Extended antiretroviral prophylaxis to reduce breast-milk HIV-1 transmission

Estimates of peripartum and postnatal mother-to-child transmission probabilities of HIV for use in Spectrum and other population-based models

BACKGROUND

The Global Plan Towards the Elimination of New HIV Infections among Children and Keeping Their Mothers Alive aims to reduce by 2015 the number of new infections in children, in 22 priority countries, by at least 90% from 2009 levels. Mathematical models, such as Spectrum, are used to estimate national and global trends of the number of infants infected through mother-to-child transmission (MTCT). However, other modelling exercises have also examined MTCT under different settings. MTCT probabilities applied in models to populations that are assumed to receive antiretroviral interventions need to reflect the most current risk estimates.

METHODS

The UNAIDS Reference Group on Estimates, Modelling and Projections held a consultation to review data on MTCT probabilities. Published literature, recent conferences and data from personal communications with principle investigators were reviewed. Based on available data, peripartum and postnatal transmission probabilities were estimated for different antiretroviral drug regimens and maternal CD4 levels including for women with incident infection.

RESULTS

Incident infections occurring during pregnancy are estimated to be associated with a 30% probability of MTCT; incident infections during breast feeding lead to a 28% probability of postnatal MTCT. The 2010 WHO recommended regimens (Options A or B) are estimated to be associated with a 2% peripartum transmission probability and 0.2% transmission probability per month of breast feeding. Peripartum and postnatal transmission probabilities were lowest for women who were taking antiretroviral therapy before the pregnancy namely 0.5% peripartum and 0.16% per month of breast feeding, respectively.

DISCUSSION

These updated probabilities of HIV transmission (applied to Spectrum in April 2011) will be used to estimate new child HIV infections and track progress towards the 2015 targets of the Global Plan.

Disclosure of maternal HIV status to children: considerations for research and practice in sub-Saharan Africa

An estimated 2.8 million children are born to HIV-infected mothers each year, 2.5 million of whom are likely to be HIV-exposed but uninfected. In sub-Saharan Africa up to 40% of pregnant women are HIV-infected, resulting in large numbers of HIV-uninfected children living with at least one HIV-infected parent. These parents face many challenges, including the dilemma of when and how to disclose their HIV status to their children, particularly those who are pre-adolescent. This article summarizes the current evidence on maternal HIV disclosure to their HIV-uninfected children, explores the reported benefits of disclosure to children and mothers, highlights the gaps in knowledge and areas for future research, and discusses possible future intervention models focusing on primary school-aged children in sub-Saharan Africa.

Comparing competing risk outcomes within principal strata, with application to studies of mother-to-child transmission of HIV

In randomized trials to prevent breast milk transmission of human immunodeficiency virus (HIV) from mother to infant, investigators are often interested in assessing the effect of a treatment or intervention on the cumulative risk of HIV infection by time (age) t in infants who are alive and uninfected at a certain time point τ(0)  < t. Such comparisons are challenging for two reasons. First, infants are typically randomized at birth (time 0 < τ(0) ) such that comparisons between trial arms among the subset of infants alive and uninfected at τ(0) are subject to selection bias. Second, in most mother-to-child transmission (MTCT) trials competing risks are often present, such as death or cessation of breastfeeding prior to HIV infection. In this paper, we present methods for assessing the causal effect of a treatment on competing risk outcomes within principal strata. In MTCT trials, the causal effect of interest is that of treatment on the risk of HIV infection by time t > τ(0) within the principal stratum of infants who would be alive and uninfected by τ(0) regardless of randomization assignment. We develop large sample nonparametric bounds and a semiparametric sensitivity analysis model for drawing inference about this causal effect. We present a simulation study demonstrating that the proposed methods perform well in finite samples. We apply the proposed methods to a large, recent MTCT trial.

Prevention on parent to child transmission of HIV - what is new?

Prevention of Mother-To-Child Transmission (PMTCT) of HIV has been at the forefront of research in the field of HIV/AIDS since the PACTG 076 proved successful in 1994. This was followed by many trials with single, dual, or triple Anti Retroviral Therapy (ART), with or without breast-feeding, with different modes of delivery. These trials aimed and promised to find a relatively simple, low-cost intervention that could virtually eliminate the risk of HIV transmission from mother to child, cutting across all geographic boundaries. However, translation of the findings from most of these research studies into successful national PMTCT programs and health policies has not been optimal. In the west, parent to child transmission of HIV has been virtually eliminated due to universal coverage, screening, planned conception wherever possible, thorough evaluation and appropriate antenatal, intranatal and postnatal interventions. In contrast, in resource limited settings where the magnitude of the problem is the greatest accounting for more than 95 % of all vertical transmissions of HIV, there is a constant struggle dealing with the birth of an infected infant every minute. It is time to make optimal choices to prevent the transmission of HIV from an infected mother to her child and virtually eliminate this largely preventable scourge in children.

Rash, hepatotoxicity and hyperbilirubinemia among Kenyan infants born to HIV-infected women receiving triple-antiretroviral drugs for the prevention of mother-to-child HIV transmission

We compared adverse events among breast-feeding neonates born to Kenyan mothers receiving triple-antiretroviral therapy, including either nevirapine or nelfinavir. Nevirapine-exposed infants had an absolute increase in the risk of rash but no significant risk differences for hepatotoxicity or high-risk hyperbilirubinemia compared with nelfinavir-exposed infants. From an infant-safety perspective, nevirapine-based regimens given during pregnancy and breast-feeding are viable options where alternatives to breast milk are not safe, affordable or feasible.

A review of reproductive health research, guidelines and related gaps for women living with HIV

The study of pregnancy and motherhood in women living with HIV (WLWH) has concentrated on the health of the unborn baby and the prevention of mother-to-child transmission, whereas consideration of the broader aspects of women's reproductive health has been largely overlooked. The rights of WLWH with respect to their reproductive health should be exactly the same as non-HIV-positive women, however, inequalities exist due to discrimination and also because the treatment guidelines used in the care of women are often based on insufficient evidence. The purpose of this article is to review the available literature on reproductive health issues for WLWH and to identify gaps requiring further investigation. Our review indicates that further research is warranted into a number of aspects of reproductive health among WLWH. Currently, access to the relevant reproductive health resources and services, such as advice on contraception and fertility services, for WLWH is far from optimal in many developed countries and most developing countries. More data are needed on the most appropriate family planning options with the consideration of drug interactions between contraceptives and antiretroviral therapy and the risk of HIV transmission. Also, more research is needed to improve understanding of the maternal health challenges facing WLWH. Similarly, our understanding of the impact of HIV on the physical and emotional health of pregnant women and new mothers is far from complete. Answering these questions and countering these inequalities will help to ensure the reproductive health and child-bearing intentions of WLWH become an integral part of HIV medicine.

