Background:  This subject is of critical importance to developing countries and for global child health. In industrialized countries, where breastfeeding can be safely avoided, rates of HIV infection due to antenatal and intrapartum transmission have fallen from about 25% down to 1 to 2%; in Sweden the infection appears to have been eliminated. The measures producing these dramatic reductions in mother-to-child transmission (MTCT) are the most successful of all the prevention interventions in the entire field of HIV/AIDS. The many ART trials, which have been the bedrock on which the above public health triumphs have been achieved, and which have been conducted in formula-feeding and breastfeeding populations, will be alluded to briefly. The key point to be made is that continued breastfeeding in these trials, resulted in attrition of efficacy assessed at 4 to 6 weeks of age.

Methods:  The case for supporting breastfeeding by HIV-infected mothers, who have been properly counseled and who have freely chosen their preferred infant feeding method (usually breast- or formula-feeding), will be made. The well-recognized advantages and disadvantages of breastfeeding and formula-feeding will be recalled. Attention will be drawn to new data from large multi-country trials, including a seminal Lancet series on child survival, demonstrating the substantial benefits of breastfeeding, even for HIV-infected women. Breastfeeding prevented 13% (n = 1,301,000 deaths) of all deaths. Data from a huge diarrhea outbreak in Botswana will be presented to show the hazards of formula feeding even in middle-income countries.

Results:  Early cessation of breastfeeding (<6 months) reduces HIV transmission but has been reported to increase morbidity and mortality in infants born to HIV positive African women.

Conclusions:  The role of innate immunity, antibodies, cellular reservoirs, and free virus in the pathogenesis of breast-milk transmission will be highlighted. Interventions potentially useful to reduce breastfeeding transmission of HIV will be identified. These include:  primary HIV prophylaxis for women, chemo- and immuno-prophylaxis, infant nutrition policies, and feeding options. For example, a number of African studies have shown that exclusive breastfeeding is associated with a lower HIV transmission than mixed breastfeeding; exclusive breastfeeding by HIV-positive women is accompanied by a lower infant morbidity and mortality.