Evaluation and comparison of risk-based and universal prenatal HCV screening programs in Alberta, Canada

Abstract

Canadian clinical practice guidelines currently recommend risk-based screening for hepatitis C virus (HCV) in pregnant individuals. However, no provinces or territories have ever compared the effectiveness of risk-based versus universal screening for diagnosing prenatal HCV. We aimed to evaluate and compare HCV screening programs after implementing a universal population-level pilot program among prenatal patients in Alberta, Canada. The Alberta Prenatal Screening Program for Select Communicable Diseases was amended to include universal HCV antibody screening. Cohorts of pregnant individuals screened for HCV through risk-based or universal programs were generated over one-year periods. HCV screening rates and prevalence was analyzed and compared between cohorts to evaluate effectiveness of screening methods. Social and demographic risk factors for HCV positive individuals were compared between screening cohorts to identify which populations may be overlooked with risk-based guidelines. HCV antibody screening rates were 11.9% and 99.9% among pregnant individuals in the risk-based and universal cohorts respectively. HCV prevalence among the cohorts was 0.07% and 0.11% (difference=0.04%, p=0.032), with an average of 21 additional HCV positive pregnant individuals identified annually with universal screening. HCV positive prenatal patients diagnosed through universal screening were more likely to engage in high-risk sexual behaviours/sex work compared to those diagnosed through risk-based screening (47.6% versus 12.5%, respectively p=0.035), suggesting risk-based screening is missing these high-risk women. Universal HCV screening diagnoses significantly higher numbers of pregnant individuals infected with HCV compared to risk-based screening. Universal HCV screening or amending risk-based guidelines to incorporate more proxy variables for risk factors should be considered to improve prenatal HCV screening guidelines in Canada and help achieve HCV elimination in the next decade. Hepatitis C virus (HCV) is a bloodborne pathogen that can cause severe liver disease and be vertically transmitted from a mother to her baby during pregnancy. Pregnant individuals in Alberta are currently only tested for HCV if they disclose to their physician engagement in activities that put them at risk for acquiring the infection (risk-based screening). Using a population-wide universal prenatal HCV screening program, our work shows testing based on patient disclosed risk alone significantly underdiagnoses HCV in pregnant individuals and suggests individuals engaging in sex work or risky sexual behaviours are being overlooked with the current risk-based program. Our outcomes represent the first province-wide study to evaluate and compare prenatal HCV risk-based and universal screening programs in Canada and can be used as evidence-based data for updating prenatal HCV screening policies across the country and in similar jurisdictions.