Immunoprophylaxis of infection with hepatitis B virus in infants born to hepatitis B surface antigen-positive carrier mothers

Navigating Perinatal Challenges: A Comprehensive Review of Hepatitis B Viral Infection and Pregnancy Outcomes

Hepatitis B viral infection poses a significant challenge during pregnancy, as the risk of vertical transmission carries serious consequences for both maternal and neonatal well-being. This comprehensive review delves into the intricacies surrounding hepatitis B infection during the perinatal period, shedding light on its impact on pregnancy outcomes and stressing the necessity of addressing it within the broader framework of perinatal care. By scrutinizing current evidence, diagnostic methodologies, management techniques, and preventive measures, this review emphasizes the urgent need for enhanced screening protocols, timely interventions, and augmented public health initiatives. Notably, key findings underscore the elevated likelihood of chronic hepatitis B virus (HBV) infection in infants and its enduring implications for the health of both mothers and newborns. The imperative call to action advocates for a multifaceted approach, engaging healthcare professionals, policymakers, and public health agencies to optimize strategies for management and prevention, thereby striving for improved outcomes for pregnant women and their infants affected by hepatitis B viral infection.

Milk Transmission of HTLV-1 and the Need for Innovative Prevention Strategies

Breastfeeding is recommended by the World Health Organization for at least 6 months up to 2 years of age, and breast milk protects against several diseases and infections. Intriguingly, few viruses are transmitted via breastfeeding including Human T-cell leukemia virus Type 1 (HTLV-1). HTLV-1 is a highly oncogenic yet neglected retrovirus, which primarily infects CD4+ T-cells in vivo and causes incurable diseases like HTLV-1-associated inflammatory conditions or Adult T-cell leukemia/lymphoma (ATLL) after lifelong viral persistence. Worldwide, at least 5–10 million people are HTLV-1-infected and most of them are unaware of their infection posing the risk of silent transmissions. HTLV-1 is transmitted via cell-containing body fluids such as blood products, semen, and breast milk, which constitutes the major route of mother-to-child transmission (MTCT). Risk of transmission increases with the duration of breastfeeding, however, abstinence from breastfeeding as it is recommended in some endemic countries is not an option in resource-limited settings or underrepresented areas and populations. Despite significant progress in understanding details of HTLV-1 cell-to-cell transmission, it is still not fully understood, which cells in which organs get infected via the oral route, how these cells get infected, how breast milk affects this route of infection and how to inhibit oral transmission despite breastfeeding, which is an urgent need especially in underrepresented areas of the world. Here, we review these questions and provide an outlook how future research could help to uncover prevention strategies that might ultimately allow infants to benefit from breastfeeding while reducing the risk of HTLV-1 transmission.

Risks of Infectious Diseases in Newborns Exposed to Alternative Perinatal Practices

The purpose of this report is to educate providers about the risk of infectious diseases associated with emerging alternative peripartum and neonatal practices. This report will provide information pediatricians may use to counsel families before birth and to appropriately evaluate and treat neonates who have been exposed to these practices.

Optimal Voluntary Vaccination of Adults and Adolescents Can Help Eradicate Hepatitis B in China

Hepatitis B (HBV) is one of the most common infectious diseases, with a worldwide annual incidence of over 250 million people. About one-third of the cases are in China. While China made significant efforts to implement a nationwide HBV vaccination program for newborns, a significant number of susceptible adults and teens remain. In this paper, we analyze a game-theoretical model of HBV dynamics that incorporates government-provided vaccination at birth coupled with voluntary vaccinations of susceptible adults and teens. We show that the optimal voluntary vaccination brings the disease incidence to very low levels. This result is robust and, in particular, due to a high HBV treatment cost, essentially independent from the vaccine cost.

Timely Birth Dose Vaccine to Prevent Vertical Transmission of Hepatitis B: A Single Center Experience on the Road to the WHO Elimination Goals in Italy

Italy was one of the first industrialized countries to implement a program of routine vaccination against hepatitis B virus (HBV) infection. However, currently, no HBV vaccine is administered at birth if the screened mother is HBsAg negative, whilst babies born to HBsAg positive mothers are given vaccine and hepatitis B immunoglobulin, within 12–24 post-delivery hours. A single center retrospective analysis of policies and practices to prevent mother-to-child transmission of HBV was carried out, to evaluate their adherence to HBV care guidelines. Paired maternal-infant medical records for consecutive live births, between January 2015 and December 2019, were reviewed at the AOU Città della Salute e Scienza di Torino, where a total of 235/35,506 babies (0.7%) were born to HBsAg positive mothers. Markers of active viral replication, i.e., HBV DNA level and/or HBeAg, were reported in only 66/235 (28%) of the mothers’ medical records. All newborns had immunoprophylaxis at birth: 61% at <12 h, 31% between 12 and 24 h, 7% between 24 and 36 h and 1% at >36 h. In 2019, two cases of vertical HBV transmission occurred, despite timely immunoprophylaxis, as their mothers’ viral load was detected too late for antiviral prophylaxis. Missed early identification of pregnant women with high viremia levels or late vaccinations may contribute to perinatal HBV infection. Immunoprophylaxis should be given to babies born to HBsAg positive mothers at the latest within 12 h. In Italy, policies aimed at achieving the WHO 2030 goal of eliminating viral hepatitis should be further implemented.

Perinatal hepatitis B virus transmission in Lao PDR: A prospective cohort study

Background

Mother-to-child transmission of hepatitis B virus (HBV) is the main cause of new infections worldwide. We aimed at assessing the percentage of infants successfully immunized in two major hospitals in Vientiane, Lao PDR where HB immune globulin (HBIg) is not available.

Methods

We studied a prospective cohort of chronically HBV infected pregnant women and their infants until 6 months post-partum from January 2015 to March 2017. All infants received HB vaccine at birth and 6, 10 and 14 weeks thereafter, and HBV status was assessed at 6 months of age. HBV surface gene sequencing was performed in infected mother-infant pairs.

Results

Of 153 mothers with HB surface antigen (HBsAg), 60 (39%) had detectable serum HBe antigen (HBeAg). HBeAg positive pregnant women were younger than those negative (median age 26 versus 28 years; p = 0.02) and had a significantly higher HBV viral load at delivery (median 8.0 versus 4.0 log₁₀ IU/mL, p <0.001). Among the 120 infants assessed at 6 months of age, 5 (4%) were positive for HBsAg and had detectable HBV viral load by polymerase chain reaction. All were born to mothers with HBeAg and viral load >8.5 log₁₀ IU/mL. However, only four (3.3%, 95% CI 0.5% to 7.0%) had a virus strain closely related to their mother’s strain. HBV surface gene mutations were detected in 4 of the 5 infected infants. Anti-HBs antibody levels were below 10 IU/L in 10 (9%) uninfected infants at 6 months of age.

Conclusions

Mother-to-child transmission occurred less frequently than expected without the use of HBIg. Adding HBIg and/or maternal antiviral prophylaxis may have prevented some of these infections. The observation of unsatisfactory levels of anti-HBs antibodies in 9% of the uninfected infants at 6 months highlights the need for improvement of the universal immunization procedures.

Revaccination against hepatitis B in late teenagers who received vaccination during infancy: Yes or no?

