Factors affecting the duration of exclusive breastfeeding among HIV-infected and -uninfected women in Lusaka, Zambia

Pooled Prevalence and Determinants of Prelacteal Feeding Practice in Eastern Africa Evidence from Demographic and Health Survey Data: A Multilevel Study

Background

Despite the benefits of breast milk and colostrum for the health and survival of children, early prelacteal feeding is commonly practiced worldwide, particularly in low- and middle-income countries. The aim of this study was to evaluate the pooled prevalence and determinants of prelacteal feeding in Eastern Africa.

Methods

This study was carried out within 11 East African countries from 2010 to 2018, a pooled study of prelacteal feeding was performed. For assessing model fitness and contrast, intra-class correlation coefficient, median odds ratio, proportional change in variance, and deviance were used. In order to identify possible covariates associated with prelacteal feeding in the study area, the multilevel multivariable logistic regression model was adapted. Adjusted Odds Ratio was used with 95% confidence interval to declare major prelacteal factors.

Results

The pooled prevalence of prelacteal feeding in Eastern Africa was 12% (95% CI: 11.42–12.53%), with the highest prevalence of prelacteal feeding in the Comoros (39%) and the lowest in Malawi (3%). Multilevel multivariable logistic regression model; wealth index (AOR = 1.22; 95% CI 1.03–1.34), ANC visit (AOR = 1.42; 95% CI: 1.12–1.79), institutional delivery (AOR = 0.58; 95% CI: 0.58–0.64), small birth size (AOR = 1.14; 95% CI: 1.30–1.26), delivery type (AOR = 2.61; 95% CI: 2.30–2.96), and high community ANC visit (AOR = 0.90; 95% CI: 0.84–0.97) were significantly associated with prelacteal feeding in Eastern Africa.

Conclusion

In East Africa, the magnitude of prelacteal feeding was still high. The possible determinants of prelacteal feeding in Eastern Africa were wealth index, birth interval, delivery mode, place of delivery, ANC visit, and community ANC visit. Structural improvements are required for women with caesarean births to achieve optimal breastfeeding practice in Eastern Africa.

Role of antenatal plasma cytomegalovirus DNA levels on pregnancy outcome and HIV-1 vertical transmission among mothers in the University of Zimbabwe birth cohort study (UZBCS)

INTRODUCTION

Despite being a leading infectious cause of childhood disability globally, testing for cytomegalovirus (CMV) infections in pregnancy is generally not done in Sub-Sahara Africa (SSA), where breastfeeding practice is almost universal. Whilst CMV and human immunodeficiency virus (HIV) are both endemic in SSA, the relationship between antenatal plasma CMV-DNA, HIV-1-RNA levels and HIV-1-mother to child transmission (MTCT) including pregnancy outcomes remains poorly described.

METHODS

Pregnant women at least 20 weeks' gestational age at enrolment were recruited from relatively poor high-density suburbs in Harare, Zimbabwe. Mother-infant dyads were followed up until 6 months postpartum. In a case-control study design, we tested antenatal plasma CMV-DNA levels in all 11 HIV-1 transmitting mothers, as well as randomly selected HIV-infected but non-transmitting mothers and HIV-uninfected controls. CMV-DNA was detected and quantified using polymerase chain reaction (PCR) technique. Antenatal plasma HIV-1-RNA load was quantified by reverse transcriptase PCR. Infants' HIV-1 infection was detected using qualitative proviral DNA-PCR. Predictive value of antenatal plasma CMV-DNAemia (CMV-DNA of > 50 copies/mL) for HIV-1-MTCT was analyzed in univariate and multivariate regression analyses. Associations of CMV-DNAemia with HIV-1-RNA levels and pregnancy outcomes were also explored.

RESULTS

CMV-DNAemia data were available for 11 HIV-1 transmitting mothers, 120 HIV-infected but non-transmitting controls and 46 HIV-uninfected mothers. In a multivariate logistic regression model, we found a significant association between CMV-DNAemia of > 50 copies/mL and HIV-1 vertical transmission (p = 0.035). There was no difference in frequencies of detectable CMV-DNAemia between HIV-infected and -uninfected pregnant women (p = 0.841). However, CMV-DNA levels were higher in immunosuppressed HIV-infected pregnant women, CD4 < 200 cells/µL (p = 0.018). Non-significant associations of more preterm births (< 37 weeks, p = 0.063), and generally lower birth weights (< 2500 g, p = 0.450) were observed in infants born of HIV-infected mothers with CMV-DNAemia. Furthermore, in a multivariate analysis of HIV-infected but non-transmitting mothers, CMV-DNAemia of > 50 copies/mL correlated significantly with antenatal plasma HIV-1-RNA load (p = 0.002).

