Prenatal hepatitis B screening, and hepatitis B burden among children, in Ontario: a descriptive study

Toxoplasma gondii Seropositivity and Co-Infection with TORCH Complex Pathogens in Pregnant Women from Araçatuba, Brazil

This study examined the seropositivity of T. gondii and coinfections with other TORCH pathogens among pregnant women attending 17 Basic Health Units (UBS) in Araçatuba, SP, Brazil. Of the 711 pregnant women seen at these UBS, only 297 were tested for T. gondii. Of the women tested for T. gondii (n = 297), 26.9% had IgG antibodies, 6.7% had IgM, and 32.0% tested positive for either or both. Only 1.4% showed both IgG and IgM antibodies, while 67.7% were non-reactive. The seropositivity was 17.1% for syphilis, 63.2% for rubella, 0.9% for hepatitis C, 0.9% for dengue, 17.9% for COVID-19, and 0.9% for herpes simplex (types 1/2). Coinfections with syphilis, rubella, and herpes simplex were also noted. Higher education levels appeared to protect against T. gondii seropositivity. The findings highlight a significant prevalence of T. gondii among pregnant women, with variation across UBSs, pointing to socioeconomic, behavioral, and environmental factors as influential. We also observed co-occurrence with other infections, such as syphilis, rubella, and herpes simplex. The study underscores the need for targeted public health interventions to reduce the risks of congenital infections.

Epidemiology, linkage to care and natural history of women of childbearing age with chronic hepatitis B: A population-based study

Pregnant women with chronic hepatitis B (CHB) are a priority population for hepatitis B care. Identification of HBV status prior to pregnancy would facilitate timely maternal interventions and perinatal care. In our study, we aimed to study the epidemiology of CHB among women of childbearing age (WoCBA, 18-49 years) in Alberta, Canada. We retrospectively analysed Alberta Analytics databases to study CHB epidemiology, natural history and care linkage among WoCBA in Alberta, between April 2012 and March 2021. A Poisson regression was conducted to estimate incidence of newly identified CHB cases and prevalence trends, whereas predictors of care linkage were determined using logistic regression. Age/sex-adjusted incidence of newly identified CHB among WoCBA between 2015 and 2020 was 36.2/100,000 person/years, highest among individuals aged 30-39 years. Incidence of newly identified CHB decreased from 52.6 to 18.2/100,000 between 2015 and 2020, but prevalence increased from 131.7 to 248.6/100,000 in the same period. Newly identified CHB incident cases (n = 2124) had lower survival rates than age/sex-matched Canadians, with a standardized mortality ratio of 5.7 (95% CI 2.6-11.0). Increasing age (years) at diagnosis (HR, 1.2; 95% CI 1.1-1.3) was independently associated with mortality. Comorbid hepatocellular carcinoma, anti-HBV treatment and year of diagnosis were not significantly associated with mortality. Of the 1927 women with 2436 hepatitis B surface antigen-positive pregnancies from 2012 to 2020, only 27.6% had recommended HBV assessment during pregnancy. Of those women meeting criteria for antiviral therapy to prevent mother-to-child transmission (MTCT), only 66.4% received treatment. Suboptimal management during pregnancy and overall lower survival rates highlight the need to address care linkage barriers in women of childbearing age living with CHB.

Evaluation of Prenatal Hepatitis C Virus Prevalence Using Universal Screening, and Linkage to Care in a Real-World Setting in Ontario

OBJECTIVES

International infectious disease/obstetrical societies have recently recommended universal hepatitis C virus (HCV) prenatal screening and these same recommendations are forthcoming in Canada. At present, there is no formal analysis of universal HCV screening or linkage to care of pregnant people in Ontario. The objectives of our study were to determine the seroprevalence of HCV using 2 different methods to evaluate universal screening, as well as identify opportunities that may improve linkage to care.

METHODS

To assess seroprevalence in a large urban area, we aimed to test 12 000 de-identified samples submitted for prenatal HIV testing in the catchment area of Toronto Public Health for HCV antibodies. Then, to assess the seroprevalence as well as the operational impact and follow-up in a real-world setting, we completed a Quality Improvement Project (QIP) for 1 year at a large tertiary care obstetrical centre in London, Ontario.