The significance of vaccination against hepatitis B during infancy is recognized worldwide, however, whether booster or revaccination after a period of time following the primary vaccination is required remains controversial. Recently, cross-sectional epidemiological surveys found that HBsAg prevalence in subjects born after the implementation of mass vaccination was increased with age, which was attributed to waning of anti-HBs over time. However, comprehensive analysis of the closely related cross-sectional surveys showed that the age-specific increased HBsAg prevalence was more likely associated with the carry-over of the infection occurred in early life, likely due to imperfect coverage of hepatitis B vaccination at the beginning of its introduction. Latest studies showed that booster response could be observed in the majority of individuals vaccinated 30 years ago. Moreover, confirmed breakthrough HBV infection with severe consequences in successfully vaccinated individuals is extremely rare. Thus far no compelling evidence has been acquired to support booster vaccination in adolescence. The uncertainty regarding the duration of protection of hepatitis B vaccination, especially beyond 30 years after the primary vaccination, merits a systematically designed study to follow the same cohort of participants longitudinally, which differs from the cross-sectional studies reported previously, can hopefully offer more direct evidence to help us to determine whether revaccination of hepatitis B vaccine is necessary.

Management of Pregnant Women and Children: Focusing on Preventing Mother-to-Infant Transmission

Hepatitis B virus (HBV) immunization has been effectively preventing chronic HBV infection with >90% efficacy in countries with universal neonatal immunization. Perinatal mother-to-infant transmission of HBV remains the major cause of chronic HBV infection despite immunization. Maternal hepatitis B e-antigen (HBeAg) and high viral load have been noted to be the most important risk factors for transmission. In recent years, short-term antiviral therapy for pregnant women in the third trimester has been shown to be highly effective in reducing 90% of vaccine failure in children. It is important to monitor maternal aminotransferase elevations postpartum. Long-term outcome of mothers and children is needed and awaits further investigations. Despite the above-mentioned preventive measures, it is also important to monitor high-risk children at 1 year of age with hepatitis B surface antigen and anti-hepatitis B to identify those with chronic HBV infection. Most of the children with chronic HBV infection were in the immune-tolerant phase. The goals for antiviral treatment in children are to reduce severity of liver injury, achieve HBeAg seroconversion, and prevent development of liver fibrosis and cancer. Studies on antiviral therapy are undergoing to elucidate the optimal indication and drug treatment for children. The ideal future goal of treatment is to eradicate chronic HBV infection globally.

A review of strategies to prevent mother-to-infant transmission of hepatitis B virus infection

Hepatitis B virus (HBV) infection causes long-term, life-threatening liver diseases worldwide. HBV is transmitted through either the horizontal or mother-to-infant route, which is the major route of transmission in endemic areas. Administration of hepatitis B immunoglobulin and hepatitis B vaccine to newborns of infected mothers prevents mother-to-infant transmission. Implementation of a universal hepatitis B vaccination program has proven successful in eliminating the infection and related complications. Nevertheless, efforts are still needed to improve global coverage of the hepatitis B vaccine. Infants born to highly viremic mothers are still at risk of infection despite current immunoprophylaxis. An increasing number of reports have shown promising efficacy and safety profiles with the use of nucleoside/nucleotide analogues in highly viremic pregnant women to prevent mother-to-infant transmission.

Mobilising a global response to hepatitis: Lessons learned from the HIV movement

Hepatitis caused by hepatitis B and C virus is increasingly becoming a significant global health threat, with widespread prevalence that may have severe disease and economic impacts in the future. Yet, preventative measures are not implemented universally and high costs of medicines limits treatment efforts. The global response to HIV/AIDS faced similar issues, but overcame them through a global movement that brought attention to the crisis and ultimately resulted in the creation and implementation of and access to better tools for HIV prevention and treatment. This also included effective policies and programmes behind and supporting the movement. Such could be done for hepatitis, specifically using lessons from the HIV response. Here, we will discuss the current and potentially severe future burden of hepatitis globally, the challenges in addressing this epidemic, and how principles applied from the global HIV response can facilitate a successful and similar hepatitis movement.

Management of mother-to-child transmission of hepatitis B virus: Propositions and challenges

Chronic hepatitis B virus (HBV) infection due to mother-to-child transmission (MTCT) during perinatal period remains an important global health problem. Despite standard passive-active immunoprophylaxis with hepatitis B immunoglobulin (HBIG) and hepatitis B vaccine in neonates, up to 9% of newborns still acquire HBV infection, especially these from hepatitis B e antigen (HBeAg) positive mothers. Management of HBV infection in pregnancy still need to draw careful attention because of some controversial aspects, including the failure of passive-active immunoprophylaxis in a fraction of newborns, the effect and necessity of periodical hepatitis B immunoglobulin (HBIG) injection to the mothers, the safety of antiviral prophylaxis with nucleoside/nucleotide analogs, the benefit of different delivery ways, and the safety of breastfeeding. In this review, we highlight these unsettled issues of preventive strategies in perinatal period, and we further aim to provide an optimal approach to the management of preventing MTCT of HBV infection.

Is mother-to-infant transmission the most important factor for persistent HBV infection?

Of the infants born to hepatitis B surface antigen (HBsAg)-positive mothers globally, 42.1% who did not receive hepatitis B virus (HBV) passive-active immunoprophylaxis and 2.9% of infants who received the immunoprophylaxis acquired HBV infection perinatally. Moreover, perinatal infection occurred in 84.2% (18.8%-100%) and 8.7% (0.0-21.0%) of infants born to hepatitis B e-antigen (HBeAg)-positive mothers who did not and did receive immunoprophylaxis, respectively; by contrast, the infection rates were 6.7% (0.0-15.4%) and 0.4% (0.0-2.5%) for infants born to HBeAg-negative-carrier mothers, respectively. The chronicity rates of HBV infection acquired perinatally were 28.2% (17.4%-33.9%) in infants born to HBeAg-negative mothers and 64.5% (53.5%-100%) in infants born to HBeAg-positive mothers. HBV mother-to-child transmission was more frequent in East Asia relative to other areas. In addition to differences in the endemic HBV genotype, the interchange of allelic dominance in genetic polymorphisms in HLA class II and NF-κB between the Chinese and European populations may explain why chronic HBV infection frequently affects the Chinese. The risk of progressing into chronic infection was inversely related to the age of children at the time of horizontal transmission. To further diminish HBV chronic infection, it is necessary to enforce antiviral treatment after the 28th week of gestation for HBeAg-positive mothers and to improve the health habits of carrier mothers and household sanitary conditions.

Immunization interventions to interrupt hepatitis B virus mother-to-child transmission: a meta-analysis of randomized controlled trials

BACKGROUND

This study aimed to determine the clinical efficacy of various immune interventions on mother-to-child transmission (MTCT) of hepatitis B virus (HBV).

METHODS

We retrieved different immune strategies on how to prevent MTCT reported in the literature from Chinese and English electronic databases from the viewpoint of intrauterine and extrauterine prevention. Relative risk (RR) and 95% confidence interval (CI) methods were used.

RESULTS

Twenty-five articles on intrauterine prevention and 16 on extrauterine prevention were included in the analysis. Intrauterine prevention could reduce infants' HBV infection rate (RR = 0.36, 95% CI: 0.28-0.45) and increase their anti-hepatitis B surface-positive rate (RR = 2.42, 95% CI: 1.46-4.01) at birth. Compared with passive immunization, passive-active immunization could reduce infants' HBV infection rate (RR = 0.66, 95% CI: 0.52-0.84) at birth, even at more than 12 months of age (RR = 0.54, 95% CI: 0.42-0.69). Subgroup analysis demonstrated similar results except for pregnant women who were hepatitis B surface antigen-positive. Funnel plots and Egger's tests showed publication bias mainly in intrauterine prevention not in extrauterine one.

CONCLUSIONS

The long-term protective effect of pregnant women injected with hepatitis B immunoglobulin during pregnancy should be further validated by large-scale randomized trials. Newborns of pregnant women who carried HBV should undergo a passive-active immunization strategy.

