Measures to reduce mother-to-child transmission of Hepatitis B virus in China: a meta-analysis

Society for Maternal-Fetal Medicine Consult Series #69: Hepatitis B in pregnancy: updated guidelines

More than 290 million people worldwide, and almost 2 million people in the United States, are infected with hepatitis B virus, which can lead to chronic hepatitis B, a vaccine-preventable communicable disease. The prevalence of chronic hepatitis B infection in pregnancy is estimated to be 0.7% to 0.9% in the United States, with >25,000 infants born annually at risk for chronic infection due to perinatal transmission. Given the burden of disease associated with chronic hepatitis B infection, recent national guidance has expanded both the indications for screening for hepatitis B infection and immunity and the indications for vaccination. The purpose of this document is to aid clinicians caring for pregnant patients in screening for hepatitis B infection and immunity status, discuss the perinatal risks of hepatitis B infection in pregnancy, determine whether treatment is indicated for maternal or perinatal indications, and recommend hepatitis B vaccination among susceptible patients. The following are the Society for Maternal-Fetal Medicine recommendations: (1) we recommend triple-panel testing (hepatitis B surface antigen screening, antibody to hepatitis B surface antigen, and total antibody to hepatitis B core antigen) at the initial prenatal visit if not previously documented or known to have been performed (GRADE 1C); (2) we recommend universal hepatitis B surface antigen screening alone at the initial prenatal care visit for all pregnancies where there has been a previously documented negative triple-panel test (GRADE 1B); (3) we recommend that individuals with unknown hepatitis B surface antigen screening status be tested on any presentation for care in pregnancy; we also recommend that those with clinical hepatitis or those with risk factors for acute hepatitis B infection be tested at the time of admission to a birthing facility when delivery is anticipated (GRADE 1B); (4) we do not recommend altering routine intrapartum care in individuals chronically infected with hepatitis B; administration of neonatal immunoprophylaxis is standard of care in these situations (GRADE 1B); (5) we do not recommend cesarean delivery for the sole indication of reducing perinatal hepatitis B virus transmission (GRADE 1B); (6) we recommend that individuals with HBV infection can breastfeed as long as the infant has received immunoprophylaxis at birth (GRADE 1C); (7) we suggest individuals with hepatitis B infection who desire invasive testing may have the procedure performed after an informed discussion on risks and benefits in the context of shared decision-making and in the context of how testing will affect clinical care (GRADE 2C); (8) in individuals with hepatitis viral loads >200,000 IU/mL (>5.3 log 10 IU/mL), we recommend antiretroviral therapy with tenofovir (tenofovir alafenamide at 25 mg daily or tenofovir disoproxil fumarate at 300 mg daily) in the third trimester (initiated at 28-32 weeks of gestation) as an adjunctive strategy to immunoprophylaxis to reduce perinatal transmission (GRADE 1B); (9) we recommend administering hepatitis B vaccine and hepatitis B immunoglobin within 12 hours of birth to all newborns of hepatitis B surface antigen-positive pregnant patients or those with unknown or undocumented hepatitis B surface antigen status, regardless of whether antiviral therapy has been given during the pregnancy to the pregnant patient (GRADE 1B); and (10) we recommend hepatitis B vaccination in pregnancy for all individuals without serologic evidence of immunity or documented history of vaccination (GRADE 1C).

Enhancing interventions for prevention of mother-to-child- transmission of hepatitis B virus

Prevention of mother-to-child transmission of hepatitis B virus (HBV) infection is a cornerstone of efforts to support progress towards elimination of viral hepatitis. Current guidelines recommend maternal screening, antiviral therapy during the third trimester of high-risk pregnancies, universal and timely HBV birth dose vaccination, and post-exposure prophylaxis with hepatitis B immunoglobulin for selected neonates. However, serological and molecular diagnostic testing, treatment and HBV vaccination are not consistently deployed, particularly in many high endemicity settings, and models predict that global targets for reduction in paediatric incidence will not be met by 2030. In this article, we briefly summarise the evidence for current practice and use this as a basis to discuss areas in which prevention of mother-to-child transmission can potentially be enhanced. By reducing health inequities, enhancing pragmatic use of resources, filling data gaps, developing advocacy and education, and seeking consistent investment from multilateral agencies, significant advances can be made to further reduce vertical transmission events, with wide health, societal and economic benefits.