CONCLUSION

Antenatal plasma CMV-DNA of > 50 copies/mL may be an independent risk factor for HIV-1-MTCT and higher plasma HIV-1-RNA load, raising the possibility that controlling antenatal CMV-DNAemia might improve infant health outcomes. Further studies with larger sample sizes are warranted to confirm our findings.

Infant feeding knowledge, perceptions and practices among women with and without HIV in Johannesburg, South Africa: a survey in healthcare facilities

BACKGROUND

South Africa has a history of low breastfeeding rates among women with and without Human Immunodeficiency Virus (HIV). In this study, we assessed infant feeding knowledge, perceptions and practices among pregnant and postpartum women with and without HIV, in the context of changes in infant feeding and Prevention of Mother-to-Child Transmission of HIV (PMTCT) guidelines.

METHODS

This was a cross-sectional survey conducted from April 2014 to March 2015 in 10 healthcare facilities in Johannesburg, South Africa. A total of 190 pregnant and 180 postpartum women (74 and 67, respectively, were HIV positive) were interviewed using a semi-structured questionnaire. Multiple regression analyses assessed factors associated with an intention to exclusively breastfeed, and exclusive breastfeeding of infants less than six months of age.

RESULTS

Women with HIV had better overall knowledge on safe infant feeding practices, both in general and in the context of HIV infection. There were however gaps in knowledge among women with and without HIV. Information from healthcare facilities was the main source of information for all groups of women in the study. A greater percentage of women without HIV 80.9% (93/115), reported an intention to exclusively breastfeed, compared to 64.9% (48/74) of women with HIV, p = 0.014. Not having HIV was positively associated with a reported intention to breastfeed, Adjusted Odds Ratio (AOR) 3.60, 95% CI 1.50, 8.62. Other factors associated with a reported intention to exclusively breastfeed were prior breastfeeding experience and higher knowledge scores on safe infant feeding practices in the context of HIV infection. Among postpartum women, higher scores on general knowledge of safe infant feeding practices were positively associated with reported exclusive breastfeeding, AOR 2.18, 95% CI 1.52, 3.12. Most women perceived that it was difficult to exclusively breastfeed and that cultural factors were a barrier to exclusive breastfeeding.

CONCLUSIONS

While a greater proportion of women are electing to breastfeed, HIV infection and cultural factors remain an important influence on safe infant feeding practices. Healthcare workers are the main source of information, and highlight the need for accurate and consistent messaging for both women with and without HIV.

Growth of HIV-exposed uninfected, compared with HIV-unexposed, Zambian children: a longitudinal analysis from infancy to school age

Background

Early growth of HIV-exposed, uninfected (HEU) children is poorer than that of their HIV-unexposed, uninfected (HUU) counterparts but there is little longitudinal or longer term information about the growth effects of early HIV exposure.

Methods

We performed a longitudinal analysis to compare growth of HEU and HUU infants and children using data from two cohort studies in Lusaka, Zambia. Initially 207 HUU and 200 HEU infants from the Breastfeeding and Postpartum Health (BFPH) study and 580 HUU and 165 HEU from the Chilenje Infant Growth, Nutrition and Infection Study (CIGNIS) had anthropometric measurements taken during infancy and again when school-aged, at which time 66 BFPH children and 326 CIGNIS children were available. We analysed the data from the two cohorts separately using linear mixed models. Linear regression models were used as a secondary analysis at the later time points, adjusting for breastfeeding duration. We explored when the main group differences in growth emerged in order to estimate the largest ‘effect periods’.

Results

After adjusting for socioeconomic status and maternal education, HEU children had lower weight-for-age, length-for-age and BMI-for-age Z-scores during early growth and these differences still existed when children were school-aged. Exposure group differences changed most between 1 and 6 weeks and between 18 months and ~7.5 years.

Conclusions

HEU children have poorer early growth than HUU children which persists into later growth. Interventions to improve growth of HEU children need to target pregnant women and infants.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-017-0828-6) contains supplementary material, which is available to authorized users.

