Perinatal HIV transmission rates may be higher among mothers infected postnatally

The risk of vertical transmission of HIV via breast-feeding was more than 35% among Chinese women who had been infected by blood transfusion postnatally, according to results of a recent study.

The study included 104 women from seven counties in the Hubei and Hebei regions of China. All women included in the study had contracted HIV through a blood transfusion due to excessive bleeding during vaginal delivery or cesarean section and had exclusively breast-fed their children.

The women involved had had 106 children at 12 healthcare facilities between 1994 and 2000. All of the children had survived to age 5 years; the survival curve of the children and the survival curve of the mothers were similar, according to the results. The retrospective case study was conducted from January 2000 through June 2008.

Perinatal infection occurred in 38 (35.8%; 95% CI, 26.7%-44.9%) children. None of those children had ever received a blood transfusion.

Breast feeding lasted for an average of 16.5 months (range, 1 to 28 months).

Mastitis or cracked nipples were reported by 16 of the 104 mothers. Of the children born to those 16 mothers, 10 had HIV. The risk of HIV transmission among mothers in whom a history of breast disease was present during the lactation period of interest was 62.5% (95% CI, 35.4%-84.9%). Transmission risk was 31.1% (95% CI, 21.5%-40.7%) among mothers with no history of breast disease during lactation.

The researchers observed no statistically significant accumulation of infections beyond six months of breast-feeding. They wrote that this may indicate that most transmissions occurred shortly after birth.

Liang K et al. J Infect Dis. 2009;200:682-686.