Spatiotemporal and Seasonal Trends of Class A and B Notifiable Infectious Diseases in China: A Retrospective Analysis (Preprint)

BACKGROUND

China is the most populous country globally and has made significant achievements in the control of infectious diseases over the last decades. The 2003 SARS epidemic triggered the initiation of the China Information System for Disease Control and Prevention (CISDCP). Since then, numerous studies have investigated the epidemiological features and trends of individual infectious diseases in China; however, few considered the changing spatiotemporal trends and seasonality of these infectious diseases over time.

OBJECTIVE

This study aims to systematically review the spatiotemporal trends and seasonal characteristics of class A and class B notifiable infectious diseases in China during 2005-2020.

METHODS

We extracted the incidence and mortality data of 8 types (27 diseases) of notifiable infectious diseases from the CISDCP. We used the Mann-Kendall and Sen's methods to investigate the diseases' temporal trends, Moran I statistic for their geographical distribution, and circular distribution analysis for their seasonality.

RESULTS

Between January 2005 and December 2020, 51,028,733 incident cases and 261,851 attributable deaths were recorded. Pertussis (P=.03), dengue fever (P=.01), brucellosis (P=.001), scarlet fever (P=.02), AIDS (P<.001), syphilis (P<.001), hepatitis C (P<.001) and hepatitis E (P=.04) exhibited significant upward trends. Furthermore, measles (P<.001), bacillary and amebic dysentery (P<.001), malaria (P=.04), dengue fever (P=.006), brucellosis (P=.03), and tuberculosis (P=.003) exhibited significant seasonal patterns. We observed marked disease burden-related geographic disparities and heterogeneities. Notably, high-risk areas for various infectious diseases have remained relatively unchanged since 2005. In particular, hemorrhagic fever and brucellosis were largely concentrated in Northeast China; neonatal tetanus, typhoid and paratyphoid, Japanese encephalitis, leptospirosis, and AIDS in Southwest China; BAD in North China; schistosomiasis in Central China; anthrax, tuberculosis, and hepatitis A in Northwest China; rabies in South China; and gonorrhea in East China. However, the geographical distribution of syphilis, scarlet fever, and hepatitis E drifted from coastal to inland provinces during 2005-2020.

CONCLUSIONS

The overall infectious disease burden in China is declining; however, hepatitis C and E, bacterial infections, and sexually transmitted infections continue to multiply, many of which have spread from coastal to inland provinces.

The safety and efficacy of tenofovir disoproxil fumarate used throughout pregnancy for mothers with chronic hepatitis B

BACKGROUND

Antiviral therapy throughout pregnancy in women with chronic hepatitis B (CHB) during pregnancy has been suggested; however, the data of tenofovir disoproxil fumarate (TDF) are limited. The aim of this study was to evaluate the safety and efficiency in women with CHB.

METHODS

It was a single-center, retrospectively study. Eighty-one women received TDF 300 mg/day before pregnancy. Sixty-three women did not receive antiviral treatment. All infants in both groups received immunoprophylaxis. Mothers and infants were followed at least postpartum 7 months. The primary endpoint was the safety of mothers and infants. The secondary endpoints were mother-to-child transmission (MTCT) rate and hepatitis B virus (HBV) DNA suppression.

RESULTS

TDF was well tolerated in the mothers. The rates of neonatal congenital abnormalities were similar between the two groups (3.7% or 3/81 versus 3.3% or 2/63, P = 1.000). There were also no significant differences in infant length and weight, Apgar score (1 minute), rate of low birth weight, gestational age, or rate of cesarean section between the two groups. TDF significantly reduced the viral load (3.4 ± 0.5 log IU/mL versus 6.3 ± 1.5 log IU/mL, P < 0.001) and the ALT levels (19.9 ± 10.2 versus 46.8 ± 44.8 U/L, P < 0.001) before delivery. At 7-month postpartum, the MTCT rate was 0% in the TDF-treated group when compared with 6.3% (4/63) in the untreated group (P = 0.035).

CONCLUSION

TDF used throughout pregnancy can safely reduce the rate of MTCT.