Factors are not the same for risk of stopping exclusive breast-feeding and introducing different types of liquids and solids in HIV-affected communities in Ghana

Exclusive breast-feeding (EBF) for 6 months supports optimal infant growth, health and development. This paper examined whether maternal HIV status was associated with EBF and other infant feeding practices. Pregnant women were enrolled after HIV counselling, and their babies were followed up for up to 1 year. Data on household socio-economics and demographics, maternal characteristics and infants' daily diet were available for 482 infants and their mothers (150 HIV-positive (HIV-P), 170 HIV-negative (HIV-N) and 162 HIV-unknown (HIV-U)). Survival analyses estimated median EBF duration and time to introduction of liquids and foods; hazards ratios (HR) used data from 1-365 and 1-183 d, adjusting for covariates. Logistic regression estimated the probability of EBF for 6 months. Being HIV-P was associated with a shorter EBF duration (139 d) compared with HIV-N (163 d) and HIV-U (165 d) (P=0·004). Compared with HIV-N, being HIV-P was associated with about a 40 % higher risk of stopping EBF at any time point (HR 1·39; 95 % CI 1·06, 1·84; P=0·018) and less than half as likely to complete 6 months of EBF (adjusted OR 0·42; 95 % CI 0·22, 0·81; P=0·01). Being HIV-P tended to be or was associated with a higher risk of introducing non-milk liquids (HR 1·34; 95 % CI 0·98, 1·83; P=0·068), animal milks (HR 2·37; 95 % CI 1·32, 4·24; P=0·004) and solids (HR 1·56; 95 % CI 1·10, 2·22; P=0·011) during the first 6 months. Weight-for-age Z-score was associated with EBF and introducing formula. Different factors (ethnicity, food insecurity, HIV testing strategy) were associated with the various feeding behaviours, suggesting that diverse interventions are needed to promote optimal infant feeding.

Exclusive breastfeeding and HIV/AIDS: a crossectional survey of mothers attending prevention of mother-to-child transmission of HIV clinics in southwestern Nigeria

Introduction

Prevention of Mother-To-Child-Transmission (PMTCT) of Human Immunodeficiency Virus (HIV) guideline recommends replacement feeding where it is acceptable, feasible, affordable, sustainable and safe. Where this is un-achievable, exclusive breastfeeding (EBF) is recommended during the first six months of life.

Methods

A hospital-based cross-sectional study was conducted among 600 HIV-positive using a two-stage sampling technique. Data on socio-demographics, infant feeding choice and factors influencing these choices were collected using semi-structured questionnaires.

Results

Majority of the mothers (86.0%) were married and aged 31.0 ± 5.7years. Slightly above half (53.0%) had≤2 children and more than two-third had disclosed their HIV status to their spouses. About two-third (61.0%) were traders with 75.0% earning monthly income ≤N5,000.00k. Half of the mothers had ≥4 antenatal care visits and 85.0% had infant feeding counselling. Infant feeding choices among the mothers were EBF (61.0%), ERF (26.0%) and MF (13.0%). The choice of EBF was influenced by spouse influence (84.0%), family influence (81.0%) and fear of stigmatisation (53.0%). Predictors of EBF were; monthly income (AOR = 2.6, C.I. =1.4-4.5), infant feeding counselling (AOR = 2.7, C.I. = 1.6-6.9) and fear of stigmatisation (AOR = 7. 2, C.I. = 2.1-23.6).

Conclusion

HIV positive mothers are faced with multiple challenges as they strive to practice exclusive breastfeeding. More extensive and comprehensive approach of infant feeding counseling with emphasis on behavioural change programmes in the context of HIV/AIDS within communities is advocated.

Growth and health outcomes at school age in HIV-exposed, uninfected Zambian children: follow-up of two cohorts studied in infancy

BACKGROUND

Early growth and health of HIV-exposed, uninfected (HEU) children is poorer than that of their HIV-unexposed, uninfected (HUU) counterparts but there is little information about longer term effects of early HIV exposure. We previously recruited two cohorts of HEU and HUU Zambian infants and documented the poorer infant growth and health of the HEU compared to the HUU children. We followed up HEU and HUU children from these cohorts when they were school-aged and compared their growth, health, biochemical markers of acute or chronic disease, and school grades.

METHODS

We recruited 111 HEU and 279 HUU children aged 6-12 years. We measured anthropometry, determined health by questionnaire and clinical examination, viewed the child's most recent school report, and measured blood pressure, haemoglobin (Hb), HbA1c, glucose, cholesterol, and C-reactive protein (CRP).

