Immunoprophylaxis Failure of Infants Born to Hepatitis B Carrier Mothers Following Routine Vaccination

Screening for viral hepatitis carriage

Viral hepatitis during pregnancy is common globally. In this review, we focus on the antenatal screen for hepatitis A, B, C and E, the prevention of mother-to-child transmission (MTCT) of hepatitis B and C, and the management of hepatitis A, B, C and E during pregnancy. Neonatal timely administration of hepatitis B immunoglobulin and hepatitis B vaccine is the cornerstone for preventing MTCT of hepatitis B virus (HBV), and perinatal antiviral prophylaxis with tenofovir disoproxil fumarate in mothers with positive HBeAg or HBV DNA >2 × 105 IU/ml also plays important roles in further reducing MTCT. Avoidance of risk practices in managing labor and delivery process of women with HCV infection may be useful to reduce MTCT of HCV. Early recognition of severe hepatic injury or liver failure associated with hepatitis viruses by regular liver function tests is critical to prevent maternal mortality associated with hepatitis.

Impact of timing on protection of combined immunoprophylaxis in preventing mother-to-child transmission of hepatitis B virus: a retrospective study

Objective: To evaluate the impact of timing combined immunoprophylaxis on mother-to-child transmission (MTCT) of the hepatitis B virus (HBV) in pregnant women living with hepatitis B. Methods: A retrospective cohort study was included HBsAg-positive pregnant women who delivered full-term at Tianjin Third Central Hospital from January 2019 to December 2021. The objective of this study is to determine whether early administration of hepatitis B immune globulin (HBIG) and the first dose of hepatitis B vaccination after birth can further improve protection. Result: A total of 694 pregnant women living with hepatitis B were included; 93 infants from these mothers were lost to follow-up [including moving (n = 21), emigrating (n = 26), changing contact information (n = 27), and other reasons (n = 19)], leaving 601 infants for analysis. The incidence in babies born to mothers with hepatitis B was 1.50% (9/601). Based on the different timing of combined immunoprophylaxis administration after birth, 601 infants were divided into two groups (within 2 h and within 2-12 h). The incidence in babies born to mothers with hepatitis B were 0.32% (1/308) and 2.73% (8/293) for infants who received combined immunoprophylaxis within 2 h and between 2 and 12 h of birth, respectively (p = 0.037). The infection incidence of infants born to HBeAg-positive mothers and HBeAg-positive mothers who did not receive antiviral treatment during pregnancy was lower in the 2-h group compared to the 2-12 h group (0.72% vs. 5.84%, p = 0.04 and 1.20% vs. 9.46%, p = 0.047). Conclusion: Using combined immunoprophylaxis as soon as possible (within two hours of birth) may protect against MTCT of HBV more.

Effects of antiviral therapy and drug withdrawal on postpartum hepatitis in pregnant women with chronic HBV infection

OBJECTIVE

To investigate the effect of antiviral therapy and drug withdrawal on the incidence of hepatitis B after delivery in pregnant women with chronic hepatitis B virus (CHB) infection who received tenofovir disoproxil fumarate (TDF) treatment.

METHODS

Eligible CHB pregnant women were enrolled, and received TDF at 32 weeks gestation. The drug was stopped immediately or at 6 weeks after delivery. The HBV biomarkers and clinical biochemical parameters were monitored during gestation and 24 weeks after delivery.

RESULTS

There were 264 women completed the observation, including 96 untreated subjects in control group. Among 168 treated subjects, 131 cases stopped drug immediately after delivery and 37 cases delayed the drug withdrawal at 6 weeks after delivery. The incidence of postpartum hepatitis in control, immediate drug withdrawal, and delayed drug withdrawal were 28.1% (27/96), 23.7% (31/131), and 24.3% (9/37), showing no significant difference (χ² = 0.607, p = 0.738). No factor was found to be associated with the occurrence of postpartum hepatitis. It's noteworthy that 96.3% of postpartum hepatitis in control group and 92.3% of postpartum hepatitis in immediate drug withdrawal group occurred within 12 weeks after delivery. While in delayed drug withdrawal group, the rate of postpartum hepatitis occurred within 12 weeks after delivery was 77.7%.

CONCLUSION

Withdrawing antiviral drug immediately or at 6 weeks after delivery did not affect the incidence of postpartum hepatitis in CHB women, but delaying drug withdrawal might delay the onset of postpartum hepatitis.

CLINICAL TRIAL REGISTRATION NUMBER

NCT03214302.

Hepatitis B surface antigen prevalence and the rates of mother-to-child transmission of hepatitis B virus after the introduction of infant vaccination programs in South East Asia and Western Pacific regions: a systematic review

OBJECTIVES

Infant vaccination against the hepatitis B virus began in the World Health Organization South East Asia Region and the Western Pacific Region between 1983 and 2016. This systematic review examined the seroprevalence of hepatitis B surface antigen (HBsAg) in children and the rate of mother-to-child transmission (MTCT) in these regions between 1990 and 2020.

METHODS

MEDLINE and EMBASE were searched for articles published between January 1990 and September 2020, which reported seroprevalence of HBsAg in children aged 0-15 years and/or the rate of MTCT in the South East Asia Region and Western Pacific Region. A pragmatic review identified supporting information. This review was registered in the International Prospective Register of Systematic Reviews (#CRD42020211707).

