Epidemiology of Hepatitis B and C Virus Infections and Liver Cancer in Vietnam

Impact of hepatitis B vaccination programs in Vietnam evaluated by estimating HBsAg prevalence

Background

Vietnam introduced a 3-dose hepatitis B (HBV) immunization program comprising 1 dose immediately after birth and 2 or 3 in infancy in the past 20 years, but the impact of the vaccine has not been systematically evaluated. Thus, we conducted this survey aiming to estimate the age-specific chronic HBV prevalence in the general population and to evaluate HBV immunization effectiveness.

Methods

Population-based, four-stage cluster sampling was used in the South Central Coast region of Vietnam. The point-of-care Determine rapid test was used to assess hepatitis B surface antigen (HBsAg) positivity.

Results

A total of 2,075 samples were included in the study. HBsAg prevalence was significantly higher among adults aged 20-39 years than in the population aged 1-19 years (8.0% [95% confidence interval 5.0-12.0] vs. 2.0% [95% confidence interval 1.0-6.0], p<0.01). HBsAg prevalence decreased after implementation of the 3-dose vaccination schedule during infancy from 1997 to 2002, whereas the change in prevalence after implementation of the birth dosing was not significant. A slight increase in HBsAg prevalence was observed for the cohort born in 2011, 2012, and 2013, when there was a vaccine shortage and media reports of immunization resistance.

Conclusions

This is the first population-based assessment of the introduction of the HBV vaccine in Vietnam performed by estimating the HBsAg prevalence across a wide range of ages. The results showed that the HBV immunization policy effectively reduces HBsAg prevalence in general, although birth dosing of the vaccine and low immunization coverage should be carefully monitored.

Changing epidemiology of liver disease in Asia: Dual infection of HBV and HCV

Transmission of hepatitis B virus (HBV) and hepatitis C virus (HCV) is similar regarding the mode of transmission and related risk factors. Therefore, it is not rare to encounter dual HBV/HCV infection in populations at risk of parenteral exposure to hepatitis viruses. Besides, in HBV endemic countries before the era of global HBV vaccination, dual HBV/HCV infection was clinically significant likely because of HCV superinfection over pre-existing HBsAg carriage. Universal childhood HBV vaccination was implemented worldwide since 1992. Public education programs for prevention of new hepatitis viral infections have been actively promoted recently by World Health Organization. Apart from preventive measures, potent anti-HBV agents effective in the control of viral replication have been introduced gradually in the past three decades. Direct acting antiviral agents capable of curing HCV infection in more than 97% of patients with chronic hepatitis C have also been widely implemented in the past decade. These interventions will change the epidemiology of new HBV or HCV mono-infection and dual HBV/HCV infection. Understanding the evolution in the epidemiology of dual HBV/HCV infection is important for evaluation of current public health policy towards infectious disease control in different countries. The changing prevalence of dual HBV/HCV infection in certain Asia-Pacific countries will be re-visited based on endemicity of HBV or HCV, as well as in populations at risk of parenteral viral infection.

Design synthesis of Y-90 glass microspheres and study of their therapeutic effects on mouse liver cancer cell line Hep3B

In this article, a system for synthesizing Y-90 glass microspheres (Y-90-GM) was successfully designed in the Da Lat nuclear reactor (Vietnam), and the therapeutic effects of Y-90-GM on mice liver cancer cell line Hep3B were studied. The effects of synthesis factors, including heating time, heating temperature, gas flow rate, sample conduit length and diameter, were investigated to establish the optimal parameters. The size and shape of Y-90-GM were checked by field emission scanning electron microscope, and the radioactivity measurement was performed on a dosimeter. The results indicated that the optimal conditions for the synthesis of Y-90-GM were determined as the heating temperature of 1600 °C, heating time of 2 h, conduit length and diameter of 50 cm and 3.6 cm, and gas/oxygen flow rate of 15 mph. The Y-90-GM samples obtained at the optimal parameters have a size of 18-30 μm with a density of 3.53 g cm^-3 and a specific radioactivity of 630 mCi g^-1. The results of the therapeutic study on mice liver cancer cell line Hep3B showed that after two weeks of treatment with Y-90-GM (1mCi/mouse), the tumor volume was reduced by about 30.7% and after 3 consecutive treatment cycles, the liver cancer tumor was completely reduced. It was demonstrated that Y-90-GM is promising radiopharmaceuticals in the treatment of liver cancer by the radioembolization method.

