HIV, infant feeding, and maternal and child health

In 1997 the UN Policy Statement highlighted that, as a general principle and in all populations, irrespective of HIV infection rates, breastfeeding should be protected, promoted and supported. It also clearly emphasised that HIV-positive mothers have to be empowered to make a fully informed choice about infant feeding and have to be supported in implementing their decisions.

In October 2000, UNICEF, WHO and UNAIDS reviewed evidence that accumulated in the course of three years. There were research findings that required specific attention. The results published by Coutsoudis et al. (Lancet, 1999) suggested benefits of exclusive breastfeeding over mixed feeding, with exclusive breastfeeding carrying a similar risk of transmission of HIV compared to exclusive formula feeding (presented in Breastfeeding Briefs no 29). A follow-up analysis of the data, published by Coutsoudis et al. in 2001 (Breastfeeding Briefs no 31-32), also concluded that infants exclusively breastfed for 3 months or more had no excess risk of HIV infection over 6 months than those never breastfed. After analysing the data, the UN clearly reiterated the 1997 Policy on HIV and Infant Feeding and specified in the recommendations that:

• When replacement feeding is acceptable, feasible, affordable, sustainable and safe, then avoidance of all breastfeeding by the HIV positive mother is recommended.

• In the absence of any of these conditions, exclusive breastfeeding is recommended during the first months of life.

This recommendation was again reviewed by WHO in 2001 in the light of the findings of Nduati et al. which suggested that HIV positive mothers had higher mortality rates if they breastfed their infants. These results conflicted with findings of a South African study that found no increase in death among HIV nursing mothers. An editorial in the Lancet points out that these conflicting results must lead to further research, not to recommendations (Note 1). On 7 June 2001, WHO issued a statement that warned against rushing to quick conclusions leading to a shift in the policy (Note 2). WHO stated that the limitations of the Nduati data call for a cautious interpretation and reiterated again the importance of proper support, clinical as well as nutritional, to mothers who are HIV infected.

HIV and the infant feeding component of programmes on prevention of mother-to-child transmission of HIV haves been most challenging. This is because research has not yet provided definite responses to issues such as the effect of exclusive breastfeeding and the impact of anti-retroviral therapy during lactation on the transmission rates. Much research that has looked at breastfeeding and HIV did not take into account the WHO 1991 definitions for individual infant feeding patterns (exclusive breastfeeding, predominant breastfeeding, partial breastfeeding, etc.). It was thus impossible to separate the data in this respect and provide useful guidance for programme managers. In 2001, WHO, in collaboration with UNICEF and experts, issued an assessment tool for research to assist scientists in designing research protocols.

The 2000 recommendation about using replacement feeding only when it is acceptable, feasible, affordable, sustainable and safe is certainly a step in the right direction. However, all these conditions are extremely situation specific. Therefore it is crucial that a proper detailed situation analysis is performed so that the counsellors for HIV positive mothers have a good understanding of the range of options and conditions and can effectively assist mothers in making an informed choice. The experience for counselling of HIV positive mothers in various parts of the world suggests that many counsellors are not fully equipped with knowledge and skills and are often acting on the basis of prejudice, personal experience and under time pressure.

Notes

1. Newell ML. Does breastfeeding really affect mortality among HIV-1 infected women? Lancet 2001;357:1634
2. WHO. New data on the prevention of mother-to-child transmission of HIV and their policy and implications. Geneva, 7 June 2001

Highlights

1. Nduati R, John G, Mbori-Ngacha D, Richardson B, Overbaugh J, Mwatha A, Ndinya-Achola J, Bwayo J, Onyango FE, Hughes J, Kreiss J. Effect of breastfeeding and formula feeding on transmission of HIV-1: a randomized clinical trial. JAMA 2000;283:1167-74

2. Nduati R, Richardson BA, John G, Mbori-Ngacha D, Mwatha A, Ndinya-Achola J, Bwayo J, Onyango FE, Kreiss J. Effect of breastfeeding on mortality among HIV-1 infected women: a randomised trial. Lancet 2001;357:1651-5