RESULTS

Anthropometric measures were lower among HEU than HUU children, significantly so for hip circumference (age- and sex-adjusted difference -1.74 cm; 95% confidence interval (CI) -3.24, -0.24; P = 0.023) and mid-upper-arm circumference (adjusted difference -0.63 cm, 95% CI -1.23, -0.04; P = 0.037) and with borderline effects for body mass index, thigh circumference and subscapular skinfolds. HEU children had significantly lower total, trunk, and limb fat percentages. All anthropometric and body composition differences became non-significant after adjustment for sociodemographic variables which differed between HEU and HUU children. More HEU than HUU children reported minor illnesses and were prescribed medication at the time of visit. There were no differences in biochemical markers between groups. HEU children had lower math grades than HUU children even after adjustment for socioeconomic variables.

CONCLUSIONS

Although HEU children were smaller and had lower percent fat than HUU children, this appeared to be due mainly to their poorer socioeconomic status. Reasons for lower school grades require further research.

Growth patterns among HIV-exposed infants receiving nevirapine prophylaxis in Pune, India

Background

India has among the highest rates of infant malnutrition. Few studies investigating the growth patterns of HIV-exposed infants in India or the impact of timing of HIV infection on growth in settings such as India exist.

Methods

We used data from the Six Week Extended Nevirapine (SWEN) trial to compare the growth patterns of HIV-infected and HIV-exposed but uninfected infants accounting for timing of HIV infection, and to identify risk factors for stunting, underweight and wasting. Growth and timing of HIV infection were assessed at weeks 1, 2, 4, 6, 10, 14 weeks and 6, 9, 12 months of life. Random effects multivariable logistic regression method was used to assess factors associated with stunting, underweight and wasting.

Results

Among 737 HIV-exposed infants, 93 (13%) were HIV-infected by 12 months of age. Among HIV-infected and uninfected infants, baseline prevalence of stunting (48% vs. 46%), underweight (27% vs. 26%) and wasting (7% vs. 11%) was similar (p>0.29), but by 12 months stunting and underweight, but not wasting, were significantly higher in HIV-infected infants (80% vs. 56%, 52% vs. 29%, p< 0.0001; 5% vs. 6%, p=0.65, respectively). These differences rapidly manifested within 4–6 weeks of birth. Infants infected in utero had the worst growth outcomes during the follow-up period. SWEN was associated with non-significant reductions in stunting and underweight among HIV-infected infants and significantly less wasting in HIV-uninfected infants. In multivariate analysis, maternal CD4 < 250, infant HIV status, less breastfeeding, low birth weight, non-vaginal delivery, and infant gestational age were significant risk factors for underweight and stunting.

Conclusion

Baseline stunting and underweight was high in both HIV-infected and uninfected infants; growth indices diverged early and were impacted by timing of infection and SWEN prophylaxis. Early growth monitoring of all HIV-exposed infants is an important low-cost strategy for improving health and survival outcomes of these infants.

Trial Registration

NCT00061321

The roles of the immune system in women's reproduction: evolutionary constraints and life history trade-offs

Life history theory posits that, as long as survival is assured, finite resources are available for reproduction, maintenance, and growth/storage. To maximize lifetime reproductive success, resources are subject to trade-offs both within individuals and between current and future investment. For women, reproducing is costly and time-consuming; the bulk of available resources must be allocated to reproduction at the expense of more flexible systems like immune function. When reproducing women contract infectious diseases, the resources required for immune activation can fundamentally shift the patterns of resource allocation. Adding to the complexity of the reproductive-immune trade-offs in women are the pleiotropic effects of many immune factors, which were modified to serve key roles in mammalian reproduction. In this review, we explore the complex intersections between immune function and female reproduction to situate proximate immunological processes within a life history framework. After a brief overview of the immune system, we discuss some important physiological roles of immune factors in women's reproduction and the conflicts that may arise when these factors must play dual roles. We then discuss the influence of reproductive-immune trade-offs on the patterning of lifetime reproductive success: (1) the effect of immune activation/infectious disease on the timing of life history events; (2) the role of the immune system, immune activation, and infectious disease on resource allocation within individual reproductive events, particularly pregnancy; and (3) the role of the immune system in shaping the offspring's patterns of future life history trade-offs. We close with a discussion of future directions in reproductive immunology for anthropologists.

Cost of individual peer counselling for the promotion of exclusive breastfeeding in Uganda

Background

Exclusive breastfeeding (EBF) for 6 months is the recommended form of infant feeding. Support of mothers through individual peer counselling has been proved to be effective in increasing exclusive breastfeeding prevalence. We present a costing study of an individual peer support intervention in Uganda, whose objective was to raise exclusive breastfeeding rates at 3 months of age.