Seroprevalence of Hepatitis B, C and D in Vietnam: A systematic review and meta-analysis

Background

Vietnam has one of the greatest disease burdens from chronic viral hepatitis. Comprehensive prevalence data are essential to support its elimination as a public health threat.

Methods

We searched Medline and Embase from 1990 to 2021 for seroprevalence data relating to Hepatitis B (HBV), C (HCV) and D (HDV) in Vietnam. We estimated pooled prevalence with a DerSimonian-Laird random-effects model and stratified study populations into i) low-risk ii) high-risk exposure and iii) liver disease. We further estimated prevalence by decade and region and rates of HIV-coinfection.

Findings

We analysed 72 studies, including 120 HBV, 114 HCV and 23 HDV study populations. Pooled HBV prevalence was low in blood donors (1.86% [1.82-1.90]) but high in antenatal populations (10.8% [10.1-11.6]) and adults in the general population (10.5% [10.0-11.0]). It was similar or modestly increased in groups at highest risk of exposure, suggesting the epidemic is largely driven by chronic infections acquired in childhood. HCV pooled prevalence in the general population was lower than historical estimates: 0.26% (0.09-0.51) have active infection defined by detectable antigen or HCV RNA. In contrast, there is an extremely high prevalence of active HCV infection in people who inject drugs (PWID) (57.8% [56.5-59.1]), which has persisted through the decades despite harm-reduction interventions. HDV appears mainly confined to high-risk groups.

Interpretation

Blood safety has improved, but renewed focus on HBV vaccination at birth and targeted HCV screening and treatment of PWID are urgently required to meet elimination targets. Large cross-sectional studies are needed to better characterize HDV prevalence, but mass screening may not be warranted.

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Identification of NS5B Resistance-Associated Mutations in Hepatitis C Virus Circulating in Treatment Naïve Vietnamese Patients

Introduction

Treatment of HCV infection with peginterferon and ribavirin results in a low sustained virologic response rate, but has a number of undesirable adverse effects. Direct-acting antivirals (DAAs) offer a high efficacy, low risk, and a short treatment time. However, the existence of resistance-associated mutations, particularly in the NS5B polymerase, can attenuate the efficacy of DAAs. The objective of this study was to identify amino acid changes in the NS5B gene linked to DAA resistance in treatment-naive Vietnamese chronic hepatitis C patients.

Methods

Blood samples and treatment data were collected from 100 HCV-infected patients hospitalized at the National Hospital for Tropical Diseases between January and December 2020; the plasma was then isolated and stored at –80°C for molecular analysis. The NS5B gene fragments of 100 samples were amplified with specified primers and the nucleotide sequences were obtained using the Sanger sequencing system. The nucleotide sequences were then analyzed and compared to identify substitutions in the NS5B region.

Results

A total of 100 HCV isolates from patients were classified into three genotypes, including genotypes 1, 3, and 6. The NS5B sequence analysis revealed many amino acid mutations in all genotypes, although these mutations were not strongly associated with resistance to DAAs like S282T. Analytical data on ribavirin–resistance mutations revealed that Q309R was predominantly found in genotype 1a, D310N was mostly found in genotype 1b, and N244I, T329I, A333E were not observed. The following mutations were shown to be related with DAAs resistance: E237G, S282R, L320F, V321A, and V321I. Furthermore, NS5B-resistance mutations were not associated with clinical characteristics, long-term virological response, or improvements in clinical parameters (liver enzymes or liver fibrosis index).

