Global prevalence of hepatitis B virus infection and prevention of mother-to-child transmission

Switching from tenofovir disoproxil fumarate to tenofovir alafenamide in virologically suppressed patient with chronic hepatitis B

BACKGROUND AND AIM

Our study evaluated the outcomes of switching from tenofovir disoproxil fumarate (TDF) to tenofovir alafenamide (TAF) in patients with chronic hepatitis B (CHB). We assessed viral and biochemical responses as well as changes in the estimated glomerular filtration rate (eGFR) and bone mineral density (BMD).

METHODS

This retrospective multicenter study included CHB patients who achieved virologic response (VR) (HBV DNA < 20 IU/mL) while on TDF and were subsequently switched to TAF between April 2018 and October 2021.

RESULTS

This study included 309 patients with a median age of 59 years, and 42.1% were male. The mean duration of TDF and TAF administration were 54.0 and 37.5 months, respectively. All patients maintained VR after switching to TAF. Alanine aminotransferase (ALT) normalization rate significantly increased 6 months after switching (74.8%-83.5%; P = 0.008). Adjusted eGFR significantly improved at 6 months (+5.55 ± 10.52 mL/min/1.73 m2; P < 0.001) and 12 months (+6.02 ± 10.70 mL/min/1.73 m2; P < 0.001) after switching. In the subgroup of patients with renal impairment (eGFR < 60 mL/min/1.73 m2), significant improvement in renal function was observed at 6 months (+0.6 ± 10.5 mL/min/1.73 m2; P < 0.001) and 12 months (+1.0 ± 10.7 mL/min/1.73 m2; P < 0.001) after switching to TAF. In patients with osteoporosis (n = 182), switching to TAF resulted in significant improvement in spine and hip BMD at 12 months, with increases of 9.7% (95% CI: 7.0-12.5) and 9.4% (95% CI: 7.0-11.8), respectively.

CONCLUSION

In this real-world study, switching to TAF was effective and safe in patients, with notable improvements in ALT levels, renal function, and BMD.

Asian Pacific association for the study of liver (APASL) guidelines: hepatitis B virus in pregnancy

Hepatitis B virus (HBV) infection still remains a major public health issue in the Asia-Pacific region. Most of the burden of HBV-related disease results from infections acquired in infancy through perinatal or early childhood exposure to HBV in Asia-Pacific. Hepatitis B during pregnancy presents unique management issues for both the mother and fetus. These APASL guidelines provide a comprehensive review and recommendations based on available evidence in the literature, for the management of females with HBV infection through every stage of pregnancy and postpartum. These also address the concerns, management challenges, and required follow-up of children born to hepatitis B-positive mothers.

Development, Production, and Characterization of Hepatitis B Subviral Envelope Particles as a Third-Generation Vaccine

Vaccination still represents the most efficient and inexpensive strategy in the control of hepatitis B virus (HBV) infection. However, about 10% of the population vaccinated with the current S yeast-derived vaccine fail to induce an adequate immune response. Our group has developed a new-generation hepatitis B vaccine candidate composed by the three surface proteins of the HBV. Here we describe the methods to develop and characterize a stable CHO-K1 recombinant cell line able to produce and secrete hepatitis B subviral envelope particles (HBV-SVPs) containing L and M glycoproteins in addition to S glycoprotein. In addition, Western blot and immunogold electron microscopy techniques to evaluate the size, morphology, and composition of the particles are explained. Finally, immunization protocols are described in order to study the immunogenicity of HBV-SVPs and the ability of the antibodies triggered by these particles to recognize the binding site of HBV with the hepatocyte.

