Discrepancy in impact of maternal milk on vertical transmission between Hepatitis B virus and Human cytomegalovirus.

OBJECTIVES

This study aims to elucidate the role of breastfeeding on vertical transmission of HCMV and HBV and to investigate the difference in perinatal transmission via breast milk between HBV and HCMV.

METHODS

This detailed study monitored the kinetics of viral DNA load in maternal milk for both HBV and HCMV, demonstrated the rate of transmission to infants, and compared HBV infection rate with that of HCMV.

RESULTS

There was no difference in overall DNAlactia+ between HBV (23.86%) and HCMV (29.54%, P=0.140) for seropositive mothers, while HBsAg prevalence (0.75%) was significantly lower than HCMV IgG+ (27.44%, P<0.001) for the breast-fed babies. Between breast-fed babies of seropositive mothers and those of seronegative mothers, HBV infection rate had no difference (HBsAg+: 0.75% vs 0%, P=0.538; DNAemia+: 0.38% vs 0%, P=0.664), but HCMV infection rate of the former was significantly higher than that of the latter (IgG+: 27.07% vs 18.00%, P=0.045; DNAemia+: 15.79% vs 4.00%, P=0.027).

CONCLUSIONS

Breastfeeding is not a risk factor for maternal-to-infant transmission of HBV after the recommended prophylaxis is implemented. However, viral DNA positive breast milk is a main source for vertical transmission of HCMV to infants who are not protected by a standard immunoprophylaxis protocol.