Prevention of materno-foetal transmission of hepatitis B in sub-Saharan Africa: the evidence, current practice and future challenges

Hepatitis B (HBV) infection is highly endemic in sub-Saharan Africa (SSA), where more than 8% of the population remain chronic HBV carriers. SSA has one of the highest HBV-related liver cancer rates in the world (CA Cancer J Clin, 55, 2005, 74) and HBV-related liver cancer is the most common cause of premature death in West Africa (Lancet Oncol, 9, 2008, 683; Hepatology, 39, 2004, 211). As such, HBV represents a significant global threat to health in the African continent. Most SSA countries have elected to vaccinate all children against HBV through the WHO-sponsored Expanded Program of Immunization and the current recommendation from WHO-AFRO is for birth-dose HBV vaccination to prevent maternal/child transmission (MFT) and early horizontal transmission of HBV. However, in Africa, HBV vaccine coverage remains low and HBV birth-dose vaccination has not been implemented. HBV transmission from mother to child in the early perinatal period therefore remains a significant contributor to the burden of HBV-related disease in SSA. This review explores the evidence for materno-foetal transmission of HBV in SSA, outlining current practice for HBV MFT prevention and identifying the significant challenges to implementation of HBV prevention in SSA.

Prevention of mother to child transmission of hepatitis B infection

The likelihood of developing chronic hepatitis B infection and its complications is most when infection is transmitted vertically. Awareness of the current recommendations for managing babies of mothers who are hepatitis B carriers is not universal, resulting in failure of follow up, despite the serious long term implications, including development of hepatic carcinoma. We review the current guidelines of managing babies born to mothers who are hepatitis B carriers.

Hepatitis B vaccination with or without hepatitis B immunoglobulin at birth to babies born of HBsAg-positive mothers prevents overt HBV transmission but may not prevent occult HBV infection in babies: a randomized controlled trial

Vertical transmission of Hepatitis B virus HBV can result in a state of chronic HBV infection and its complications. HBV vaccination with or without hepatitis B immunoglobulin (HBIG) prevents transmission of overt infection to the babies. However, whether it also prevents occult HBV infection in babies is not known. Consecutive pregnant women of any gestation found to be HBsAg positive were followed till delivery, and their babies were included in the study. Immediately after delivery, babies were randomized to receive either HBIG or placebo in addition to recombinant HBV vaccine (at 0, 6, 10 and 14 weeks). The primary end-point of the study, assessed at 18 weeks of age, was remaining free of any HBV infection (either overt or occult) plus the development of adequate immune response to vaccine. The babies were further followed up for a median of 2 years of age to determine their eventual outcome. Risk factors for HBV transmission and for poor immune response in babies were studied. Of the 283 eligible babies, 259 were included in the trial and randomized to receive either HBIG (n=128) or placebo (n=131) in addition to recombinant HBV vaccine. Of the 222 of 259 (86%) babies who completed 18 weeks of follow-up, only 62/222 (28%) reached primary end-point. Of the remaining, 6/222 (3%) developed overt HBV infection, 142/222 (64%) developed occult HBV infection, and 12/222 (5%) had no HBV infection but had poor immune response. All 6 overt infections occurred in the placebo group (P=0.030), while occult HBV infections were more common in the HBIG group (76/106 [72%] vs. 66/116 [57%]; P=0.025). This may be due to the immune pressure of HBIG. There was no significant difference between the two groups in frequency of babies developing poor immune response or those achieving primary end-point. The final outcome of these babies at 24 months of age was as follows: overt HBV infection 4%, occult HBV infection 42%, no HBV infection but poor immune response 8% and no HBV infection with good immune response 28%. Women who were anti-HBe positive were a low-risk group, and their babies were most likely to remain free of HBV infection (occult or overt) and had good immune response to the vaccine. Maternal HBeAg-positive status and negativity for anti-HBe predicted not only overt but also any infection (both overt and occult) in babies. In addition, high maternal HBV DNA and treatment with vaccine alone were significant factors for overt HBV infection in babies. The current practice of administration of vaccine with HBIG at birth to babies born of HBsAg-positive mothers is not effective in preventing occult HBV infection in babies, which may be up to 40%. Because the most important risk factors for mother-to-baby transmission of HBV infection are the replicative status and high HBV DNA level in mothers; it will be worthwhile investigating the role of antivirals and HBIG administration during pregnancy to prevent mother-to-child transmission of HBV infection.

Chronic hepatitis B infection in adolescents who received primary infantile vaccination

Hepatitis B virus (HBV) infection is a global health issue. Universal infantile hepatitis B (HB) vaccination is very efficacious. However, HBV infections among those immunized subjects have been reported. The long-term efficacy of postnatal passive-active HB vaccination in high-risk subjects is not well explored. A total of 8,733 senior high school students who were born after July 1987 were assayed for hepatitis B surface antigen (HBsAg) and antibodies to HBsAg (anti-HBs). The overall HBsAg and anti-HBs-positive rates were 1.9% and 48.3%, respectively. The HBsAg-positive rate was 15% in HB immunoglobulin (HBIG) recipients (adjusted odds ratio [OR]: 15.63; 95% confidence interval [CI]: 10.99-22.22). Among students who did not receive HBIG, there was a significantly negative association between HB vaccination dosage and HBsAg-positive rate (P for trend = 0.011). Adjusted ORs for those who received 4, 3, and 1 to 2 doses were 1.00, 1.52 (95% CI: 0.91-2.53), and 2.85 (95% CI: 1.39-5.81), respectively. Among HBIG recipients, the HBsAg-positive rate was significantly higher in subjects with maternal hepatitis B e antigen (HBeAg) positivity and who received HBIG off-schedule. A booster dose of HB vaccination was administered to 1974 HBsAg- and anti-HBs-negative subjects. Prebooster and a postbooster blood samples were drawn for anti-HBs quantification. The proportions of postbooster anti-HBs titer <10 mIU/mL was 27.9%. Subjects with prebooster anti-HBs titers of 1.0-9.9 mIU/mL had significantly higher postbooster anti-HBs titers than those with prebooster anti-HBs titers of <1.0 mIU/mL (P < 0.0001).

CONCLUSION

Having maternal HBeAg positivity is the most important determinant for HBsAg positivity in adolescents who received postnatal passive-active HB vaccination 15 years before. A significant proportion of complete vaccinees may have lost their immunological memories against HBsAg.

HBV perinatal transmission

Hepatitis B is a serious public health problem all around the world. It is a blood-borne and sexually transmitted DNA virus in adults, but mother to child transmission of hepatitis B virus also occurs in infants born to hepatitis B surface antigen positive mothers.

Vaccines for prevention of mother-to-child transmission of HIV

PURPOSE OF REVIEW

This review outlines data available on HIV immunization for the interruption of mother-to-child transmission of HIV. There is a critical need for low cost, safe, and universally accessible methods to interrupt mother-to-child transmission of HIV in utero, intrapartum and though breastfeeding including when the mother acquires HIV infection while breastfeeding her child. Active immunization is the only strategy with this potential.

RECENT FINDINGS

There are recent findings in three major areas: studies in neonatal macaques, demonstrating encouraging results in terms of providing partial protection from repeat oral SIV and SHIV challenge with active or passive immunization but limited immunologic correlates of protection; safety and immunogenicity of three different canarypox HIV vaccine constructs with and without gp120 envelope subunit boost in infants and studies evaluating the importance of neutralizing antibody in mother-to-child transmission of HIV.

SUMMARY

To protect infants born to HIV-infected women completely an effective prophylactic vaccine is critical. Candidate vaccines tested in this population to date demonstrate safety, tolerability and immunogenicity. Based on the ongoing risk of infection and the tremendous potential for benefit, further studies of candidate vaccines should proceed in this population.

Emerging hepatitis B virus infection in vaccinated populations: a rising concern?