Demographics, Biochemical Characteristics, and Phases of Chronic Hepatitis B Virus Infection: Retrospective Analysis From a Secondary Care Setup

Introduction Hepatitis B virus (HBV) is the leading cause of cirrhosis in the developing world. Despite the development of effective vaccine(s) and direct-acting antivirals (DAAs) such as tenofovir and entecavir, the eradication of chronic HBV remains a distant dream in endemic regions. Factors such as treatment naivety, longer duration of disease, late diagnosis, family history of liver disorders and hepatocellular carcinoma, fatty liver disease, multiple comorbidities, alcoholism, use of tobacco products, noncompliance to drugs, and loss to follow-up all contribute to disease progression and development of complications. In order to promote a better understanding of the treatment initiation, duration, and eventual outcomes, the European Association for the Study of the Liver (EASL) updated its guidelines in 2017 and introduced a new staging system for chronic HBV. Since these guidelines are relatively recent, data regarding the new staging is virtually absent in local/regional settings. Moreover, it has been observed that patients presenting to secondary care setups at major urban centers have disease characteristics quite distinct from those of their rural counterparts or patients presenting to tertiary care setups, even in the same cities. Additionally, there is scarce published data with regard to this aspect. With this study, we hope to make progress on all of those fronts. Objective We aimed to evaluate the demographics, biochemical characteristics, and phases of chronic HBV at the secondary care level. Methods This was a retrospective observational cohort conducted at the Sindh Government Hospital, Liaquatabad from January to December 2020. Patients of either gender who were aged ≥12 years, and diagnosed as a case of chronic HBV were eligible to be enrolled in the study. Only treatment-naive patients were enrolled in the study. Demographics, biochemical characteristics, and phases of HBV (in light of the updated guidelines issued by EASL in 2017 with respect to HBV) were recorded and analyzed. Patient confidentiality was ensured at all times. Results A total of 102 patients were enrolled in the study. The mean age of our cohort was 34.31 ±12.42 years, and the male-to-female ratio was 3:2. All referrals were made from within the city district. Housewives and laborers made up the majority of our patients. The mean alanine transaminase (ALT) levels were 39.83 ±21.33 IU/L; otherwise, the biochemical profile of the patients was unremarkable. Phase III was the most frequently recorded stage of chronic HBV; 41 (40.19%) of the patients were diagnosed with it. However, nearly half of the patients had chronic active hepatitis (phases II and IV). Only a single case each of hepatitis Delta virus and decompensated liver disease (DCLD) was recorded. Conclusions All patients of chronic HBV presenting at the secondary care level were referred locally, were relatively older, and exhibited a higher frequency of chronic active hepatitis (phases II and IV). This corresponded to borderline elevations of ALT. But the remainder of the biochemical profile was largely unremarkable due to the very low prevalence of cirrhosis among these patients.

Seroprevalence and factors associated with hepatitis B infection among the hill tribe adult population in Thailand: a cross-sectional study

Background

Hepatitis B virus (HBV) infection is one of the greatest public health burdens, particularly for people living with several barriers to access to health care services, such as the hill tribe adult population in Thailand. People aged 25 years and over who are out of the target population for HBV immunization under the national Expanded Program on Immunization (EPI) are at risk of HBV infection. The study aimed to estimate the prevalence and determine the factors associated with HBV infection among hill tribe adults aged 25 years and over living in Chiang Rai Province, Thailand.

Methods

A cross-sectional study design was used to collect information on hill tribe adults aged 25 years and over living in 36 selected hill tribe villages in Chiang Rai Province. All people living in the selected villages who met the criteria were invited to participate in the study. A validated questionnaire and a 5-mL blood specimen were used as research instruments. Hepatitis B surface antigen (HBsAg), antibody to hepatitis B surface (anti-HBs), and antibody to hepatitis B core (anti-HBc) were detected by using the Wondfo Test Kit^@, which has high sensitivity and specificity. Logistic regression was used to detect the associations between variables at the significance level of α = 0.05.

Results

A total of 1491 individuals were recruited into the analysis; 60.8% were females, 81.3% were aged between 30 and 60 years, and 86.0% were married. The majority were illiterate (54.9%), were Buddhist (55.7%), worked in agricultural sectors (87.3%), and had an annual income of less than 50,000 baht per year (72.9%). The overall prevalence of hepatitis B infection was 26.6%; 7.6% were positive for HBsAg, 19.2% were positive for anti-HBs, and 18.9% were positive for anti-HBc. In the multivariate analysis, three variables were found to be associated with hepatitis B infection: those who were in the Yao and Lisu tribes had a 1.64-fold (95% CI = 1.08–2.49) and a 1.93-fold (95% CI = 1.10–3.31) greater chance, respectively, of HBV infection than did those in the Karen tribe; those who were Christian had a 1.41-fold (95% CI = 1.06–1.87) greater chance of HBV infection than did those who were Buddhist; and those who did not use alcohol had a 1.29-fold (95% CI = 1.01–1.65) greater chance of HBV infection than did those who used alcohol.