Lopinavir/Ritonavir versus Lamivudine peri-exposure prophylaxis to prevent HIV-1 transmission by breastfeeding: the PROMISE-PEP trial Protocol ANRS 12174

BACKGROUND

Postnatal transmission of HIV-1 through breast milk remains an unsolved challenge in many resource-poor settings where replacement feeding is not a safe alternative. WHO now recommends breastfeeding of infants born to HIV-infected mothers until 12 months of age, with either maternal highly active antiretroviral therapy (HAART) or peri-exposure prophylaxis (PEP) in infants using nevirapine. As PEP, lamivudine showed a similar efficacy and safety as nevirapine, but with an expected lower rate of resistant HIV strains emerging in infants who fail PEP, and lower restrictions for future HIV treatment. Lopinavir/ritonavir (LPV/r) is an attractive PEP candidate with presumably higher efficacy against HIV than nevirapine or lamivudine, and a higher genetic barrier to resistance selection. It showed an acceptable safety profile for the treatment of very young HIV-infected infants. The ANRS 12174 study aims to compare the risk of HIV-1 transmission during and safety of prolonged infant PEP with LPV/r (40/10 mg twice daily if 2-4 kg and 80/20 mg twice daily if >4 kg) versus Lamivudine (7,5 mg twice daily if 2-4 kg, 25 mg twice daily if 4-8 kg and 50 mg twice daily if >8 kg) from day 7 until one week after cessation of BF (maximum 50 weeks of prophylaxis) to prevent postnatal HIV-1 acquisition between 7 days and 50 weeks of age.

METHODS

The ANRS 12174 study is a multinational, randomised controlled clinical trial conducted on 1,500 mother-infant pairs in Burkina Faso, South Africa, Uganda and Zambia. We will recommend exclusive breastfeeding (EBF) until 26th week of life and cessation of breastfeeding at a maximum of 49 weeks in both trial arms.HIV-uninfected infants at day 7 (± 2 days) born to HIV-1 infected mothers not eligible for HAART who choose to breastfeed their infants.The primary endpoint is the acquisition of HIV-1 (as assessed by HIV-1 DNA PCR) between day 7 and 50 weeks of age. Secondary endpoints are safety (including resistance, adverse events and growth) until 50 weeks and HIV-1-free survival until 50 weeks.

DISCUSSION

This study will provide a new evidence-based intervention to support HIV-1-infected women not eligible for HAART to safely breastfeed their babies.

Stavudine concentrations in women receiving postpartum antiretroviral treatment and their breastfeeding infants

First-line antiretroviral treatment regimens in resource-limited settings used in breastfeeding mothers often include stavudine (d4T). Limited data describing d4T concentrations in breast milk are available. We analyzed d4T concentrations in 52 mother-infant pairs using ultra-performance liquid chromatography-tandem mass spectrometry (lower limit of quantification: 5 ng/mL in plasma, 20 ng/mL in breast milk). Median (interquartile range) d4T concentrations were 86 (36-191) ng/mL in maternal plasma, 151 (48-259) ng/mL in whole milk, 190 (58-296) ng/mL in skim milk, and <5 (<5 to <5) ng/mL in infant plasma. Although d4T is concentrated in breast milk relative to maternal plasma, the infant d4T dose received from breast milk is very small and not clinically significant.

Kinetics of nevirapine and its impact on HIV-1 RNA levels in maternal plasma and breast milk over time after perinatal single-dose nevirapine

OBJECTIVE

To determine kinetics after single-dose nevirapine and the impact on HIV RNA [viral load (VL)] in maternal plasma and breast milk (BM).

METHODS

Cohort of 120 HIV-1-infected pregnant Ugandan women received perinatal single-dose nevirapine alone and followed up with their infants through 24 weeks postdelivery. We assessed the relationship of nevirapine concentration (tandem mass spectroscopy) and HIV-1 VL (Roche AMPLICOR HIV-1 Kit, version 1.5) in maternal plasma and BM over time.

RESULTS

At week 1 postpartum, NVP (≥10 ng/mL) was detected in all 53 plasma and 47 of 51 (92.2%) BM samples with median (interquartile ranges) of, respectively, 171 (78-214) ng/mL and 112 (64-158) ng/mL, P = 0.075, which decreased subsequently with traces persisting through week 4 in plasma. Plasma and BM VL dropped by week 1 and were highly correlated at delivery (R = 0.71, P < 0.001) and week 1 (R = 0.69, P < 0.001) but not thereafter. At week 1, VL correlated inversely with NVP concentration in plasma (R = 0.39, P = 0.004) and BM (R = 0.48, P = 0.013). There was a VL rebound in both compartments, which peaked at week 4 to levels greater than those at week 1 [significantly in plasma (P < 0.001) but not in BM] and remained stable thereafter. Median VL was consistently greater (11- to 50-fold) in plasma than BM at all time points (all P < 0.001).

CONCLUSIONS

After single-dose nevirapine, NVP concentration was comparably high through week 1, accompanied by suppression of plasma and BM VL. A longer "tail" (>1 week) of potent postnatal antiretroviral drugs is warranted to minimize the observed VL rebound and potential for NVP resistance as a result of persistent NVP traces.

Child mortality levels and trends by HIV status in Blantyre, Malawi: 1989-2009

INTRODUCTION

Continuous evaluation of child survival is needed in sub-Saharan Africa where HIV prevalence among women of reproductive age continues to be high. We examined mortality levels and trends over a period of ∼20 years among HIV-unexposed and -exposed children in Blantyre, Malawi.

METHODS

Data from 5 prospective cohort studies conducted at a single research site from 1989 to 2009 were analyzed. In these studies, children born to HIV-infected and -uninfected mothers were enrolled at birth and followed longitudinally for at least 2 years. Information on sociodemographic, HIV infection status, survival, and associated risk factors was collected in all studies. Mortality rates were estimated using birth-cohort analyses stratified by maternal and infant HIV status. Multivariate Cox regression models were used to determine risk factors associated with mortality.

RESULTS

The analysis included 8286 children. From 1989 to 1995, overall mortality rates (per 100 person-years) in these clinic-based cohorts remained comparable among HIV-uninfected children born to HIV-uninfected mothers (range 3.3-6.9) or to HIV-infected mothers (range 2.5-7.5). From 1989 to 2009, overall mortality remained high among all children born to HIV-infected mothers (range 6.3-19.3) and among children who themselves became infected (range 15.6-57.4, 1994-2009). Only lower birth weight was consistently and significantly (P < 0.05) associated with higher child mortality.

CONCLUSIONS

HIV infection among mothers and children contributed to high levels of child mortality in the African setting in the pretreatment era. In addition to services that prevent mother-to-child transmission of HIV, other programs are needed to improve child survival by lowering HIV-unrelated mortality through innovative interventions that strengthen health infrastructure.