Conclusion

Although NS5B mutations were found in treatment-naive Vietnamese patients, changes in the NS5B gene did not appear to be highly correlated with HCV ribavirin and DAA antiviral resistance.

Income Inequalities in Hepatitis B Vaccination and Willingness to Pay Among Women of Reproductive Age in Hanoi, Vietnam

BACKGROUND

Hepatitis B virus (HBV) infection is endemic in Vietnam and can be transmitted from mother to child. Vaccination of women of reproductive age (WRA) can reduce this transmission. Because adult HBV vaccination in Vietnam follows a fee-for-service model, research is needed to determine the effect of household income on willingness to pay (WTP) to ensure equitable access to the vaccine.

METHODS

A cross-sectional study was performed in Hanoi, Vietnam, in April 2018, among WRA. Questionnaires were administered to assess household income, HBV history, vaccination status, vaccine awareness, and WTP for the vaccine. Multivariable logistic and interval regression were performed to assess the impact of household income on WTP for HBV vaccine.

RESULTS

This study found that 62.3% of all participants were willing to pay for the HBV vaccine with no differences in WTP across income quintiles. There were significant differences among household income levels in awareness of HBV vaccination and WTP amount beyond US$4.50 with the lowest awareness and WTP amount among women from the lowest income quintiles.

CONCLUSIONS

Our data suggest the need to subsidize HBV vaccination for low-income women to ensure more equitable access to HBV vaccination. We propose that a sliding-scale payment method may be an effective strategy in light of limited funding to support vaccination expansion. An education campaign focusing on lower-income households should also be implemented in conjunction with this program. Further research would be required to evaluate consumer acceptance of this payment scheme and to develop an appropriate sliding scale to maximize vaccine uptake.

Predominance of HBV Genotype B and HDV Genotype 1 in Vietnamese Patients with Chronic Hepatitis

Hepatitis delta virus (HDV) coinfection will additionally aggravate the hepatitis B virus (HBV) burden in the coming decades, with an increase in HBV-related liver diseases. Between 2018 and 2019, a total of 205 HBV patients clinically characterized as chronic hepatitis B (CHB; n = 115), liver cirrhosis (LC; n = 21), and hepatocellular carcinoma (HCC; n = 69) were recruited. HBV surface antigen (HBsAg), antibodies against surface antigens (anti-HBs), and core antigens (anti-HBc) were determined by ELISA. The presence of hepatitis B viral DNA and hepatitis delta RNA was determined. Distinct HBV and HDV genotypes were phylogenetically reconstructed and vaccine escape mutations in the “a” determinant region of HBV were elucidated. All HBV patients were HbsAg positive, with 99% (n = 204) and 7% (n = 15) of them being positive for anti-HBc and anti-HBs, respectively. Anti-HBs positivity was higher among HCC (15%; n = 9) compared to CHB patients. The HBV-B genotype was predominant (65%; n = 134), followed by HBV-C (31%; n = 64), HBV-D, and HBV-G (3%; n = 7). HCC was observed frequently among young individuals with HBV-C genotypes. A low frequency (2%; n = 4) of vaccine escape mutations was observed. HBV-HDV coinfection was observed in 16% (n = 33) of patients with the predominant occurrence of the HDV-1 genotype. A significant association of genotypes with alanine aminotransferase (ALT) and aspartate aminotransferase (AST) enzyme levels was observed in HBV monoinfections. The prevalence of the HDV-1 genotype is high in Vietnam. No correlation was observed between HDV-HBV coinfections and disease progression when compared to HBV monoinfections.

Usefulness of Mac-2 binding protein glycosylation isomer in non-invasive probing liver disease in the Vietnamese population

BACKGROUND

Early diagnosis is critical for successful intervention before liver disease progresses to cirrhosis and hepatocellular carcinoma.

AIM

To examine a novel biomarker for probing early liver disease quickly using an automated immunology system.