RESULTS

Of 115 included studies, 77 (24 countries) reported HBsAg prevalence, and 38 (nine countries) reported MTCT. The seroprevalence of HBsAg ranged between 0.0% and 27.4%, with a decreasing trend over time in each country. MTCT rates were 0.0-5.2% in infants of mothers who are hepatitis B e antigen-negative and 2.7-53.0% in infants of mothers who are hepatitis B e antigen-positive.

CONCLUSION

After the introduction of infant hepatitis B virus vaccination programs, the countries in South East Asia Region and Western Pacific Region observed a reduction in HBsAg seroprevalence in children. Nevertheless, the risk of MTCT persists, emphasizing the importance of antenatal screening to identify high-risk pregnancies.

Incidence of mother-to-child transmission of hepatitis B in relation to maternal peripartum antiviral prophylaxis: A systematic review and meta-analysis

INTRODUCTION

Mother-to-child transmission (MTCT) of the hepatitis B virus (HBV) is a serious public health challenge. Estimating HBV MTCT incidence by region under different prophylaxis regimens is critical to understanding the regional disease burden and prioritizing interventions. This study aimed to calculate HBV MTCT incidence under different prophylaxis regimens globally and regionally and identify the HBV DNA threshold for maternal peripartum antiviral prophylaxis.

MATERIAL AND METHODS

This review was registered in advance in PROSPERO (CRD 42019120567). We searched PubMed, Embase, China National Knowledge Infrastructure, ClinicalTrials.gov, and Cochrane Library databases for studies on MTCT in pregnant women with chronic HBV infection from their inception until June 13, 2022. MTCT was defined as hepatitis B surface antigen (HBsAg) or HBV DNA seropositivity in infants aged 6-12 months. We calculated the pooled HBV MTCT incidence using the DerSimonian-Laird random-effects model.

RESULTS

Among 300 studies, 3402 of 63 293 infants had HBV due to MTCT. Without prophylaxis regimens, the pooled HBV MTCT incidence was 31.3%, ranging from 0.0% (95% confidence interval [CI] 0.0%-6.0%; European Region) to 46.1% (95% CI 29.7%-63.0%; Western Pacific Region). Following the introduction of the hepatitis B vaccine, the HBV MTCT incidence decreased from 82.9% to 15.9% in HBeAg-positive women and from 10.3% to 2.3% in HBeAg-negative women. Maternal peripartum antiviral treatment alongside infant immunoprophylaxis further decreased MTCT incidence to 0.3% (95% CI 0.1%-0.5%). Despite infant immunoprophylaxis, the incidences of MTCT at maternal HBV DNA levels of <2.30, 2.00-3.29, 3.00-4.29, 4.00-5.29, 5.00-6.29, 6.00-7.29 and ≥7.00 log₁₀  IU/ml were 0.0% (95% CI 0.0%-0.0%), 0.0% (95% CI 0.0%-0.0%), 0.0% (95% CI 0.0%-0.5%), 0.6% (95% CI 0.0%-2.6%), 1.0% (95% CI 0.0%-3.1%), 4.3% (95% CI 1.8%-7.5%), and 9.6% (95% CI 7.0%-12.5%), respectively.

CONCLUSIONS

HBV MTCT incidence varies across regions. The Western Pacific Region bears the heaviest burden. Peripartum antiviral prophylaxis plus infant immunoprophylaxis is promising for interrupting HBV MTCT. Regarding the HBV DNA threshold for peripartum antiviral prophylaxis, maternal HBV DNA of 4.00 log₁₀  IU/ml or greater seems justified.

Efficacy of the hepatitis B vaccine alone in the prevention of hepatitis B perinatal transmission in infants born to hepatitis B e antigen-negative carrier mothers

Background

Vertical mother-to-child transmission (MTCT) of the hepatitis B virus (HBV) remains an important issue. Timely administration of hepatitis B immunoglobulin (HBIG) and of the HBV vaccine is effective in preventing MTCT in infants born to HBV-infected mothers. However, HBIG is often not easily available in low-income countries or regions.

Methods

We compared in a retrospective cohort study the HBV vaccine efficacy alone and in combination with HBIG in preventing vertical MTCT in infants born to HBeAg-negative carrier mothers in Jiangsu province, China. Based on the administration of the HBV vaccine and HBIG shortly after birth, children were divided into two groups: Group 1, administration of the HBV vaccine alone, and Group 2, concurrent use of HBIG and of the HBV vaccine.

Results

A total of 620 infants born to HBeAg-negative carrier mothers were enrolled into this study. Group 1 included 195 children who had received the HBV vaccine alone after birth, and Group 2, 425 children who had received both HBIG and the HBV vaccine. Children were followed up to the age of 68 and 42 months, respectively. MTCT of HBV occurred in 0% (0/195) in Group 1 (HBV vaccine alone) and 0% (0/425) in Group 2 (HBV vaccine and HBIG) (p = 1.00).

Conclusion

In this retrospective cohort study, we found that HBV vaccination alone shortly after birth was effective in preventing MTCT of HBV in infants born to HBeAg-negative carrier mothers.

Hepatitis B Viral Markers in the Human Milk of HBsAg-Positive Mothers: An Observational Study

BACKGROUND

Quantification of viral antigens and viral loads in human milk samples from mothers infected with hepatitis B virus is largely unknown.

RESEARCH AIM

The aim of the study was to quantitatively measure the levels of viral antigens and deoxyribonucleic acid of hepatitis B virus in human milk from mothers infected with hepatitis B virus.