RESULTS

From 2019 to 2021, 11 999 de-identified samples were screened from Toronto with a seroprevalence of 0.40 (95% CI 0.29-0.53). In London, 5771 people were screened in 2021 with a seroprevalence of 0.55% (95% CI 0.38-0.78). Taken together, those aged 26-35 years had the highest positivity; in the QIP, 9% had no documented risk factor, and 59% of individuals were not linked to the next step in HCV care.

CONCLUSIONS

HCV prenatal seroprevalence in Ontario is comparable to hepatitis B virus, and ∼15-30-fold higher than HIV. Diagnosis in pregnancy is critical to facilitate referrals for treatment between pregnancies and could increase screening among children born to positive women.

Prevalence of Hepatitis B in Canadian First-Time Blood Donors: Association with Social Determinants of Health

Hepatitis B is transmitted sexually, by blood contact, and vertically from mother to child. Chronic hepatitis B is often seen in immigrants from higher-prevalence countries and their Canadian-born children. We assessed the relationship between hepatitis B and social determinants of health. Included were 1,539,869 first-time Canadian blood donors from April 2005 to December 2022. All donations were tested for hepatitis B markers. Logistic regression was fit with chronic hepatitis B as the dependent variable and age, sex, year, and ethnocultural composition and material deprivation quintiles as independent variables. Chronic hepatitis B prevalence was 47.5/100,000 (95% CI 41.5-53.5, years 2017-2022). Chronic hepatitis B prevalence was elevated in males, older age groups, and those living in more materially deprived and higher ethnocultural neighbourhoods. Of 212,518 donors from 2020 to 2022 with race/ethnicity data, chronic hepatitis B prevalence was highest in East Asians. The findings are consistent with infections in immigrants, acquired in their country of origin, in their Canadian-born children and in those with other risks. As blood donors are a low-risk population unaware of their infection and unlikely to seek testing, our results highlight the ongoing public health challenges of diagnosing chronic hepatitis B and treating it when appropriate.

Introduction of the Hepatitis B Vaccine-Birth Dose: Methods of Improving Rates in a Milieu of Vaccine Hesitancy

The hepatitis B virus is a public health threat, chronically infecting over 240 million persons worldwide. The hepatitis B vaccine is 90% effective in preventing perinatal transmission if the first dose is given within the first 24 h of life, followed by a minimum of two subsequent doses. Antigua and Barbuda instituted a hospital-based birth dose vaccination policy in October 2021. Data were extracted from hospital logbooks from November 2021 to October 2022, and a database was created. Frequency distributions of the hepatitis B birth dose, barriers to administration, and maternal and healthcare system factors were analyzed. The positive maternal HBsAg prevalence rate was 0.6%. The timely and total birth dose coverage was 72% and 81%, respectively. In total, 10.5% of parents refused the vaccine, of which 76% either felt uncomfortable or preferred to wait. Moreover, 100% of hepatitis B-exposed babies were vaccinated, with 83% of them receiving the Hepatitis B Immunoglobulin. Barriers to vaccine administration included vaccination hesitancy, gaps in knowledge of medical staff, and the inconsistent vaccination supply. Instituting a quality improvement team, health information system, robust educational efforts, and addressing barriers will make achieving the WHO programmatic targets of eliminating mother-to-child transmission of hepatitis B by 2030 possible.

Pathway to global elimination of hepatitis B: HBV cure is just the first step

Hepatitis B (HBV) is a major cause of global morbidity and mortality, and the leading cause of liver cancer worldwide. Significant advances have recently been made toward the development of a finite HBV treatment that achieves permanent loss of HBsAg and HBV DNA (so-called "HBV cure"), which could provide the means to eliminate HBV as a public health threat. However, the HBV cure is just one step toward achieving WHO HBV elimination targets by 2030, and much work must be done now to prepare for the successful implementation of the HBV cure. In this review, we describe the required steps to rapidly scale-up future HBV cure equitably. We present key actions required for successful HBV cure implementation, integrated within the World Health Organization (WHO) Global Health Sector Strategy (GHSS) 2022-2030 framework. Finally, we highlight what can be done now to progress toward the 2030 HBV elimination targets using available tools to ensure that we are preparing, but not waiting, for the cure.