Efficacy of antiviral therapy during the second or the third trimester for preventing mother-to-child hepatitis B virus transmission: a systematic review and meta-analysis

For pregnant women with high viral load, antiviral therapy has been administered in addition to active and passive immune prophylaxis as a crucial adjunctive therapy to interrupt mother-to-child hepatitis B virus (HBV) transmission (MTCT). However, the time of antiviral therapy onset remains controversial. A systematic review and meta-analysis was conducted to compare the efficacy of antiviral therapy during the second or the third trimester for prevention of HBV vertical transmission. We searched nine databases for observational studies and randomized controlled trials that enrolled pregnant women with positive HBsAg treated with antivirals. The outcomes of interest were maternal HBV-DNA levels prior to delivery and the rates of HBV MTCT. We included nine studies that enrolled 1,502 pregnant women. The average HBV-DNA level before treatment was approximately 8 log₁₀ copies/mL. Compared to the onset of antiviral intervention in the third trimester, the beginning of treatment in the second trimester distinctly reduced maternal predelivery HBV-DNA levels. However, no significant difference in HBV MTCT was found between the second and third trimester groups. Furthermore, the subgroup analysis showed that there were no significant differences between groups beginning treatment at different times (second or third trimester) with regard to HBV MTCT or other evaluated endpoints. For pregnant women with HBV-DNA levels less than or equal to 8 log₁₀ copies/mL, the beginning of antiviral treatment can be delayed until the third trimester.

Hepatitis B infection and risk factors among children living with HIV in Yaounde, Cameroon: an integrated management

Background

The endemicity of hepatitis B virus (HBV) prompted the systematic immunization of newborns in Cameroon since 2005. In the frame of a considerable burden of HIV/HBV co-infection (17.5%), monitoring HBV among children living with HIV (CLHIV) would guide toward HIV/HBV integrated paediatric care. We sought to ascertain the prevalence and determinants of HBV infection in the population of CLHIV and performance of commonly used rapid diagnosis tests (RDTs).

Methods

Cross-sectional study conducted from February through June 2017 in a subset of CLHIV ≤15 years old at the Essos Hospital Centre, Yaounde, Cameroon. HBV was tested by HBsAg ELISA sandwich in duplicates for each sample, and the mean optical density was calculated. The Determinants of HBV-prevalencewere evaluated, and p < 0.05 was the significance threshold. The performance of two HBV RDTs (Diaspot vs. HBV-5) was evaluated in comparison to ELISA (used as gold standard).

Results

Of the 83 CLHIV enrolled (54.2% female, mean age 8.7 [±3.8] years, 60% vaccinated against HBV, all breastfed), HBV-prevalence was 2.41% (2/83). HBV-positivity was significantly associated with unknown maternal HBV status (2.9% [2/69] vs. 0.0% [0/14], p = 0.0097) and vaginal delivery (2.4% [2/82] vs. 0.0% [0/1], p = 0.0018). Moreover, the most likely to be positive were aged 11 and 15 years, and had experienced neither anti-HBV vaccination nor anti-HBV serum administration, and both had not been treated with any antiseptic solution at birth. Regarding the performance of Diaspot vs. HBV-5 respectively, sensitivity was 100% (2/2) vs. 50% (1/2), while specificity was 100% (45/45) vs. 97.8% (44/45); positive and negative predictive values of Diaspot versus HBV-5 were respectively 100% (2/2) and 100% (45/45) versus 50% (1/2) and 97.8% (44/45).

Conclusion

HBV-infection in the population of CLHIV appears at a moderate prevalence, suggesting a decreased burden likely due to preventive measures including the wide vaccine coverage. Focusing on mothers with unknown HBV status and promoting safer delivery mode (caesarean section) for HBV-positive motherswould contribute toward pediatric HBV elimination. In context of limited resources, Diaspot test appears more reliable to rollout HBV-infection in the population of CLHIV. As findings are limited to a small sample size, studies on a wider population would be relevant.

A Functional Variant in Ubiquitin Conjugating Enzyme E2 L3 Contributes to Hepatitis B Virus Infection and Maintains Covalently Closed Circular DNA Stability by Inducing Degradation of Apolipoprotein B mRNA Editing Enzyme Catalytic Subunit 3A