Methods

We costed the peer support intervention, which was offered to 406 breastfeeding mothers in Uganda. The average number of counselling visits was about 6 per woman. Annual financial and economic costs were collected in 2005-2008. Estimates were made of total project costs, average costs per mother counselled and average costs per peer counselling visit. Alternative intervention packages were explored in the sensitivity analysis. We also estimated the resources required to fund the scale up to district level, of a breastfeeding intervention programme within a public health sector model.

Results

Annual project costs were estimated to be US$56,308. The largest cost component was peer supporter supervision, which accounted for over 50% of total project costs. The cost per mother counselled was US$139 and the cost per visit was US$26. The cost per week of EBF was estimated to be US$15 at 12 weeks post partum. We estimated that implementing an alternative package modelled on routine public health sector programmes can potentially reduce costs by over 60%. Based on the calculated average costs and annual births, scaling up modelled costs to district level would cost the public sector an additional US$1,813,000.

Conclusion

Exclusive breastfeeding promotion in sub-Saharan Africa is feasible and can be implemented at a sustainable cost. The results of this study can be incorporated in cost effectiveness analyses of exclusive breastfeeding promotion programmes in sub-Saharan Africa.

HIV-negative status is associated with very early onset of lactation among Ghanaian women

This is a longitudinal cohort study investigating the association between maternal HIV status and the reported onset of lactation. The Research to Improve Infant Nutrition and Growth project recruited 442 mothers from 3 antenatal clinics in the eastern region of Ghana, based on positive, negative, and unknown HIV status. Onset of lactation was assessed by maternal perception and validated with 2 subsamples: measurement of infant breast milk intake (n = 40) and daily infant weight measurement for 2 weeks (n = 150). Multivariate logistic regression was used to identify predictors of very early onset of lactation (onset of lactation < 6 hours). Predictors of very early onset of lactation include HIV-negative status (odds ratio = 2.68; P = .014), multiparity (odds ratio = 2.93; P = .009), vaginal delivery (odds ratio = 2.55; P = .035), and having a male child (odds ratio = 1.86; P = .032). The findings indicate an association between maternal HIV status and very early onset of lactation.

Social determinants of mixed feeding behavior among HIV-infected mothers in Jos, Nigeria

Mixed feeding confers excess risk of mother-to-child transmission (MTCT) of HIV compared with exclusive breastfeeding and exclusive formula feeding. We undertook a qualitative and quantitative cross-sectional survey to identify the social determinants of mixed feeding among a subset of the 469 HIV-infected women enrolled in a MTCT prevention program in Jos, Nigeria. Formula was provided free-of-cost. Of the 91 participants, 68 (75%) exclusively formula fed, 7 (8%) exclusively breastfed, and 16 (18%) practiced mixed feeding. Of the mixed feeding women, seven primarily formula fed and nine primarily breastfed. Women who primarily formula fed described family pressure as the reason for mixed feeding, while women who primarily breastfed reported insufficient breast milk. In a multivariate analysis, lack of partner support of the feeding decision predicted mixed feeding behavior (OR: 4.2; 95% CI: 1.2-14.9; p=0.03). Disclosure of HIV status was significantly correlated (p<0.001) with partner support. HIV prevention interventions aimed at reducing mixed feeding should encourage supportive partner relationships that facilitate disclosure of HIV status. Attention should also be made to the differing pressures faced by women attempting to exclusively breast feed and exclusively formula feed.

Growth faltering due to breastfeeding cessation in uninfected children born to HIV-infected mothers in Zambia

BACKGROUND

The effect of breastfeeding on growth in HIV-exposed infants is not well described.

OBJECTIVE

The objective was to evaluate the effect of early breastfeeding cessation on growth.

DESIGN

In a trial conducted in Lusaka, Zambia, HIV-infected mothers were randomly assigned to exclusive breastfeeding for 4 mo followed by rapid weaning to replacement foods or exclusive breastfeeding for 6 mo followed by introduction of complementary foods and continued breastfeeding for a duration of the mother's choice. Weight-for-age z score (WAZ), length-for-age z score (LAZ), and weight-for-length z score (WLZ) and the self-reported breastfeeding practices of 593 HIV-uninfected singletons were analyzed. Generalized estimating equations were used to adjust for confounders.