Progress, challenges, and new opportunities for the prevention of mother-to-child transmission of HIV under the US President's Emergency Plan for AIDS Relief

In June 2011, the Joint United Nations Programme on HIV/AIDS, the US President's Emergency Plan for AIDS Relief (PEPFAR), and other collaborators outlined a transformative plan to virtually eliminate pediatric AIDS worldwide. The ambitious targets of this initiative included a 90% reduction in new pediatric HIV infections and a 50% reduction in HIV-related maternal mortality--all by 2015. PEPFAR has made an unprecedented commitment to the expansion and improvement of prevention of mother-to-child HIV transmission (PMTCT) services globally and is expected to play a critical role in reaching the virtual elimination target. To date, PEPFAR has been instrumental in the success of many national programs, including expanded coverage of PMTCT services, an enhanced continuum of care between PMTCT and HIV care and treatment, provision of more efficacious regimens for antiretroviral prophylaxis, design of innovative but simplified PMTCT approaches, and development of new strategies to evaluate program effectiveness. These accomplishments have been made through collaborative efforts with host governments, United Nations agencies, other donors (eg, the Global Fund for AIDS, Tuberculosis, and Malaria), nongovernmental organizations, and private sector partners. To successfully meet the ambitious global targets to prevent new infant HIV infections, PEPFAR must continue to leverage the existing PMTCT platform, while developing innovative approaches to rapidly expand quality HIV services. PEPFAR must also carefully integrate PMTCT into the broader combination prevention agenda for HIV, so that real progress can be made toward an "AIDS-free generation" worldwide.

Pooled individual data analysis of 5 randomized trials of infant nevirapine prophylaxis to prevent breast-milk HIV-1 transmission

BACKGROUND

In resource-limited settings, mothers infected with human immunodeficiency virus type 1 (HIV-1) face a difficult choice: breastfeed their infants but risk transmitting HIV-1 or not breastfeed their infants and risk the infants dying of other infectious diseases or malnutrition. Recent results from observational studies and randomized clinical trials indicate daily administration of nevirapine to the infant can prevent breast-milk HIV-1 transmission.

METHODS

Data from 5396 mother-infant pairs who participated in 5 randomized trials where the infant was HIV-1 negative at birth were pooled to estimate the efficacy of infant nevirapine prophylaxis to prevent breast-milk HIV-1 transmission. Four daily regimens were compared: nevirapine for 6 weeks, 14 weeks, or 28 weeks, or nevirapine plus zidovudine for 14 weeks.

RESULTS

The estimated 28-week risk of HIV-1 transmission was 5.8% (95% confidence interval [CI], 4.3%-7.9%) for the 6-week nevirapine regimen, 3.7% (95% CI, 2.5%-5.4%) for the 14-week nevirapine regimen, 4.8% (95% CI, 3.5%-6.7%) for the 14-week nevirapine plus zidovudine regimen, and 1.8% (95% CI, 1.0%-3.1%) for the 28-week nevirapine regimen (log-rank test for trend, P < .001). Cox regression models with nevirapine as a time-varying covariate, stratified by trial site and adjusted for maternal CD4 cell count and infant birth weight, indicated that nevirapine reduces the rate of HIV-1 infection by 71% (95% CI, 58%-80%; P < .001) and reduces the rate of HIV infection or death by 58% (95% CI, 45%-69%; P < .001).

CONCLUSIONS

Extended prophylaxis with nevirapine or with nevirapine and zidovudine significantly reduces postnatal HIV-1 infection. Longer duration of prophylaxis results in a greater reduction in the risk of infection.

The glory of guidelines and the twilight of reality: controversies and challenges in the prevention and treatment of HIV in children

Since the discovery of HIV 30 years ago, we have learned much about HIV in children and adolescents. Dramatic declines have occurred in mother-to-child transmission of HIV in resource-rich countries. Resource-poor countries struggle with improving prevention of mother-to-child transmission due to the lack of universal antiretroviral treatment for pregnant and nursing mothers. In children infected with HIV, pharmacokinetic, safety and efficacy data have been determined for many of the older drugs. Data are lacking for the newer, safer and more effective currently available drugs, resulting in the pediatric guidelines lagging behind adult recommendations. Although guidelines for prevention and treatment are helpful, the way they are created causes them to lag behind new scientific evidence, and in some situations they will be confusing or only based on expert opinion. Improving prevention of HIV infection in adolescents and young adults and in treating those who become HIV infected is crucially important. The next 10 years hold tremendous opportunities for improvements in prevention and treatment of HIV in children, adolescents and young adults.

Antiretroviral prophylaxis for breastfeeding transmission in Malawi: drug concentrations, virological efficacy and safety

BACKGROUND

Limited information is available on antiretroviral concentrations in women/infant pairs receiving prophylaxis for breastfeeding transmission of HIV and on the relationship between drug levels and the virological and haematochemistry parameters.

METHODS

Patient population included HIV-positive pregnant women receiving antiretroviral prophylaxis from gestational week 25 until 6 months after delivery and their breastfed infants. Blood and breast milk samples were collected at delivery, and at months 1, 3 and 6 postpartum. Drug concentrations were measured by liquid chromatography-mass spectrometry.

RESULTS

Overall, 66 women were studied: 29 received zidovudine (ZDV), lamivudine (3TC) and nevirapine (NVP), 28 stavudine (d4T), 3TC and NVP, and 9 ZDV, 3TC and lopinavir/ritonavir (LPV/r). Women who received >9 weeks of pre-partum prophylaxis were significantly more likely to have an undetectable viral load both in plasma and in breast milk at delivery. No emergence of resistance mutations was observed in breast milk. Breast milk/plasma concentration ratios were 0.6 for ZDV, 3TC and NVP, 1.0 for d4T and 0.4 for LPV/r. Only NVP reached significant levels in the infants. No correlation with any adverse events, including infant anaemia, was observed with drug concentrations. Two infants who acquired HIV infection had non-nucleoside reverse transcriptase inhibitor mutations at month 6.

CONCLUSIONS

Maternal administration of these three regimens up to 6 months postpartum was effective and safe for both mothers and infants. No significant correlation was found between drug concentrations and infant haematological parameters, supporting the hypothesis that other factors may contribute to the development of anaemia in these settings.

Analysis of HIV early infant diagnosis data to estimate rates of perinatal HIV transmission in Zambia

Background

Mother-to-child transmission of HIV (MTCT) remains the most prevalent source of pediatric HIV infection. Most PMTCT (prevention of mother-to-child transmission of HIV) programs have concentrated monitoring and evaluation efforts on process rather than on outcome indicators. In this paper, we review service data from 28,320 children born to HIV-positive mothers to estimate MTCT rates.

Method

This study analyzed DNA PCR results and PMTCT data from perinatally exposed children zero to 12 months of age from five Zambian provinces between September 2007 and July 2010.

