Chronic hepatitis B in Asian women of childbearing age

Relationship between different hepatitis B virus infection status and gestational diabetes mellitus prevalence among pregnant women with chronic HBV infection: A retrospective study

To investigate the relationships between different hepatitis B virus (HBV) infection status and gestational diabetes mellitus (GDM) and analyse the potential risk factors, we conducted an observational retrospective study in HBV-infected pregnant women to compare the differences of GDM prevalence and clinical outcomes between groups divided by HBV infection status. Spearman's correlation coefficient was used to evaluate the correlations among hepatitis B e antigen (HBeAg), HBV DNA and liver function. Logistic regression model was used to analyse the risk factors. In all, 1390 HBsAg-positive pregnant women were enrolled. HBeAg titre and HBV DNA, ALT and AST were correlated (r = 0.743, p < 0.001; r = 0.813, p < 0.001). Overall GDM prevalence was 21%. GDM prevalence of HBV-infected women with abnormal liver function was higher than those with normal liver function (26.8% vs. 20%, p = 0.027). Age over 35 years and abnormal liver function over 5 times ULN and 1-2 times ULN were independent risk factors for GDM prevalence with odds ratio (OR) of 1.858 (95% CI 1.227-2.815), 1.589 (95% CI 1.023-2.468) and 2.203 (95% CI 1.029-4.718), respectively. GDM prevalence in HBV-infected pregnancies with abnormal liver function was higher than those with normal liver function. Age over 35 years and abnormal liver function were independent risk factors for GDM in HBV-infected women.

Association of Toll-Like Receptor 2 (TLR2) Expression in Placenta and Intrauterine Exposure to Hepatitis B Virus

Introduction

The placenta is a specialized organ that only performs during pregnancy and serves as an immunological barrier in preventing pathogens to reach the fetus. It has been known that toll-like receptors (TLRs) on the placenta respond to antigens, such as zymosan, lipopolysaccharide, and other viral infections. This study analyzes the distribution of TLR2 protein and hepatitis B DNA virus (HBV DNA) virus identification to gain an understanding of hepatitis B viral transmission from the mother to child.

Methods

We performed enzyme-linked immunoadsorbent assay of HBeAg, HBsAg titer, Anti-HBs, and Anti-HBc to 59 HBsAg-positive pregnant women and identified HBV DNA using nested PCR in their cord blood during delivery for evidence of exposure to HBV DNA. The expression of TLR2 protein in the placenta was performed using immunohistochemistry analysis.

Results

Intrauterine exposure to the hepatitis B virus occurred in 69.5% of all pregnant women who were HbsAg positive. TLR2 expression was predominantly identified in syncytiotrophoblast and cytotrophoblast cells with the highest score in mothers aged 20–35 years (75%), multigravida (58.3%), and mothers with term pregnancies (70.8%). Statistical analysis results showed that placental TLR2 expression did not indicate any association with hepatitis B virus DNA identified in cord blood with a p value of 0.730 and an OR of 0.650 (95% CI 0.173–2.440).

Conclusion

TLR2 expression is not associated with intrauterine exposure of hepatitis B virus.

Determinants of overall knowledge and health behaviours in relation to hepatitis B and C among ever-married women in Pakistan: evidence based on Demographic and Health Survey 2017-18

Background

In 2019, around 5 million and 10 million people were affected by hepatitis B virus (HBV) and hepatitis C virus (HCV) respectively in Pakistan. On World Hepatitis Day 2019, Pakistan’s Government announced the Prime Minister’s Plan to eliminate HBV and HCV from the country by 2030. In order to achieve this goal, adequate knowledge about HBV and HCV regarding mode of transmission, symptoms of the disease, and awareness about available treatments and vaccines is imperative. The present study aims to investigate the determinants related to overall knowledge about and behaviour in relation to HBV and HCV amongst married women in Pakistan.

Methods

Secondary data analysis was carried out using the Pakistan Demographic and Health Survey (PDHS) 2017–18. A series of questions regarding women’s knowledge about how to avoid HBV and HCV and their health behaviour in relation to HBV and HCV were posed to 12,364 ever-married women of reproductive age (15–49 years). Bivariate and multivariable logistic and linear regression was applied to examine the effects of sociodemographic characteristics and covariates on women’s overall knowledge and health behaviour regarding HBV and HCV.

Results

The findings highlight that the majority of women (88.3%) have heard of HBV and HCV. Nonetheless, only 34.8% had comprehensive knowledge about how to avoid HBV and HCV. Few women (11.3%) had been tested for HBV or HCV during the year preceding the survey. Furthermore, the results indicate that women living in urban areas, being older, and having more than 10 years of schooling, reported better knowledge and health behaviours regarding HBV and HCV.

