Effect of Breastfeeding and Formula Feeding on Transmission of HIV-1
Summary of published clinical trial

Transmission of human immunodeficiency virus type 1 (HIV-1) is known to occur through breastfeeding, but the magnitude of risk has not been precisely defined. Studies have led to estimates of transmission risk during acute maternal infection of 29% (95% CI 16%-42%) and for women with established infection of 14% (95% CI 7%-22%). Whether breast milk HIV-1 transmission risk exceeds the risk of formula feeding-associated diarrhoeal mortality in developing countries is unknown.
A randomised clinical trial1 was conducted in Nairobi to determine the frequency of breast milk transmission of HIV-1 and to compare mortality rates and HIV-1-free survival in breastfed and formula-fed infants. Over five and a half years 425 HIVseropositive women were enrolled in the study. Women were eligible for inclusion if they were Nairobi residents and had access to municipal treated water. Participants did not use antiretroviral therapy. At about 32 weeks of pregnancy women were randomised to breastfeed or formula feed. The formula group were given free formula and shown how to prepare it. They were told to boil water and feed with a cup to minimise bacterial contamination.
Compliance with the assigned feeding method was:
- 96% in the breastfeeding group (defined by any use of breast milk) 83% were exclusively breastfed at 6 weeks, 62% at 3 months and 9% at 6 months.
- 70% in the formula feeding group (defined by complete avoidance of breast milk).
This comparatively low compliance in the formula group results from the fact that breastfeeding is the norm in Kenya and women experienced pressure from family and community and were in some cases concerned about maintaining confidentiality about their HIV- status.
Of the 401 infants in the study analysis2 92 were HIV-1 infected, 61 of these were in the breastfeeding group and 31 in the formula group. At 24 months the cumulative probability of HIV-1 infection was significantly higher for infants in the breastfeeding group than the formula feeding group. The estimated rate of breast milk HIV-1 transmission was 16.2% during the first 2 years of life. Breast milk transmission accounted for 44% in the group exposed to breast milk. The data suggest that substantial transmission occurs early (by 6 months 75% of all breast milk transmission had occurred). Another important finding was that the 2-year mortality rates in the 2 groups were similar. However the HIV-1 free survival at 2 years was significantly lower in the breastfeeding group than in the formula feeding group (58% vs 70% respectively; P = 0.02)
This important study throws some light on risk difference between HIV-1 transmission and formulae associated diarrhoeal mortality. Though the study showed that in this setting the use of formula prevented 44% of infant HIV-1 infections the authors caution about generalisability of results. While HIV-1 transmission via breast milk may be comparable across populations given similar exposure, the risks associated with formula are community specific. In this trial mortality in both groups was similar even though participants had access to clean water and extensive instruction on safe formula use. In developing country situations (especially emergencies involving refugee or displaced populations) where clean water and formula feeding knowledge is limited, the balance of risks and benefits could be shifted. Furthermore, formula is unaffordable to many (about $300 for 6 months in Kenya). Also, an intervention aimed at reducing HIV transmission through promoting use of infant formula amongst HIV sero-positive women requires antenatal HIV-1 testing and a healthcare infrastructure to provide education on formula feeding. The authors conclude that given the high sero-positive prevalence in pregnant women in sub-Saharan Africa the priority is to find ways to make a spectrum of preventative interventions widely accessible.
1Nduati R, et al., Effect of Breastfeeding and Formula Feeding on Transmission of HIV-1: A Randomised Clinical Trial. JAMA, March, 2000-Vol 283, No. 9 p 1167.
2At time of delivery only 408 remained in the study. After exclusion of stillbirths and second born twins the number in the study declined to 401.
More like this
FEX: Infant feeding strategies and PMTCT - Mashi trial from Botswana
Summary of published research1 Arecently published paper compares the efficacy and safety of two infant feeding strategies for the prevention of postnatal mother-to-child HIV...
FEX: Infant feeding patterns and HIV–1 transmission
Letters in the Lancet1 In the last issue of Field Exchange we summarised an article published in the Lancet by Anna Coutsoudis and colleagues which found that there are...
