Design, participants and setting: A prospective, observational study of perinatal transmission of HBV. Participants were pregnant women attending Sydney South West Area Health Service antenatal clinics who tested positive for hepatitis B surface antigen (HBsAg), and their babies. All babies were routinely offered hepatitis B immunoglobulin (HBIG) and HBV vaccination. Babies positive for HBsAg at 9-month follow-up underwent further virological testing, including HBV DNA sequencing. The study was conducted between August 2002 and May 2008.
Main outcome measures: HBV DNA levels and demographic characteristics of HBsAg-positive pregnant women; proportion of their infants with active HBV infection at 9-month follow-up; maternal characteristics affecting transmission rate; HBV DNA sequencing of infected infants and their mothers.
Results: Of 313 HBsAg-positive pregnant women, 213 (68%) were HBV DNA-positive and 92 (29%) were positive for hepatitis B “e” antigen (HBeAg); 138 babies born to HBV DNA-positive mothers were tested for HBV infection (HBsAg positivity) at about 9 months of age. Four cases of transmission were identified. All four mothers had very high HBV DNA levels (> 108 copies/mL) and were HBeAg-positive. Three of the four infants were infected with wild-type HBV strains, with identical maternal/infant isolates. The fourth mother–infant pair had an S gene variant, HBV D144E, which has been previously reported in association with vaccine/HBIG escape. (Unfortunately, HBIG was inadvertently omitted from the immunisation schedule of this infant.) Transmission rates were 4/138 (3%) from HBV DNA-positive mothers overall, 4/61 (7%) from HBeAg-positive mothers, and 4/47 (9%) from mothers with very high HBV DNA levels. No transmission was seen in 91 babies of mothers with HBV DNA levels < 108 copies/mL.
- 1. Canho R, Grosheide PM, Mazel JA, et al. Ten-year neonatal hepatitis B vaccination program, the Netherlands, 1982–1992: protective efficacy and long term immunogenicity. Vaccine 1997; 15: 1624-1630.
- 2. Xiao XM, Li AZ, Chen X, et al. Prevention of vertical hepatitis B transmission by hepatitis B immunoglobulin in the third trimester of pregnancy. Int J Gynaecol Obstet 2007; 96: 167-170.
- 3. van Zonneveld M, van Nunen AB, Niesters HG, et al. Lamivudine treatment during pregnancy to prevent perinatal transmission of hepatitis B virus infection. J Viral Hepat 2003; 10: 294-297.
- 4. Song YM, Sung J, Yang S, et al. Factors associated with immunoprophylaxis failure against vertical transmission of hepatitis B virus. Eur J Pediatr 2007; 166: 813-818.
- 5. O’Sullivan BG, Gidding HF, Law M, et al. Estimates of chronic hepatitis B virus infection in Australia, 2000. Aust N Z J Public Health 2004; 28: 212-216.
- 6. National Health and Medical Research Council. Australian immunisation handbook. 9th ed. Canberra: NHMRC, 2008.
- 7. Ayres A, Locarnini S, Bartholomeusz A. HBV genotyping and analysis for unique mutations. Methods Mol Med 2004; 95: 125-149.
- 8. Yuen LK, Ayres A, Littlejohn M, et al. SeqHepB: a sequence analysis program and relational database system for chronic hepatitis B. Antiviral Res 2007; 75: 64-74.
- 9. Hall TA. BioEdit: a user friendly biological sequence alignment editor and analysis program for Windows 95/98/NT. Nucleic Acids Symp Ser 1999; 41: 95-98.
- 10. Carman WF. The clinical significance of surface antigen variants of hepatitis B virus. J Viral Hepat 1997; 4 Suppl 1: 11-20.
- 11. Ngui SL, Andrews NJ, Underhill GS, et al. Failed postnatal immunoprophylaxis for hepatitis B: characteristics of maternal hepatitis B virus as risk factors. Clin Infect Dis 1998; 27: 100-106.
- 12. Li XM, Yang YB, Hou HY, et al. Interruption of HBV intrauterine transmission: a clinical study. World J Gastroenterol 2003; 9: 1501-1503.
- 13. Li XM, Shi MF, Yang YB, et al. Effect of hepatitis B immunoglobulin on interruption of HBV intrauterine infection. World J Gastroenterol 2004; 10: 3215-3217.
- 14. Lee SD, Lo KJ, Tsai YT, et al. Role of caesarean section in prevention of mother–infant transmission of hepatitis B virus. Lancet 1988; 2: 833-834.
- 15. Ngui SL, O’Connell S, Egin RP, et al. Low detection rate and maternal provenance of hepatitis B virus S gene mutants in cases of failed postnatal immunoprophylaxis in England and Wales. J Infect Dis 1997; 176: 1360-1365.
- 16. Lee PI, Chang LY, Lee CY, et al. Detection of hepatitis B surface gene mutation in carrier children with or without immunoprophylaxis at birth. J Infect Dis 1997; 176: 427-430.
- 17. Wang Z, Zhang J, Yang H, et al. Quantitative analysis of HBV DNA level and HBeAg titer in hepatitis B surface antigen positive mothers and their babies: HBeAg passage through the placenta and the rate of decay in babies. J Med Virol 2003; 71: 360-366.
- 18. Wang JS, Chen H, Zhu QR. Transformation of hepatitis B serologic markers in babies born to hepatitis B surface antigen positive mothers. World J Gastroenterol 2005; 11: 3582-3585.
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