METHODS

Fifty-five pairs of milk and serum samples from mothers with positive hepatitis B surface antigen, including 11 hepatitis B e antigen positive, were quantitatively tested to measure viral antigens by microparticle enzyme immunoassay and viral loads by real-time polymerase chain reaction assay.

RESULTS

The median level of hepatitis B surface antigen in the human milk samples of mothers with positive or negative hepatitis B e antigen was each lower than that in the sera, respectively (1.10 vs. 4.32 log₁₀ IU/ml, t = 10.693, p < .001; -0.77 vs. 2.53 log₁₀ IU/ml, t = -25.135, p < .001). The titers of hepatitis B surface antigen or hepatitis B e antigen in the human milk samples were each correlated with that in maternal serum. The detectable level of deoxyribonucleic acid of hepatitis B virus in human milk ranged from 1.42-5.27 log₁₀ IU/ml, whereas that in maternal sera was 1.44-8.66 log₁₀ IU/ml. The viral level in human milk was not correlated with that in maternal circulation.

CONCLUSION

The present study data illustrate the relatively low titers of viral markers in the milk of mothers with positive hepatitis B surface antigen.

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

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

Knowledge, perception and expectation of management of hepatitis B infection among pregnant hepatitis B carriers in Hong Kong

Lack of awareness regarding the risk of hepatitis B virus (HBV) infection and the interventions available during pregnancy among the pregnant carriers may influence their willingness and adherence to the management. This study assessed the knowledge, perception and expectation of HBV infection among pregnant HBV carriers in Hong Kong. A prospective multicentre cross-sectional questionnaire study was carried out between August 2019 and April 2021. The general knowledge on HBV, perception and expectation, and interventions to reduce vertical transmission were questioned. Obtaining ≥70% correct answers was defined as having sufficient knowledge. 422 (82.7%) were known carriers. Only 18.4% of women had sufficient overall knowledge. The correct answer rates and percentage of sufficient knowledge were statistically lower for HBV knowledge specific to pregnancy compared with general knowledge (42.5% vs. 58.5%, p < 0.001; 8.8% vs. 30.2%, p < 0.001 respectively). Multiple logistic regression showed higher education and receiving HBV medical care within a year prior to pregnancy were associated with sufficient overall (OR 3.46; 95% CI 2.05-5.83 and OR 2.76; 95% CI 1.62-4.7, p < 0.001), and general knowledge (OR 2.86; 95% CI 1.81-4.51 and OR 2.14; 95% CI 1.33-3.44, p < 0.05). 298 (58.4%), 357 (70.0%) and 150 (29.4%) women believed they should receive care by obstetrician, hepatologist or general practitioner respectively. 46.9% did not want to initiate antiviral treatment due to the cost, perceived teratogenicity and maternal side effects. The knowledge of HBV among pregnant carriers in Hong Kong was poor despite the majority of them being aware of their carrier status prior to the pregnancy.

The optimal interval for post-vaccination serological test in infants born to mothers with positive hepatitis B surface antigen

Postvaccination serologic testing (PVST) is utilized to monitor the success or failure of vaccination against hepatitis B virus (HBV) infection in infants of hepatitis B surface antigen (HBsAg) positive mothers. This secondary analysis of 1255 infants of HBsAg-positive mothers at 7-14 months age included in two prospective studies aimed to determine the optimal interval for PVST after three hepatitis B vaccine doses. HBsAg and anti-HBs were quantitatively tested with microparticle enzyme immunoassay. The average PVST interval was 3.8 ± 2.2 months. Overall, 1.7% (21/1255) infants had anti-HBs <10 mIU/mL. The non-response rates were 1.6%, 1.1%, 0.9%, 0.7%, 1.1%, 0.7%, and 5.7% when PVST was performed at an interval of 1, 2, 3, 4, 5, 6, and 7-8 months after the third vaccine dose, respectively. Compared with 1 month of PVST interval, the non-response rate in infants who underwent PVST 7-8 months was significantly higher (χ² = 4.616, P = .032). Anti-HBs titers were significantly declined in infants with medium responses when PVST was performed with longer intervals (χ² = 27.592, P < .001), actually declined from interval of 6, and 7-8 months (Z = -3.177, P = .001 and Z = -3.715, P < .001), respectively. These results indicate that PVST may be performed at the age of 7-12 months for infants vaccinated on 0, 1, and 6-month schedule. To identify non-responders as early as possible, we suggest that PVST is performed at 7 months age or 1 month after the final vaccine dose.

Elimination of hepatitis B virus infection in children: experience and challenge in China

ABSTRACT

Chronic hepatitis B virus (HBV) infection is a serious health issue because of its severe sequelae. Prevention of mother-to-child transmission (MTCT) of HBV is critical to eliminate chronic HBV infection. Here, we reviewed the progress toward the elimination of HBV infection in children in China in the recent decade. A universal hepatitis B vaccination program started from 2002 has been intensified, with the coverage of timely birth dose >95% of all newborn infants from 2012. Since 2011, China has taken a nationwide program to administer hepatitis B immunoglobulin (HBIG) with free of charge in all neonates of HBV-infected mothers, leading to a significant increment of timely use of HBIG. The prevalence of hepatitis B surface antigen (HBsAg) was declined from around 10% among children in 1980s to <0.5% among children born after 2011. Administration of oral antiviral agents in HBV-infected pregnant women with HBV DNA >2 × 105 U/mL during the third trimester is increasing, which will further reduce MTCT of HBV. However, there are some challenges in the elimination of HBV infection in children, which need to overcome by the concerted efforts. Nevertheless, it is anticipated that China will achieve the goal set by the World Health Organization that the prevalence of HBsAg in children aged <5 years is ≤0.1% by 2030.