FEX: Infant Feeding Alternatives for HIV Positive Mothers in Kenya
By Tom Oguta, Abiud Omwega and Jaswant Sehmi Tom Oguta is currently a PhD student of Nutrition at the University of Nairobi. He has worked as a Research Officer at KIRDI...
FEX: HIV Transmission and Breast-feeding
Published paper The high prevalence of HIV infection in many developing countries has given rise to increasing concern about the risk of transmitting the virus through...
FEX: Infant feeding and HIV transmission
Summary of Published paper The observation that mother-to-child transmission by HIV-1 infected women can occur through breastfeeding has resulted in policies that recommend...
FEX: Counselling on infant feeding choice: Some practical realities from South Africa
By Tanya Doherty (pictured), Mickey Chopra and Mike Colvin Tanya is currently a senior scientist at the Health Systems Trust and Medical Research Council in Capetown, South...
en-net: Publications on Flash heating of breastmilk
Am greatly interested in literature about flash heating of breastmilk, in the context of HIV. Are there any publications about the effectiveness and efficacy of this...
FEX: NGOnut discussion summaries - cassava poisoning, and HIV and breastfeeding
The following are edited summaries of e-mail correspondence from the NGO Nutrition Association (NGO Nut) which may be of interest to readers. The NGO Nut was recently set up...
FEX: Effects of breastfeeding: Implications for Policies on HIV and Infant Feeding
Summary of published paper The recognition that HIV is transmitted through breast-milk has raised important questions about strategies that promote breastfeeding in areas of...
en-net: Infant feeding and Ebola Outbreak
Posted on behalf of Fabienne Rousseau, ACF I have a question related to infant feeding in the context of the Ebola outbreak in West Africa. Our teams are engaged in...
en-net: breastfeeding
What knowledge gaps are there currently in breastfeeding? What are some of the challenges mothers are getting in practising exclusive breasfeeding, especially in third world...
FEX: Livelihood assessment approaches in emergencies
A paper and recently summarised editorial1,2 Violations of the International Code of Marketing of Breastmilk Substitutes have been previously reported in Field Exchange3. A...
FEX: Issue 29 Editorial
There are two major themes running through this issue of Field Exchange. The first is a focus on Southern Africa and the programmatic challenges presented by HIV/AIDS and the...
FEX: Diarrhoea risk associated with not breastfeeding in Botswana
Summary of report and presentation1 Between November 2005 and February 2006, there were unusually heavy rains and flooding in Botswana, and by January 2006, there was an...
FEX: Infant Feeding Patterns and Risk of Death
Summary of published paper1 Current WHO guidelines recommend that HIV positive mothers should avoid breastfeeding only if replacement feeding is acceptable, feasible,...
FEX: Cotrimoxazole as a Prophylaxis for HIV Positive Malnourished Children
Summary of review1 By Susan Thurstans, AAH Susan Thurstans is the HIV adviser with Action Against Hunger (AAH), based in Malawi Thanks to Amador Gomez, Technical Advisor,...
en-net: Should you recommend wet nursing in HIV prevalent areas where replacement feeding is not safe but there is no HIV testing available?
Current WHO guidance on infant feeding and HIV (2010) emphasises a public health approach to infant feeding choice in the HIV context. It emphasises that feeding...
FEX: Using IMRs to inform policy decisions on infant feeding and HIV
Summary of published research1 Feeding bottles in a camp in Pakistan A recently published paper presents an analysis of the impact of WHO infant feeding recommendations in...
FEX: HIV and Child Mortality
Summary of published research1 HIV contributes substantially to child mortality, but factors underlying these deaths are inadequately described. With individual data from seven...
en-net: Breastfeeding and its benefits
Dear All, this page appeared today under health issues on the BBC News website. I am very interested in knowing your views on this issues that has been raised before mothers...
Reference this page
Effect of Breastfeeding and Formula Feeding on Transmission of HIV-1. Field Exchange 11, December 2000. p2. www.ennonline.net/fex/11/effect
(ENN_3452)