(introduction...)

Breast-milk transmission of HIV has been well documented. The first reports indicating the possibility of HIV-1 transmission through breast milk were in breastfed infants of women who were infected postnatally through blood transfusion or through heterosexual exposure (Palasanthiran et al., 1993; Van de Perre et al., 1991; Stiehm and Vink, 1991; Hira et al., 1990; Colebunders et al., 1988; Lepage et al., 1987; Ziegler et al., 1985;). There were also reports of infants, with no other known exposure to HIV, who were infected through wet-nursing and through pooled breast milk (Nduati et al., 1994; Colebunders et al., 1988;).

Generally, higher rates of mother-to-child transmission of HIV are observed where most infants are breastfed rather than where fewer infants are breastfed. However, other reasons for variations in transmission rates, such as maternal nutritional status, stage of HIV disease and possible differences in transmission of HIV subtypes cannot be excluded. Additional evidence is provided by results from prospective studies which indicate that among infants born to HIV-infected mothers, those who are breastfed are more likely to be infected than those who are formula-fed, even allowing for other factors known to be associated with mother-to-child transmission of HIV (European Collaborative Study, 1992; Ryder, 1991; Blanche et al., 1989; Tovo et al., 1988; Tess et al., 1998a).