Conclusion

This study provides evidence that women’s sociodemographic characteristics create differences in their overall knowledge about and attitudes towards HBV and HCV. This research emphasized that there is a need to create awareness about the causes and prevention of HBV and HCV in order to achieve the goal of eliminating these diseases in Pakistan by 2030.

A Nomogram for Predicting Non-Rebound in HBV-Infected Pregnant Women With Mother-to-Child Transmission Prevention

Background: Current guidelines recommend that pregnancies with mother-to-child transmission (MTCT) prevention can cease antiviral treatment after delivery. We aimed to develop a nomogram for predicting non-rebound in HBV-infected pregnant women with MTCT prevention after post-partum nucleos(t)ide analogs (NAs) withdrawal based on parameters before treatment cessation.

Methods: Pregnant women receiving antiviral therapy for MTCT prevention and who withdrew from taking NAs after delivery were included in this study. We used the least absolute shrinkage and selection operator (LASSO) logistics and a two-way stepwise regression to select prognostic factors for the risk model, and the concordance index (C-index) was used to assess its discrimination. Internal validation was performed through bootstrapping.

Results: Of 92 included patients, 16 and 76 experienced non-rebound and virologic rebound within 48 weeks of post-partum NAs cessation, respectively. Platelet to lymphocyte ratio (PLR) at 34 ± 2 weeks of gestation, a reduction in hepatitis B surface antigen (HBsAg) from baseline to 34 ± 2 weeks of gestation, and hepatitis B virus (HBV) DNA declining from baseline to the end of treatment (EOT) were entered into the final risk model. Its C-index was 0.91 (95% CI, 0.82–0.99), and it reached as high as 0.88 after bootstrapping validation. The decision curve and decision tree were further developed to facilitate the application of this model.

Conclusions: We developed a nomogram for predicting non-rebound in pregnant women with MTCT prevention after the withdrawal of antiviral agents, which facilitates physicians in making appropriate treatment recommendations.

Sociocultural barriers to hepatitis B health literacy in an immigrant population: a focus group study in Korean Americans

BACKGROUND

Chronic hepatitis B (CHB) is a major global health issue disproportionately affecting Asian Americans and other immigrant populations in the United States. Despite the high risk of morbid complications from CHB, the majority of individuals with CHB do not access healthcare due to a complex of barriers. These barriers influence health literacy which may affect behaviors linked to hepatitis B care. We aimed to identify and evaluate various sociocultural factors and how they interact with health literacy to impact CHB care and health seeking in a Korean American population.

METHODS

A total of 28 Korean American individuals with CHB were divided into 5 different focus discussion groups. This study investigated the participants' sociocultural backgrounds as well as their awareness and utilization of the healthcare system that could influence their health literacy and behaviors in accessing care.

RESULTS

Our analysis identified and concentrated on three themes that emerged from these discussions: low risk perception and knowledge of CHB and its complications; language, immigrant status, and stigma; and financial and institutional barriers. The participants' overall awareness of the disease and prevention methods demonstrated poor understanding of important characteristics and potential outcomes of the disease. Additionally, differences in cultural expectations and a lack of understanding and utilization of healthcare systems affected health literacy in further limiting participants' motivation to seek care.

CONCLUSIONS

The present study suggests that there are culture-specific barriers to health literacy governing individuals' health behavior in accessing hepatitis B care. These findings may inform strategies for developing culturally tailored resources and programs and for facilitating the implementation of community-wide hepatitis B education and screening initiatives in immigrant communities.

The safety of antiviral therapy and drug withdrawal for the prevention of mother-to-child transmission of HBV during pregnancy