Conclusions

It is necessary to develop and implement effective public health interventions among hill tribe adult populations who are not part of the EPI-targeted population, particularly Christians, those in the Lisu and Yao tribes, and those who do not use alcohol, to reduce the HBV infection rate, save lives and reduce medical expenses.

Hepatitis B vaccine development and implementation

Vaccination against hepatitis B is the most effective strategy to control HBV infection. The first licensed hepatitis B vaccine was developed by the purification of hepatitis B surface antigen (HBsAg) from plasma of asymptomatic HBsAg carriers. Then, the recombinant DNA technology enabled the development of recombinant hepatitis B vaccine. A series of three doses vaccine can elicit long-term protection more than 30 y. Concurrent use of hepatitis B immunoglobulin and hepatitis B vaccine has substantially reduced the mother-to-child transmission of HBV, nearly zero infection in children of carrier mother with negative hepatitis B e antigen (HBeAg) and 5-10% infection in children of HBeAg-positive mothers. By the end of 2018, 189 countries adopted universal hepatitis B vaccination program, which has dramatically reduced the global prevalence of HBsAg in children <5 y of age, from 4.7% in the prevaccine era to 1.3% in 2015. However, the implementation of universal hepatitis B vaccination in some regions is suboptimal and timely birth dose vaccine is not routinely administered in more than half of newborn infants. Optimal worldwide universal hepatitis B vaccination requires more efforts to overcome the social and economic challenges.

Seroprevalence and factors associated with hepatitis B virus infection among the hill tribe youths, northern Thailand

Background

Hepatitis B virus (HBV) infection is a major viral infection, particularly in people living in the Western Pacific region, including the hill tribe people living in northern Thailand. This study aimed to estimate the prevalence of HBV infection and to detect the factors associated with HBV infection among hill tribe youths in Thailand.

Methods

A cross-sectional study was conducted to estimate the prevalence and determine the factors associated with HBV infection among hill tribe youths living in northern Thailand. A validated questionnaire and 5 mL blood sample were used for data collection. The Wondfo Diagnostic Kit®, the Wondfo One Step HBsAg Serum/Plasma Test®, and the Wondfo One Step HBsAg Serum/Plasma Test® were used for anti-HBsAg, HBsAg, and total anti-HBc detections, respectively. Logistic regression was used to detect associations between variables with an α = 0.05 significance level.

Results

A total of 836 participants were included in the study; 62.7% were female, 58.9% were aged 15–17 years, 58.7% were Buddhist, 78.4% graduated high school, and 89.1% had no income. The majority were Akha (30.0%), Yao (16.3%), and Hmong (15.8%); 13.2% smoked, 21.5% used alcohol, 13.3% had tattoos, 3.9% experienced drug injection from illegal practitioners, and 35.7% had no history of HBV immunization. The prevalence of HBsAg was 3.0%; anti-HBs, 10.2%; and total anti-HBc, 8.1%. In the multivariate analysis, four variables were found to be significantly associated with HBV infection among the hill tribe youths: age, tribe, work experience, and number of partners. Those aged 18–20 years and 21–24 years had 2.13 times (95%CI = 1.35–3.29) and 2.39 times (95%CI = 1.05–3.90) greater odds of HBV infection, respectively, than those aged 15–17 years. Akha, Lahu, and Hmong youths had 3.12 times (95%CI = 1.07–9.12), 3.71 times (95%CI = 1.21–11.41), and 3.84 times (95%CI = 1.26–11.69) greater odds of HBV infection, respectively, than Lisu youths. Those who had experience working outside of the village had a 1.77 times (95%CI = 1.18–2.98) greater chance of HBV infection than those who did not have experience working outside of the village, and those who had ≥2 partners had a 2.66 times (95%CI = 1.96–3.87) greater chance of HBV infection than those who had no partner.

Conclusions

Effective HBV prevention programs should be promoted in Akha, Lahu, and Hmong youth populations, particularly to those who have sexual partners, work outside of the village and are aged 18–24 years.