Results

The majority of children (58.6%) had a PCR test conducted between age six weeks and six months. Exclusive breastfeeding (56.8%) was the most frequent feeding method. An estimated 45.9% of mothers were below 30 years old and 93.3% had disclosed their HIV status. In terms of ARV regimen for PMTCT, 32.7% received AZT+single dose NVP (sdNVP), 30.9% received highly active antiretroviral treatment (HAART), 19.6% received sdNVP only and 12.9% received no ARVs. Transmission rates at six weeks when ARVs were received by both mother and baby, mother only, baby only, and none were 5.8%, 10.5%, 15.8% and 21.8% respectively. Transmission rates at six weeks where mother received HAART, AZT+sd NVP, sdNVP, and no intervention were 4.2%, 6.8%, 8.7% and 20.1% respectively. Based on adjusted analysis including ARV exposures and non ARV-related parameters, lower rates of positive PCR results were associated with 1) both mother and infant receiving prophylaxis, 2) children never breastfed and 3) mother being 30 years old or greater.

Overall between September 2007 and July 2010, 12.2% of PCR results were HIV positive. Between September 2007 and January 2009, then between February 2009 and July 2010, proportions of positive PCR results were 15.1% and 11% respectively, a significant difference.

Conclusion

The use of ARV drugs reduces vertical transmission of HIV in a program setting. Non-chemoprophylactic factors also play a significant role in HIV transmission. The overall change in the proportions of positive PCR results over time is more likely an indication of better PMTCT implementation. Determination of the outcomes of PMTCT in program settings is feasible but requires accurate documentation and analysis.

Antiretroviral prophylaxis for HIV prevention in heterosexual men and women

BACKGROUND

Antiretroviral preexposure prophylaxis is a promising approach for preventing human immunodeficiency virus type 1 (HIV-1) infection in heterosexual populations.

METHODS

We conducted a randomized trial of oral antiretroviral therapy for use as preexposure prophylaxis among HIV-1-serodiscordant heterosexual couples from Kenya and Uganda. The HIV-1-seronegative partner in each couple was randomly assigned to one of three study regimens--once-daily tenofovir (TDF), combination tenofovir-emtricitabine (TDF-FTC), or matching placebo--and followed monthly for up to 36 months. At enrollment, the HIV-1-seropositive partners were not eligible for antiretroviral therapy, according to national guidelines. All couples received standard HIV-1 treatment and prevention services.

RESULTS

We enrolled 4758 couples, of whom 4747 were followed: 1584 randomly assigned to TDF, 1579 to TDF-FTC, and 1584 to placebo. For 62% of the couples followed, the HIV-1-seronegative partner was male. Among HIV-1-seropositive participants, the median CD4 count was 495 cells per cubic millimeter (interquartile range, 375 to 662). A total of 82 HIV-1 infections occurred in seronegative participants during the study, 17 in the TDF group (incidence, 0.65 per 100 person-years), 13 in the TDF-FTC group (incidence, 0.50 per 100 person-years), and 52 in the placebo group (incidence, 1.99 per 100 person-years), indicating a relative reduction of 67% in the incidence of HIV-1 with TDF (95% confidence interval [CI], 44 to 81; P<0.001) and of 75% with TDF-FTC (95% CI, 55 to 87; P<0.001). Protective effects of TDF-FTC and TDF alone against HIV-1 were not significantly different (P=0.23), and both study medications significantly reduced the HIV-1 incidence among both men and women. The rate of serious adverse events was similar across the study groups. Eight participants receiving active treatment were found to have been infected with HIV-1 at baseline, and among these eight, antiretroviral resistance developed in two during the study.

CONCLUSIONS

Oral TDF and TDF-FTC both protect against HIV-1 infection in heterosexual men and women. (Funded by the Bill and Melinda Gates Foundation; Partners PrEP ClinicalTrials.gov number, NCT00557245.).

Clinical care versus ethical obligations: HIV-1 and -2 co-infection with hepatitis B in a pregnant Jehovah's Witness

Co-infection with HIV-1 and -2 is rare, even in west Africa. We present the case of a 38-year-old pregnant Jehovah's Witness presenting late in pregnancy with triple infection with HIV-1, HIV-2 and hepatitis B virus. There was a successful outcome in averting vertical transmission despite objections to management based on religious and cultural beliefs.

Maternal and infant antiretroviral regimens to prevent postnatal HIV-1 transmission: 48-week follow-up of the BAN randomised controlled trial

BACKGROUND

In resource-limited settings where no safe alternative to breastfeeding exists, WHO recommends that antiretroviral prophylaxis be given to either HIV-infected mothers or infants throughout breastfeeding. We assessed the effect of 28 weeks of maternal or infant antiretroviral prophylaxis on postnatal HIV infection at 48 weeks.

METHODS

The Breastfeeding, Antiretrovirals, and Nutrition (BAN) Study was undertaken in Lilongwe, Malawi, between April 21, 2004, and Jan 28, 2010. 2369 HIV-infected breastfeeding mothers with a CD4 count of 250 cells per μL or more and their newborn babies were randomly assigned with a variable-block design to one of three, 28-week regimens: maternal triple antiretroviral (n=849); daily infant nevirapine (n=852); or control (n=668). Patients and local clinical staff were not masked to treatment allocation, but other study investigators were. All mothers and infants received one dose of nevirapine (mother 200 mg; infant 2 mg/kg) and 7 days of zidovudine (mother 300 mg; infants 2 mg/kg) and lamivudine (mothers 150 mg; infants 4 mg/kg) twice a day. Mothers were advised to wean between 24 weeks and 28 weeks after birth. The primary endpoint was HIV infection by 48 weeks in infants who were not infected at 2 weeks and in all infants randomly assigned with censoring at loss to follow-up. This trial is registered with ClinicalTrials.gov, number NCT00164736.

FINDINGS

676 mother-infant pairs completed follow-up to 48 weeks or reached an endpoint in the maternal-antiretroviral group, 680 in the infant-nevirapine group, and 542 in the control group. By 32 weeks post partum, 96% of women in the intervention groups and 88% of those in the control group reported no breastfeeding since their 28-week visit. 30 infants in the maternal-antiretroviral group, 25 in the infant-nevirapine group, and 38 in the control group became HIV infected between 2 weeks and 48 weeks of life; 28 (30%) infections occurred after 28 weeks (nine in maternal-antiretroviral, 13 in infant-nevirapine, and six in control groups). The cumulative risk of HIV-1 transmission by 48 weeks was significantly higher in the control group (7%, 95% CI 5-9) than in the maternal-antiretroviral (4%, 3-6; p=0·0273) or the infant-nevirapine (4%, 2-5; p=0·0027) groups. The rate of serious adverse events in infants was significantly higher during 29-48 weeks than during the intervention phase (1·1 [95% CI 1·0-1·2] vs 0·7 [0·7-0·8] per 100 person-weeks; p<0·0001), with increased risk of diarrhoea, malaria, growth faltering, tuberculosis, and death. Nine women died between 2 weeks and 48 weeks post partum (one in maternal-antiretroviral group, two in infant-nevirapine group, six in control group).