The efficacy of prenatal antiviral therapy (AVT) for preventing the vertical transmission of hepatitis B virus (HBV) is well demonstrated. However, data are limited regarding the safety of postpartum cessation of AVT, which may induce alanine aminotransferase (ALT) elevation. We aimed to investigate the necessity of prolonging maternal AVT after delivery. Chronic hepatitis B mothers at the immune-tolerant phase with HBV DNA levels >6 log10  IU/mL were prospectively enrolled and received AVT during the third trimester until delivery. Patients were offered to discontinue AVT either at delivery or postpartum week (PPW) 6. In addition, mothers who deferred AVT during pregnancy served as the control group. All mothers were followed until PPW 52 for clinical and virological parameters of hepatitis flares. Among 118 mothers recruited, 91 received AVT with 53 (group A) and 24 (group B) discontinue their treatment at delivery and PPW 6, respectively. Twenty-seven mothers who deferred AVT during pregnancy were followed as the control (group C). A total of 104 of 118 mothers who completed the study, 50% (52/104) had postpartum-elevated ALT levels, which were mild and moderate except 6 of 104 (5.77%) of patients had levels ≥5 times the upper limit of normal; 70% (36/52) of the ALT flares occurred within 12 weeks after delivery. In subgroup analyses, the frequency of ALT elevation was similar among the groups A vs B vs C (50.9% [27/53] vs 58.3% [14/24] vs 40.7% [11/27], respectively; P  = .447), as well as the mean peak ALT level (108.4/74.1/126.7 U/L in groups A/B/C, respectively; P = .291). Although postpartum ALT flares were common for mothers with or without AVT during pregnancy, most cases of ALT elevation were mild to moderate. Our study observed that extending AVT to PPW 6 did not affect maternal outcomes and ATV should be discontinued at birth. Close monitoring is warranted as severe flares rarely occurred.

The prevalence of HBsAg, knowledge and practice of hepatitis B prevention among pregnant women in the Limbe and Muyuka Health Districts of the South West region of Cameroon: a three-year retrospective study

Introduction

hepatitis B infection is caused by the hepatitis B virus (HBV). HBV is transmitted through sexual intercourse, by exchange of saliva during kissing and also to newborns of infected mothers. In the Global Burden of Diseases 2010, 786,000 deaths were attributed to HBV. Studies in Cameroon, reported the prevalence of HBV as high as 10.1% and 12% among blood donors in hospital blood banks. This study therefore, aims at determining the prevalence of HBsAg, knowledge and practices of pregnant women on HBV prevention and transmission in the Limbe Health District (LHD) and Muyuka Health District (MHD).

Methods

ANC registers were exploited from the health centers for a period of three years (2014-2016) in order to determine the prevalence of HBV infection. 270 women attending ANC were selected by exhaustive sampling. Knowledge and practices of participants on HBV prevention and transmission was assessed using a structured questionnaire.

Results

the prevalence of HBV in the LHD and MHD were 5.7% and 7.5% respectively. Pregnant women in the LHD demonstrated good knowledge but adopted poor practices whereas in the MHD, pregnant women demonstrated poor knowledge and adopted poor practices regarding the mode of transmission and prevention of HBV infection. There was a significant association between the prevalence of HBsAg and marital status (p = 0.000) in the LHD and age (p = 0.022) in the MHD.

Conclusion

this study indicated a high prevalence of HBV among pregnant women in the LHD and MHD, knowledge and practices were identified as potential risk factors.

Knowledge regarding hepatitis B mother-to-child transmission among healthcare workers in South China

To determine the knowledge regarding hepatitis B virus (HBV) mother-to-child transmission (MTCT) and its prevention and treatment among healthcare workers (HCWs) in Guangdong Province, China, an HBV endemic area. An HBV knowledge questionnaire was administered to 900 HCWs from the 3rd Affiliated Hospital of Sun Yat-Sen University and 2 rural hospitals in Guangdong Province. The 27 items in the questionnaire fell into 3 sections: HBV MTCT general knowledge, respondents' practices of preventing HBV MTCT and awareness of the resources of preventing HBV MTCT. The data collected were coded and analysed using SPSS software version 20. In total, 503 of 900 HCWs responded to the survey (response rate: 55.9%). Eighty-four individuals responded correctly to all of the knowledge questions: 58 were doctors, and 26 were nurses (P < .05). Doctors more often performed practices than nurses (t = 3.591, P < .01). Participants from the infectious disease department demonstrated a significantly higher proportion of correct answers and resource utilization than other specialties (χ²  = 14.052, 7.998, P < .01). In terms of the average knowledge score, t test or ANOVA showed that there were significant differences between the specialty groups (t = 3.110, P < .01), hospital level groups (t = 2.337, P < .05) and age groups (F = 3.020, P < .05). Respondents' initiative increased with hospital level and age (t = 2.993, 7.493, P < .01). A considerable percentage of HCWs has misconceptions about HBV MTCT. Healthcare workers, in particular nurses, those working in noninfectious disease departments or township hospitals and younger medical staff, lack systematic and comprehensive knowledge about HBV MTCT and are in urgent need of HBV-related training.

