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Mother‐to‐child transmission of hepatitis B: Examining viral cut‐offs, maternal HB sAg serology and infant testing
Author(s) -
Thilakanathan Cynthuja,
Wark Gabrielle,
Maley Michael,
Davison Scott,
Lawler Joseph,
Lee Aimei,
Shackel Nicholas,
Nguyen Vi,
Jackson Kathy,
Glass Anne,
Locarnini Stephen A.,
Levy Miriam T.
Publication year - 2018
Publication title -
liver international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.873
H-Index - 110
eISSN - 1478-3231
pISSN - 1478-3223
DOI - 10.1111/liv.13736
Subject(s) - viral load , medicine , hbsag , transmission (telecommunications) , viral hepatitis , virology , antiviral therapy , serology , cohort , immunology , hepatitis b virus , virus , antibody , chronic hepatitis , electrical engineering , engineering
Background & Aims Antipartum antiviral therapy in the setting of high viral load is recommended to prevent mother‐to‐child transmission of hepatitis B although recommended viral load cut‐offs vary. Quantitative HB sAg has been proposed as an alternative screening strategy to identify high viral load in this setting. Guidelines suggest testing all infants for vaccine response and infection. We set out to re‐examine viral load cut‐offs; the predictive value of quantitative HB sAg and the need for follow‐up infant testing in our cohort. Methods A retrospective cohort study of 469 HB sAg positive mother‐baby pairs from 2 tertiary hospitals in Sydney was performed. Antiviral therapy (lamivudine or tenofovir disoproxil fumarate) was offered to women with viral load ≥6 log 10 IU / mL (high) from 32 weeks gestation. Transmission and vaccine response was analysed according to viral load. The utility of quantitative HB sAg in identifying high viral load was examined. Results Mother‐to‐child transmission only occurred in setting of high viral load, in 0.85% (1/117) of those who received antiviral therapy and in 8.66% (2/23) of those who chose not to. Quantitative HB sAg did not accurately identify high‐risk mothers HBV DNA ≥6 log 10 IU / mL . Successful infant vaccine response was 98.7% overall, and 99.4% when viral load was <6 log 10 IU / mL . Conclusion Antiviral therapy initiated at 32 weeks when maternal viral load is ≥6 log 10 IU / mL almost completely abrogates transmission. Quantitative HB sAg does not reliably predict high viral load. When maternal viral load is <6 log 10 IU / mL , high vaccine efficacy and zero transmission suggests testing infants is of little value.