INTERPRETATION

In resource-limited settings where no suitable alternative to breastfeeding is available, antiretroviral prophylaxis given to mothers or infants might decrease HIV transmission. Weaning at 6 months might increase infant morbidity.

FUNDING

US Centers for Disease Control and Prevention.

Trends in birth weight and gestational age for infants born to HIV-infected, antiretroviral treatment-naive women in Malawi

BACKGROUND

We analyzed birth outcomes among infants of treatment-naive, HIV-infected women from a series of mother-to-child transmission of HIV studies in Blantyre, Malawi.

METHODS

Data from 6 prospective studies at 1 research site were analyzed. Mean birth weight (BW) and gestational age (GA), and frequency of low birth weight (LBW; <2500 g) and preterm (PT) birth (GA < 37 weeks) were estimated. We assessed risk factors for LBW and PT birth using mixed-effects logistic regression. Adjusted odds ratios (AOR) and 95% confidence intervals from earlier studies (1989-1994) and later studies (2000-2007) are presented separately.

RESULTS

The analysis included 8874 HIV-exposed infants. Mean BW and GA ranged from 2793 to 3079 g, and from 37.8 to 39.0 weeks. Greater maternal age was consistently (during both the early and late periods) associated with lower odds of LBW and PT birth; AOR (95% confidence intervals) for both outcomes in the early and late periods, respectively, were 0.98 (0.96-1.00) and 0.97 (0.95-0.99). Female infant gender was consistently associated with higher odds of PT birth during both periods and with higher odds of LBW during the later period. During the early period, higher maternal education was associated with lower odds of LBW (AOR 0.67 [0.48-0.95]) and PT birth (AOR 0.70 [0.51-0.95]), and later birth year was associated with lower odds of PT birth (AOR 0.35 [0.19-0.70]).

CONCLUSIONS

BW and GA remained stable within each time period. This analysis provides important baseline information for monitoring HIV treatment effects on birth outcomes. Modifiable factors affecting BW and GA should continue to be explored.

The contribution of maternal HIV seroconversion during late pregnancy and breastfeeding to mother-to-child transmission of HIV

BACKGROUND

The prevention of mother-to-child transmission (PMTCT) of HIV has been focused mainly on women who are HIV positive at their first antenatal visit, but there is uncertainty regarding the contribution to overall transmission from mothers who seroconvert after their first antenatal visit and before weaning.

METHOD

A mathematical model was developed to simulate changes in mother-to-child transmission of HIV over time, in South Africa. The model allows for changes in infant feeding practices as infants age, temporal changes in the provision of antiretroviral prophylaxis and counseling on infant feeding, as well as temporal changes in maternal HIV prevalence and incidence.

RESULTS

The proportion of mother-to-child transmission (MTCT) from mothers who seroconverted after their first antenatal visit was 26% [95% confidence interval (CI): 22% to 30%] in 2008, or 15,000 of 57,000 infections. It is estimated that by 2014, total MTCT will reduce to 39,000 per annum, and transmission from mothers seroconverting after their first antenatal visit will reduce to 13,000 per annum, accounting for 34% (95% CI: 29% to 39%) of MTCT. If maternal HIV incidence during late pregnancy and breastfeeding were reduced by 50% after 2010, and HIV screening were repeated in late pregnancy and at 6-week immunization visits after 2010, the average annual number of MTCT cases over the 2010-2015 period would reduce by 28% (95% CI: 25% to 31%), from 39,000 to 28,000 per annum.

CONCLUSION

Maternal seroconversion during late pregnancy and breastfeeding contributes significantly to the pediatric HIV burden and needs greater attention in the planning of prevention of MTCT programs.

Valacyclovir suppressive therapy reduces plasma and breast milk HIV-1 RNA levels during pregnancy and postpartum: a randomized trial

BACKGROUND

The effect of herpes simplex virus type 2 (HSV-2) suppression on human immunodeficiency virus type 1 (HIV-1) RNA in the context of prevention of mother-to-child transmission (PMTCT) interventions is unknown.

METHODS

Between April 2008 and August 2010, we conducted a randomized, double-blind trial of twice daily 500 mg valacyclovir or placebo beginning at 34 weeks gestation in 148 HIV-1/HSV-2 coinfected pregnant Kenyan women ineligible for highly active antiretroviral therapy (CD4 > 250 cells/mm(3)). Women received zidovudine and single dose nevirapine for PMTCT and were followed until 12 months postpartum.

RESULTS

Mean baseline plasma HIV-1 RNA was 3.88 log(10) copies/mL. Mean plasma HIV-1 was lower during pregnancy (-.56 log(10) copies/mL; 95% confidence interval [CI], -.77 to -.34) and after 6 weeks postpartum (-.51 log(10) copies/mL; 95% CI, -.73 to -.30) in the valacyclovir arm than the placebo arm. Valacyclovir reduced breast milk HIV-1 RNA detection at 6 and 14 weeks postpartum compared with placebo (30% lower, P = .04; 46% lower, P = .01, respectively), but not after 14 weeks. Cervical HIV-1 RNA detection was similar between arms (P = .91).

CONCLUSIONS

Valacyclovir significantly decreased early breast milk and plasma HIV-1 RNA among women receiving PMTCT.

CLINICAL TRIALS REGISTRATION

NCT00530777.

Extended prophylaxis with nevirapine and cotrimoxazole among HIV-exposed uninfected infants is well tolerated

OBJECTIVE

Nevirapine and cotrimoxazole are associated with hematologic toxicities and skin-rash. Safety of their concurrent use for prophylaxis over extended periods among HIV-exposed uninfected infants has not been previously assessed.

DESIGN

Secondary data analysis of the 'HIV Prevention Trials Network-046 protocol' (version 2.0), a phase-III, randomized, placebo-controlled trial that assessed efficacy and safety of nevirapine prophylaxis against breast milk transmission of HIV-1.

METHODS

Trial infants received 6-month study nevirapine/placebo, and standard-of-care peripartum single-dose nevirapine+/- zidovudine 'tail', and cotrimoxazole prophylaxis from 6 weeks through breastfeeding cessation. Adverse events were monitored using United States Division of AIDS Toxicity Tables (2004). Risk of neutropenia, anemia and skin-rash in the cotrimoxazole + nevirapine and the cotrimoxazole + placebo groups were compared using negative-binomial regression.