Hepatitis B Virus Infection in Pregnancy: An Update on Evidence-Based Management

Importance

Vertical hepatitis B virus (HBV) transmission is the important route of chronic HBV infection. Although infant immunoprophylaxis is effective, a significant number of infants still become infected, most are associated with intrauterine infection. New evidences support intrauterine treatment in cases of high risk.

Objective

The aim of this study was to review the current evidences and recommendations for management of HBV infection in pregnancy.

Evidence Acquisition

Original research articles, review articles, and guidelines were reviewed.

Results

The management can be summarized as follows: (1) all pregnant women should be screened for hepatitis B surface antigen (HBsAg) and antibody to HBsAg. High-risk HBsAg-negative pregnant women without immunity should be vaccinated during pregnancy. (2) HBsAg-positive pregnant women should undergo further workup for liver status and indicative factors for immunoprophylaxis failure. (3) Pregnant women should be treated with HBV DNA levels greater than 200,000 IU/mL or 6 log copies/mL. (4) Antiviral drug should be started around 28 to 32 weeks. The first-line drug is tenofovir disoproxil fumarate. (5) Delivery route should be chosen based only on obstetric indications. (6) Breastfeeding is not contraindicated because it does not increase the risk of transmission in neonates with HBV vaccine and immunoglobulin administration. (7) Neonates born to HBsAg-positive mothers should receive HBV vaccine and immunoglobulin after birth as soon as possible. (8) Follow-up of the mothers and neonates is important. Beware of hepatitis flare after birth and after antiretroviral drug discontinuation; alanine transaminase assessment every 1 to 3 months until 6 months is suggested. Also, the schedule of infant vaccination and follow-up of serologic testing at 9 to 12 months old is needed.

Reduced mother-to-child transmission of hepatitis B after implementation of completely charge-free active-passive immunoprophylaxis: an observational cohort study

Objectives: China has implemented universal hepatitis B vaccination since 2002 and provided charge-free hepatitis B immunoglobulin (HBIG) to infants of HBV-infected mothers since July 2011. We aimed to compare mother-to-child transmission (MTCT) in children born before and since July 2011.Methods: In total, 5,149 children of HBV-infected mothers were tested for HBV markers. Group one contained 1,160 children born during August 2002-June 2011 and group two contained 3,989 children born during July 2011-June 2016.Results: In total, 92 (1.8%, 95% confidence interval [95%CI] 1.4-2.2) children were infected with HBV. None (0%, 95%CI 0.0-0.1) of 3,716 children of mothers with negative hepatitis B e antigen (HBeAg) was infected, whereas 92 (6.4%, 95%CI 5.2-7.8) of 1,433 children of HBeAg-positive mothers were infected (p < 0.0001). Among children of HBeAg-positive mothers, MTCT occurred in 10.3% (19/185) (95%CI 6.3-15.6) in group one and 5.8% (73/1,248) (95%CI 4.6-7.3) in group two (p = 0.02).Conclusions: Implementing charge-free active-passive immunoprophylaxis greatly reduces MTCT of HBV in children of HBeAg-positive mothers, highlighting the importance of timely administration of both hepatitis B vaccine and HBIG to prevent MTCT. The still remaining MTCT suggests that reducing maternal virus load before delivery is an additional important measure.

Viral hepatitis and pregnancy

The management of viral hepatitis in the setting of pregnancy requires special consideration. There are five liver-specific viruses (hepatitis A, B, C, D, E), each with unique epidemiology, tendency to chronicity, risk of liver complications and response to antiviral therapies. In the setting of pregnancy, the liver health of the mother, the influence of pregnancy on the clinical course of the viral infection and the effect of the virus or liver disease on the developing infant must be considered. Although all hepatitis viruses can harm the mother and the child, the greatest risk to maternal health and subsequently the fetus is seen with acute hepatitis A virus or hepatitis E virus infection during pregnancy. By contrast, the primary risks for hepatitis B virus (HBV), hepatitis C virus (HCV) and hepatitis D virus are related to the severity of the underlying liver disease in the mother and the risk of mother-to-child transmission (MTCT) for HBV and HCV. The prevention of MTCT is key to reducing the global burden of chronic viral hepatitis, and prevention strategies must take into consideration local health-care and socioeconomic challenges. This Review presents the epidemiology of acute and chronic viral hepatitis infection in pregnancy, the effect of pregnancy on the course of viral infection and, conversely, the influence of the viral infection on maternal and infant outcomes, including MTCT.