RESULTS

WAZ scores declined precipitously between 4.5 and 15 mo. The decline was slower in the breastfed infants. At 9, 12, and 15 mo, mean WAZs were, respectively, -0.74, -0.92, and -1.06 in infants who were reportedly breastfed and were -1.07, -1.20, and -1.31 in the weaned infants (P = 0.003, 0.007, and 0.02, respectively). No differences were observed past 15 mo. Breastfeeding practice was not associated with LAZ, which declined from -0.98 to -2.24 from 1 to 24 mo. After adjustment for birth weight, maternal viral load, body mass index, education, season, and marital and socioeconomic status, not breastfeeding was associated with a 0.28 decline in WAZ between 4.5 and 15 mo (P < 0.0001). During the rainy season, not breastfeeding was associated with a larger WAZ decline (0.33) than during the dry season (0.22; P for interaction = 0.02).

CONCLUSIONS

Early growth is compromised in uninfected children born to HIV-infected Zambian mothers. Continued breastfeeding partially mitigates this effect through 15 mo. Nutritional interventions to complement breastfeeding after 6 mo are urgently needed. This trial was registered at clinicaltrials.gov as NCT00310726.

Time-independent maternal and infant factors and time-dependent infant morbidities including HIV infection, contribute to infant growth faltering during the first 2 years of life

Studies investigating the predictors of growth in infants born to HIV-infected women in developing countries are limited. Using data from 886 Tanzanian HIV-infected women and their infants, we examined the impact of maternal socioeconomic and immunological status, infant characteristics at birth, and HIV, diarrhea and respiratory infections on infants' monthly length-for-age (LAZ) and length-for-weight (WLZ) z-scores during the first 2 years of life. We used restricted cubic splines to estimate average adjusted growth curves by categories of each predictor. LAZ decreased significantly during the first 2 years. WLZ increased from birth to 4 months but decreased significantly thereafter. Greater maternal schooling significantly reduced deterioration in LAZ and WLZ scores from birth to 24 months, while maternal CD4 cell counts >or=200 mm(-3) at baseline were associated with reduced deterioration in LAZ scores. Infants born pre-term or with low-birth weight were significantly more stunted and wasted than their reference groups at all time points though their rate of growth faltering was slower. Infant-HIV status was strongly associated with significantly greater deterioration in LAZ and WLZ scores, beginning at about 4 months of age. Episodes of diarrhea or respiratory infections were related to significantly lower WLZ but not LAZ scores, independent of infant-HIV status. In conclusion, maternal schooling, immunological status and infant infections are important predictors of early growth in children born to HIV-positive women.

Breastfeeding and AIDS in the developing world

PURPOSE OF REVIEW

In developing countries where replacement feeding is generally not feasible or safe, hundreds of thousands of infants acquire HIV infection during breastfeeding. Data from recently completed studies provide insight into the safety and hazards of different feeding approaches as well as the use of antiretroviral therapy to prevent postnatal transmission.

RECENT FINDINGS

Several studies confirm that the benefits of avoiding or shortening breastfeeding are offset by adverse outcomes in those infants who escape infection. Reductions in HIV transmission achieved with either formula feeding or early weaning are counterbalanced by increases in uninfected child mortality resulting in no net benefit for HIV-free survival. However, exclusive breastfeeding is associated with a significant decrease in HIV transmission risk. Antiretroviral treatment during breastfeeding to the mother or her infant appears to reduce the risk of postnatal transmission. Studies evaluating daily nevirapine to the breastfeeding infant suggest protection during the period of treatment. Similarly, infants born to breastfeeding women receiving antiretroviral therapy are at lower risk of acquiring HIV.

SUMMARY

While awaiting further studies defining optimal approaches to preventing HIV transmission during breastfeeding, promoting exclusive breastfeeding and assuring antiretroviral treatment for women with advanced HIV disease will likely prevent the majority of needless maternal and infant deaths.

The HIV-exposed, uninfected African child

The increasing success of prevention of mother-to-child HIV transmission programmes means that in Africa, very large numbers of HIV-exposed, uninfected (HIV-EU) children are being born. Any health problems that these children may have will thus be of enormous public health importance, but to date have been largely neglected. There is some evidence that HIV-EU African children are at increased risk of mortality, morbidity and slower early growth than their HIV-unexposed counterparts. A likely major cause of this impaired health is less exposure to breast milk as mothers are either less able to breastfeed or stop breastfeeding early to protect their infant from HIV infection. Other contributing factors are parental illness or death resulting in reduced care of the children, increased exposure to other infections and possibly exposure to antiretroviral drugs. A broad approach for psychosocial support of HIV-affected families is needed to improve health of HIV-EU children. High quality programmatic research is needed to determine how to deliver such care.

