Breastfeeding and HIV transmission – Authors' reply

Abstract

In their Comment on the paper by Hoosen Coovadia and colleagues Wendy Holmes and Felicity Savage expose their personal biases by warmly embracing the papers findings and fail to contextualise its importance. The paper describes the risks of mixed feeding (both formula and breast feeding) compared with exclusive breast feeding in infants of HIV-positive women. Coovadia and colleagues note mortality in the first 3 months of life was roughly doubled in the group receiving formula feeding compared with the exclusive breast feeding group (15% vs 6%) and cautiously describe this as a concern without offering any explanation. They do however acknowledge an obvious selection bias in that mothers who chose to formula feed were significantly more likely (p<0.0003) to have CD4-cell counts of less than 200 per microL than were mothers who exclusively breastfed. Holmes and Savage fail to recognise or choose to ignore this major bias and instead highlight the finding as important in adding to the accumulation of new evidence on the hazards of formula feeding. They support this assertion by oddly referencing a Botswanian study that found breastfeeding plus zidovudine prophylaxis was not as effective as formula feeding in preventing postnatal HIV transmission and was associated with a similar mortality rate at 18 months. A more balanced Comment could have discussed the limitations of comparing mortality outcomes at 6 months (as opposed to say 2 or 5 years when the full effect of HIV-infection-related deaths secondary to breastfeeding would be overt) the feasibility of supporting exclusive breastfeeding in nonresearch settings and the papers relevance to the development of infant feeding policies for urban HIV-positive parents who might prefer formula feeding recognising its acceptability safety and efficacy in diverse urban settings such as Abidjan Cote dIvoire; Soweto South Africa; and Bangkok Thailand. (excerpt)