Cost Effectiveness of Implementing a Universal Birth Hepatitis B Vaccination Program in Ontario

BACKGROUND AND OBJECTIVE

The World Health Organization recommends a universal hepatitis B vaccination within the first 24 h of birth. However, hepatitis B vaccines are given during adolescence in many jurisdictions including in Ontario, Canada. The objective of this study was to assess the cost effectiveness of shifting the hepatitis B vaccination timing from adolescence to birth.

METHODS

A state-transition model of 18 health states representing the natural history of acute and chronic hepatitis B was developed to conduct a cost-utility analysis. Most input parameters were obtained from the Canadian literature or publicly available provincial data. The model followed a lifetime model time horizon with health outcomes and costs being discounted at 1.5% annually. Deterministic and probabilistic sensitivity analyses were performed to test the robustness of the model. Analyses were conducted from a public-payer perspective with all costs adjusted to 2021 Canadian dollars.

RESULTS

Hepatitis B vaccination in newborns dominated the current strategy of adolescent vaccination. The probabilistic analysis showed that the newborn strategy was cost effective in 100% of the iterations at a willingness-to-pay threshold of $50,000/quality-adjusted life-year and cost saving in 79.39% of the iterations. A microsimulation projected that a newborn vaccination may lead to reductions in cases by 16.1% in acute hepatitis B, 43.2% in chronic hepatitis B, 48.2% in hepatocellular carcinoma, and 51.9% in hepatitis B liver-related death.

CONCLUSIONS

Our analysis suggests that changing the age of the hepatitis B vaccination recommendation from adolescent to newborn is cost effective and mostly a cost-saving strategy. Newborn vaccination may lead to cost and health benefits while aligning with best available evidence and guidance from the World Health Organization.

Canadian SARS-CoV-2 serological survey using antenatal serum samples: a retrospective seroprevalence study

BACKGROUND

Insufficient data on the rate and distribution of SARS-CoV-2 infection in Canada has presented a substantial challenge to the public health response to the COVID-19 pandemic. Our objective was to assess SARS-CoV-2 seroprevalence in a representative sample of pregnant people throughout Canada, across multiple time points over 2 years of the pandemic, to describe the seroprevalence and show the ability of this process to provide prevalence estimates.

METHODS

This Canadian retrospective serological surveillance study used existing serological prenatal samples across 10 provinces over multiple time periods: Feb. 3-21, 2020; Aug. 24-Sept. 11, 2020; Nov. 16-Dec. 4, 2020; Nov. 15-Dec. 3, 2021; and results from the province of British Columbia during a period in which the SARS-CoV-2 B.1.1.529 (Omicron) variant was predominant, from Nov. 15, 2021, to June 11, 2022. Age and postal code administrative data allowed for comparison with concurrent polymerase chain reactivity (PCR)-positive results collected by Statistics Canada and the Canadian Surveillance of COVID-19 in Pregnancy (CANCOVID-Preg) project.

RESULTS

Seropositivity in antenatal serum as early as February 2020 indicates SARS-CoV-2 transmission before the World Health Organization's declaration of the pandemic. Seroprevalence in our sample of pregnant people was 1.84 to 8.90 times higher than the recorded concurrent PCR-positive prevalence recorded among females aged 20-49 years in November-December 2020. Overall seropositivity in our sample of pregnant people was low at the end of 2020, increasing to 15% in 1 province by the end of 2021. Seroprevalence among pregnant people in BC during the Omicron period increased from 5.8% to 43% from November 2021 to June 2022.

INTERPRETATION

These results indicate widespread vulnerability to SARS-CoV-2 infection before vaccine availability in Canada. During the time periods sampled, public health tracking systems were under-reporting infections, and seroprevalence results during the Omicron period indicate extensive community spread of SARS-CoV-2 infection.