The epidemiology of hepatitis B virus infection in women of reproductive age in highly endemic areas in China

We describe the epidemiology of hepatitis B virus (HBV) infection among women of reproductive age residing in areas of China that are highly endemic for chronic HBV, and provide evidence useful for decision-makers to guide strategies for preventing mother-to-child transmission of HBV, and assess the impact of perinatal transmission PMTCT by projecting HBsAg prevalence trends without interventions. We conducted a cross-sectional HBV serological survey of women, 15-49 years of age, residing in Fujian, Guangdong, Guangxi and Hainan provinces. Demographic and other subject-level data were collected in face-to-face interviews, after which we obtain blood specimens. Specimens were tested for HBV sero-markers by ELISA (Beijing Wantai Biological Pharmacy), and HBV DNA was tested with PCR (Hunan Sansure Biotech). Weighted HBsAg and HBV (either HBsAg+ or anti-HBc+ indicating either present or past infection) prevalences were 11.82% and 57.16%, respectively. Among the HBsAg-positive women, 27% were also HBeAg positive. The proportion of individuals with HBV DNA loads >10⁵ IU/mL declined with increasing age. Among HBsAg-negative women, 0.9% had occult HBV infection. The prevalence of chronic HBV infection among reproductive women in these highly endemic provinces is high, posing a threat to maternal health and risk of mother-to-child transmission. Prevention of mother-to-child transmission remains critically important.

Safety and efficacy of telbivudine for chronic hepatitis B during the entire pregnancy: Long-term follow-up

The management of hepatitis B virus (HBV) infection in pregnancy is a unique issue. Telbivudine (LdT) is recommended to block HBV mother-to-child transmission (MTCT) in the third trimester. However, the safety of LdT treatment during the entire pregnancy for the long-term growth of infants is unclear. The aim of this study was to evaluate the efficacy and long-term safety of LdT for the entire pregnancy period. This retrospective cohort study included 40 pregnant women and 43 children from 2011 to 2017. The antiviral effects and maternal abnormalities were evaluated. In addition, adverse events regarding infants at delivery and HBV vaccination outcomes were recorded. The status of physical development in the children during follow-up was also evaluated. Among pregnant women, the rates of HBV DNA flare were 5.00% during pregnancy and 7.50% postpartum, and the HBeAg seroconversion rates were 7.50% during pregnancy and 7.50% postpartum. No severe maternal abnormalities were observed. Regarding the infants, no one was positive for HBsAg, and only one infant was negative for anti-HBs in children over 7 months of age. Furthermore, no birth defects or severe adverse events were observed at delivery, and 97.67% normal height and 93.02% normal weight in children were observed on follow-up until 5 years of age. In conclusion, LdT use for the entire pregnancy is both effective for treating pregnant women and blocking HBV MTCT. Moreover, LdT is safe for women and infants. Most importantly, the long-term follow-up indicated that LdT is safe and does not affect the growth of children.

Strategies to prevent mother-to-child transmission of hepatitis B

Mother-to-child transmission is the main way of hepatitis B virus (HBV) infection. Thus, blocking mother-to-child transmission is an important means to control the epidemic of HBV. However, the management of pregnant women with HBV still has many problems, such as the lack of uniform guidelines on the treatment. Although passive-active immunoprophylaxis, including hepatitis B immunoglobulin and hepatitis B virus vaccine, is widely used at birth to interrupt HBV transmission, mother-to-child transmission of HBV still occurs in some infants. In recent years nucleoside analog has been widely used in clinical practice. This paper summarizes and analyzes a variety of programs of blocking mother-to-child transmission, aiming to make strategies to prevent mother-to-child transmission of HBV more standardized and effective.

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

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

Seroprevalence and Predictors of Hepatitis B Virus Infection among Pregnant Women Attending Routine Antenatal Care in Arba Minch Hospital, South Ethiopia

Hepatitis B virus (HBV) is a serious cause of liver disease affecting millions of people throughout the world. When HBV is acquired during pregnancy, prenatal transmission can occur to the fetus. Therefore, this study is aimed at estimating seroprevalence and associated factors of HBV infection among pregnant women attending Antenatal Clinic (ANC) of Arba Minch Hospital, Southern Ethiopia. A facility based cross-sectional study was conducted on 232 pregnant women visiting ANC from February to April, 2015. Data regarding sociodemographic and associated factors were gathered using questionnaire. Serum samples were tested for hepatitis B surface antigen (HBsAg) by Enzyme Linked Immunosorbent Assay. Data was analyzed using SPSS version 20. The overall seroprevalence of HBV infection was 4.3% (95% CI: 2.2-6.9%). Multivariate analysis showed that history of abortion (AOR = 7.775; 95% CI: 1.538-39.301) and having multiple sexual partners (AOR = 7.189; 95% CI: 1.039-49.755) were independent predictors of HBsAg seropositivity. In conclusion, the prevalence of HBV infection is intermediate. Therefore, screening HBV infection should be routine part of ANC; health information on having single sexual partner for women of childbearing age and on following aseptic techniques during abortion should be provided to health facilities working on abortion.