Viral Hepatitis in pregnancy

The global prevalence of viral hepatitis is very high and seems to be rising over the years. The infection can profoundly affect pregnant women causing significant maternal and perinatal morbidity and mortality with some strains much worse than others. Hepatitis A (HAV) and E (HEV) which are transmitted mainly through the faecal-oral route present as acute hepatitis during pregnancy and are responsible for most local epidemic outbreaks. HAV infection remains self-limiting during pregnancy, while HEV has a higher prevalence and causes significant morbidity. It is also associated with a very high maternal mortality rate (20 %) and requires special attention in endemic areas. HEV vaccines do exist, but the WHO has yet to approve them for general use. Hepatitis B is the most prevalent form and is part of the ante-natal screening program. The presence of HBeAg is associated with high viral loads and infectivity. Antiviral therapy, preferably tenofovir (TDF), is recommended for mothers with viral load ≥ 200,000 IU/mL₂), with the neonates receiving both active and passive immunisations. Hepatitis C and D are usually found as chronic infections in the pregnant and non-pregnant populations. Screening for hepatitis C during pregnancy and its subsequent management is still unsettled, but the introduction of direct-acting antiviral (DAA) drugs will change the picture if their safety is established in pregnancy. HDV is an incomplete virus linked to HBV and cannot establish an infection on its own. Controlling HBV is paramount to controlling HDV. HEV is quite prevalent and looked upon as hepatotropic. It seems to be quite prevalent in some blood donor populations and has a high co-infection rate with HCV. It has a high Mother-to-Child-Transmission (MTCT) but causes little or no illness in infected infants, and antenatal screening is not justified. This review summarises the prevalence, clinical picture, maternal, perinatal effects, and the management and prevention of hepatitis A, B, C, D, E and G viral infections during pregnancy.

Hepatitis B Infection and Mother-to-Child Transmission in Haiphong, Vietnam: A Cohort Study with Implications for Interventions

Background

There is little data available on HBV infection and mother-to-child transmission (MTCT) in Vietnam.

Objective

This study is aimed at assessing the prevalence of HBV infection and the current situation of MTCT in Haiphong, Vietnam.

Methods

A transversal survey of 1721 pregnant women followed by an observational prospective cohort study of 183 HBV-infected women was conducted at Haiphong Gyneco-Obstetric Hospital. Women were followed up up to 12-month postpartum; use of prevention measures and the MTCT rate were evaluated. HBV infection in children was defined by a HBsAg-positive test at 12 months of age.

Results

At baseline, 183 of 1721 pregnant women (10.6%) tested HBsAg positive. Among them, 23.0% were HBeAg positive, 26.2% had a detectable load of HBV DNA, and 13.1% had a HBV DNA load ≥ 200,000 IU/mL. All women underwent MTCT prevention antiviral therapy. At delivery, 98.9% of newborns receive a HBV vaccine birth dose, and 82% received HBIG. At 12 months of age, 94.7% have received the scheduled HBV vaccines. Eight percent of infants born from followed-up women were HBsAg positive. The mother's HBeAg-positive status was associated with a higher risk of HBV infection in infants.

Conclusion

The HBV prevalence and MTCT rates are high in Haiphong. A strong national plan to increase the access to preventive measures and to monitor results is needed in order to decrease this prevalence.

Accuracy of HBeAg to identify pregnant women at risk of transmitting hepatitis B virus to their neonates: a systematic review and meta-analysis

BACKGROUND

Prevention of mother-to-child transmission (MTCT) of hepatitis B virus (HBV) involves neonatal immunoprophylaxis, with a birth dose of hepatitis B vaccine and immune globulin, and provision of peripartum antiviral prophylaxis in highly viraemic women. However, access to assays to quantify HBV DNA levels remains inadequate in resource-poor settings. This study was commissioned by WHO and aimed to identify the HBV DNA threshold for MTCT, to assess the sensitivity and specificity of hepatitis B e antigen (HBeAg) testing to identify pregnant women with HBV DNA levels above this threshold, and to predict MTCT of HBV infection on the basis of HBeAg testing.

METHODS

For this systematic review and meta-analysis, we searched the PubMed, EMBASE, Scopus, CENTRAL, CNKI, and Wanfang databases for studies of pregnant women with chronic HBV infection without concurrent antiviral therapy, published between Jan 1, 2000, and April 3, 2019. Studies were eligible for inclusion if MTCT in mother-child pairs could be stratified by different levels of maternal HBV DNA during pregnancy, if maternal HBeAg status could be stratified by HBV DNA level, and if the MTCT status of infants could be stratified by maternal HBeAg status during pregnancy. Studies that selected pregnant women on the basis of HBeAg serostatus or HBV DNA levels were excluded. Aggregate data were extracted from eligible studies by use of a pre-piloted form; study authors were contacted to clarify any uncertainties about potential duplication or if crucial information was missing. To pool sensitivities and specificities of maternal HBeAg to identify highly viraemic women and to predict MTCT events, we used the DerSimonian-Laird bivariate random effects model. This study is registered with PROSPERO, CRD42019138227.

FINDINGS

Of 9007 articles identified, 67 articles (comprising 66 studies) met the inclusion criteria. The risk of MTCT despite infant immunoprophylaxis was negligible (0·04%, 95% CI 0·00-0·25) below a maternal HBV DNA level of 5·30 log₁₀ IU/mL (200 000 IU/mL) and increased above this threshold. The pooled sensitivity of HBeAg testing to identify HBV DNA levels of 5·30 log₁₀ IU/mL or greater in pregnant women was 88·2% (83·9-91·5) and pooled specificity was 92·6% (90·0-94·5). The pooled sensitivity of HBeAg testing in predicting MTCT of HBV infection despite infant immunoprophylaxis was 99·5% (95% CI 91·7-100) and pooled specificity was 62·2% (55·2-68·7).