Hepatitis B Blood Donor Screening Data: An Under-Recognized Resource for Canadian Public Health Surveillance

Hepatitis B surveillance is essential to achieving Canada's goal of eliminating hepatitis B by 2030. Hepatitis B rates, association of infection with vaccine age-eligibility, and risk factors were analyzed among 1,401,603 first-time Canadian blood donors from 2005 to 2020. Donors were classified as having likely chronic or likely resolved/occult infections based on hepatitis B surface antigen, anti-hepatitis B core antigen, and hepatitis B nucleic acid test results. Likely chronically infected and control donors (ratio 1:4) participated in risk-factor interviews. The 2019 rate of likely chronic infection was 61.9 per 100,000 (95% CI 46.5-80.86) and 1449.5 per 100,000 for likely resolved/occult infections (95% CI 1370.7-1531.7). Likely chronic infections were higher in males (OR 3.2; 95% CI 2.7-3.7) and the vaccine-ineligible birth cohort (OR 1.9; 95% CI 1.6-2.2). The main risk factors were living with someone who had hepatitis (OR 12.5; 95% CI 5.2-30.0) and ethnic origin from a high-prevalence country (OR 8.4; 95% CI 5.9-11.9). Undiagnosed chronic hepatitis B may be more prevalent in Canada than currently determined by traditional passive hepatitis B reporting. Blood donor data can be useful in informing hepatitis B rates and evaluating vaccination programs in Canada.

Cost-effectiveness modelling of birth and infant dose vaccination against hepatitis B virus in Ontario from 2020 to 2050

BACKGROUND

The World Health Organization recommends universal birth dose vaccination for hepatitis B virus (HBV), yet only 3 provinces and territories in Canada provide birth dose vaccination, and Canadian-born children in Ontario are acquiring HBV before adolescent vaccination. We sought to determine whether birth and/or infant HBV vaccination is cost-effective.

METHODS

We used a dynamic HBV model that incorporates population by year, disease stage, sex and the influence of immigration to quantify the disease and economic burden of chronic HBV infection in Ontario from 2020 to 2050. We compared 4 vaccination scenarios, which included a birth dose vaccine and variations of the 2 subsequent doses (either alone or as a part of the hexavalent vaccine) and a hexavalent-only strategy in infancy with the current adolescent vaccination strategy. Our costing estimates were based on values from 2020.

RESULTS

All 4 infant vaccination approaches prevented an additional 550-560 acute and 160 chronic pediatric HBV infections from 2020 to 2050 compared with adolescent vaccination. Whereas birth dose could be cost-effective, incorporating vaccination into a hexavalent vaccine was cost saving. By 2050, the hexavalent approach led to $428 000 in cost savings per disability-adjusted life years averted.

INTERPRETATION

At the current prevalence in Ontario, a switch to birth dose or infant dose will be cost-effective or even cost saving. Introducing any form of infant HBV immunization in Ontario will prevent acute and chronic pediatric HBV infections.

Hepatitis B and C in Pregnancy and Children: A Canadian Perspective

In 2016, the World Health Organization released a plan to eliminate viral hepatitis as a public health threat by 2030. For Canada to achieve the recommended decreases in HBV- and HCV-related new diagnoses and deaths, an increase in services is urgently required. Identifying those at risk of, or who have acquired HBV and HCV, remains a challenge, especially with the emergence of new priority populations such as pregnant persons and children. Importantly, prenatal, and pediatric care are times when individuals are often already engaged with the healthcare system, leading to the potential for opportunistic or co-localized care and interventions. At present, Canada may not be maximizing all available virologic tools that could lead to increases in prevention, identification, improved management, or even cure. Here, we describe the continuum of care that includes preconception, prenatal, postpartum, and pediatric stages; and identify current global and Canadian recommendations, findings, and opportunities for improvement.

Feasibility of hepatitis B elimination in high-income countries with ongoing immigration

BACKGROUND & AIMS

Addressing HBV is vital to meeting the World Health Organization (WHO)'s viral hepatitis elimination goals, as 47% of viral hepatitis complications can be attributed to HBV. The objective of this study is to develop an agent-based model determining which integrated strategies involving vaccination, screening, and treatment would achieve the WHO's goals.

METHODS

We developed an agent-based model to characterize the HBV epidemic in a high-income country with ongoing immigration. The spread of HBV was simulated through sexual networks and perinatal transmission. Model parameters were estimated from the literature and calibrated against historical HBV data. Sensitivity analyses were performed to assess the uncertainty.