RESULTS

Incidence of neutropenia and/or anemia, and skin-rash was highest during the first 6 weeks of life and declined, thereafter, regardless of study group. Time to first adverse event after 6 weeks was similar in cotrimoxazole + nevirapine and cotrimoxazole + placebo groups: hazard ratio (95% confidence interval) was 1.26 (0.96-1.66) for neutropenia and/or anemia (all grades), 1.27 (0.80-2.03) for neutropenia and/or anemia (grade ≥3) and 1.16 (0.46-2.90) for skin-rash (grade ≥2). There were no statistically significant differences in immediate (6 weeks-6 months) and long-term (6-12 months) adverse event risk among infants on cotrimoxazole + nevirapine versus cotrimoxazole + placebo.

CONCLUSION

Extended nevirapine and cotrimoxazole prophylaxis through 6 months of age among HIV-exposed uninfected infants did not appear to increase the immediate or long-term risk of neutropenia, anemia or skin-rash. Concurrent use beyond 6 months, however, needs to be evaluated.

Efficacy and safety of an extended nevirapine regimen in infant children of breastfeeding mothers with HIV-1 infection for prevention of postnatal HIV-1 transmission (HPTN 046): a randomised, double-blind, placebo-controlled trial

BACKGROUND

Nevirapine given once-daily for the first 6, 14, or 28 weeks of life to infants exposed to HIV-1 via breastfeeding reduces transmission through this route compared with single-dose nevirapine at birth or neonatally. We aimed to assess incremental safety and efficacy of extension of such prophylaxis to 6 months.

METHODS

In our phase 3, randomised, double-blind, placebo-controlled HPTN 046 trial, we assessed the incremental benefit of extension of once-daily infant nevirapine from age 6 weeks to 6 months. We enrolled breastfeeding infants born to mothers with HIV-1 in four African countries within 7 days of birth. Following receipt of nevirapine from birth to 6 weeks, infants without HIV infection were randomly allocated (by use of a computer-generated permuted block algorithm with random block sizes and stratified by site and maternal antiretroviral treatment status) to receive extended nevirapine prophylaxis or placebo until 6 months or until breastfeeding cessation, whichever came first. The primary efficacy endpoint was HIV-1 infection in infants at 6 months and safety endpoints were adverse reactions in both groups. We used Kaplan-Meier analyses to compare differences in the primary outcome between groups. This study is registered with ClinicalTrials.gov, number NCT00074412.

FINDINGS

Between June 19, 2008, and March 12, 2010, we randomly allocated 1527 infants (762 nevirapine and 765 placebo); five of whom had HIV-1 infection at randomisation and were excluded from the primary analyses. In Kaplan-Meier analysis, 1·1% (95% CI 0·3-1·8) of infants who received extended nevirapine developed HIV-1 between 6 weeks and 6 months compared with 2·4% (1·3-3·6) of controls (difference 1·3%, 95% CI 0-2·6), equating to a 54% reduction in transmission (p=0·049). However, mortality (1·2% for nevirapine vs 1·1% for placebo; p=0·81) and combined HIV infection and mortality rates (2·3%vs 3·2%; p=0·27) did not differ between groups at 6 months. 125 (16%) of 758 infants given extended nevirapine and 116 (15%) of 761 controls had serious adverse events, but frequency of adverse events, serious adverse events, and deaths did not differ significantly between treatment groups.

INTERPRETATION

Nevirapine prophylaxis can safely be used to provide protection from mother-to-child transmission of HIV-1 via breastfeeding for infants up to 6 months of age.

FUNDING

US National Institutes of Health.

Effects of cessation of breastfeeding in HIV-1-exposed, uninfected children in Malawi

BACKGROUND

We assessed morbidity rates during short intervals that accompanied weaning and cumulative mortality among HIV-exposed, uninfected infants enrolled in the postexposure prophylaxis of infants in Malawi (PEPI-Malawi) trial.

METHODS

Women were counseled to stop breastfeeding (BF) by 6 months in the PEPI-Malawi trial. HIV-uninfected infants were included in this analysis starting at age 6 months. Breastfeeding and morbidity (illness and/or hospital admission and malnutrition [weight-for-age Z-score, ≤2]) were assessed during age intervals of 6-9, 9-12, and 12-15 months. BF was defined as any BF at the start and end of the interval and no breastfeeding (NBF) was defined as NBF at any time during the interval. The association of NBF with morbidity at each mutually exclusive interval was assessed using Poisson regression models controlling for other factors. Cumulative mortality among infants aged 6-15 months with BF and NBF was assessed using an extended Kaplan-Meier method.

RESULTS

At age 6 months, 1761 HIV-uninfected infants were included in the study. The adjusted rate ratios for illnesses and/or hospital admission for NBF, compared with BF, was 1.7 (P < .0001) at 6-9 months, 1.66 (P = .0001) at 9-12 months, and 1.75 (P = .0008) at 12-15 months. The rates of morbidity were consistently higher among NBF infants during each age interval, compared with BF infants. The 15 months cumulative mortality among BF and NBF children was 3.5% and 6.4% (P = .03), respectively.

CONCLUSIONS

Cessation of BF is associated with acute morbidity events and cumulative mortality. Prolonged BF should be encouraged, in addition to close monitoring of infant health and provision of support services.

What will it take to eliminate pediatric HIV? Reaching WHO target rates of mother-to-child HIV transmission in Zimbabwe: a model-based analysis

BACKGROUND

The World Health Organization (WHO) has called for the "virtual elimination" of pediatric HIV: a mother-to-child HIV transmission (MTCT) risk of less than 5%. We investigated uptake of prevention of MTCT (PMTCT) services, infant feeding recommendations, and specific drug regimens necessary to achieve this goal in Zimbabwe.

METHODS AND FINDINGS

We used a computer model to simulate a cohort of HIV-infected, pregnant/breastfeeding women (mean age, 24 y; mean CD4, 451/µl; breastfeeding duration, 12 mo). Three PMTCT regimens were evaluated: (1) single-dose nevirapine (sdNVP), (2) WHO 2010 guidelines' "Option A" (zidovudine in pregnancy, infant nevirapine throughout breastfeeding for women without advanced disease, lifelong combination antiretroviral therapy for women with advanced disease), and (3) WHO "Option B" (pregnancy/breastfeeding-limited combination antiretroviral drug regimens without advanced disease; lifelong antiretroviral therapy with advanced disease). We examined four levels of PMTCT uptake (proportion of pregnant women accessing and adhering to PMTCT services): reported rates in 2008 and 2009 (36% and 56%, respectively) and target goals in 2008 and 2009 (80% and 95%, respectively). The primary model outcome was MTCT risk at weaning. The 2008 sdNVP-based National PMTCT Program led to a projected 12-mo MTCT risk of 20.3%. Improved uptake in 2009 reduced projected risk to 18.0%. If sdNVP were replaced by more effective regimens, with 2009 (56%) uptake, estimated MTCT risk would be 14.4% (Option A) or 13.4% (Option B). Even with 95% uptake of Option A or B, projected transmission risks (6.1%-7.7%) would exceed the WHO goal of less than 5%. Only if the lowest published transmission risks were used for each drug regimen, or breastfeeding duration were shortened, would MTCT risks at 95% uptake fall below 5%.