Hepatitis B virus (HBV) infection is a common infectious disease, in which nuclear covalently closed circular DNA (cccDNA) plays a key role in viral persistence, viral reactivation after treatment withdrawal, and drug resistance. A recent genome-wide association study has identified that the ubiquitin conjugating enzyme E2 L3 (UBE2L3) gene is associated with increased susceptibility to chronic HBV (CHB) infection in adults. However, the association between UBE2L3 and children with CHB and the underlying mechanism remain unclear. In this study, we performed two-stage case-control studies including adults and independent children in the Chinese Han population. The rs59391722 allele in the promoter of the UBE2L3 gene was significantly associated with HBV infection in both adults and children, and it increased the promoter activity of UBE2L3. Serum UBE2L3 protein levels were positively correlated with HBV viral load and hepatitis B e antigen (HBeAg) levels in children with CHB. In an HBV infection cell model, UBE2L3 knockdown significantly reduced total HBV RNAs, 3.5-kb RNA, as well as cccDNA in HBV-infected HepG2-Na+ /taurocholate cotransporting polypeptide cells and human primary hepatocytes. A mechanistic study found that UBE2L3 maintained cccDNA stability by inducing proteasome-dependent degradation of apolipoprotein B mRNA editing enzyme catalytic subunit 3A, which is responsible for the degradation of HBV cccDNA. Moreover, interferon-α (IFN-α) treatment markedly decreased UBE2L3 expression, while UBE2L3 silencing reinforced the antiviral activity of IFN-α on HBV RNAs, cccDNA, and DNA. rs59391722 in UBE2L3 was correlated with HBV DNA suppression and HBeAg loss in response to IFN-α treatment of children with CHB. Conclusion: These findings highlight a host gene, UBE2L3, contributing to the susceptibility to persistent HBV infection; UBE2L3 may be involved in IFN-mediated viral suppression and serve as a potential target in the prevention and treatment of HBV infection.

Lamivudine use in pregnant HBsAg-females effectively reduces maternal viremia

BACKGROUND AND STUDY AIMS

Mother-infant hepatitis B virus (HBV) transmission is the current leading cause of chronic infection. We aimed to assess the efficacy of lamivudine use in hepatitis B surface antigen (HBsAg)-positive pregnant women to decrease viral load and thus aid in the prevention of transmission.

PATIENTS AND METHODS

A study of 73 mother-infant pairs. All mono-infected HBsAg-positive pregnant females of any age, who were a candidate for lamivudine during pregnancy were recruited, and a comparison group of HBsAg-positive pregnant females who did not receive any antiviral treatment. All infants received HBV immunoglobulin and vaccine at birth and completed the vaccination schedule and tested after 6 months of age. HBV viral markers and viral load quantitation were performed to all enrolled participants.

RESULTS

34 (46.6%) females were enrolled in the lamivudine group; 9 (26.5%) received the drug in the last trimester, 25 (73.5%) all through. The comparison group was 39 (53.4%) females; 32 (82.1%) were not candidate for antiviral during pregnancy, and 7 (17.9%) were diagnosed late near delivery. Seventy-one infants tested after full immunization, with their ages ranged between 6.5 and 18 months. Only one infant (1.4%) was positive for HBsAg and HBV DNA in the non-treated group. Maternal viremia near delivery showed a significant reduction in cases that used lamivudine during pregnancy.

CONCLUSION

The use of lamivudine during pregnancy can effectively lower maternal viral load. Timely conducted post-vaccination serological testing is crucial to detect positive cases and immunize susceptible infants.

Spatio-Temporal Epidemiology of Viral Hepatitis in China (2003-2015): Implications for Prevention and Control Policies

Viral hepatitis, as one of the most serious notifiable infectious diseases in China, takes heavy tolls from the infected and causes a severe economic burden to society, yet few studies have systematically explored the spatio-temporal epidemiology of viral hepatitis in China. This study aims to explore, visualize and compare the epidemiologic trends and spatial changing patterns of different types of viral hepatitis (A, B, C, E and unspecified, based on the classification of CDC) at the provincial level in China. The growth rates of incidence are used and converted to box plots to visualize the epidemiologic trends, with the linear trend being tested by chi-square linear by linear association test. Two complementary spatial cluster methods are used to explore the overall agglomeration level and identify spatial clusters: spatial autocorrelation analysis (measured by global and local Moran's I) and space-time scan analysis. Based on the spatial autocorrelation analysis, the hotspots of hepatitis A remain relatively stable and gradually shrunk, with Yunnan and Sichuan successively moving out the high-high (HH) cluster area. The HH clustering feature of hepatitis B in China gradually disappeared with time. However, the HH cluster area of hepatitis C has gradually moved towards the west, while for hepatitis E, the provincial units around the Yangtze River Delta region have been revealing HH cluster features since 2005. The space-time scan analysis also indicates the distinct spatial changing patterns of different types of viral hepatitis in China. It is easy to conclude that there is no one-size-fits-all plan for the prevention and control of viral hepatitis in all the provincial units. An effective response requires a package of coordinated actions, which should vary across localities regarding the spatial-temporal epidemic dynamics of each type of virus and the specific conditions of each provincial unit.