Unsolved problems and future perspectives of hepatitis B virus vaccination

Hepatitis B virus (HBV) infection is still a serious worldwide problem, and vaccination is the most effective strategy for primary prevention of the infection. Although universal vaccination may be required for total eradication, several countries, including Japan, have not yet adopted universal vaccination programs. Some individuals are non-responders to HBV vaccine and several mechanisms responsible for their poor response have been proposed. To overcome non-response, third generation vaccines with pre-S proteins have been developed. These vaccines have shown better anti-HBs responses and may also be effective in preventing infection by HBV with S mutant. Improvement of vaccine efficacy by intradermal administration, or co-administration with cytokines or adjuvants, may also be effective in non-responders. The necessity, timing and method of booster vaccination in responders with decreased anti-HBs responses, and effective vaccination against S-mutant HBV, are issues requiring resolution in the global prevention of HBV infection.

Growth and development of children prenatally exposed to telbivudine administered for the treatment of chronic hepatitis B in their mothers

OBJECTIVES

We studied the growth and development of children prenatally exposed to telbivudine used to treat chronic hepatitis B virus (HBV) infection in their mothers.

METHODS

Maternal abnormalities during pregnancy and delivery and infant congenital anomalies, physical development status, developmental quotient (DQ), HBV vertical transmission status, and HBV vaccination outcomes of 54 infants were evaluated (2010-2013).

RESULTS

No fetal abnormalities were observed during pregnancy or delivery. Postpartum, three infants (5.56%) had abnormalities: ankyloglossia, cutaneous hemangioma, and vaginal canal leak. Height and weight were within the normal range at birth and at 6 weeks, but were higher than the reference at 12 months (p<0.05). Body mass index increased gradually with age (p<0.05). DQ scores were normal (84.81%, 229/270) in 37 children (68.52%), abnormal or suspicious for a developmental delay (15.19%, 41/270) in 17 children (31.48%), and indicated a developmental delay (4.07%, 11/270) in seven children (12.96%). There were no significant differences in developmental delay between children prenatally exposed to telbivudine and controls (p>0.05). HBV vertical transmission was successfully blocked in all infants. The effective HBV vaccination rate was 98.15% (53/54).

CONCLUSIONS

The growth and development of children prenatally exposed to telbivudine was normal, indicating that telbivudine treatment during pregnancy is safe and effective.

A study of immunoprophylaxis failure and risk factors of hepatitis B virus mother-to-infant transmission

Hepatitis B virus (HBV) infection is of high prevalence in China. Mother-to-infant transmission is the major route for HBV transmission and subsequent chronicity. This study aimed to investigate current HBsAg-positive rate among pregnant women and immunoprophylaxis outcome in China. Multicenter prospective study was conducted in 10 centers. From 2008 to 2012, 67,720 pregnant women were screened and 1,150 HBsAg-carrier mothers and their infants aged 8-12 months were studied in four out of all centers, among whom HBV markers (HBsAg, HBsAb, HBeAg, HBeAb, and HBcAb) and HBV DNA (in three centers) were measured. The results showed that HBsAg-positive rate of pregnant women was 6.7 % (4,533/67,720) and infants' immunoprophylaxis failure rate was 3.4 % (39/1,150). Immunoprophylaxis failure infants were all born to mothers of HBeAg-positive and HBV DNA ≥6 log10 copies/ml. Among infants of HBeAg-positive mothers, multivariable analyses showed the following: mother's age <28 years vs ≥28 years, RR = 0.157, 95 % confidence interval (CI) [0.067, 0.369], p = 0.000; Neonates receiving vaccine vs vaccine plus hepatitis B immune globulin (HBIG), RR = 0.371, 95 % CI [0.167, 0.825], p = 0.015. Pregnant women receiving HBIG in the third trimester, vaginal delivery and breastfeeding had no significant effects on HBV mother-to-infant transmission.

CONCLUSIONS

Pregnant women are still of high HBsAg prevalence in China. HBV mother-to-infant transmission still occurs after passive-active immunization. Pregnant women of high HBV replication levels are the major risk population of HBV mother-to-infant transmission. Passive-active immunization is necessary for neonates of HBeAg-positive mothers. Mother's age <28 years and neonate receiving vaccine only were the risk factors for HBV mother-to-infant transmission. Breastfeeding did not put children at risk of mother-to-infant transmission.

