Breastfeeding Around the World: Maternal Infections

The infection that is of main concern is HIV, the virus that causes AIDS. HIV is transmitted through breast milk ( WHO, 2004-1 , AAP Ped AIDS, 2003 ). Nduati randomized HIV positive East African women into breastfeeding and formula feeding groups and found increased HIV transmission rates in the breastfed infants compared to those fed formula ( Nduati, 2000 ). A meta-analysis of 4085 breastfed infants who were born to HIV infected mothers in Africa, showed that 993 infants (24%) were infected by the end of the studies. Of the 993 infected infants, 122 (12%) were infected at birth, 225 (23%) were infected by 1 month of age, 223 (22%) were definitely infected after 1 month of age, and 454 (46%) were infected at unknown time ( BF and HIV, 2004 , Bulterys, 2004 ).

1. The WHO policy on infant feeding for mothers who are HIV negative or who don't know their HIV status is, "Exclusive breastfeeding for the first six months of life, with adequate and safe complementary feeding from age six months and continued breastfeeding for up to two years and beyond." ( WHO, 2003-2 ).

2. When children are born to mothers who are HIV positive, the WHO recommends:
   1. "Exclusive breastfeeding is recommended for HIV-infected women for the first 6 months of life unless replacement feeding is acceptable, feasible, affordable, sustainable and safe for them and their infants before that time." and "At six months, if replacement feeding is still not acceptable, feasible, affordable, sustainable and safe, continuation of breastfeeding with additional complementary foods is recommended, while the mother and baby continue to be regularly assessed. All breastfeeding should stop once a nutritionally adequate and safe diet without breast milk can be provided."

   2. "When replacement feeding is acceptable, feasible, affordable, sustainable and safe, avoidance of all breastfeeding by HIV-infected mothers is recommended." This is the recommendation that is followed in the developed world.

   3. When both the breastfeeding mother and their infant or young child "are known to be HIV-infected they should be strongly encouraged to continue breastfeeding" ( WHO, 2006-1 ).
   ( WHO, 2003-2 ).

3. The risk of transmitting HIV through breast milk seems to be greater for:
   1. mothers who become acutely affected with HIV during the time they are breastfeeding, in distinction to mothers who were HIV positive during pregnancy ( Van de Perre, 1991 ; Hira, 1990 ),

   2. Mothers who give mixed breast milk and other foods or milks instead of exclusive breastfeeding in the first six months of life.

      In South Africa, Coovadia and Coutsoudis encouraged exclusive breastfeeding for 6 months in a cohort of HIV infected mothers who received nevirapine at the birth of their infant. Median duration of exclusive breastfeeding was 159 days (5 months). Breastfed infants who received solid foods along with breastfeeding were more likely to be infected with HIV at 6 months (Hazard Ratio of 10.87) than infants exclusively breastfed. Cumulative mortality at 3 months of age was 6.1% in exclusively breastfed infants compared to 15.1% in infants given formula (Hazard Ratio 2.06) ( Coovadia, 2007 ). Prior work in South Africa showed that continued breastfeeding longer than 6 months of age with the addition of complementary foods was associated with continued transmission of HIV to the infants.( Coutsoudis, 2001 ).

   3. Mothers with a large amount of HIV virus in their breast milk or blood, or mothers with advanced HIV disease that is manifested by immune deficiency ( WHO, 2004-1 , Rousseau, 2003 , Manigart, 2004 ).

   4. Maternal mastitis, breast abscesses or nipple lesions ( WHO, 2004-1 , AAP Ped AIDS, 2003 ).

4. Decreased maternal transmission of HIV to the breastfed infant has been associated with higher amounts of the following substances in the breast milk:
   1. antiviral substances such as lactoferrin, lysozyme, and epidermal growth factor,

   2. HIV specific killer T lymphocytes,

   3. secretory IgA and IgM ( AAP Ped AIDS, 2003 ).

5. In the United States and the developed world, women who are HIV positive are encouraged not to breastfeed their infants ( AAP Ped AIDS, 2003 ; AAP Breastfeeding, 2005 ).

6. Research in clinical settings is continuing on treating the HIV infected mother who is breastfeeding and/or the breastfed infant of the HIV infected mother with highly active anti-HIV medications. A trial in the Ivory Coast in an urban area with electricity and piped water inside or outside homes showed that when mothers and infants received anti-HIV prophylaxis in the perinatal period and were encouraged to exclusively breastfeed their infants for 4 months with weaning to replacement feeding or use only replacement feeding from birth, there was no difference in mortality or morbidity in the first 2 years of life ( Becquet, 2007 ).

   The Mashi Study in Botswana, compared infants born to HIV infected mothers who were breastfed and given zidovudine for the first 6 months of life with infants who were fed formula and received 1 month of zidovudine after birth. At 7 months of age, the HIV infection rate of infants in the 6 month breastfeeding group was 9.0% compared to 5.6% in the group receiving formula. However the overall infant mortality rate at 7 months was 9.3% in the formula fed group compared to 4.9% in the breastfed group. By 18 months of age, cumulative mortality or HIV infection was the 13.9% in the formula fed infants compared to 15.1% in the breastfed infants ( Thior, 2006 ).

   Trials are ongoing with different regimens of anti-HIV drugs being given to the breastfeeding mother and her infant. Results of early trials show decreased HIV transmission during the perinatal period which results in decreased infection rates in the child at 18 months of age ( Moodley, 2003 , Jackson, 2003 , Coovadia, 2004 ).

7. Preliminary results from trials in Kenya, Malawi, Uganda, and Botswana of exclusive breastfeeding in the infant of the HIV infected mother with rapid weaning at 3-6 months of age have shown increased incidence of severe gastroenteritis and mortality from gastroenteritis within the first 3 months after early weaning from breastfeeding ( WHO, 2006-1 ).

8. Evaluation of the information regarding maternal to child transmission of HIV reveals that the combination of effective available HIV testing and counseling, use of antiretroviral medications for the mother and infant, support for choice of feeding, and exclusive breastfeeding for 6 months with the addition of complementary foods at 6 months of age may be the most effective strategy in preventing HIV infection in the infant and maximizing infant survival ( Coutsoudis, 2002 , Bertolli, 2003 , Coutsoudis, 2003 , Ross, 2004 , WHO, 2006-1 ).

An infant whose mother has acute infectious tuberculosis can be infected through close contact. This can happen whether or not the baby is breastfed. In the developed world, these women may need to be separated from their infants until they are not infectious. They should be encouraged to express their breast milk to build and maintain their milk supply so that they can breastfeed their baby when they are no longer infectious. The expressed breast milk can be fed to the baby ( Lawrence, 1999-2 ).

In the developing world, the diagnosis may not be made in the mother. The infant will usually receive a BCG immunization at birth to prevent serious infection and breastfeeding will be continued, as is the norm.