Annals of Tropical Paediatrics (2003) 23, 91–106ReviewHIV transmission through breastfeeding: problems andpreventionM. O. OGUNDELE & J. B. S. COULTERLiverpool School of Tropical Medicine, Liverpool, UK(Accepted March 2003)Summary The greatest burden of HIV infection in women and their children is disproportionately borne bythe poorest countries, especially in sub-Saharan Africa. Breastfeeding is a major health-promoting factor for infantsand children in developing countries but the risk of mother-to-child transmission (MTCT) of HIV by this routeis challenging traditional practices and health policies in low-resource countries. Maternal and infant factorscontributing to the risk of MTCT through breastfeeding are still poorly understood and not well researched.Factors identi ed include: advanced clinical stages of infection in the mother; high maternal plasma HIV-1 load;presence of mastitis; and infant oral thrush. In many developing countries, international agencies are providingsupport and recommendations for preventing MTCT of HIV-1 by breastfeeding. Preventive strategies supportedby WHO/UNICEF and charitable agencies in some sentine l centres in sub-Saharan Africa include routineantenatal voluntary counselling and testing (VCT), PCR testing of infants of seropositive mothers at 6 weeks ofage, various combinations of a shortened period (3–6 mths) of exclusive breastfeeding, perinatal administrationof antiretrovirals (ARV) such as nevirapine and provision of aVordable and safe infant replacement feeds ( presentlygiven free by UNICEF in some centres). Many problems, however, have hindered eVec tive implementation ofthese interventions. In many poor communities, even where VCT facilities are available, acceptance of HIV testingis low because there is fear of stigmatisation by the spouse, family or community and compliance with complexdrug regimens is therefore poor. Other problems include the exorbitant cost of antiretroviral drugs, inadequatelyresourced health care systems and unavailability or poor acceptance of safe breast-milk alternatives. The rate ofmixed feeding is high and so the risk of MTCT is increased. Continued promotion of exclusive breastfeedingfor at least 6 months, irrespective of HIV status, followed by a properly prepared, high energy, nutritiouscomplementary diet, with the possibility of early weaning to an animal milk formula, still appears to be the mostappropriate option for the poor in countries with high levels of MTCT not deriving any bene t from the abovestrategies. While a longer period of breastfeeding would probably increase the risk of MTCT in vulnerablecommunities, a shorter duration would certainly increase infant morbidity and mortality. Results of investigationsof the eYc acy of ARV for protecting the infants of HIV-infected mothers during the breastfeeding periodare awaited.IntroductionSaharan Africa.1In sub-Saharan Africa, 8%of adults are HIV-infected, the disease beingIt is estimated that 95% of adults and childrenslightly more prevalent in women than in men,with HIV/AIDS are in developing countriesthe peak prevalence b eing in women agedand that 80% of HIV-infected women and15–25 years, whe n they ar e most fertile.2,390% of newly infected children are in sub-Mother-to-child transmission (MTCT) ofHIV can occur during pregnancy, deliveryor breastfeeding and is responsible for moreReprint requests to: Dr J. B. S. Coulter, Liverpool Schoolthan 90% of HIV infections in childrenof Tropical Medicine, Pembroke Place, LiverpoolL3 5QA, U.K. E-mail: [email protected] HIV types 1 and 2 can be© 2003 The Liverpool School of Tropical MedicineDOI: 10.1179/02724930323500216192M. O. Ogundele & J. B. S. Coultertransmitted from mother to child, but HIV-2Evidence of MTCT Throughis transmitted much less frequently as it isBreastfeedingless pathogenic.4The actual timing and quanti cation of The earliest reports in dicating the possibilityMTCT pre- and postnatally are not known of H IV-1 transmission by breast-milk con-with any degree of certainty but severalcerned breastfed infants of women infectedrough estimates have been made. Kourtisafter delivery by blood transfusion or hetero-et al.postulated that MTCT most frequentlysexual exposure.11There were also reportsoccursin uterobetween the 38th week ofof infants with no other known sourcegestation and delivery (50%), 30% duringof exposure to HIV who were infectedlabour and only 20% before the 38th weekthrough wet-nursing and pooled breast-of pregnancy.5In women who breastfeed,milk.12Additional evidence was provided by30–35% of MTCT occurs postnatally.6prospective studies of the incidence of HIVin breastfed infants born to HIV-infectedmothers who seroconverted in the post-Bene ts of Breastfeedingpartum period compared with seronegativecontrol women.13–15HIV particles haveIn the pre-HIV era, breastfeeding wasbeen detected in both cellular and cell-freean important factor in maintaining childbreast-milk components (Table 1).health by providing optimum nutrition andprotection ag ainst common childhood infec-tions, especially respiratory and diarrhoealinfections, and by promoting child-spacing.7Rate and timing of MTCTFor the 1st 4–6 months of life, breast-milkEstimates of the rate of MTCT in womenprovides clean, pure, adequate nutritionwho have not received antiretrovirals rangeat optimal temperature and with the rightfrom 15 to 20% in Europe, from 16 tobalance of proteins, carbohydrates and30% in the USA, from 25 to 40% in sub-micronutrients as well as hormones andSaharan Africa and from 13 to 48% innucleotides. Breast-milk contains long-chainSouth and South-East A sia.16Reasons forpolyunsaturated fatty acids thought to bethese variations include diVerent prevalencesessential for the developing br ain.8It canof breastfeeding, maternal and obstetricalso provide a signi cant degree of nutritionrisk factors and methodological diVerencesover the next 6 months or more.1It protectsbetween studies.16Other factors includeagainst a host of environmental insults tomaternal nutritional status, stage of HIVwhich the growing infant has not been pre-disease, HIV type4and, possibly, diVerencesviously exposed, thus allowing the immunein transmission of HIV-1 subtypes.system to develop naturally without undueBecause of limitations in the technologypremature stress.9for HIV testing, it is not possible to determineIn developing and industrialised nations,the timing or degree of early
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