Early growth of infants of HIV-infected and uninfected Zambian women

OBJECTIVE

Parental HIV infection may affect even those exposed children who remain uninfected. We investigated early growth, an indicator of overall health, of infants born to Zambian mothers recruited for a study of breastfeeding and postpartum health.

METHODS

HIV-infected and uninfected women in Lusaka were followed regularly from late pregnancy to 16 weeks postpartum. Infant weight and length were measured at birth, 6 and 16 weeks. Infant HIV status could not be specifically determined in this cohort so comparisons were between all infants of HIV-uninfected mothers (n = 184) and those infants of HIV-infected mothers who were known to be alive and showed no clinical evidence of HIV infection at age 2-4 years (n = 85).

RESULTS

Most infants were exclusively or predominantly breastfed until 16 weeks. At all time points infants of HIV-infected mothers tended to have lower weight and length standard deviation (Z) scores (significant for weight at 6 weeks; P = 0.04), even after adjustment for their lower gestational age at birth, compared with infants of uninfected mothers. In multivariate analyses the major factors affecting weight or length at 6 or 16 weeks of age were birth weight or length, and maternal subclinical mastitis, primiparity and weight during pregnancy.

CONCLUSIONS

Early growth of infants of HIV-infected mothers is less than that of uninfected mothers, in part associated with subclinical mastitis, and this effect cannot be overcome with intensive support of mothers to follow international recommendations regarding exclusive breastfeeding.

Factors associated with postpartum physical and mental morbidity among women with known HIV status in Lusaka, Zambia

The objective of our study was to investigate factors associated with postpartum physical and mental morbidity among women in Lusaka, Zambia with particular reference to known HIV status. Our study was part of the Breastfeeding and Postpartum Health (BFPH) longitudinal cohort study conducted between June 2001 and July 2003. Women were recruited at 34 weeks gestation and followed up to 16 weeks postpartum. Data on maternal health were collected at 3, 7, 10, and 14 days and at 3, 4, 5, 6, 9, 12, and 16 weeks postpartum. Maternal mental health data were collected from April 2002 onwards at recruitment and at seven days and six weeks postpartum. Data on physical morbidity were collected for 429 women (218 HIV-negative, 211 HIV-positive) and data on mental morbidity were collected for 272 women (134 HIV-negative, 138 HIV-positive). Multivariate logistic regression was used to examine factors associated with postpartum physical or mental morbidity. Postpartum physical morbidity was associated with HIV status, parity > or =5 and age < 20 years. Neither antenatal nor postpartum mental morbidity, as indicated by a self-reporting questionnaire 20-item (SRQ-20) score > or =7, were associated with HIV status or with postpartum physical morbidity in this population. Larger comparative studies are required to corroborate or contest these findings.

Maternal micronutrient status and decreased growth of Zambian infants born during and after the maize price increases resulting from the southern African drought of 2001–2002

Objective

To investigate the effects on maternal micronutrient status and infant growth of the increased maize prices that resulted from the southern African drought of 2001–2002.

Design

Longitudinal cohort study.

Setting

A maternal and child health clinic in Lusaka, Zambia.

Subjects

Maternal and infant health and nutrition data and maternal plasma were being collected for a study of breast-feeding and postpartum health. Samples and data were analysed according to whether they were collected before (June to December 2001), during (January 2002 to April 2003) or after (May 2003 to January 2004) the period of increased maize price. Season and maternal HIV status were controlled for in analyses.

Results

Maize price increases were associated with decreased maternal plasma vitamin A during pregnancy (P = 0.028) and vitamin E postpartum (P = 0.042), with the lowest values among samples collected after May 2003 (vitamin A: 0.96 μmol l−1, 95% confidence interval (CI) 0.84–1.09, n = 38; vitamin E: 30.8 μmol mmol−1 triglycerides, 95% CI 27.2–34.8, n = 64) compared with before January 2002 (vitamin A: 1.03 μmol l−1, 95% CI 0.93–1.12, n = 104; vitamin E: 38.9 μmol mmol−1 triglycerides, 95% CI 34.5–43.8, n = 47). There were no significant effects of sampling date on maternal weight, haemoglobin or acute-phase proteins and only marginal effects on infant weight. Infant length at 6 and 16 weeks of age decreased progressively throughout the study (P-values for time of data collection were 0.51 at birth, 0.051 at 6 weeks and 0.026 at 16 weeks).

Conclusions

The results show modest effects of the maize price increases on maternal micronutrient status. The most serious consequence of the price increases is likely to be the increased stunting among infants whose mothers experienced high maize prices while pregnant. During periods of food shortages it might be advisable to provide micronutrient supplements even to those who are less food-insecure.