RESULTS

We predict that under the current strategies, the incidence of acute hepatitis B, and HBV-attributable decompensated cirrhosis and hepatocellular carcinoma would decrease by 64.5%, 9.4%, and 10.5% between 2015-2030, respectively. However, the incidence of chronic hepatitis B and liver-related deaths would increase by 26.6% and 1.0% between 2015-2030, respectively. Results were sensitive to the number of immigrants and HBV prevalence in immigrants.

CONCLUSIONS

The results suggest that the current vaccination, screening, and treatment strategies will be inadequate to achieve WHO elimination goals. Even with extensive integrated scale-up in vaccination, screening, and treatment, the morbidity and mortality targets may not be reachable, highlighting the need for a re-evaluation of the global strategy for HBV, the importance of developing curative therapy for HBV, and of establishing tailored strategies to prevent long-term sequelae and improve health in immigrants.

LAY SUMMARY

We have developed a model that reflects the dynamics of hepatitis B virus (HBV) transmission in a high-income country with ongoing immigration, which enabled us to forecast the epidemiology of HBV for policy-level decision making. Our analysis suggests that current vaccination, screening, and treatment strategies are inadequate to achieve the WHO goals of eliminating chronic hepatitis B. Even with extensive integrated scale-up in vaccination, screening, and treatment, the morbidity and mortality targets may not be reachable.

The viral hepatitis B care cascade: A population-based comparison of immigrant groups

BACKGROUND AND AIMS

The global burden of viral hepatitis B is substantial, and monitoring infections across the care cascade is important for elimination efforts. There is little information on care disparities by immigration status, and we aimed to quantify disease burden among immigrant subgroups.

APPROACH AND RESULTS

In this population-based, retrospective cohort study, we used linked laboratory and health administrative records to describe the HBV care cascade in five distinct stages: (1) lifetime prevalence; (2) diagnosis; (3) engagement with care; (4) treatment initiation; and (5) treatment continuation. Infections were identified based on at least one reactive antigen or nucleic acid test, and lifetime prevalence was estimated as the sum of diagnosed and estimated undiagnosed cases. Care cascades were compared between long-term residents and immigrant groups, including subgroups born in hepatitis B endemic countries. Stratified analyses and multivariable Poisson regression were used to identify drivers for cascade progression. Between January 1997 and December 2014, 2,014,470 persons were included, 50,475 with infections, of whom 30,118 were engaged with care, 11,450 initiated treatment, and 6554 continued treatment >1 year. Lifetime prevalence was estimated as 163,309 (1.34%) overall, 115,722 (3.42%) among all immigrants, and 50,876 (9.37%) among those from highly endemic countries. Compared to long-term residents, immigrants were more likely to be diagnosed (adjusted rate ratio [aRR], 4.55; 95% CI, 4.46, 4.63), engaged with care (aRR, 1.07; 95% CI, 1.04, 1.09), and initiate treatment (aRR, 1.09; 95% CI, 1.03, 1.16).

CONCLUSIONS

In conclusion, immigrants fared well compared to long-term residents along the care cascade, having higher rates of diagnosis and slightly better measures in subsequent cascade stages, although intensified screening efforts and better strategies to facilitate linkage to care are still needed.

Chronic hepatitis B in pregnant women: Current trends and approaches

Chronic hepatitis B (CHB) is a significant public health problem worldwide. The aim of the present review is to summarize the actual trends in the management of CHB in pregnant women. The prevalence of hepatitis B virus (HBV) infection in pregnant women is usually comparable to that in the general population in the corresponding geographic area. All women have to be screened for hepatitis B surface antigen (HBsAg) during pregnancy. Additional examinations of pregnant women with CHB may include maternal hepatitis B e antigen, HBV viral load, alanine aminotransferase level, and HBsAg level. The management of pregnancy depends on the phase of the HBV infection, which has to be determined before pregnancy. In women of childbearing age with CHB, antiviral therapy can pursue two main goals: Treatment of active CHB, and vertical transmission prevention. During pregnancy, tenofovir is the drug of choice in both cases. A combination of hepatitis B immunoglobulin and vaccine against hepatitis B should be administered within the first 12 h to all infants born to mothers with CHB. In such cases, there are no contraindications to breastfeeding.