Comparative Effectiveness of Prophylactic Strategies for Perinatal Transmission of Hepatitis B Virus: A Network Meta-analysis of Randomized Controlled Trials

BACKGROUND

Perinatal transmission is the main route of hepatitis B virus (HBV) transmission. While several measures have been attempted as means of preventing perinatal HBV transmission, the optimal strategy remains inconclusive.

METHODS

We conducted a comprehensive search, through December 2016, for randomized controlled trials (RCTs) that compared the following measures among pregnant women with HBV infection: placebo/none, active immunoprophylaxis (hepatitis B vaccine series starting at birth [HBVac]), passive-active immunoprophylaxis (hepatitis B immunoglobulin and vaccine [HBIG+HBVac]), prenatal HBIG administration (HBIG/HBIG+HBVac), and prenatal antiviral therapy (AVT/HBIG+HBVac). Direct, indirect, and network meta-analyses were performed for all treatment comparisons.

RESULTS

Fifteen RCTs involving 2706 infants of HBV carrier mothers were eligible for analysis. Network meta-analysis demonstrated similar results as direct and indirect comparisons. HBVac alone significantly reduced the risk of hepatitis B infection in infants of HBV carrier mothers (relative risk [RR], 0.32; 95% confidence interval [CI], 0.21-0.50). The combination of immunoglobulin with vaccine is superior to vaccine alone (RR, 0.37; 95% CI, 0.20-0.67). Prenatal HBIG administration and antiviral therapy offer further advantages over current passive-active immunoprophylaxis for infants of highly viremic (HBV DNA level higher than 2 × 105 IU/mL) mothers (RR, 0.47; 95% CI, 0.29-0.75; and RR, 0.31; 95% CI, 0.10-0.99, respectively). There was no significant publication bias.

CONCLUSIONS

Based on the universal infantile vaccination program, HBIG for infants born to HBV carrier mothers further reduces transmission. For highly viremic mothers whose children are still at risk for transmission under current immunoprophylaxis, prenatal HBIG administration or antiviral therapy in late pregnancy may be considered if more long-term evidence supports its efficacy and safety.

Immunization against Viral Hepatitis B: Lessons Learnt from Kingdom of Cambodia

An account of immunization against hepatitis B virus in Cambodia is given.

How to cite this article: Sreng B, Vichit O, Vuthikol Y, Aun C, Samnang C. Immunization against Viral Hepatitis B: Lessons Learnt from Kingdom of Cambodia. Euroasian J Hepato-Gastroenterol 2017;7(1):43-47.

Hepatitis B immunoglobulin during pregnancy for prevention of mother-to-child transmission of hepatitis B virus

BACKGROUND

Hepatitis is a viral infection of the liver. It is mainly transmitted between people through contact with infected blood, frequently from mother to baby in-utero. Hepatitis B poses significant risk to the fetus and up to 85% of infants infected by their mothers at birth develop chronic hepatitis B virus (HBV) infection. Hepatitis B immunoglobulin (HBIG) is a purified solution of human immunoglobulin that could be administered to the mother, newborn, or both. HBIG offers protection against HBV infection when administered to pregnant women who test positive for hepatitis B envelope antigen (HBeAg) or hepatitis B surface antigen (HBsAg), or both. When HBIG is administered to pregnant women, the antibodies passively diffuse across the placenta to the child. This materno-fetal diffusion is maximal during the third trimester of pregnancy. Up to 1% to 9% infants born to HBV-carrying mothers still have HBV infection despite the newborn receiving HBIG plus active HBV vaccine in the immediate neonatal period. This suggests that additional intervention such as HBIG administration to the mother during the antenatal period could be beneficial to reduce the transmission rate in utero.

OBJECTIVES

To determine the benefits and harms of hepatitis B immunoglobulin (HBIG) administration to pregnant women during their third trimester of pregnancy for the prevention of mother-to-child transmission of hepatitis B virus infection.

SEARCH METHODS

We searched the The Cochrane Hepato-Biliary Group Controlled Trials Register, CENTRAL, MEDLINE Ovid, Embase Ovid, Science Citation Index Expanded (Web of Science), SCOPUS, African Journals OnLine, and INDEX MEDICUS up to June 2016. We searched ClinicalTrials.gov and portal of the WHO International Clinical Trials Registry Platform (ICTRP) in December 2016.