Evaluation of the impact of hepatitis B vaccination in adults in Jiangsu province, China

Hepatitis B immunization programs for newborns, children, and adolescents in China have shown remarkable results. To establish whether there would be any benefit in extending the program to cover older individuals, we examined both the epidemiology of hepatitis B virus (HBV) infection and the coverage of hepatitis B vaccinations among adults born before routine vaccinations were implemented. We then evaluated the impact of hepatitis B vaccination in adults aged 20-59 years. A large-scale cross-sectional epidemiological survey of HBV infection was performed in the province of Jiangsu, south-east China, between September 2009 and March 2010. A total of 86,732 adults aged 20-59 years were included, of which 8,615 (9.9%, 95% CI = 9.7-10.1%) were HBsAg sero-positive. Self-reported vaccination status suggested that the coverage was approximately 23.7% (95% CI = 23.4-24.0%). It was shown that higher HBV vaccination coverage was associated with a lower rate of HBsAg seropositivity among adults. There was a negative correlation between hepatitis B vaccination coverage and HBsAg prevalence (correlation coefficient = -0.805, p = 0.016), which might demonstrate the combined effects of vaccination and pre-vaccination HBsAg screening. In the unvaccinated group, the HBsAg-positive rate had an obvious upward trend with age growing among 20-39 year-olds (Trend χ2 = 22.605, P<0.001), while the vaccinated group showed no such trend (Trend χ2 = 3.462, P = 0.063). Overall, hepatitis B vaccination in adults might reduce the rate of HBsAg positivity. Therefore, routine immunization of adults aged 20-39 years should be seriously considered.

Transplacental Transfer of Hepatitis B Neutralizing Antibody during Pregnancy in an Animal Model: Implications for Newborn and Maternal Health

Despite the success of postexposure prophylaxis (PEP) of the newborn in preventing mother-to-child transmission of hepatitis B virus), in non-US clinical trials, administering hepatitis B immune globulin (HBIG) to mothers at the end of pregnancy (in addition to passive-active PEP of the newborn) only partially improved outcomes. That is, a significant percentage of newborns became infected during their first year of life. We used a relevant animal model for human IgG transplacental transfer to study dose, time and subclass dependence of HBV neutralizing antibody (nAb) maternal, and fetal levels at the end of pregnancy. Pregnant guinea pigs received 50 or 100 IU/kg HBIGIV 2-5 days before delivery. Human total IgG, IgG subclasses, and nAb in mothers and their litters were measured. In vitro analyses of guinea pig Fc neonatal receptor binding to HBIGIV, as well as to all human IgG subclasses, were also performed. Our study showed that nAb transferred transplacentally from the pregnant guinea pigs to their litters; no transfer occurred during parturition. The amount of the transferred nAb was dose and time dependent. Thus, selection of an efficacious dose in the clinic is important: microdosing may be underdosing, particularly in cases of high viraemia.

Chronic hepatitis B prevalence among children and mothers: results from a nationwide, population-based survey in Lao People's Democratic Republic

BACKGROUND

Hepatitis B is regarded as a serious public health issue in Lao People's Democratic Republic (Lao PDR), a Southeast Asian country. However, disease epidemiology among the general population is not well known, and thus a nationwide cross-sectional survey for hepatitis B surface antigen (HBsAg) prevalence in children and their mothers was conducted.

METHODS AND FINDINGS

We applied three-stage cluster sampling using probability proportionate to size. After randomly selecting child (5 to 9 years old) and mother (15 to 45 years old) pairs from the selected villages, questionnaires and HBsAg rapid tests were conducted. Data from 965 child and mother pairs were analyzed. Multivariate logistic regression analyses were used to investigate the independent association of individual background characteristics for the odds of being HBsAg positive. In total, 17 children and 27 mothers were HBsAg positive. HBsAg prevalence was estimated to be 1.7% (95% confidence interval: 0.8%-2.6%) in children, and 2.9% (95% confidence interval: 1.7%-4.2%) in their mothers after taking sampling design and weight of each sample into account. Mother's infection status was positively associated with HBsAg positivity in children (p<0.001), whereas other potential risk factors, such as ethnicity, proximity to health centers, and history of surgery, were not. There were no significant associations between mother's HBsAg status and history of surgery, and other sociodemographic factors.