Biological mechanisms of vertical human immunodeficiency virus (HIV-1) transmission

In the absence of interventions, 30-45% of exposed infants acquire human immunodeficiency virus type 1 (HIV-1) through mother-to-child transmission. It remains unclear why some infants become infected while others do not, despite significant exposure to HIV-1 in utero, during delivery and while breastfeeding. Here we discuss the correlates of vertical transmission with an emphasis on factors that increase maternal HIV-1 levels, either systemically or locally in genital secretions and breast milk. Immune responses may influence maternal viral load, and data suggest that maternal neutralising antibodies reduce infection rates. In addition, infants may be capable of mounting HIV-specific cellular immune responses. We propose that both humoral and cellular responses are necessary to reduce infection because cell-free as well as cell-associated virus appears to play a role in vertical transmission. These distinct forms of the virus may be targeted most effectively by different components of the immune system. We also discuss the use of antiretrovirals to reduce transmission, focusing on the mechanisms of action of regimens currently used in developing country settings. We conclude that prevention relies not only on reducing maternal HIV-1 levels within blood, genital tract and breast milk, but also on pre- and/or post-exposure prophylaxis to the infant. However, HIV-1 has the capacity to mutate under drug pressure and rapidly acquires mutations conferring antiretroviral resistance. This review concludes with data on persistence of low-level resistance after delivery as well as recent guidelines for maternal and infant regimens designed to limit resistance.

Risk factors for subclinical mastitis among HIV-infected and uninfected women in Lusaka, Zambia

Subclinical mastitis, defined as raised milk sodium/potassium (Na/K) ratio, is associated with poor infant growth and, among HIV-infected women, with increased milk HIV viral load. We conducted a longitudinal cohort study in Lusaka, Zambia, in order to investigate the relative importance of several potential causes of subclinical mastitis: maternal infection, micronutrient deficiencies and poor lactation practice. Women (198 HIV-infected, 189 HIV-uninfected) were recruited at 34 weeks' gestation and followed up to 16 weeks postpartum for collection of information on their health, their infant's health, infant growth and infant feeding practices. Milk samples were collected from each breast at 11 postpartum visits and blood at recruitment and 6 weeks postpartum. The geometric mean milk Na/K ratio and the proportion of women with Na/K ratio > 1.0 in one or both breasts were significantly higher among HIV-infected than among uninfected women. Other factors associated with the higher mean Na/K ratio in univariable analyses were primiparity, high maternal alpha(1)-acid glycoprotein (AGP) at 6 weeks, maternal overall morbidity and specific breast symptoms, preterm delivery, low infant weight or length, infant thrush and non-exclusive breast feeding. In multivariable analyses, primiparity, preterm delivery, breast symptoms, HIV status and raised AGP were associated with the raised Na/K ratio. Thus the main factors associated with subclinical mastitis that are amenable to intervention are poor maternal overall health and breast health. The impact of improved postpartum health care, especially management of maternal infections and especially in primiparous women, on the prevalence of subclinical mastitis and its consequences requires investigation.

Factors influencing breast milk HIV RNA viral load among Zambian women

In a longitudinal cohort study we investigated factors contributing to breast milk HIV RNA viral load among lactating women in Lusaka, Zambia. Detailed data from 135 HIV-infected women were collected by questionnaires concerning postpartum maternal and infant health and infant feeding practice. Maternal blood was collected during pregnancy and at 6 weeks postpartum. Milk samples collected from each breast at 10 days and 6 weeks postpartum plus a subset collected at other time points were analyzed for HIV RNA viral load. Increased milk viral load was associated in univariate analyses with maternal symptoms of poor health, raised plasma alpha(1)-acid glycoprotein (AGP) at week 6, raised milk sodium/potassium (Na/K) ratio, postpartum need for antibiotics, preterm delivery, and low birth weight infants. In a multiple regression 49% of variability in mean milk viral load was explained by milk Na/K ratio and need for antibiotics, with borderline contributions from plasma AGP and plasma viral load. Maternal blood hemoglobin or receipt of iron supplements and infant feeding variables such as changing the infant's diet by moving from exclusive to nonexclusive breastfeeding or adding solid foods were not associated with milk viral load. Thus maternal health was the main factor contributing to milk viral load. The lack of effect of feeding practices on milk viral load and the previously determined association of poor maternal health with reduced duration of exclusive breastfeeding in this cohort suggest the relation between exclusive breastfeeding and decreased HIV transmission may be secondary to poor maternal health.