23 Preventing Perinatal Transmission of Hepatitis B: A Quality Assurance Review

Abstract

Background: Although hepatitis B vaccination has a protective efficacy of 95%, the CDC reports that 275 million people are infected with chronic hepatitis B, resulting in 700,000 deaths per year. In the province of Ontario, a publicly-funded, 2-dose vaccine series is routinely offered to grade 7 students. However, the vertical transmission of hepatitis B is a risk for infants born to infected mothers. Therefore, prospective mothers are routinely screened for HBsAg during the first trimester of pregnancy. The Canadian Immunization Guide recommends that all infants born to infected mothers should receive hepatitis B immune globulin (HBIg) and vaccine within 12 hours of birth. As there is a paucity of literature on the timeliness of hepatitis B immunization, this study aimed to investigate time to administer HBIg and vaccine to newborns with HBsAg positive mothers. Method(s): Following REB approval, mother-infant dyads were identified by record of newborn hepatitis B vaccine order. Full review was conducted for infants born to HBsAg positive mothers between 2010 and 2015. Mother and infant charts were paired and retrospectively reviewed across 6 hospital sites in Ontario, including 2 community hospitals, 2 academic hospitals, and 2 satellite teaching hospitals. Between-group differences were tested through Welch's analysis of variance and associations were explored through Spearman's rank correlation. Statistical significance was set for P<0.05. Result(s): Of 729 identified mother-infant dyads, 460 pairs were eligible for comprehensive chart review. 269 dyads were excluded as the mother was not HBsAg positive but the vaccine was ordered because the father was hepatitis B positive, the mother's HBsAg status was unknown, or the mother was hepatitis C positive. Of 460 eligible infants, 23 infants (5.0%) were vaccinated later than 12 hours and 22 infants (4.8%) received HBIg later than 12 hours. 50 infants (10.9%) had at least one undocumented time of administration. The mean vaccination time was 5.0 hours (95% CI [4.4, 5.2]) with significant differences between sites (WF5,58=21.3, p<0.001, eta2= 0.31). The mean time of HBIg administration was 5.0 hours (95% CI [4.5, 5.2]) with significant differences between sites (Welch's F5,61=18.7, p<0.001, eta2= 0.23). On average, infants born between 2400 and 0800 were vaccinated 66 minutes later than infants born between 0800 and 1600 (p<0.05). On average, infants born to married mothers were vaccinated 65 minutes earlier than infants born to unmarried mothers (p<0.05). Conclusion(s): The majority of neonates are immunized within 12 hours but variation exists across sites. Improved recording of hepatitis B immunization times is needed. A focus on standardizing care pathways regardless of site or time of delivery may correct immunization delays. Further research is needed to explore best practices to reduce delays and evaluate the cost-benefit of universal neonatal hepatitis B immunization in Ontario. (Figure Presented).