Hepatitis B infection, especially by perinatal transmission, is endemic in Asian countries. After the first successful universal hepatitis B virus (HBV) vaccination programme for newborns in Taiwan, it became feasible to prevent HBV transmission and the resultant hepatocellular carcinoma in endemic countries. However, a small subset of vaccinated people have a suboptimal immunological response to vaccination, and the immunity of some young adults who were vaccinated as infants seems to have waned over time. Despite this loss, recent studies suggest that anamnestic anti-HBs antibody responses rapidly resume and eliminate acute HBV infection acquired through sexual contact or blood transfusion, even though the anti-HBs antibody titre has decreased below a protective level. These observations indicate prolonged protection by the HBV vaccine. Therefore, for people with a low infection risk, a universal booster vaccination is not currently recommended, but it should be considered for high-risk groups. However, we still advocate close monitoring of acute hepatitis B among patients who lack a protective level of anti-HBs antibody and suggest a wait-and-see policy to determine the necessity for booster vaccines.

Cost-Effectiveness Analysis of Hepatitis B Immunization in Vietnam: Application of Cost-Effectiveness Affordability Curves in Health Care Decision Making

OBJECTIVES

To perform a cost-effectiveness analysis and to identify the cost-effectiveness affordability levels for a newborn universal vaccination program against hepatitis B virus (HBV) in Vietnam.

METHODS

By using a Markov model, we simulated a Vietnamese birth cohort using 1,639,000 newborns in 2002 and estimated the incremental cost-effectiveness ratios for quality-adjusted life-year gained following universal newborn HBV vaccination. Two types of analyses were performed, including and excluding expenditures on the treatment of chronic hepatitis B and its complications. We used Monte Carlo simulations to examine cost-effectiveness acceptability and affordability from the payer's perspective and constructed a cost-effectiveness affordability curve to assess the costs and health effects of the program.

RESULTS

In the base-case analysis, newborn universal HBV vaccination reduced the carrier rate by 58% at a cost of US $42 per carrier averted. From the payer's perspective, incremental cost-effectiveness ratio per quality-adjusted life-year gained was US $3.77, much lower than the 2002 per-capita gross domestic product of US $440. Vaccination could potentially be affordable starting at a US $2.1 million budget. At the cost-effectiveness threshold of US $3.77 per quality-adjusted life-year and an annual budget of US $5.9 million, the probability that vaccination will be both cost-effective and affordable was 21%.

CONCLUSIONS

Universal newborn HBV vaccination is highly cost-effective in Vietnam. In low-income, high-endemic countries, where funds are limited and the economic results are uncertain, our findings on the cost-effectiveness affordability options may assist decision makers in proper health investments.

Effects of maternal screening and universal immunization to prevent mother-to-infant transmission of HBV

BACKGROUND & AIMS

Mother-to-infant transmission is the major cause of hepatitis B virus (HBV) infection among immunized children. There has been much debate about screening pregnant women and administering hepatitis B immunoglobulin (HBIG) to newborns. We analyzed the rate of HBV infection among children born to hepatitis B surface antigen (HBsAg)-positive mothers and whether HBIG administration reduces transmission.

METHODS

We analyzed data from 2356 children born to HBsAg-positive mothers, identified through prenatal maternal screens. In addition to HBV vaccines, HBIG was given to all 583 children with hepatitis B e antigen (HBeAg)-positive mothers and to 723 of 1773 children with HBeAg-negative mothers. Serology tests for HBV were performed from 2007 to 2009, when children were 0.5-10 years old.

RESULTS

A significantly greater percentage of children with HBeAg-positive mothers tested positive for antibodies against the hepatitis B core protein (16.76%) and HBsAg (9.26%) than children with HBeAg-negative mothers (1.58% and 0.29%, respectively; P < .0001 and <.001). Among the HBV-infected children, the rate of chronicity also was higher among children with HBeAg-positive mothers than children with HBeAg-negative mothers (54% vs 17%; P = .002). Similar rates of antibodies against the hepatitis B core protein (0.99% and 1.88%; P = .19) and HBsAg (0.14% and 0.29%; P = .65) were noted in children born to HBeAg-negative mothers who were or were not given HBIG. Infantile fulminant hepatitis developed in 1 of 1050 children who did not receive HBIG (.095%).

CONCLUSIONS

Children born to HBeAg-positive mothers are at greatest risk for chronic HBV infection (9.26%), despite immunization. Administration of HBIG to infants born to HBeAg-negative mothers did not appear to reduce the rate of chronic HBV infection, but might prevent infantile fulminant hepatitis. Screening pregnant women for HBsAg and HBeAg might control mother-to-infant transmission of HBV.

Maternal characteristics and hospital policies as risk factors for nonreceipt of hepatitis B vaccine in the newborn nursery

BACKGROUND

A birth dose of hepatitis B vaccine (HBV) is a primary focus of the Advisory Committee on Immunization Practices' strategy to eliminate transmission of hepatitis B virus in the United States. We sought to assess the impact of maternal characteristics and hospital policy on the receipt of a birth dose of HBV.

METHODS

A retrospective cohort study was performed using data from the 2008 Colorado birth registry. Hospital policy was assessed by state health department personnel. Univariate and multivariate logistic regression analyses were used to examine the association of maternal characteristics and hospital policy with nonreceipt of HBV.

RESULTS

A total of 64,425 infants were identified in the birth cohort, of whom 61.6% received a birth dose of HBV. Higher maternal education and income were associated with nonreceipt of HBV (master's degree vs. eighth grade or less: adjusted odds ratio [OR] = 1.66, 95% confidence interval [CI] = 1.49-1.85; >$75,000 vs. <$15,000: adjusted OR = 1.21, 95% CI = 1.13-1.30). Lack of a hospital policy stipulating a universal birth dose strongly predicted nonreceipt of a birth dose of HBV (policy with no birth dose vs. policy with a birth dose: adjusted OR = 2.21, 95% CI = 2.13-2.30).

CONCLUSIONS

Maternal characteristics such as higher education and income are associated with nonreceipt of the HBV during the perinatal period. To effectively reduce risk of perinatal hepatitis B transmission, hospitals should stipulate that all infants are offered HBV and ensure that these policies are implemented and followed.

Gaps in hospital policies and practices to prevent perinatal transmission of hepatitis B virus

OBJECTIVE

The objective of this study was to examine hospital policies and practices to prevent perinatal transmission of hepatitis B virus (HBV) in the United States and to and identify gaps.

METHODS

In March 2006, a nationally representative sample of 242 delivery hospitals in the 50 states, District of Columbia, and Puerto Rico (with at least 100 annual births) were surveyed about hospital perinatal hepatitis B prevention policies and asked to review paired maternal-infant medical records for 25 consecutive live births. Main outcome measures were hospital policies related to the prevention of perinatal transmission of hepatitis B and the proportion of infants who received recommended care.

RESULTS

A total of 190 of 242 hospitals responded to the survey and completed medical record reviews for 4762 mothers and 4786 infants. The proportion of hospitals that reported each of the 6 policies examined ranged from 63.0% to 80.6%. Among infants who were born to the 18 hepatitis B surface antigen (HBsAg)-positive women with documented prenatal test results, 62.1% received both hepatitis B vaccine and hepatitis B immunoglobulin within 12 hours, but 13.7% were unvaccinated and 19.7% did not receive hepatitis B immunoglobulin before hospital discharge. Among infants who were born to the 320 women with unknown HBsAg status, only 52.4% were vaccinated within 12 hours of birth and 20.1% were unvaccinated before discharge. Among infants who were born to HBsAg-negative mothers, 69.1% received the hepatitis B vaccine before hospital discharge. The strongest predictor of vaccine administration was having a written hospital policy for newborn hepatitis B vaccination.