3. Mbori-Ngacha D, Nduati R, John G, Reilly M, Richardson B, Mwatha A, Ndinya-Achola J, Bwayo J, Kreiss J. Morbidity and mortality in breastfed and formula-fed infants of HIV-1-infected women: a randomized clinical trial. JAMA 2001;286:2413-20

OBJECTIVES. This study was conducted to determine the frequency of breastmilk transmission of HIV-1, and to compare morbidity, nutritional status, mortality and HIV-1-free survival in breastfed and formula-fed infants. The same data were also used to examine the effect of breastfeeding on maternal death rates during two years after delivery.

METHODS. 425 HIV-1-seropositive pregnant women never treated with antiretroviral drugs were enrolled from November 1992 to July 1998 in antenatal clinics in Nairobi, Kenya. Of these, 212 were randomized to breastfeeding (BF), and 213 to formula feeding (FF). 401 mother-infant pairs were followed-up for a median period of 24 months and were included in the analysis for the first two papers, while 371 infants were included in the analysis for the third paper.

RESULTS. Compliance with the assigned feeding mode was 96% in the BF arm, and 70% in the FF arm (p<.001). Median duration of breastfeeding was 17 months. The cumulative probability of HIV-1 infection at 24 months was 36.7% in the BF arm, and 20.5% in the FF arm (p=.001). The estimated rate of breastmilk transmission was 16.2%, and 44% of HIV-1 infection in the BF arm was attributable to breast milk. Most breastmilk transmission occurred early, with 75% of the risk difference between the two arms occurring by 6 months, although transmission continued throughout the duration of exposure. The 2-year mortality rates in both arms were similar (BF 24.4% vs FF 20.0%; p=.30), even after adjusting for HIV status. The rate of HIV-1-free survival at 2 years was significantly lower in the BF arm than in the FF arm (58.0% vs 70.0%, respectively; p=.02). The incidence of diarrhoea during the two years of follow-up was similar (155 vs 149 episodes per 100 person-years, respectively). The incidence of pneumonia was identical in the two groups (62 per 100 person-years), and there were no significant differences in incidence of other recorded illnesses. Infants in the BF arm tended to have better nutritional status, significantly so during the first 6 months of life. Mortality among mothers was higher in the BF arm, than in the FF arm (18 vs 6 deaths, p=.009). The cumulative probability of maternal death at 24 months after delivery was 10.5% in the BF arm, and 3.8% in the FF arm (p=.02). BF mothers had a 3.2 times higher risk of death than FF mothers; the estimated proportion of deaths due to breastfeeding among BF mothers was 69%. There was an association between maternal death and subsequent infant death, even after infant HIV-1 infection status was controlled for.

DISCUSSION. Infants assigned to FF or BF had similar mortality rates and incidence of diarrhoea and pneumonia during the first 2 years of life. However, HIV-free survival at 2 years was significantly higher in the FF arm. According to the authors, with appropriate education and access to clean water, formula feeding can be a safe alternative to breastfeeding for infants of HIV-infected mothers in a resource-poor setting.

4. Coutsoudis A, Coovadia H, Pillay K, Kuhn L. Are HIV-infected women who breastfeed at increased risk of mortality? AIDS 2001;15:653-655

For the objectives and methods of this study, see summary in Breastfeeding Briefs no 29 and no 31-32. A total of 566 HIV positive mothers were followed after delivery for 10.4 months among those who ever breastfed (n = 410) and for 10.6 months in those who never breastfed (n = 156). Two out of 410 (0.49%) women who breastfed died compared with three out of 156 (1.92%) who never breastfed, a non statistically significant difference. Among the breastfeeding group, the proportion with any morbidity was similar for those who breastfed for more than 3 months (14%) compared with those who breastfed for less than 3 months (11%), even after controlling for CD4 cell counts and hemoglobin levels. The authors were unable to confirm any deleterious effects of breastfeeding on the health of seropositive women.