LETTERS
Exclusive breastfeeding and postnatal transmission of HIV
J. P. Dadhich
Research and Interventions, Breastfeeding Promotion Network of India. BP33 , Pitampura, New Delhi 110088, India. (email: jpdadhich@ibfan-asiapacific.org)
Editor I have some comments to make about the article by R. Bahl et al., published in the June 2005 issue of the Bulletin (1).
The abstract states that the study has two major implications:
1. " ...the extremely high risks of infant mortality associated with not being breastfed need to be taken into account when informing HIV-infected mothers about options for feeding their infants."
2. "...the risks of death are similar for infants who are predominantly breastfed and those who are exclusively breastfed" and this "suggests that in settings where rates of predominant breastfeeding are already high, promotion efforts should focus on sustaining these high rates rather than on attempting to achieve a shift from predominant breastfeeding to exclusive breastfeeding."
Before making the first of these implications, however, the authors should have stated that this is true only in resource-limited areas.
As far as the second implication is concerned, other studies contradict it. For example, the Zvitambo study carried out in Zimbabwe explicitly concludes that the risk of postnatal transmission of HIV arising from predominant breastfeeding versus that from exclusive breastfeeding varied from 1.6 to 2.7 over an 18-month period, reaching statistical significance at 12 months (2). This indicates that the early introduction of non-human milks and solid foods conveys an especially high risk, but that even non-milk liquids are likely to increase the risk. Therefore, the more strictly that HIV-positive mothers are able to breastfeed exclusively, the lower the risk of them transmitting HIV to their infants and the lower the risk their infants have of dying. 
Competing interests: none declared.
References
1. Bahl R, Frost C, Kirkwood BR, Edmond K, Martines J, Bhandari N, et al. Infant feeding patterns and risks of death and hospitalization in the first half of infancy: multicentre cohort study. Bull World Health Organ 2005; 83:418-26.
2. Iliff PJ, Piwoz EG, Tavengwa NV, Zunguza CD, Marinda ET, Nathoo KJ, et al. Early exclusive breastfeeding reduces the risk of postnatal HIV-1 transmission and increases HIV-free survival. AIDS 2005;19:699-708.