CONCLUSIONS

These findings indicate that significant gaps persist in hospital policies and practices to prevent perinatal HBV transmission in the United States. Efforts to avoid medical errors through appropriate implementation and monitoring of hospital practices are needed to eliminate perinatal HBV transmission.

Effectiveness of a bivalent Haemophilus influenzae type B-hepatitis B vaccine in preventing hepatitis B virus infection among children born to hepatitis B e antigen-positive carrier mothers

BACKGROUND

This observational study evaluated a modified immunoprophylactic regimen (hepatitis B immune globulin [HBIG]) and a dose of thimerosal-free monovalent hepatitis B (HB) vaccine shortly after birth followed by doses of thimerosal-free bivalent Haemophilus influenzae type b (Hib)-HB vaccine at 2 and 4 months of age, and a booster at 12 months of age) in infants at high risk of hepatitis B virus (HBV) infection (mothers HBeAg+).

METHODS

Children >or=6 months of age vaccinated in routine clinical practice were tested twice (>or=6 months apart) for HBV antigens surface antigen (HBsAg) and "e" antigen, and for antibody to HBsAg. Partial nucleotide sequence analysis was performed on HBV DNA isolated from infants identified with a breakthrough chronic HBV infection. A fully sequential statistical design was used to maximize patient safety and study efficiency.

RESULTS

Four of 60 children developed chronic HBV infection despite vaccination, but at no point did the cumulative number of cases reach the boundary of statistical significance. Overall, the analysis adjusted for sequential testing yielded an estimated breakthrough rate of 6.7% (90% CI: 2.3%-14.6%). In a subset of uninfected children tested for antibody to HBsAg 1 to 4 months after the second dose of Hib-HB vaccine, 90% (9/10) had >or=10 milli-International Units per milliliter (mIU/mL). The third dose of Hib-HB vaccine induced a secondary increase in the level of antibody; 94.7% (18/19) of a second group developed >or=100 mIU/mL, with a geometric mean concentration of 771 mIU/mL (95% CI: 351.4-1692.1 mIU/mL).

CONCLUSION

The tested regimen is comparably effective to historical experience with a standard one employing HBIG plus monovalent thimerosal-containing HB vaccine given at 0, 1, and 6 months of age.

Chronic hepatitis B infection in an Australian antenatal population: seroprevalence and opportunities for better outcomes

BACKGROUND

In the antenatal population, screening for Hepatitis B virus (HBV) carrier status is routinely undertaken to guide preventative measures for the newborn. There is scarce information in the literature, however, regarding the subsequent management of Hepatitis B surface antigen (HBsAg) positive mothers.

AIMS AND METHODS

Thus, we undertook this retrospective study to (i) determine the prevalence of HBsAg positivity among mothers attending two teaching hospital birth centers; (ii) determine whether HBsAg mothers received HBV education and underwent further evaluation of HBV infectivity status; and (iii) determine whether these mothers had further follow up for HBV infection post delivery.

RESULTS

Between January 2003 and December 2006, 14, 857 mothers were screened for hepatitis B virus infection. Among these, 295 mothers were positive with HBsAg seroprevalence of 2%. A more detailed review of the available 206 medical records revealed that the majority (78%) had previous documentation of infection in earlier pregnancies. However none had received education regarding HBV infectivity. In addition, liver function tests were only performed in 78% of the mothers while Hepatitis B e antigen was tested in 65% of cases. Further, 93% of the mothers had no documentation of further follow up plans or referrals for their HBV infection.

CONCLUSION

It is clear that chronic HBV infection is prevalent in the antenatal population. However, there are no strategies to ensure that infected mothers subsequently undergo further education for HBV or evaluation of infectivity. Clearly strategies are required to ensure improved follow up of hepatitis B infected mothers.

A treatment algorithm for the management of chronic hepatitis B virus infection in the United States: 2008 update

Chronic HBV infection is an important public health problem worldwide and in the United States. A treatment algorithm for the management of this disease, published previously by a panel of U.S. hepatologists, has been revised on the basis of new developments in the understanding of the disorder, the availability of more sensitive molecular diagnostic tests, and the licensure of new therapies. In addition, a better understanding of the advantages and disadvantages of new treatments has led to the development of strategies for reducing the rate of resistance associated with oral agents and optimizing treatment outcomes. This updated algorithm was based primarily on available evidence by using a systematic review of the literature. Where data were lacking, the panel relied on clinical experience and consensus expert opinion. The primary aim of antiviral therapy is durable suppression of serum HBV DNA to low or undetectable levels. Assays can now detect serum HBV DNA at levels as low as 10 IU/mL and should be used to establish a baseline level, monitor response to antiviral therapy, and survey for the development of drug resistance. Interferon alfa-2b, lamivudine, adefovir, entecavir, peginterferon alfa-2a, telbivudine, and tenofovir are approved as initial therapy for chronic hepatitis B and have certain advantages and disadvantages. Although all of these agents can be used in selected patients, the preferred first-line treatment choices are entecavir, peginterferon alfa-2a, and tenofovir. Issues for consideration for therapy include efficacy, safety, rate of resistance, method of administration, and cost.

A non-randomized vaccine effectiveness trial of accelerated infant hepatitis B immunization schedules with a first dose at birth or age 6 weeks in Côte d'Ivoire

Most African countries do not initiate hepatitis B vaccination at birth. We conducted a non-randomized controlled trial comparing hepatitis B vaccination given at age 0, 6, and 14 weeks versus the current Côte d'Ivoire schedule of 6, 10, and 14 weeks. Pregnant women were enrolled at four health centers in Abidjan. At age 9 months, 0.5% of infants in both the birth and 6-week cohorts were positive for HBsAg and all were born to HBeAg-positive women. Among infants of HBeAg-positive mothers, 9 of 24 (37.5%) in the birth cohort and 10 of 17 (58.8%) in the 6-week cohort were HBsAg positive (adjusted OR, 2.7; 95% CI: 0.7-11.0). While both vaccine schedules prevented most cases of infant HBV transmission, both also had high failure rates among infants of HBeAg-positive mothers. African infants may benefit from a birth dose but additional studies are needed to verify this hypothesis.

Exploring the native human antibody repertoire to create antiviral therapeutics

Native human antibodies are defined as those that arise naturally as the result of the functioning of an intact human immune system. The utility of native antibodies for the treatment of human viral diseases has been established through experience with hyperimmune human globulins. Native antibodies, as a class, differ in some respects from those obtained by recombinant library methods (phage or transgenic mouse) and possess distinct properties that may make them ideal therapeutics for human viral diseases. Methods for cloning native human antibodies have been beset by technical problems, yet many antibodies specific for viral antigens have been cloned. In the present review, we discuss native human antibodies and ongoing improvements in cloning methods that should facilitate the creation of novel, potent antiviral therapeutics obtained from the native human antibody repertoire.

Seroprevalence of hepatitis B viral markers among freshmen--20 years after mass hepatitis B vaccination program in Taiwan

BACKGROUND/PURPOSE

The nationwide hepatitis B vaccination program in Taiwan was well known for its efficacy in reducing the carrier rate of hepatitis B and the morbidity and mortality of hepatitis B-related diseases among children. The aim of this study was to investigate the seroprevalence of hepatitis B 20 years after this program was implemented.

METHODS

A total of 7592 freshmen from one university in Northern Taiwan participated in this study during their school entry health exam in September 2003 and September 2004. Basic data including gender, birthday, family history and vaccination history of hepatitis B by self-reported questionnaire were collected. Hepatitis B serum markers, including hepatitis B surface antigen, antibody against hepatitis B surface antigen, and antibody against hepatitis B core antigen were all checked. The differences in the seroprevalence of hepatitis B between two groups of subjects born before July 1984 and after July 1984 were examined. Multiple logistic analyses were performed for identifying the odds ratio (OR) of family history and other variables for each hepatitis B serum marker.

