Correlation between maternal hepatitis B surface antigen carrier status with social, medical and family factors in an endemic area: have we overlooked something?

Effect of hepatitis B vaccination on HBV-infection among school children in Yaounde; ten years after the introduction of HBV vaccine into routine Immunization Program in Cameroon

Introduction

since the introduction of the anti-HBV vaccine into the Expanded Program on Immunization (EPI) in 2005 in Cameroon, vaccination coverage has reached 99.0%. This coverage would indicate an increase in the number of children immune to Hepatitis B Virus (HBV) and a decrease in susceptibility to HBV-infection. This study was conducted to evaluate the effect of the HBV vaccine on pediatric HBV-infection in Yaounde, Cameroon.

Methods

this school-based cross-sectional study was conducted from February to May 2016 among 180 children from Nkomo public school. The study population was stratified into two groups: vaccinated (n=95) versus (vs) unvaccinated (n=85). Screening for HBV biomarkers was done using a rapid panel test for detection (HBsAg, HBeAg and anti-HBc) and anti-HBs titer using enzyme linked immunosorbent assay (ELISA). Statistical analyses were done using SPSS v. 22 with p < 0.05 considered significant.

Results

the mean age was 9.65 years. HBsAg (p=0.019) and anti-HBc (p=0.001) rates were detected in children aged ≥10 years and children aged < 10 years (95.95% [71/74]) were vaccinated vs 22.64% (24/106) for those aged ≥10 years (OR: 80.86; 95% CI: 23.36%-279.87%, p < 0.0001). According to anti-HBV vaccination status, HBsAg rate varied from [9.41% (8/85) to 1.05% (1/95), p=0.025], HBeAg rate varied from [2.35% (2/85) to 0% (0/95), p= 0.42] and anti-HBc rate ranged from [12.94% (11/85) to 2.10% (2/95), p= 0.011].

Conclusion

despite the variability of the anti-HBs titer, vaccination against HBV has a positive effect on the reduction of HBV-infection in children in tropical settings such as Cameroon.

Conventional and genetic risk factors for chronic Hepatitis B virus infection in a community-based study of 0.5 million Chinese adults

Despite universal vaccination of newborns, the prevalence of chronic hepatitis virus B (HBV) infection and the associated disease burden remain high among adults in China. We investigated risk factors for chronic HBV infection in a community-based study of 512,726 individuals aged 30-79 years recruited from ten diverse areas during 2004-2008. Multivariable logistic regression was used to estimate odds ratios (ORs) of hepatitis B surface antigen (HBsAg) positivity recorded at baseline by sociodemographic and lifestyle factors, and medical history. In a random subset (n = 69,898) we further assessed the association of 18 single nucleotide polymorphisms (SNPs) previously shown to be associated with HBsAg positivity and development of chronic liver disease (CLD) (1600 cases). Several factors showed strong associations with HBsAg positivity, particularly younger age (< 40 vs. ≥ 60 years: OR 1.48, 95% CI 1.32-1.66), male sex (1.40, 1.34-1.46) and urban residency (1.55, 1.47-1.62). Of the 18 SNPs selected, 17 were associated with HBsAg positivity, and 14 with CLD, with SNPs near HLA-DPB1 were most strongly associated with both outcomes. In Chinese adults a range of genetic and non-genetic factors were associated with chronic HBV infection and CLD, which can inform targeted screening to help prevent disease progression.

Immune persistence after hepatitis B vaccination in infancy - Fact or fancy?

The hepatitis B vaccine has been introduced for more than 3 decades. In Hong Kong, excellent vaccine coverage through an efficient public health care system, together with supplemental programmes and easy availability of the vaccine, meant that most young pregnant women, and university students at entrance, should have been protected. Yet significant correlations in the prevalence of HBV infection with age were found in these groups of subjects, increasing from low to high endemicity rates from late teenage to the early twenties. This can only be attributed to vaccine failure, and there is cumulating evidence that several factors are involved, including the failure to respond to a primary series of hepatitis B vaccination in infancy, the waning of antibody titer with age, and loss of anamnestic response in a significant portion of the vaccinees. The duration of protection conferred by hepatitis B vaccination in infancy should be re-examined and remedial measures undertaken if its long term protection is found to be insufficient. Otherwise, the efforts to control HBV infection, especially in high endemicity regions, with universal vaccination in infancy would be rendered futile.

Occult hepatitis B virus infection among people with a family history of chronic hepatitis B virus infection

The prevalence of occult hepatitis B virus infection (OBI) among people with a family history of chronic hepatitis B virus (HBV) infection is unclear. Serum samples were collected from 747 hepatitis B surface antigen (HBsAg)-negative people with a family history of HBV infection and 579 HBsAg-negative volunteer blood donors. The presence of HBV DNA was evaluated using nested PCR with primers specific for the X, S, and C regions of HBV. The Pre-S1/Pre-S2/ S region PCR products for the OBI group and their family members with chronic HBV infection (control group) were sequenced and compared. The prevalence of OBI was 8.0% (60/747) among HBsAg-negative people with a family history of chronic HBV infection, compared to 2.6% (15/579) among the blood donors (P < 0.05). The prevalence of HBV genotype B infection was lower in the OBI group than in the control group (P = 0.031). The substitution rates in the major hydrophilic region and the "a" determinant seemed to be higher in the OBI group (0.893 vs. 0.507; 1.042 vs. 0.403, respectively), and stop codon mutations more frequent in the OBI sequences (OBI: 2/26, 7.7% vs.