SELECTION CRITERIA

We included randomised clinical trials comparing HBIG versus placebo or no intervention in pregnant women with HBV.

DATA COLLECTION AND ANALYSIS

Two authors extracted data independently. We analysed dichotomous outcome data using risk ratio (RR) and continuous outcome data using mean difference (MD) with 95% confidence intervals (CI). For meta-analyses, we used a fixed-effect model and a random-effects model, along with an assessment of heterogeneity. If there were statistically significant discrepancies in the results, we reported the more conservative point estimate. If the two estimates were equal, we used the estimate with the widest CI as our main result. We assessed bias control using the Cochrane Hepato-Biliary Group suggested bias risk domains and risk of random errors using Trial Sequential Analysis (TSA). We assessed the quality of the evidence using GRADE.

MAIN RESULTS

All 36 included trials originated from China and were at overall high risk of bias. The trials included 6044 pregnant women who were HBsAg, HBeAg, or hepatitis B virus DNA (HBV-DNA) positive. Only seven trials reported inclusion of HBeAg-positive mothers. All 36 trials compared HBIG versus no intervention. None of the trials used placebo.Most of the trials assessed HBIG 100 IU (two trials) and HBIG 200 IU (31 trials). The timing of administration of HBIG varied; 30 trials administered three doses of HBIG 200 IU at 28, 32, and 36 weeks of pregnancy. None of the trials reported all-cause mortality or other serious adverse events in the mothers or babies. Serological signs of hepatitis B infection of the newborns were reported as HBsAg, HBeAg, and HBV-DNA positive results at end of follow-up. Twenty-nine trials reported HBsAg status in newborns (median 1.2 months of follow-up after birth; range 0 to 12 months); seven trials reported HBeAg status (median 1.1 months of follow-up after birth; range 0 to 12 months); and 16 trials reported HBV-DNA status (median 1.2 months of follow-up; range 0 to 12 months). HBIG reduced mother-to-child transmission (MTCT) of HBsAg when compared with no intervention (179/2769 (6%) with HBIG versus 537/2541 (21%) with no intervention; RR 0.30, TSA-adjusted CI 0.20 to 0.52; I² = 36%; 29 trials; 5310 participants; very low quality evidence). HBV-DNA reduced MTCT of HBsAg (104/1112 (9%) with HBV-DNA versus 382/1018 (38%) with no intervention; RR 0.25, TSA-adjusted CI 0.22 to 0.27; I² = 84%; 16 trials; 2130 participants; low quality evidence). TSA supported both results. Meta-analysis showed that maternal HBIG did not decrease HBeAg in newborns compared with no intervention (184/889 (21%) with HBIG versus 232/875 (27%) with no intervention; RR 0.68, TSA-adjusted CI 0.04 to 6.37; I² = 90%; 7 trials; 1764 participants; very low quality evidence). TSA could neither support nor refute this observation as data were too sparse. None of the trials reported adverse events of the immunoglobulins on the newborns, presence of local and systemic adverse events on the mothers, or cost-effectiveness of treatment.

AUTHORS' CONCLUSIONS

Due to very low to low quality evidence found in this review, we are uncertain of the effect of benefit of antenatal HBIG administration to the HBV-infected mothers on newborn outcomes, such as HBsAg, HBV-DNA, and HBeAg compared with no intervention. The results of the effects of HBIG on HBsAg and HBeAg are surrogate outcomes (raising risk of indirectness), and we need to be critical while interpreting the findings. We found no data on newborn mortality or maternal mortality or both, or other serious adverse events. Well-designed randomised clinical trials are needed to determine the benefits and harms of HBIG versus placebo in prevention of MTCT of HBV.

Hepatitis B Virus (HBV) Load Response to 2 Antiviral Regimens, Tenofovir/Lamivudine and Lamivudine, in HIV/ HBV-Coinfected Pregnant Women in Guangxi, China: The Tenofovir in Pregnancy (TiP) Study

BACKGROUND

 There is limited information on antiviral therapy for hepatitis B virus (HBV) infection among pregnant women coinfected with human immunodeficiency virus (HIV) and HBV.

METHODS

 A phase 2 randomized, controlled trial of a regimen containing tenofovir (TDF)/lamivudine (3TC) and a regimen containing 3TC in HIV/HBV-coinfected pregnant women in China. The HBV virological response was compared in study arms.