INTERPRETATION

Maternal HBV DNA of 5·30 log₁₀ IU/mL or greater appears to be the optimal threshold for MTCT of HBV infection despite infant immunoprophylaxis. HBeAg is accurate to identify women with HBV DNA levels above this threshold and has high sensitivity to predict cases of immunoprophylaxis failure. In areas where HBV DNA assays are unavailable, HBeAg can be used as an alternative to assess eligibility for antiviral prophylaxis.

FUNDING

World Health Organization.

Increased protection of earlier use of immunoprophylaxis in preventing perinatal transmission of hepatitis B virus

BACKGROUND

Passive-active immunoprophylaxis against mother-to-child transmission (MTCT) of hepatitis B virus (HBV) recommends administer hepatitis B immunoglobulin (HBIG) and birth dose hepatitis B vaccine in infants within 12 or 24 hours after birth. With this protocol, MTCT of HBV still occurs in 5-10% infants of HBV-infected mothers with positive hepatitis B e antigen (HBeAg).

METHODS

The present study aimed to investigate whether earlier administration of HBIG and hepatitis B vaccine after birth can further increase the protection efficacy.

RESULTS

Totally, 1140 HBV-infected pregnant women were enrolled, and 982 infants (9 twins) of 973 mothers were finally followed up at 9.6 ± 1.9 months age. HBIG and birth dose vaccine were administered in newborn infants with a median 0.17 hour (0.02-1.0) after birth. The overall rate of MTCT was 0.9% (9/982), with none (0%) of 607 infants of HBeAg-negative mothers and 9 (2.4%) of 375 infants of HBeAg-positive mothers. All nine HBV-infected infants were born to mothers with HBV DNA >2.75×106 IU/ml. Maternal HBV DNA levels >1×106 IU/ml was an independent risk factor (OR = 10.627, 95% CI: 2.135-+∞) for immunoprophylaxis failure.

CONSLUSIONS

Earlier use (within one hour after birth) of HBIG and hepatitis B vaccine can provide better protection efficacy against MTCT of HBV.

Hepatitis B vaccine development and implementation

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

Management of viral hepatitis A, C, D and E in pregnancy

Viral hepatitis can cause significant maternal and neonatal morbidity and mortality. Hepatitis A and E mainly present as acute hepatitis during pregnancy, while hepatitis C and D are usually found as chronic infection in pregnant women. Hepatitis A remains self-limiting during pregnancy while hepatitis E has a higher prevalence and manifests with a rigorous course in pregnant women. Screening of hepatitis C during pregnancy and its subsequent management during pregnancy are still a debatable topic. New treatments of hepatitis C and E require further evaluation for use in pregnancy. This review summarizes the prevalence, clinical manifestations, maternal, foetal and neonatal effects, and the management of hepatitis A, C, D and E viral infection during pregnancy.

Hepatitis B - Vertical transmission and the prevention of mother-to-child transmission

Hepatitis B virus (HBV) infection is the commonest cause of chronic hepatitis, with an estimated global prevalence of 3.5%, and which leads to significant morbidity and mortality. Mother-to-child transmission (MTCT) during pregnancy is the leading form of transmission in endemic populations, and its interruption is thus crucial as the initial step in the elimination of HBV infection, notwithstanding the availability of potent antiviral medications. The risk of MTCT is dramatically reduced by timely neonatal HBV vaccination and the administration of hepatitis B immunoglobulin after birth in high-risk infants. Maternal HBV DNA quantification during pregnancy allows the assessment of the risk of newborn immunoprophylaxis failure (IF). Maternal antiviral treatment in highly viremic women can reduce the risk of IF. However, the optimal HBV DNA cutoff level for the initiation of antiviral treatment remains to be determined.

Deep sequencing of hepatitis B surface antigen gene in the preserved umbilical cords in immunoprophylaxis failure against mother-to-child HBV transmission

BACKGROUND

Vaccine escape mutants (VEMs) are one of the causes of breakthrough infections in the mother-to-child transmission of hepatitis B virus (HBV). We hypothesized that VEMs existing as minor populations in the maternal blood are associated with breakthrough infections in children. We sought to determine whether VEMs exist as minor populations in the preserved umbilical cords of children with breakthrough infections.

CASE PRESENTATION

Two families (Family 1: three children, Family 2: two children) were enrolled. Despite immunoprophylaxis, a breakthrough infection occurred in two Family 1 children and two Family 2 children. Preserved umbilical cords, serum, and nails were used for the HBV DNA analysis. To detect VEMs, we performed direct and deep sequencing of hepatitis B surface antigen gene. The direct sequencing showed that there were no VEMs in the serum of the children or mother of Family 1 and family 2, but it identified a G145A mutant in the nails of the mother of Family 2. In Family 1, deep sequencing detected a T143S mutant as a minor population (1.7-2.0%) in the umbilical cords and serum of all three children and in the serum of the mother. A T126A mutant was also detected in the umbilical cord (9.2%) and serum (7.0%) of the first-born child of Family 1. In Family 2, the deep sequencing showed no VEMs in the umbilical cords, but it detected D144A (2.5%) and G145A (11.2%) mutants in the serum of the 2nd-born child.

CONCLUSIONS

VEMs were present as minor populations in the preserved umbilical cords of children with breakthrough infections. The VEMs did not become major populations after the breakthrough infections. The evolution of VEMs from a minor form to a major form might not be a prerequisite for breakthrough infections in mother-to-child transmission.