RESULTS

Subjects born after July 1984 were found to have a lower rate of hepatitis B surface antigen of 2.2% (95% confidence interval [CI], 1.8-2.6%) vs. 7.4% (95% CI, 5.9-8.9%), and core antibody against hepatitis B of 6.7% (95% CI, 6.0-7.3%) vs. 23.5% (95% CI, 21.1-25.9%), but a higher rate of surface antibody against hepatitis B of 74.3% (95% CI, 73.2-75.4%) vs. 69.1% (95% CI, 66.5-71.7%) compared with those born before July 1984 (all p < 0.001). Subjects with a family history of hepatitis B had higher risk of being infected by hepatitis B (OR, 4.07; 95% CI, 3.18-5.12) and becoming carriers (OR, 7.26; 95% CI, 5.05-10.44) after adjustment for sex, age, birth year, and self-reported hepatitis B vaccination history.

CONCLUSION

The seroprevalence of hepatitis B surface antigen continued to decline 20 years after neonatal hepatitis B vaccination program. It is strongly recommended that those who have a family history of hepatitis B should receive early check-up of hepatitis B status after complete vaccination or closely follow up their hepatitis B status after neonatal hepatitis B vaccination.

Hepatitis C virus infection is a risk factor for tumor recurrence after resection of small hepatocellular carcinomas

Hepatocellular carcinoma (HCC) is closely associated with chronic hepatitis B or C virus (HBV, HCV) infection. Tumor recurrence frequently occurs after surgical resection and may adversely affect the outcome. This study aimed to investigate the effect of viral hepatitis in association with HCC recurrence after resection. A total of 248 patients [HBV in 165, HCV in 44, dual HBV+HCV in 15, and non-B non-C (NBNC) in 24] who underwent curative resection for HCC were included. The cumulative recurrence rate was compared according to the etiology of the underlying hepatitis and was stratified by tumor size and other clinicopathologic parameters. Altogether, 116 patients (47%) had a tumor recurrence within 17 +/- 11 months after resection. No significant difference in recurrence was noted among the four groups of patients (HBV, HCV, HBV+HCV, NBNC) ( p = 0.248). Persistent hepatitis was more common in the HCV group ( p < 0.001) after resection. Among the 157 patients with a small (= 5 cm) tumor, the recurrence rate was significantly higher in the HCV group than in the HBV, HBV+HCV, and NBNC groups ( p = 0.036). Cox multivariate analysis showed that HCV infection [relative risk (RR) 4.4, 95% confidence interval (CI) 1.3-14.8, p = 0.018] and vascular invasion (RR 3.2, 95% CI 1.2-8.9, p = 0.044) were independent predictors of tumor recurrence. Stratified analysis in other parameters did not show significant differences in terms of tumor recurrence among the four virologic groups ( p > 0.1 for all parameters). In conclusion, patients with small HCCs and concurrent HCV infection are at a high risk of tumor recurrence after resection.

Legend of hepatitis B vaccination: the Taiwan experience

Hepatitis B, a disease entity currently affecting more than 350 million persons worldwide, is also a serious health problem in Taiwan. Liver cirrhosis and hepatoma, which are both closely correlated with hepatitis B, are among the 10 leading causes of death in Taiwan. A mass hepatitis B vaccination program, conducted by the government of Taiwan, was started in 1984. Prior to this vaccination program, a series of viral epidemiological surveys, transmission pattern studies, and pilot immunization trials proved the clinical, economic, and strategic benefits of mass immunization, thus providing the impetus for the implementation of this mass vaccination program. The success of this program has led to a decline in hepatitis B carrier rates among children in Taiwan from 10% to <1%. Furthermore, the mortality rate of fulminant hepatitis in infants and the annual incidence of childhood hepatoma have also decreased significantly in recent years. This is one of the most remarkable success stories in the field of public health.

Field evaluation of the efficacy and immunogenicity of recombinant hepatitis B vaccine without HBIG in newborn Vietnamese infants

A study involving more than 2,000 infants was conducted in Vietnam to assess the field effectiveness and immunogenicity of recombinant hepatitis B vaccine given at birth, 1 month, 2 months, without concomitant hepatitis B immune globulin (HBIG). All received a 5 microg dose of H-B-VAX II at birth. Infants born to non-carrier mothers (Group 1; N = 1798) then received 2.5 microg doses at 1 and 2 months of age, while infants of HBeAg-negative (Group 2; N = 125) or HBeAg-positive (Group 3; N = 88) carrier mothers received 5 microg doses. No Group 1 or 2 vaccinees were infected. In Group 3, 12 (14.6%) of 82 infants did become infected (estimated efficacy 84%). 98.0-98.6% of uninfected infants who were tested for anti-HBs developed a seroprotective concentration > or = 10 IU/L. In hyperendemic Vietnam, where routine maternal screening and passive-active prophylaxis of high-risk infants with vaccine plus HBIG is not feasible, administration of vaccine alone to all newborns may control effectively HBV infection.

The presence of hepatitis B surface antigen and deoxyribonucleic acid in amniotic fluid and cord blood

OBJECTIVE

It is uncertain whether neonatal infection with hepatitis B, despite treatment after delivery with immunoglobulin and vaccine, is the result of prior in utero transmission of the virus or treatment failure. Furthermore, the potential risk of hepatitis B transmission from the mother to the fetus at the time a genetic amniocentesis is performed is also a concern. In an attempt to better elucidate these controversies, amniotic fluid and cord blood specimens obtained from pregnant women positive for hepatitis B surface antigen were analyzed for the presence of hepatitis B surface antigen and hepatitis B deoxyribonucleic acid.

STUDY DESIGN

This study was a prospective longitudinal analysis that identified hepatitis B surface antigen-positive patients who presented for amniocentesis. Cord blood was obtained from these patients at the time of delivery. Cord blood was also obtained from a group of hepatitis B surface antigen-positive patients for whom no amniocentesis was performed. All samples were analyzed for the presence of hepatitis B surface antigen and hepatitis B deoxyribonucleic acid.

RESULTS

A total of 121 hepatitis B surface antigen-positive pregnant women were identified. In the 72 pregnancies in which amniocentesis was not performed, 18% of the cord blood samples were positive for hepatitis B surface antigen and 4% were positive for hepatitis B deoxyribonucleic acid. Of 47 amniocentesis fluid samples, 32% were positive for hepatitis B surface antigen but all were negative for hepatitis B virus deoxyribonucleic acid. Of 30 cord blood samples from patients who underwent an amniocentesis, 27% were positive for hepatitis B surface antigen, but all were negative for hepatitis B virus deoxyribonucleic acid.

CONCLUSIONS

This study found that hepatitis B viral deoxyribonucleic acid is rarely present in cord blood and was not identified in amniotic fluid obtained by amniocentesis. This finding suggests that in utero transmission of the virus is rare prior to the onset of labor. These data further confirm the reports in the current literature that the risk of hepatitis B transmission to the fetus during amniocentesis is low. Because hepatitis B surface antigen can exist as an isolated entity devoid of nuclear material, in some cases this protein may be able to traverse the placental and amniotic membrane barrier in a manner similar to other proteins, such as alpha-fetoprotein. Recommendations for genetic amniocentesis in women positive for hepatitis B surface antigen are discussed.