RESULTS

 The median decline in the HBV DNA level was 2.60 log10 copies/mL in the TDF/3TC arm and 2.24 log10 copies/mL in the 3TC arm (P = .41). All women achieved HBV DNA levels of <6 log10 copies/mL at delivery.

CONCLUSIONS

 Initiation of either regimen led to achievement of HBV DNA levels below the threshold associated with perinatal HBV transmission.

CLINICAL TRIALS REGISTRATION

 NCT01125696.

Prophylaxis of vertical HBV infection

INTRODUCTION

An appropriate management of HBV infection is the best strategy to finally reduce the total burden of HBV infection. Mother-to-child transmission (MTCT) is responsible for more than one third of chronic HBV infections worldwide. Because HBV infection in infancy or early childhood often leads to chronic infection, appropriate prophylaxis and management of HBV in pregnancy is crucial to prevent MTCT.

AREAS COVERED

The prevention of HBV vertical transmission is a complex task and includes: universal HBV screening of pregnant women, administration of antivirals in the third trimester of pregnancy in women with high viral load and passive-active HBV immunoprophylaxis with hepatitis B vaccine and hepatitis B immune globulin in newborns of all HBV infected women.

EXPERT OPINION

Universal screening of pregnant women for HBV infection, early identification of HBV DNA level in HBV-infected mothers, maternal treatment with class B according to FDA antivirals and passive/active anti-HBV immunoprophylaxis to newborns of HBV-positive mothers are crucial strategies for reducing vertical HBV transmission rates. Consideration of caesarean section in order to reduce the risk of vertical HBV transmission should be recommend in HBV infected pregnant women with high viral load despite antiviral therapy or when the therapy in the third trimester of pregnancy is not available.

Controversy and Strategies Exploration in Blocking Mother-to-Child Transmission of Hepatitis B

Hepatitis B, a serious infectious disease caused by the hepatitis B virus (HBV), remains a worldwide social and public health problem. Hepatitis B has a particularly high incidence rate in the world, whereas approximately 35-50% HBV carriers are infected through vertical transmission. Even after newborn immunoprophylaxis, vertical transmission still accounts for 5-10% in China according to plenty of literature in Chinese language. For these reasons, it is important to determine how to effectively intervene in mother-to-child transmission (MTCT). To date, though, intervention methods and measures remain controversial. In order to understand the mechanism of MTCT intervention further and develop effective preventions and interventions, a comprehensive analysis and presentation on some of its more controversial issues will be given in this paper. And eventually we conclude three measures and strategies for these issues: (1) emancipate the mind and seek truth from facts to understand the controversial issues pertaining to MTCT of HBV; (2) treat the basic rules and changing characteristics of MTCT blocking process of hepatitis B with holistic medical thought dialectically and (3) further explore the interaction of genetic susceptibility and environmental factors of MTCT of hepatitis B.

Viral hepatitis vaccination during pregnancy

Viral hepatitis is a serious global public health problem. It is also a common cause of jaundice and gestational complications in pregnant women. Moreover, infected mothers can transmit the virus to their fetus or neonate, which may increase disease burden and decrease quality of life. To date, commercial vaccines have been developed for hepatitis A, B, and E and are available to the general population. The Advisory Committee on Immunization Practices currently accepts emergency vaccination against hepatitis A and B during pregnancy due to benefits that overweight the potential risks. While there are limited data from trials with limited numbers of samples that suggest the efficacy or safety of hepatitis B and E vaccines in pregnant women, additional data are necessary to provide evidence of vaccination during pregnancy.

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.

Single-nucleotide substitution of Hepatitis B virus in intrauterine infection

The relationship between hepatitis B virus (HBV) gene polymorphism and intrauterine infection has not been completely illuminated. Six pairs of mother and infant from intrauterine infection group and six mothers from nonintrauterine infection group in the previous study were randomly selected and separately divided into group M (Mother group), group N (Neonate group) and group NM (Negative-mother group) in this study. We found that age, gestational weeks, HBsAg titre, HBeAg titre and HBV DNA level of mothers from group M and group NM were not significantly different. Pre-S1/S2 and S regions in HBV genome were amplified, inserted into pUC19 plasmid and sequenced. It was found that all clone sequences clustered into genotype C (AY123041) through the Genotyping tool in NCBI and phylogenetic trees. Compared with AY123041, there were 20 (11 plus 9) mutations significantly different in the three groups. Most of the mutations were synonymous in pre-S1/S2/S region, while mutations of C2990T, T3205A, A167G, C407A, A667T and A680C resulted in amino acid substitution of A90V, S162T, T47A, P127T, L213F and I218L, respectively. In addition, most of the 20 mutations caused amino acid substitution in polymerase region for the tight structure of HBV genome. The occurrence and location of mutations indicated that mutation of C2990T only existing in group NM may serve as an index for nonintrauterine infection. In contrast, the incidence of intrauterine HBV infection from mothers with mutation of T3205A was lower. Then, mutations of G403A, T670G, A673G, A167G, C407A, A667T and A680C may be closely related to intrauterine HBV infection.