Optimal timing of hepatitis B virus DNA quantification and clinical predictors for higher viral load during pregnancy

INTRODUCTION

Authorities publish recommendations on the hepatitis B virus (HBV) viral load threshold to initiate antiviral treatment but the timing of quantification during pregnancy is not well defined. HBV DNA levels in pregnancy women at 28-30 weeks predict the risk of immunoprophylaxis failure. This study compared and evaluated the correlation between HBV DNA levels before 22 and 28-30 weeks' gestation. Clinical predictive factors for HBV DNA >6, 7 and 8 log₁₀  IU/mL were studied.

MATERIAL AND METHODS

A retrospective analysis of HBV DNA levels of women <22 and 28-30 weeks of gestation was carried out in 352 pregnant HBV carriers. HBV DNA was examined using the COBAS TaqMan HBV Monitor Test coupled with the COBAS Ampliprep extraction system (Both Roche Diagnostics, Branchburg, NJ, USA).

RESULTS

A strong positive correlation was found between the viral loads of women <22 weeks (mean 16.7 weeks) and 28-30 weeks of gestation, which was independent of the viral load level and gestational age of quantification (r = 0.942, P < 0.001). Univariate analysis showed that positive hepatitis B e antigen (HBeAg), maternal age <35 years old and body mass index ≤21 kg/m² were associated with a higher mean viral load at 28-30 weeks of gestation (P < 0.05). These factors were also associated with a higher chance of viral load >6, 7 and 8 log₁₀  IU/mL at 28-30 weeks (P < 0.05). In multiple regression analysis, only the viral load of <22 weeks and positive HBeAg remained predictive of a higher mean viral load at 28-30 weeks of gestation (P < 0.05). The receiver operating characteristic curve showed that the HBV DNA of <22 weeks was an excellent predictor for different viral load cut-offs at 28-30 weeks. The area under curve was 0.986, 0.998 and 0.994 for viral load 6, 7 and 8 log₁₀  IU/mL, respectively.

CONCLUSIONS

HBV DNA quantification should be performed before 22 weeks of gestation. Viral load cut-offs similar to those at 28 weeks can be used to determine immunoprophylaxis failure at earlier gestation. Maternal positive HBeAg status was associated with a higher chance of viral load >6, 7 or 8 log₁₀  IU/mL.

Is hepatitis B antigen in cord blood an immunotolerogen playing a critical role in the pathogenesis of chronic hepatitis B?

Recently, we showed that infants with or without fetal hepatitis B e antigen (HBeAg) exposure had comparable antibody response to hepatitis B vaccination and proposed that fetal HBeAg exposure appears to not induce immunotolerance to HBV. Here, we summarized the different results on the topic of fetal HBeAg exposure in inducing immunotolerance to HBV nucleocapsid protein, and the evidence to back up that the tendency of high infection rate in infants of HBeAg-positive mothers is more likely associated with higher maternal viral loads and is less likely associated with the fetal HBeAg exposure. We consider that whether fetal HBeAg exposure plays an important role in the pathogenesis of chronic HBV infection remains to be an open question.

Prevention of perinatal hepatitis B virus transmission

PURPOSE

Chronic hepatitis B virus (HBV) infection remains endemic and continues to cause significant morbidity and mortality. It is a global health issue and the World Health Organization aims to eradicate HBV by 2030. Since vertical transmission accounts for the majority of chronic HBV infection, pregnancy offers an excellent opportunity to achieve complete HBV eradication by providing effective immunization of the offspring.

METHODS

We reviewed recent publications identified from PubMed database using a combination of the relevant keywords for HBV, pregnancy, vertical transmission, immunoprophylaxis failure and antiviral treatment.

RESULTS

We summarized the evidence of factors associated with, and measures to reduce and prevent maternal to child transmission, including the use of antiviral treatment during pregnancy to prevent immunoprophylaxis failure. Evidence suggested that highly viremia mother can be offered antenatal antiviral treatment to prevent immunoprophylaxis failure. We elaborated the viral load threshold to start maternal antiviral treatment and the importance of timely neonatal vaccination. A clinical algorithm to manage HBV carriers during pregnancy was proposed.

CONCLUSION

Eradication of HBV is achievable with optimal management of HBV carriers, especially during pregnancy by interruption of vertical transmission. Routine antenatal screening and neonatal immunoprophylaxis remain the key measures to reduce the global HBV burden, and additional antenatal antiviral treatment could further minimize the chance of persistent infection in newborns.

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.

Comparison of antibody response to hepatitis B vaccination in infants with positive or negative maternal hepatitis B e antigen (HBeAg) in cord blood: implication for the role of HBeAg as an immunotolerogen