CONCLUSIONS

Implementation of the WHO PMTCT guidelines must be accompanied by efforts to improve access to PMTCT services, retain women in care, and support medication adherence throughout pregnancy and breastfeeding, to approach the "virtual elimination" of pediatric HIV in Zimbabwe. Please see later in the article for the Editors' Summary.

Distribution of haematological and chemical pathology values among infants in Malawi and Uganda

BACKGROUND

Data on paediatric reference laboratory values are limited for sub-Saharan Africa.

OBJECTIVE

To describe the distribution of haematological and chemical pathology values among healthy infants from Malawi and Uganda.

METHODS

A cross-sectional study was conducted among healthy infants, 0-6 months old, born to HIV-uninfected mothers recruited from two settings in Blantyre, Malawi and Kampala, Uganda. Chemical pathology and haematology parameters were determined using standard methods on blood samples. Descriptive analyses by age-group were performed based on 2004 Division of AIDS Toxicity Table age categories. Mean values and interquartile ranges were compared by site and age-group.

RESULTS

A total of 541 infants were included altogether, 294 from Malawi and 247 from Uganda. Overall, the mean laboratory values were comparable between the two sites. Mean alkaline phosphatase levels were lower among infants aged ≤21 days while aspartate aminotransferase, creatinine, total bilirubin and gamma-glutamyl transferase were higher in those aged 0-7 days than in older infants. Mean haematocrit, haemoglobin and neutrophil counts were higher in the younger age-groups (<35 days) and overall were lower than US norms. Red and white blood cell counts tended to decrease after birth but increased after ∼2 months of age. Mean basophil counts were higher in Malawi than in Uganda in infants aged 0-1 and 2-7 days; mean counts for eosinophils (for age groups 8-21 or older) and platelets (for all age groups) were higher in Ugandan than in Malawian infants. Absolute lymphocyte counts increased with infant age.

CONCLUSION

The chemical pathology and haematological values in healthy infants born to HIV-uninfected mothers were comparable in Malawi and Uganda and can serve as useful reference values in these settings.

Safety and efficacy of HIV hyperimmune globulin for prevention of mother-to-child HIV transmission in HIV-1-infected pregnant women and their infants in Kampala, Uganda (HIVIGLOB/NVP STUDY)

BACKGROUND

This phase III, randomized, clinical trial compared single-dose nevirapine (sdNVP) plus HIV hyperimmune globulin (HIVIGLOB) with sdNVP alone for preventing maternal-to-child transmission of HIV. Primary objectives were to determine rates of HIV infection among infants and to assess the safety of HIVIGLOB in combination with sdNVP in HIV-infected Ugandan pregnant women and their infants.

METHODS

Mother-infant pairs were randomized to receive 200 mg of nevirapine to women in labor and 2 mg/kg NVP to newborns within 72 hours after birth (sdNVP arm) or to receive sdNVP plus a single intravenous 240-mL dose of HIVIGLOB given to women at 36- to 38-week gestation and a single intravenous 24-mL dose to newborns within 18 hours of birth (HIVIGLOB/sdNVP arm). Risk of HIV infection was determined using Kaplan-Meier and risk ratio estimates at birth, 2, 6, 14 weeks, 6, and 12 months of age.

RESULTS

Intent-to-treat analysis included 198 HIVIGLOB/sdNVP and 294 sdNVP mother-infant pairs. At 6 months of age, the primary endpoint, there was no statistically significant difference in HIV transmission in the HIVIGLOB/sdNVP arm vs. the sdNVP arm [18.7% vs. 15.0%; risk ratio = 1.240 (95% confidence interval: 0.833 to 1.846); P = 0.290]. Similarly, the proportion of serious adverse events in the HIVIGLOB/sdNVP and sdNVP arms, respectively, for mothers (18.9% vs. 19.3%; P = 0.91) and infants (62.6% vs. 59.5%; P = 0.51) was not significantly different.

CONCLUSIONS

Giving mother-infant pairs an infusion of peripartum HIV hyperimmune globulin in addition to sdNVP for preventing maternal-to-child transmission was as safe as sdNVP alone but was no more effective than sdNVP alone in preventing HIV transmission.

Birth weight for gestational age norms for a large cohort of infants born to HIV-negative women in Botswana compared with norms for U.S.-born black infants

Background

Standard values for birth weight by gestational age are not available for sub-Saharan Africa, but are needed to evaluate incidence and risk factors for intrauterine growth retardation in settings where HIV, antiretrovirals, and other in utero exposures may impact birth outcomes.

Methods

Birth weight data were collected from six hospitals in Botswana. Infants born to HIV-negative women between 26-44 weeks gestation were analyzed to construct birth weight for gestational age charts. These data were compared with published norms for black infants in the United States.

Results

During a 29 month period from 2007-2010, birth records were reviewed in real-time from 6 hospitals and clinics in Botswana. Of these, 11,753 live infants born to HIV-negative women were included in the analysis. The median gestational age at birth was 39 weeks (1^st quartile 38, 3^rd quartile 40 weeks), and the median birth weight was 3100 grams (1^st quartile 2800, 3^rd quartile 3400 grams). We constructed estimated percentile curves for birth weight by gestational age which demonstrate increasing slope during the third trimester and leveling off beyond 40 weeks. Compared with black infants in the United States, Botswana-born infants had lower median birth weight for gestational age from weeks 37 through 42 (p < .02).

Conclusions

We present birth weight for gestational age norms for Botswana, which are lower at term than norms for black infants in the United States. These findings suggest the importance of regional birth weight norms to identify and define risk factors for higher risk births. These data serve as a reference for Botswana, may apply to southern Africa, and may help to identify infants at risk for perinatal complications and inform comparisons among infants exposed to HIV and antiretrovirals in utero.

Randomized controlled trials of HIV/AIDS prevention and treatment in Africa: results from the Cochrane HIV/AIDS Specialized Register

Introduction

To effectively address HIV/AIDS in Africa, evidence on preventing new infections and providing effective treatment is needed. Ideally, decisions on which interventions are effective should be based on evidence from randomized controlled trials (RCTs). Our previous research described African RCTs of HIV/AIDS reported between 1987 and 2003. This study updates that analysis with RCTs published between 2004 and 2008.

Objectives

To describe RCTs of HIV/AIDS conducted in Africa and reported between 2004 and 2008.

Methods

We searched the Cochrane HIV/AIDS Specialized Register in September 2009. Two researchers independently evaluated studies for inclusion and extracted data using standardized forms. Details included location of trials, interventions, methodological quality, location of principal investigators and funders.

