Prevention of perinatal hepatitis B virus transmission: are we missing something?

Background The prevention of perinatal Hepatitis B virus (HBV) is crucial to reach the WHO's challenge to eliminate viral hepatitis as public health threat by 2030. After diagnosing 2 infants infected by vertical transmission, a retrospective analysis of policies and practices to prevent HBV congenital infection was conducted to assess any potential risk. Methods Paired maternal-infant medical records between 2017 and 2019 were reviewed at A.O.U Città della Salute e Scienza di Torino, the italian hospital with the highest number of deliveries. Data included maternal HBSAg and coinfection (HIV, HCV) status and the administration of prophylaxis in newborns at risk. Other serologic markers of HBV maternal infection were not available. Results 132 (0,6%) newborns from HBsAg positive mothers were identified between 2017-2019 among 21143 newborns. In this group pre-natal HBSAg status was known in 127 (96,2%), the remaining were tested during the hospitalization. Regarding maternal coinfection 130 (98%) were tested for HIV (1 positive), only 60 (45.1%) for HCV (all negative). All newborns received immunoprophylaxis consisting in the administration of vaccination and immunoglobulin: 119 (89%) within 24 hours (63% within 12 hours), 12 (9%) between 24-36 hours and 2 (1,6%) after 36 hours. The 2 cases of vertical transmission, even if correctly vaccinated, show a vaccination failure of 1,5%. Conclusions Although most of the mothers were tested for HBSAg status and all newborns were given immunoprophylaxis, vaccination failure seems to explain the 2 cases of vertical transmission. Since the lack in early maternal serologic screening and the late vaccination time could increase the risk of HBV infection, to achieve WHO goal we suggest to implement a multidisciplinary pathway to identify HBV positive mothers, to treat in case of high viral load, to provide a timely immunoprophylaxis considering a early vaccination and to set up a structured postnatal serologic check for newborns at risk. Key messages Vaccination failure must be considered in the service organization, a structured postnatal serologic check for all newborns at risk should be implemented to detect potential vaccination failure. A multidisciplinary pathway to identify HBV positive mothers, with a full serological markers set, should be implemented to give a correct maternal therapy and newborn prophylaxis.