CONTROL

0/31, 0%). However, none of these differences was statistically significant (P = 0.237, 0.199, 0.201, respectively). In summary, the prevalence of OBI among HBsAg-negative people with a family history of chronic HBV infection was significantly higher than that in Chinese blood donors. However, S region mutations and the escape mechanism are not likely to be the major causes of increased prevalence of OBI.

Hepatitis B and pregnancy: An update review article

Chronic hepatitis B, as a global health problem, is a disease that begins in the prenatal period and its complications gradually become clear later in life. About 5% of women worldwide are carriers of chronic hepatitis B virus (HBV). The most common method of transmission of HBV around the world is from mother to infant. This article aims to review the unique challenges of hepatitis B in pregnancy. Data for this review were collected from our previous studies and experiences plus various data banks, such as PubMed, EMBASE, ISI Web of science, Scopus, Google Scholar and Iranian databases. A comprehensive search was performed using the combinations of the keywords to review relevant literature and higher education journals. All published data up to February 2014 have been included in this review. This article addresses several interesting aspects. First, hepatitis B in pregnancy can vary regarding prevalence, virus behavior, prenatal transmission and outcome of the pregnancy. Second, the women of reproductive age with chronic HBV remain a major source for continued spread of the virus. Finally, pregnant women need screening in prenatal care to enable early intervention when necessary.

Age-specific prevalence of hepatitis B virus infection in young pregnant women, Hong Kong Special Administrative Region of China

Objective

To investigate the age-specific prevalence of hepatitis B virus (HBV) infection in young pregnant women in Hong Kong Special Administrative Region (SAR), China, and to determine whether an increase in prevalence occurs during adolescence.

Methods

HBV prevalence was quantified using data from routine antenatal screening for hepatitis B surface antigen (HBsAg) in 10 808 women aged 25 years or younger born in Hong Kong SAR and managed at a single hospital between 1998 and 2011. The effect on prevalence of maternal age, parity and birth before or after HBV vaccine availability in 1984 was assessed, using Spearman’s correlation and multiple logistic regression analysis.

Findings

Overall, 7.5% of women were HBsAg-positive. The prevalence ranged from 2.3% to 8.4% in those aged ≤ 16 and 23 years, respectively. Women born in or after 1984 and those younger than 18 years of age were less likely to be HBsAg-positive (odds ratio, OR: 0.679; 95% confidence interval, CI: 0.578–0.797) and (OR: 0.311; 95% CI: 0.160–0.604), respectively. For women born before 1984, there was no association between HBsAg carriage and being younger than 18 years of age (OR: 0.60; 95% CI: 0.262–1.370) Logistic regression analysis showed that the prevalence of HBsAg carriage was influenced more by the woman being 18 years old or older (adjusted OR, aOR: 2.80; 95% CI: 1.46–5.47) than being born before 1984 (aOR: 1.42; 95% CI: 1.21–1.67).

Conclusion

Immunity to HBV in young pregnant women who had been vaccinated as neonates decreased in late adolescence.

Impact of neonatal hepatitis B vaccination programme on age-specific prevalence of hepatitis B infection in teenage mothers in Hong Kong

We examined the impact of the neonatal hepatitis B immunization programme, first provided to all neonates born to mothers screened positive for hepatitis B surface antigen (HBsAg) in late 1983, on the age-specific prevalence of HBsAg carriage in teenage mothers managed in 1998–2008. HBsAg carriage was found in 2.5%, 2.7%, 8.8% and 8.0% of mothers aged ≤ 16, 17, 18, and 19 years, respectively (P=0.004), which was also correlated with advancing age (P=0.011). While neither difference nor correlation with age was found in mothers born before 1984, the prevalence of 1.2%, 1.5%, 7.1% and 8.3%, respectively, was significantly different among (P=0.008) and correlated with (P=0.002) age in mothers born 1984 onwards. Regression analysis indicated there was a significantly higher incidence of HBsAg carriage from age 17 onwards (adjusted odds ratio 2.55, 95% confidence interval 1.07–6.10, P=0.035), suggesting that the protective effect of the vaccine declined in late adolescence.

Deficient knowledge on hepatitis B infection in pregnant women and prevalence of hepatitis B surface antigen carriage in an endemic area: a review

Hepatitis B infection is a major global health problem. Vertical transmission is the commonest route of spreading hepatitis B virus (HBV) in many endemic areas. In order to control such transmission in Hong Kong, neonatal immunization programme was implemented for more than two decades. A declining prevalence of HBV infection was expected. However, the prevalence remained unabated at around 10% in recent studies. We suspect that one of the explanations of this persistent high prevalence is deficient knowledge on infection with the HBV and its prevention. Our paper gives an overview of the knowledge on HBV infection among Chinese population in both high and low endemic areas and discusses the potential factors that influenced the knowledge on as well as the implication of the sources of information for HBV infection, which was not addressed in previous studies.