CONCLUSIONS

Despite the slow implementation of the hepatitis B vaccination program, HBsAg prevalence among children and their mothers was not high in Lao PDR compared to reports from neighboring countries. The reasons for the differences in prevalence among these countries are unclear. We recommend that prevalence surveys be conducted in populations born before and after the implementation of a hepatitis B vaccination program to better understand the epidemiology of hepatitis B.

Safety of telbivudine treatment for chronic hepatitis B for the entire pregnancy

Orally administered nucleus(t)ide analogues (NA) have brought about a simple, safe and effective therapeutic approach for chronic hepatitis B (CHB). However, treatment duration is long and some female patients become pregnant during treatment. In recent years, there have been gradually increasing reports on the safety of telbivudine (LdT) treatment for chronic hepatitis B virus (HBV) infection in the third trimester of pregnancy to block mother-to-infant transmission (MTIT) of HBV; however, the safety of LdT treatment for chronic HBV infection for the entire pregnancy has not been reported. The aim of the present study was to evaluate the safety of LdT treatment for chronic HBV infection for the entire pregnancy and provide a reference for HBV-infected fertile women on how to block MTIT of HBV. Eighty-six pregnant women who received LdT treatment either before or in early pregnancy were enrolled in the study. Adverse events were prospectively observed for the entire pregnancy and perinatal period, and short-term and long-term follow-up of infants was conducted, monitoring the abnormalities of infants and blocking rate of MTIT with LdT treatment. Eighty-six pregnant women treated with LdT had a total of 89 pregnancies: 6 (6.7%) had early embryonic death or spontaneous abortion, 1 (1.1%) had ectopic pregnancy and three had a second pregnancy after initial abortion. Fifty-one mothers completed pregnancy: one had induction of labour at 24 weeks of pregnancy for cleft lip and palate of the foetus and 50 delivered 52 full-term live infants. One infant had right ear accessories, and the total occurrence of congenital abnormality was 3.8%. Thirty-nine infants were followed up for more than 6 months and completed all examinations for MTIT. None of the infants were HBsAg positive, resulting in a 100% success rate of blocking MTIT. All mothers maintained good liver function during the third trimester of pregnancy; 86% maintained complete virological response (HBV DNA <500 copies/mL) prior to delivery, and none developed progression of liver disease. Factors leading to increased adverse effects and drug resistance were not found. LdT treatment is safe and effective in chronic HBV-infected pregnant mothers for the entire pregnancy.

HBV perinatal transmission

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

Safety of lamivudine treatment for chronic hepatitis B in early pregnancy

AIM: To evaluate the safety of lamivudine (LAM) treatment for chronic hepatitis B in early pregnancy.

METHODS: A total of 92 pregnant women who received LAM treatment either before pregnancy or in early pregnancy were enrolled in this study. All of the pregnant women volunteered to take lamivudine during pregnancy and were not co-infected with hepatitis C virus, human immunodeficiency virus, cytomegalovirus, or other viruses. All infants received passive-active immunoprophylaxis with 200 IU hepatitis B immunoglobulin and three doses of 10 μg hepatitis B vaccines (0-1-6 mo) according to the guidelines for the prevention and treatment of chronic hepatitis B. Adverse events were observed throughout the entire pregnancy and perinatal period, and the effectiveness of lamivudine treatment for blocking mother-to-infant transmission of hepatitis B virus (HBV) was evaluated. All adverse events in mothers and infants during pregnancy and the perinatal period and the HBV mother-to-infant transmission blocking rate were compared with the literature.

RESULTS: Among the 92 pregnant women, spontaneous abortions occurred in 11 cases, while 3 mothers had a second pregnancy after the initial abortion; 72 mothers delivered 73 live infants, of whom 68 infants were followed up for no less than 6 mo, and 12 mothers were still pregnant. During pregnancy, the main maternal adverse events were vaginitis (12/72, 16.7%), spontaneous abortion (11/95, 11.6%), and gestational diabetes (6/72, 8.3%); only one case had 1-2 degree elevation of the creatine kinase level (195 U/L). During the perinatal period, the main maternal adverse events were premature rupture of the membranes (8/72, 11.1%), preterm delivery (5/72, 6.9%), and meconium staining of the amniotic fluid (4/72, 5.6%). In addition, 2 infants were found to have congenital abnormalities; 1 had a scalp hemangioma that did not change in size until 7 mo, and the other had early cerebral palsy, but with rehabilitation training, the infant’s motor functions became totally normal at 2 years of age. The incidence of adverse events among the mothers or abnormalities in the infants was not higher than that of normal mothers or HBV-infected mothers who did not receive lamivudine treatment. In only 2 cases, mother-to-infant transmission blocking failed; the blocking rate was 97.1% (66/68), which was higher than has been previously reported.