METHODS

This was a cross-sectional study. 140 patients at various stages of liver disease were randomly selected. The cohort consisted of patients who were treatment naïve and currently undergoing therapy. We included patients with diverse liver disease etiologies. Mac-2 binding protein glycosylation isomer (M2BPGi) levels in addition to different clinical parameters, co-morbidities and transient elastography results were collected and compared.

RESULTS

M2BPGi levels were significantly correlated with transient elastography for liver fibrosis staging across all disease etiologies. Statistically significant differences were observed in patients with F0-1; F2 and > F3 liver fibrosis. Further examination showed that M2BPGi levels were two-fold higher in F4 than F3 hepatitis C (HCV) patients. M2BPGi was observed to be etiology-specific and HCV patients had higher mean M2BPGi levels. We also observed significant correlations with aspartate aminotransferase to platelet ratio index and fibrosis-4 index as well as HBV DNA levels. Mean M2BPGi levels for HBV patients with a viral load lower than 2000 IU/mL was 1.75-fold lower than those with a viral load greater than 2000 IU/mL.

CONCLUSION

M2BPGi was observed to be a good indicator of early liver disease in patients with different etiologies. Our results provide reference cut-offs for different causes of liver disease and demonstrated the utility of this marker for early disease monitoring. This is useful for remote regions in developing countries.

Projecting Cancer Incidence for 2025 in the 2 Largest Populated Cities in Vietnam

The population size and projected demographics of Vietnam's 2 largest cities, Ho Chi Minh City (HCMC) and Hanoi, will change dramatically over the next decade. Demographic changes in an aging population coupled with income growth and changes in lifestyle will result in a very different distribution of common cancers in the future. The study aimed to project the number of cancer incidence in the 2 largest populated cities in Vietnam for the year 2025. Cancer incidence data from 2004 to 2013 collected from population-based cancer registries in these 2 cities were provided by Vietnam National Cancer Institute. Incidence cases in 2013 and the previous decades average annual percent changes of age-standardized cancer incidence rates combined with expected population growth were modeled to project cancer incidence for each cancer site by gender to 2025. A substantial double in cancer incidence from 2013 to 2025 resulted from a growing and aging population in HCMC and Hanoi. Lung, colorectum, breast, thyroid, and liver cancers, which represent 67% of the overall cancer burden, are projected to become the leading cancer diagnoses by 2025 regardless of genders. For men, the leading cancer sites in 2025 are predicted to be lung, colorectum, esophagus, liver, and pharynx cancer, and among women, they are expected to be breast, thyroid, colorectum, lung, and cervical cancer. We projected an epidemiological transition from infectious-associated cancers to a high burden of cancers that have mainly been attributed to lifestyle in both cities. We predicted that with 16.9% growth in the overall population and dramatic aging with these 2 urban centers, the burdens of cancer incidence will increase sharply in both cities over the next decades. Data on projections of cancer incidence in both cities provide useful insights for directing appropriate policies and cancer control programs in Vietnam.

Epidemiological Characteristics of Advanced Hepatocellular Carcinoma in the Northern Region of Vietnam

Epidemiological characteristics of hepatocellular carcinoma (HCC) in Southern Vietnam has been well reported as in Globocan 2018 while data from the North has still not been fully presented. Therefore, we conducted this retrospective descriptive study on 198 advanced HCC patients treated at 3 major hospitals in Northern Vietnam to describe demographic features, HCC risk factors, and correlation among them in patients with advanced HCC. This information will lead to prevention efforts and provide information for allocating funds for treatment. The median age at diagnosis was 57 years (range: 19-86) and the male/female ratio was 8.9/1. The proportions of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection were 81.3% and 5.6%, respectively. Hepatitis C virus infection rate was significantly higher in patients <50 years old (12.5% vs 3.3%, P = .016). There was no significant difference in age or viral hepatitis infection status by gender. Only 7.6% of patients diagnosed with advanced HCC were asymptomatic. In conclusion, with the high rate of HBV infection among patients with advanced HCC, it is necessary for increasing prevention efforts in HBV screening. Furthermore, HCV infection should be noticed in patients with advanced HCC younger than 50 years old.