Burden of Chronic Hepatitis B in Alberta, Canada
Date
2023-10-12
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Abstract
Limited recent data exist on chronic hepatitis B (CHB) burden in the North American general population, especially among women of childbearing age (WoCBA). Despite evidence supporting peripartum tenofovir disoproxil fumarate (TDF) prophylaxis in reducing mother-to-child transmission (MTCT), long-term outcomes of untreated and TDF-treated CHB pregnant women are understudied. We aimed to identify the CHB burden in Alberta, Canada, among all ages and WoCBA (18-49 years) and assess clinical outcomes in a multiethnic cohort of CHB patients during pregnancy and postpartum. We retrospectively searched Alberta Analytics administrative databases to describe CHB epidemiology and natural history in all ages and WoCBA between fiscal years 2012-2020. We also examined care linkage among hepatitis B surface antigen (HBsAg)-positive pregnant women during the same period. Furthermore, we collected real-world clinical data during pregnancy and postpartum in women with CHB between 2011-2019. From 2015-2020, the CHB incidence declined to 13.4/100,000 (from 36.4/100,000) for all ages and 18.2/100,000 (from 52.6/100,000) for WoCBA. However, prevalence increased to 210.3/100,000 (from 98.9/100,000) for all ages and 248.6/100,000 (from 131.7/100,000) for WoCBA. CHB patients had lower survival rates than age/sex-matched Canadians (standardized mortality ratios of 3.9 and 5.7 for all ages and WoCBA, respectively). Among 1,927 women (2,436 HBsAg-positive pregnancies) between 2012-2020, 27.6% had recommended hepatitis B-directed assessment during pregnancy and 66.4% of those eligible for antiviral prophylaxis received treatment. In 341 women (446 pregnancies) followed for a median of 33 months postpartum, 19% received TDF (64/341, 53/64 for MTCT prevention). In HBeAg-positive patients (65/341), alanine aminotransferase (ALT) flares were more common, especially in those who stopped TDF postpartum. HBsAg clearance occurred in 2.6% (9/341, 2/9 TDF treated) at a median of 30 months, and 37% (24/65) of hepatitis B e antigen (HBeAg)-positive patients had HBeAg loss at a median of 17 months postpartum. In conclusion, CHB incidence decreased in Alberta among all ages and WoCBA. Our study demonstrates frequent ALT flares, particularly after TDF withdrawal, HBeAg clearance in 37%, and HBsAg loss in 2.9% of patients during long-term postpartum follow-up. The lower survival and suboptimal management of CHB during pregnancy emphasize addressing barriers to guideline recommended HBV care in WoCBA.
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Keywords
Hepatitis B, Epidemiology, Incidence, Prevalence, Burden of Disease, Survival, Natural History, Prenatal Transmission, Pregnancy, Women of Childbearng Age, Postpartum, Tenofovir Disoproxil Fumarate, Linkage to Care
Citation
Kochaksaraei, G. S. (2023). Burden of chronic hepatitis B in Alberta, Canada (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.