Treatment of breast milk

In vitro studies have demonstrated that heat treatment of breast milk to which a known quantity of HIV had been added, using the Holder pasteurization method (at 62.5^oC for 30 minutes), reduces the infectious titre of cell-free and cell-associated virus by more than five logs and six logs, respectively (Orloff et al., 1993).

As discussed earlier, breast milk contains substances that inhibit infectious agents (Goldman, 1993). Several studies have reported that HIV is inactivated when milk is left to stand at room temperature for half an hour (Orloff et al., 1993; Newburg et al., 1992; Isaacs and Thormar, 1990). In the first two of these studies, the inhibitory effects of breast milk were attributed to a milk-lipase-activated factor that released fatty acids which were thought to dissolve or disrupt the viral envelope. Newburg et al demonstrated that human milk glycosaminoglycans inhibit binding of HIV glycoprotein gp120 to host cell CD4 receptors. There is a need to evaluate alternatives for treating breast milk, which utilize or enhance the action of naturally occurring anti-HIV factors to prevent breast-milk transmission of HIV.

However, all strategies to modify or treat breast milk to render it non-infectious would involve expressing milk, and some women may find it difficult to sustain this process for long periods of time. This should not prevent the option being offered, and professional support should be provided when women choose it. Expression and heat treatment may also be a temporary solution during periods of increased transmission risk, as in cases of cracked nipples or breast abscess, and for low-birth-weight or sick infants for whom the risk of artificial feeding is greater.

Heat treatment of breast milk is recommended for all milk banks, which should also screen milk donors for HIV.