(RO)2 Program

Background: Hepatitis B Virus (HBV) remains a major global health challenge, with significant morbidity and mortality associated with chronic infections. Methods: This study examines the epidemiology, screening, and risk factors associated with HBV in Romania, focusing on a comprehensive national screening program, LIVE(RO)2, involving 320,000 individuals (majority of them considered vulnerable population). A questionnaire was used to collect information on the potential risk factors for HBV transmission. Results: The overall prevalence rate of HBV chronic infection among all the participants tested was 1.67% (confidence interval: 1.63-1.72%), with significant differences (p = 0.0001) between participants from the main geographical regions of residence (North-East 1.89%, South 1.38%, South-East 2.06%, and South-West 1.54%). Male persons aged 30-49 or 60-69 years old, from the rural and Eastern parts of Romania and non-Romanian ethnia, with a low level of education, unvaccinated, not married, unemployed, with family members with hepatitis, with personal histories of blood or blood product transfusion, surgical interventions, tattooing, hospitalizations, imprisonment, haemodialysis, unsafe sexual contacts, or with sexual transmitted infectious diseases were risk factors associated with HBsAg seropositivity. Conclusions: Our findings highlight significant demographic and epidemiological patterns of reduced HBV prevalence even in vulnerable persons, as well as modified risk factors and the impact of socio-economic factors.

The dual role of regulatory T cells in hepatitis B virus infection and related hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a major contributor to cancer-related deaths worldwide. Hepatitis B virus (HBV) infection is a major etiologic factor leading to HCC. While there have been significant advancements in controlling HBV replication, achieving a complete cure for HBV-related HCC (HBV-HCC) remains an intricate challenge. HBV persistence is attributed to a myriad of mechanisms, encompassing both innate and adaptive immune responses. Regulatory T cells (Tregs) are pivotal in upholding immune tolerance and modulating excessive immune activation. During HBV infection, Tregs mediate specific T cell suppression, thereby contributing to both persistent infection and the mitigation of liver inflammatory responses. Studies have demonstrated an augmented expression of circulating and intrahepatic Tregs in HBV-HCC, which correlates with impaired CD8+ T cell function. Consequently, Tregs play a dual role in the context of HBV infection and the progression of HBV-HCC. In this comprehensive review, we discuss pertinent studies concerning Tregs in HBV infection, HBV-related cirrhosis and HCC. Furthermore, we summarize Treg responses to antiviral therapy and provide Treg-targeted therapies specific to HBV and HCC.