Efficacy of a mass hepatitis B immunization program after switching to recombinant hepatitis B vaccine: a population-based study in Taiwan

To study the efficacy of immunization against hepatitis B after plasma-derived vaccine was replaced by recombinant vaccine, 2-year-old Taiwanese children were recruited by stratification random sampling and tested for hepatitis B markers. They were grouped according to maternal infectivity and children's immunization status. Of 2010 children, 2.5% had hepatitis B surface antigen (HBsAg), 94.1% had its antibody (anti-HBs), 6.8% had core antibody, and 3.3% were seronegative. Children of highly infectious mothers immunized with hepatitis B immunoglobulin and vaccine on schedule had a lower HBsAg-positive rate and a higher anti-HBs-positive rate than those with vaccine only and off-schedule. The efficacy of the Taiwanese mass hepatitis B immunization was maintained after switching to recombinant hepatitis B vaccine.

Impact of hepatitis B immunisation as part of the EPI

Since 1992, hepatitis B vaccine has been an integrated part of Thailand's expanded programme on immunisation (EPI). Based on the data from five representative provinces, we have evaluated its impact on the countrywide prevalence of HBV infection and carrier rate. The population studied comprised 400-488 healthy and immuno-competent, subjects per area. The subjects' ages ranged from 6 months to 18 years. We examined their sera for viral hepatitis markers using commercially available test kits and established the coverage rate of hepatitis B vaccination after its inclusion into the EPI to be 71.2-94.3%. The number of individuals undergoing the complete course of vaccinations had increased four-fold. Consequently, only 0.7% of the children born after the implementation of this the novel EPI strategy were HBV carriers.

Preclinical evaluation of two human anti-hepatitis B virus (HBV) monoclonal antibodies in the HBV-trimera mouse model and in HBV chronic carrier chimpanzees

Two human monoclonal antibodies (mAbs) against hepatitis B surface antigen (HBsAg) generated in the Trimera mouse system are described. Both mAbs 17.1.41 and 19.79.5 are of the IgG1 isotype and have high affinity constants for HBsAg binding in the range of 10(-10) mol/L. Monoclonal antibody 17.1.41 recognizes a conformational epitope on the a determinant of HBsAg whereas mAb 19.79.5 recognizes a linear one. The 2 mAbs bind to a panel of hepatitis B virus (HBV) subtypes with distinct patterns. The neutralizing activity of these antibodies was tested in 2 different animal model systems. Administration of each mAb to HBV-Trimera mice, a system that provides a mouse model for human hepatitis B infection, reduced the viral load and the percentage of HBV-DNA-positive mice in a dose-dependent manner. These 2 mAbs were more effective than a polyclonal antibody preparation (Hepatect; Biotest Pharma, Dreieich, Germany) in both inhibition of HBV liver infection and reduction of viral load. A single administration of a mixture of these mAbs into HBV chronic carrier chimpanzees resulted in immediate reduction in HBsAg levels followed by recurrence to initial levels within few days. Thus, these mAbs may be potential candidates for preventive therapy or in combination with other antiviral agents against HBV. Further studies in humans are needed to assess these mAbs in various clinical indications.

Nationwide vaccination: a success story in Taiwan

In the early 1980s, 15-20% of the population of Taiwan were estimated to be hepatitis B virus (HBV) carriers. A programme of mass vaccination against hepatitis B was therefore launched in 1984. In the first 2 years, newborns of all HBVsurface antigen (HBsAg)-positive mothers were vaccinated. Since 1986, all newborns, and then year by year pre-school children, primary school children, adolescents, young adults and others have also been vaccinated. Vaccination coverage is over 90% for newborns, with 79% of pregnant women screened for HBsAg. The proportion of babies born to highly infectious carrier mothers who also became carriers decreased from 86-96% to 12-14%; the decrease was from 10-12% to 3-4% for babies of less infectious mothers. Between 1989 and 1993, the prevalence of HBsAg in children aged 6 years also fell from 10.5 to 1.7%. The average annual incidence of hepatocellular carcinoma in children aged 6-14 years decreased significantly from 0.7 per 100,000 in 1981-1986 to 0.36 per 100,000 in 1990-1994 (P<0.01). Similarly, the annual incidence of hepatocellular carcinoma in children aged 6-9 years declined from 0.52 per 100,000 for those born in 1974-1984 to 0.13 per 100,000 for those born in 1986-1988 (P<0.001). The mass vaccination programme is highly effective in controlling chronic HBV infection and in preventing liver cancer in Taiwan. If a coverage rate of 90% of all newborns vaccinated against hepatitis B can be maintained, by the year 2010 the carrier rate in Taiwan is expected to decline to <0.1%.

Update on diagnosis, management, and prevention of hepatitis B virus infection

Acute and chronic hepatitis B virus (HBV) infection is a leading cause of liver disease worldwide. It is estimated that approximately 350 million people worldwide have chronic HBV infection and that 1 million persons die each year from HBV-related chronic liver disease. In the past decade, significant progress in the understanding of the molecular virology and pathogenesis of HBV infection has been made. In addition, effective treatment modalities have been developed for persons with chronic infection. Worldwide, prevention of HBV transmission has become a high priority. In 1992, the Global Advisory Group to the World Health Organization recommended that all countries integrate hepatitis B vaccine into national immunization programs by 1997. Currently, 80 countries have done so and several others are planning to. Many countries have reported dramatic reductions in the prevalence of chronic HBV infection among children born since the hepatitis B vaccine was introduced into infant immunization schedules. Recent reports from Taiwan indicate a reduction in the incidence of liver cancer among children as a result of widespread hepatitis B vaccination programs.

Treatment of chronic hepatitis B: new antiviral therapies

Chronic hepatitis B infection is the most important cause of cirrhosis and hepatocellular carcinoma worldwide. Interferon-alpha has been shown to be effective in approximately one third of patients, and response seems to be sustained in long-term follow-up studies in Western countries. New treatments using lamivudine and other nucleoside analogues such as famciclovir, lobucavir, and adfovir showed promising results although sustained suppression of viral replication is unusual after discontinuation of therapy. The results of recent clinical studies using these nucleoside analogues are discussed in detail in this review. Other important issues such as drug resistance and the role of combination therapy are also addressed.

Chronic hepatitis virus infection in children

Hepatitis B and C viruses (HBV and HCV) are the two main hepatitis viruses causing chronic liver diseases in children. In hyperendemic areas, nearly half of the primary infection in chronic HBV carriers occurs during the perinatal period through the transmission from hepatitis B e antigen (HBeAg)-positive mothers. The other half are from horizontal transmission mainly through intrafamilial spread or injection using unsterilized needles. During the natural course of chronic HBV infection, spontaneous HBeAg/anti-HBe seroconversion occurs very rarely (2% annually) before 3 years of age. After 3 years of age, the HBeAg seroconversion rate increases gradually to 5% per year. Those with mothers who are hepatitis B carriers tend to clear HBeAg slower than those whose mothers are non-carriers. Transplacental HBeAg may cause T cell tolerance in infected children. Universal HBV immunization programmes have been effective in reducing the hepatitis B carrier rate more than 10-fold, and the incidence of hepatocellular carcinoma in children has also been decreased significantly. Hepatitis C virus infection occurs mainly in high-risk children, such as those who received blood products (blood diseases, malignancies, post-open heart surgery etc.), children of HCV-infected mothers, and in hyperendemic areas, from injection using unsterile needles. Mother-to-infant transmission occurs on average in 5% of infants of viraemic mothers. The maternal HCV-RNA titre is the most important factor determining the infectivity. Chronicity developed in 60-80% of HCV-infected children. Although transient or persistent elevation of aminotransferases occurs frequently in chronically HCV-infected children, liver histology showed minimal or mild changes only. The most prevalent genotype of HCV in children is Ib. Screening of the blood products for HCV antibody has markedly reduced the rate of HCV infection in children at risk. However, vaccine development is needed to prevent mother-to-infant transmission and other routes of infections.