CONCLUSION: Lamivudine treatment is safe for chronic HBV-infected pregnant mothers and their fetuses with a gestational age of less than 12 wk or throughout the entire pregnancy.

Human antibodies can cross guinea pig placenta and bind its neonatal Fc Receptor: implications for studying immune prophylaxis and therapy during pregnancy

Despite increased use of monoclonal and polyclonal antibody therapies, including during pregnancy, there is little data on appropriate animal models that could humanely be used to understand determinants of protection and to evaluate safety of these biologics in the mother and the developing fetus. Here, we demonstrate that pregnant guinea pigs can transport human IgG transplacentally at the end of pregnancy. We also observe that human IgG binds to an engineered soluble variant of the guinea pig neonatal Fc receptor in vitro in a manner similar to that demonstrated for the human variant, suggesting that this transplacental transport mirrors the receptor-based mechanism seen in humans. Using an intravenous antihepatitis B-specific immune globulin preparation as an example, we show that this transport results in neutralizing activity in the mother and the newborn that would potentially be prophylactic against hepatitis B viral infection. These preliminary data lay the groundwork for introducing pregnant guinea pigs as an appropriate model for the evaluation of antibody therapies and advancing the health of women and neonates.

Amendments to hypotheses on the proximate causes of variation in human sex ratios at birth with parental infection with hepatitis B virus or Toxoplasma gondii

In a recent paper in this Journal, I offered hypotheses on the offspring sex ratios of women infected with the parasite Toxoplasma gondii, and on the offspring sex ratios of people who are carriers of hepatitis B virus (HBV) (James, 2008). Subsequent research suggests that these hypotheses need amending. A detailed account of the amendments is given elsewhere in a specialized journal (James, 2010a). Here they are summarized.

Chronic hepatitis B in Asia-new insights from the past decade

Chronic hepatitis B virus (HBV) infection is a major health problem in the Asia-Pacific region. In the past decade, much progress has been made in the understanding and management of this disease. The introduction of universal vaccination has significantly reduced the incidence of perinatal infection in most Asia-Pacific countries. As the majority of the adult population have not been immunized at birth, we are still facing a large population of young HBV-infected patients in the coming two decades. The study of long-term longitudinal databases has provided deeper insight into the clinical significance of HBV DNA suppression, hepatitis B e antigen (HBeAg) seroconversion and hepatitis B surface antigen (HBsAg) seroclearance in chronic hepatitis B. With a better understanding on the natural history of HBV infection, one can now stratify the risk of chronic hepatitis B patients for adverse clinical outcomes and use this to individualize management. The introduction of non-invasive assessment of liver fibrosis can potentially reduce the necessity of liver biopsy. There have also been great advances in the development of antiviral therapy in the past decade. However, the high cost of HBV antiviral drugs poses major challenges to health authorities in many Asia-Pacific countries. Properly performed cost-effective analysis and understanding on the best timing of stopping antiviral drugs will be important to facilitate the most appropriate allocation of resources.

Chronic hepatitis B in Asian women of childbearing age

Hepatitis B virus (HBV) infection is a serious clinical problem affecting approximately 2 billion people worldwide. An estimated 350 million live with chronic hepatitis B (CHB) infection and are at an increased risk for serious liver sequelae and death from acute or chronic consequences of CHB infection. Individuals with CHB have a 20-30% risk of early death from complications, including liver cirrhosis and hepatocellular carcinoma. In the Asia-Pacific region, half of the CHB burden results from vertical or mother-to-child transmission, with early childhood horizontal transmission accounting for the remaining half. Screening and vaccination are key factors in the successful prevention and control of HBV infection. Over the last 20 years, the implementation of screening programs and universal HBV vaccination for all individuals born in endemic areas have reduced the prevalence of HBV infection and HBV-related liver diseases among individuals younger than 30 years. Women of childbearing age are key stakeholders in preventing HBV infection and, as such, play a critical role in reducing the vertical and horizontal transmission of HBV. Further efforts are needed to implement screening and educational programs for women of childbearing age, particularly those with CHB, to prevent the transmission of HBV to newborns, spouses, other household members, and sexual partners. In addition, healthcare workers need to learn how to avoid iatrogenic transmission in the healthcare setting. This article reviews these issues and highlights areas in which their engagement with public health efforts serves to improve quality of life and society as a whole.