[Prophylaxis of mother-to-infant transmission of hepatitis B virus]

Hepatitis B virus (HBV) infection is a worldwide health problem and mother-to-infant (or vertical) transmission is the main source of chronic infection in Asian countries. Administration of HBV vaccine to the infant at birth, with or without concurrent specific immunoglobulin, efficiently prevents such transmission (efficacy>90%). In France, testing Ag HBs is mandatory during pregnancy in all pregnant women. Infants born to Ag HBs-positive mothers should receive the first injection of vaccine and one injection of specific immunoglobulins at birth. Vaccination should thereafter be completed according to a three-injection protocol (at 1 and 6 months) or a four-injection protocol in case of prematurity. Failure of immunoprophylaxis can be observed when the viral load is very high in the mother during pregnancy (HBV-DNA levels>200,000 IU/mL). In such women, antiviral therapy with analogs (lamivudine, telbivudine, or tenofovir) during the third trimester of pregnancy and 1 month post-partum, in association with accurate immunoprophylaxis, may prevent vertical transmission. The optimal cut-off value of maternal viral load for antiviral therapy in late pregnancy and post-partum to prevent vertical transmission is still under debate.

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.

Overview of hepatitis B prevalence, prevention, and management in the Pacific Islands and Territories

There are over 500-750 000 deaths per year because of hepatitis B virus (HBV)-related cirrhosis and liver cancer worldwide and the World Health Organization Western Pacific Region has some of the highest endemic levels of HBV in the world, particularly within China, South East Asia and Pacific Island Countries and Territories (PICT). The PICT have unique ethnic diversity and a very high prevalence of smoking and metabolic syndrome, both important risk factors for liver fibrosis and liver cancer. However, in contrast to many Asian countries, there is little published data on HBV prevalence and related liver disease burden in PICT. In this review, the available published literature and World Health Organization data for HBV prevalence and related liver disease and liver cancer burden in PICT is outlined, and unmet needs for improving HBV prevention and control in the region are highlighted.

Overview and recent trends of systematic reviews and meta-analyses in hepatology

A systematic review (SR) is a research methodology that involves a comprehensive search for and analysis of relevant studies on a specific topic. A strict and objective research process is conducted that comprises a systematic and comprehensive literature search in accordance with predetermined inclusion/exclusion criteria, and an assessment of the risk of bias of the selected literature. SRs require a multidisciplinary approach that necessitates cooperation with clinical experts, methodologists, other experts, and statisticians. A meta-analysis (MA) is a statistical method of quantitatively synthesizing data, where possible, from the primary literature selected for the SR. Review articles differ from SRs in that they lack a systematic methodology such as a literature search, selection of studies according to strict criteria, assessment of risk bias, and synthesis of the study results. The importance of evidence-based medicine (EBM) in the decision-making for public policy has recently been increasing thanks to the realization that it should be based on scientific research data. SRs and MAs are essential for EBM strategy and evidence-based clinical practice guidelines. This review addresses the current trends in SRs and MAs in the field of hepatology via a search of recently published articles in the Cochrane Library and Ovid-MEDLINE.

Vertical transmission of hepatitis B virus: challenges and solutions

More than 240 million people worldwide are chronically infected with hepatitis B virus (HBV). Mother-to-child transmission remains the most important mechanism of infection in countries with a high prevalence of HBV. Universal screening of all pregnant women, at-birth prophylaxis with specific anti-HBV immune globulin, as well as HBV vaccination for newborns of infected mothers are effective in reducing the risk of vertical transmission. However, in cases of a high viral load and hepatitis B e antigen positivity, there is a residual risk of HBV transmission to the newborn despite prophylaxis. This review focuses on the above-indicated strategies and on the efficacy and safety of antiviral drugs administered during the third trimester of pregnancy.

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.