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

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.

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.

Maternal neighbourhood-level social determinants of health and their association with paediatric hepatitis C screening among children exposed to hepatitis C in pregnancy

BACKGROUND

Current guidelines recommend HCV screening by 18 months of age for those exposed to HCV in utero; yet, screening occurs in the minority of children.

OBJECTIVES

To evaluate the association between maternal neighbourhood-level social determinants of health (SDOH) and paediatric HCV screening in the general population in a publicly funded healthcare system in Canada.

METHODS

Retrospective cohort study using administrative healthcare data held at ICES. Children born to individuals positive for HCV RNA in pregnancy from 2000 to 2016 were identified and followed for 2 years. Major SDOH were identified, and the primary outcome was HCV screening in exposed children (HCV antibody and/or RNA). Associations between SDOH and HCV screening were determined using multivariate Poisson regression models adjusting for confounding.

RESULTS

A total of 1780 children born to persons with +HCV RNA were identified, and 29% (n = 516) were screened for HCV by age two. Most mothers resided in the lowest income quintile (42%), and most vulnerable quintiles for material deprivation (41%), housing instability (38%) and ethnic diversity (26%) with 11% living in rural locations. After adjustment for confounding, maternal rural residence (risk ratio [RR] 0.82, 95% confidence interval [CI] 0.62, 1.07) and living in the highest dependency quintile (RR 0.83, 95% CI 0.65, 1.07) were the SDOH most associated with paediatric HCV screening. Younger maternal age (RR 0.98 per 1-year increase, 95% CI 0.97, 0.99), HIV co-infection (RR 1.69, 95% CI 1.16, 2.48) and GI specialist involvement (RR 1.18, 95% CI 1.00, 1.39) were associated with higher probabilities of screening.

CONCLUSIONS

Among children exposed to HCV during pregnancy, rural residences and living in highly dependent neighbourhoods showed a potential association with a lower probability of HCV screening by the age of 2. Future work evaluating barriers to paediatric HCV screening among rural residing and dependent residents is needed to enhance the screening.