Decreasing hepatitis D virus infection in Taiwan: an analysis of contributory factors

Superinfection of hepatitis D virus (HDV) among hepatitis B virus (HBV) carriers is mainly through heterosexual contact in Taiwan. This study investigated the change of HDV endemicity and its associated contributory factors. Seventy-seven patients with acute HDV superinfection among 527 consecutive exacerbating hepatitis B surface antigen (HBsAg) carriers were identified over the past 12 years. The prevalence decreased significantly by each 3-year period from June 1983 to May 1995 (23.7, 15.5, 13.1 and 4.2%, respectively, P < 0.001). This trend was more significant in the hepatitis B e antigen (HBeAg)-negative group (P < 0.001) than in the HBeAg-positive group (P = 0.073). Subjects with a history of paid sex and prostitutes were also recruited for analysis both in 1989 and 1996. Although not statistically significant, there was a trend showing a decrease in the prevalence of serum antibody against HDV (anti-HDV) in each risk group: it was lower in 1996 among HBsAg-positive brothel-goers (10.3 vs 6.9%), licensed prostitutes (54.5 vs 50%) and unlicensed prostitutes (36.1 vs 30.8%). Accumulation of anti-HDV-positive subjects in risk groups may mask the actual decrease of new HDV-infected cases. The prevalence of the HBsAg carrier rate among all prostitutes has significantly decreased (18.3 vs 12.2%, P = 0.015). The efficacy of each preventive strategy was examined and mapped with the trend. It was concluded that active preventive measures directed against promiscuity and sexually transmitted disease and the promotion of disposable needles may have contributed to the decrease in HDV endemicity.

Prevention of hepatitis B and C virus infection for prevention of cirrhosis and hepatocellular carcinoma

In Taiwan, cirrhosis and hepatocellular carcinoma (HCC) have been common in medical practice since the 1960s. In 1969, Taiwan was shown to be a hyperendemic area of hepatitis B virus (HBV) infection with a high rate of hepatitis B surface antigen (HBsAg) positivity, 19% of the population being infected before the fourth decade of life. There is evidence indicating that more than 80% of chronic hepatitis, cirrhosis and HCC are the sequelae of chronic HBV infection. In 1984, after 3 years of preparation, a programme to control cirrhosis and HCC began. All neonates born to HBsAg+ mothers were given Pasteur plasma-derived vaccine 5 micrograms i.m. at 1, 5 and 9 weeks with a booster at 12 months. In 1986, all neonates were included in this programme. In addition, beginning in 1987, all non-vaccinated preschool children were also immunized and susceptible medical personnel and people from HBsAg+ households were recommended to receive the vaccine. Using data obtained from the 7-year evaluation study on the efficacy of this vaccine and some historical data, the HBsAg positivity rate in people born in the first few years after 1986 was estimated to be 2.6%. This rate is expected to decrease to 0.2% in those born after around 1990. In July 1992, an anti-hepatitis C virus (HCV) test was included in blood donor screening tests. This was followed by a decrease in the incidence of post-transfusion hepatitis (PTH) from 13 to 2.5% and there have been no anti-HCV+ PTH cases since. However, without immunization, the prevalence of HBsAg decreased among children in Taipei in 1989. This coincided with the widespread use of disposable syringes and needles and an improvement in the sterilization of medical instruments. Therefore, it is likely that HCV infection may also decrease as a result of these practices. Through the use of immunization and improved medical procedures, chronic hepatitis, cirrhosis and HCC may decrease in Taiwan by around 95%.

Long-term hepatitis B vaccine in infants born to hepatitis B e antigen positive mothers

Neonates of hepatitis B surface antigen (HBsAg) positive and hepatitis B encoded antigen (HBeAg) positive mothers received 10 micrograms of recombinant hepatitis B vaccine at months 0, 1, 6, or 0, 1, 2, 12, with or without immunoglobulin at birth, and were followed up to the age of 8 years for HBsAg, anti-HBc, and anti-HBs. Some were boosted at month 60. The overall vaccine protection at month 12 was 96.2%. No child became a chronic carrier beyond the age of 3 years, showing that this vaccine provides immediate protection against HBsAg carriage, and long term protection against fetally acquired HBsAg. After month 60 hepatitis B serological markers without disease, indicating re-exposure to HBV, reappeared in comparable numbers among boosted and non-boosted children (5 for a total of 167 children). This vaccine provides long-term protection against hepatitis B chronic carriage and infection in high risk neonates with or without a month 60 booster. A booster at the age of 5-6 years or 11-12 years would reduce HBV infection, viral circulation and transmission, while ensuring long-term antibody persistence.

Soroepidemiologia para o virus da hepatite B (VHB) em gestantes/parturientes e sua transmissão para recém-nascidos em Goiânia, GO

Foram coletadas, entre março de 1990 e julho de 1992, 1459 amostras sanguíneas de mulheres gestantes/parturientes na cidade de Goiânia-GO, objetivando detecção da infecção pelo vírus da hepatite B (VHB), através dos marcadores sorológicos AgHBs e anti-HBs. O percentual depositividade encontrado, pelo teste imunoenzimãtico, foi de 7,5%, sendo 0,5%para AgHBs e 7,0%para anti-HBs. A análise efetuada, considerando a faixa etária, mostra que 7 de 8 mulheres AgHBs-positivas pertenciam à faixa etária de até 30 anos, situação semelhante em relação ao anti-HBs(83/101). Das 8 mulheres positivas, 4 tiveram seus recém-nascidos submetidos a tratamento profilático com vacina (Engerix B) e imunoglobulina humana anti-hepatite B (HBIG). Além disso, 3 dessas crianças foram analisadas sorologicamente, sendo que uma era AgHBs-positiva ao nascimento. Doença sexualmente transmissível e transfusão sanguínea foram fatores de risco que coirelacionaram significantemente com a infecção. Esses resultados parece-nos reforçar a indicação de triagem à infecção pelo vírus da hepatite B no período pré-natal, assim como a adoção de medidas imunoprofiláticas nas crianças nascidas de mães positivas.

The role of transplacental hepatitis B core antibody in the mother-to-infant transmission of hepatitis B virus

AIMS/METHODS

To investigate the influence of transplacental hepatitis B core antibody (anti-HBc) on perinatal hepatitis B virus (HBV) transmission, we studied the anti-HBc titers in 294 mother-neonate pairs.

RESULTS

The anti-HBc titer was highest (10(5.13 +/- 0.80) to 10(4.36 +/- 0.97) in mothers, 10(5.13 +/- 0.76) to 10(5.52 +/- 0.98) in infants) in the 200 hepatitis B e antigen (HBeAg) positive hepatitis B surface antigen (HBsAg) carrier mothers and their infants, second highest (10(4.51 +/- 0.76) and 10(4.68 +/- 0.76)) in the 60 HBeAg-negative HBsAg carrier mothers and their infants, and lowest (10(3.11 +/- 0.76) and 10(3.24 +/- 0.83)) in the 34 non-carrier mothers and their infants (p < 0.05). One hundred and ninety-two infants of HBeAg-positive carrier mothers received hepatitis B immunoglobulin as well as hepatitis B vaccines, and were followed prospectively from birth. Ten infants became HBsAg carriers, and their mothers had significantly lower anti-HBc titers than those of the mothers of 182 infants who did not become carriers (p = 0.003), while maternal serum hepatitis B virus DNA levels (29.9 +/- 23.6 versus 39.9 +/- 58.1 pg/10 ml) did not differ in those two groups (p > 0.25). The same trend was observed in the infants' anti-HBc titers in those two groups (p = 0.0006).

CONCLUSIONS

The association of lower anti-HBc titers in HBeAg-positive carrier mother-infant pairs and the development of carrier status in the infants suggests a positive role of anti-HBc in the modulation of mother-to-infant transmission of HBV. A high maternal anti-HBc level in serum may be a negative predictor of immunoprophylaxis failure in high-risk infants.