Hepatitis B e antigen (HBeAg) has been considered to cause immunotolerance to hepatitis B virus (HBV) in newborn infants after fetal HBeAg exposure. This study compared anti-HBs responses to hepatitis B vaccination in infants who were born to HBeAg-positive and -negative mothers respectively, to investigate whether fetal HBeAg exposure may induce immunotolerance to HBV. Totally 265 infants who received recommended neonatal immunoprophylaxis against hepatitis B and had no HBV infection were included. Anti-HBs levels were compared between 124 infants with cord blood positive HBeAg and 141 infants with cord blood negative HBeAg at 7-12 months of age. The infants in two groups had similar age at the follow-up (10.0 ± 2.3 vs 10.1 ± 2.3 months, P = 0.590). Overall, 259 (97.7%) of 265 infants achieved anti-HBs levels (mIU/ml) ≥10 and 6 (2.3%) others had anti-HBs <10. Of 124 HBeAg-positive infants at birth, 46.0%, 39.5%, 12.1%, and 2.4% had anti-HBs levels (mIU/ml) ≥1000, 100-999.9, 10-99.9, and <10, respectively. Of 141 HBeAg-negative infants at birth, 35.5%, 48.9%, 13.5%, and 2.1% showed ≥1000, 100-999.9, 10-99.9, and <10, respectively. The proportions of each anti-HBs level between the two groups were comparable (all P > 0.05). Additionally, the distribution of anti-HBs response levels were also comparable in infants with high and low HBeAg levels (P = 0.818). In conclusions, the fetal HBeAg exposure does not inhibit the antibody response to neonatal hepatitis B vaccination. The data suggest that HBeAg appears not inducing immunotolerance to HBV.

Pattern and predictors of medical care received by hepatitis B carriers during pregnancy and after delivery

OBJECTIVE

The objective of the study is to evaluate the pattern and predictors of medical care received by hepatitis B virus (HBV) carriers during pregnancy and after delivery in Hong Kong.

STUDY DESIGN

The study is a retrospective analysis.

METHODS

Pregnant HBV carriers and their infants were followed up for 9-12 months after delivery. Face-to-face interviews were conducted to investigate what medical care they received for HBV before, during and after pregnancy.

RESULTS

Data were available for 412 HBV carriers. A total of 375 (91.0%) women were known HBV carriers before pregnancy. Routine antenatal screening picked out the remaining 37 (9.0%) HBV carriers; these women were younger, more likely to be smokers and had a lower level of education (P < 0.05) than known HBV carriers. In total, 356 of 412 (86.4%) HBV carriers did not receive any medical care for HBV during pregnancy. Known HBV carrier status, history of medical check-up and the use of antiviral treatment before pregnancy were significant predictors for HBV medical care during pregnancy (P < 0.05). The results show that 217 of 412 (52.6%) HBV carriers did not receive medical care for HBV after delivery. HBV medical care before pregnancy, use of antiviral treatment before pregnancy and a higher level of education were significant predictors for postpartum HBV medical care (P < 0.05). Multivariate analysis showed that HBV medical care before pregnancy (odds ratio [OR], 7.73; 95% confidence interval [CI], 3.21-18.65; P < 0.001) and the use of antiviral treatment (OR, 5.02; 95% CI, 1.41-17.81; P = 0.013) were associated with medical care during pregnancy. Medical care before pregnancy was also associated with postpartum HBV medical care (OR, 5.05; 95% CI, 3.29-7.51; P < 0.001).

CONCLUSIONS

A significant proportion of HBV carriers did not receive HBV-related medical check-ups during and after pregnancy in Hong Kong despite the majority being aware of their carrier status. Medical care before pregnancy predicted antenatal and postpartum HBV medical care.

The effect of rupture of membranes and labour on the risk of hepatitis B vertical transmission: Prospective multicentre observational study

OBJECTIVE

To evaluate the effect of rupture of membranes and labour on the risk of hepatitis B virus (HBV) vertical transmission.

STUDY DESIGN

A prospective multicentre observational study was carried out in Hong Kong between 2014-2016. Pregnant HBV carriers were recruited. The duration of rupture of membranes, labour and mode of delivery were collected prospectively. HBV DNA was examined at 28-30 weeks of gestation. All newborns received standard HBV vaccination and immunoglobulin. Hepatitis B surface antigen of infants was tested at 9-12 months of age.

RESULTS

641 pregnancies were recruited and analyzed. No statistically significant difference was found in gravida, parity, gestational age at delivery, mode of delivery, duration of rupture of membranes, duration of labour, preterm delivery, preterm rupture of membranes or birth weight (p > 0.05). Subgroup analysis in viral load > 7log₁₀IU/ml and 8log₁₀IU/ml also did not find a significant association between duration of rupture of membranes and labour with immunoprophylaxis failure.

CONCLUSIONS

Duration of rupture of membranes and labour would not affect the risk of HBV vertical transmission in infants following standard HBV vaccination and hepatitis B immunoglobulin administration.

In pursuit of control and elimination: update on hepatitis A and B epidemiology and prevention strategies

PURPOSE OF REVIEW

This review describes the impact of recommendations for routine immunization of infants and children against hepatitis A and hepatitis B, the changing epidemiology of these infections, and the remaining challenges to controlling or eliminating these diseases in the United States.

RECENT FINDINGS

Rates of hepatitis A and B have significantly declined because of childhood vaccination programs and long-term protection provided by infant immunization. However, hepatitis A immunization rates remain lower than other vaccines, and outbreaks continue to occur in part due to a growing number of susceptible adults. The Advisory Committee on Immunization Practice has updated pre and postexposure prophylaxis and travel recommendations for hepatitis A prevention in young infants, as well as recommendations to reduce ongoing perinatal transmission of hepatitis B.

SUMMARY

Pediatric healthcare providers should continue to immunize all infants against hepatitis A and B and ensure that no child outgrows the pediatric practice without being vaccinated. To address hepatitis A, providers should be aware of new recommendations for unimmunized travelers, use vaccines to prevent and control outbreaks, and ensure postexposure prophylaxis. Universal vaccination of infants against hepatitis B should begin before hospital discharge. The prevention of perinatal transmission is critical for control and possible eradication of hepatitis B.