Results

Our search identified 834 RCTs, with 68 conducted in Africa. Forty-three assessed prevention-interventions and 25 treatment-interventions. Fifteen of the 43 prevention RCTs focused on preventing mother-to-child HIV transmission. Thirteen of the 25 treatment trials focused on opportunistic infections. Trials were conducted in 16 countries with most in South Africa (20), Zambia (12) and Zimbabwe (9). The median sample size was 628 (range 33-9645). Methods used for the generation of the allocation sequence and allocation concealment were adequate in 38 and 32 trials, respectively, and 58 reports included a CONSORT recommended flow diagram. Twenty-nine principal investigators resided in the United States of America (USA) and 18 were from African countries. Trials were co-funded by different agencies with most of the funding obtained from USA governmental and non-governmental agencies. Nineteen pharmaceutical companies provided partial funding to 15 RCTs and African agencies co-funded 17 RCTs. Ethical approval was reported in 65 trials and informed consent in 61 trials.

Conclusion

Prevention trials dominate the trial landscape in Africa. Of note, few principal investigators and funders are from Africa. These findings mirror our previous work and continue to indicate a need for strengthening trial research capacity in Africa.

Interventions to prevent sexually transmitted infections, including HIV infection

The Centers for Disease Control and Prevention (CDC) Sexually Transmitted Disease (STD) Treatment Guidelines were last updated in 2006. To update the "Clinical Guide to Prevention Services" section of the 2010 CDC STD Treatment Guidelines, we reviewed the recent science with reference to interventions designed to prevent acquisition of STDs, including human immunodeficiency virus (HIV) infection. Major interval developments include (1) licensure and uptake of immunization against genital human papillomavirus, (2) validation of male circumcision as a potent prevention tool against acquisition of HIV and some other sexually transmitted infections (STIs), (3) failure of a promising HIV vaccine candidate to afford protection against HIV acquisition, (4) encouragement about the use of antiretroviral agents as preexposure prophylaxis to reduce risk of HIV and herpes simplex virus acquisition, (5) enhanced emphasis on expedited partner management and rescreening for persons infected with Chlamydia trachomatis and Neisseria gonorrhoeae, (6) recognition that behavioral interventions will be needed to address a new trend of sexually transmitted hepatitis C among men who have sex with men, and (7) the availability of a modified female condom. A range of preventive interventions is needed to reduce the risks of acquiring STI, including HIV infection, among sexually active people, and a flexible approach targeted to specific populations should integrate combinations of biomedical, behavioral, and structural interventions. These would ideally involve an array of prevention contexts, including (1) communications and practices among sexual partners, (2) transactions between individual clients and their healthcare providers, and (3) comprehensive population-level strategies for prioritizing prevention research, ensuring accurate outcome assessment, and formulating health policy.

Quantifying the impact of nevirapine-based prophylaxis strategies to prevent mother-to-child transmission of HIV-1: a combined pharmacokinetic, pharmacodynamic, and viral dynamic analysis to predict clinical outcomes

Single-dose nevirapine (sd-NVP) and extended NVP prophylaxis are widely used in resource-constrained settings to prevent vertical HIV-1 transmission. We assessed the pharmacokinetics of sd-NVP in 62 HIV-1-positive pregnant Ugandan woman and their newborns who were receiving sd-NVP prophylaxis to prevent mother-to-child HIV-1 transmission. Based on these data, we developed a mathematical model system to quantify the impact of different sd-NVP regimens at delivery and of extended infant NVP prophylaxis (6, 14, 21, 26, 52, 78, and 102 weeks) on the 2-year risk of HIV-1 transmission and development of drug resistance in mothers and their breast-fed infants. Pharmacokinetic parameter estimates and model-predicted HIV-1 transmission rates were very consistent with other studies. Predicted 2-year HIV-1 transmission risks were 35.8% without prophylaxis, 31.6% for newborn sd-NVP, 19.1% for maternal sd-NVP, and 19.7% for maternal/newborn sd-NVP. Maternal sd-NVP reduced newborn infection predominately by transplacental exchange, providing protective NVP concentrations to the newborn at delivery, rather than by maternal viral load reduction. Drug resistance was frequently selected in HIV-1-positive mothers after maternal sd-NVP. Extended newborn NVP prophylaxis further decreased HIV-1 transmission risks, but an overall decline in cost-effectiveness for increasing durations of newborn prophylaxis was indicated. The total number of infections with resistant virus in newborns was not increased by extended newborn NVP prophylaxis. The developed mathematical modeling framework successfully predicted the risk of HIV-1 transmission and resistance development and can be adapted to other drugs/drug combinations to a priori assess their potential in reducing vertical HIV-1 transmission and resistance spread.

Coverage of highly active antiretroviral therapy among postpartum women in Malawi

The expanding services of antiretroviral treatment (ART) in sub-Saharan Africa provide unique opportunities to reduce HIV/AIDS-related morbidity and mortality. In these settings, HIV prevalence among antenatal women remains high and treating eligible pregnant or breastfeeding women with antiretrovirals can substantially reduce transmission of HIV from the mother to her infant. However, identification of women eligible for treatment and ensuring access to ART services is challenging. In this analysis, we used data from a large clinical trial (the PEPI-Malawi study, 2004-09) to prevent mother-to-child transmission of HIV through extended antiretroviral prophylaxis of infants to examine barriers for wider coverage with highly active antiretroviral treatment (HAART) of postpartum women. Maternal HAART was not part of the original PEPI-Malawi clinical trial but became available through a government programme during the course of the study. Therefore, eligible women (CD4 cell count <250) who participated in the PEPI-Malawi trial were counselled and referred to the government ART clinics to initiate HAART. Of 3335 women who enrolled in the PEPI-Malawi study, 803 (24%) were eligible for HAART based on CD4 cell count. The proportion of women newly initiating HAART at the ART clinic remained low and constant (<20%) throughout the study period. However, the cumulative proportion of women receiving HAART increased substantially over time (29% in 2005 to 69% in 2009). Similarly, counselling and referral of eligible women substantially increased and became 100% during the last two years. There were no statistically significant differences in characteristics of eligible women who received or did not receive HAART postpartum. Despite limitations of not being able to obtain detailed data, the main barriers appeared to be related to the health-care system delivery of ART services. Issues of physical space, more personnel and better delivery need to be addressed to increase access to HAART in these settings.

Growth of infants born to HIV-infected women in South Africa according to maternal and infant characteristics

OBJECTIVE

To evaluate growth parameters assessed by weight and length in HIV-infected and HIV-uninfected infants born to HIV-infected mothers in South Africa from birth to 6 months of age.

METHODS

We calculated z-scores for weight-for-age (WAZ), length-for-age (LAZ) and weight-for-length (WLZ) among a cohort of 840 mother-infant dyads. Multivariable Cox proportional hazards models with time-varying covariates were used to estimate the risk of falling <-2 z-scores for WAZ, LAZ, and WLZ as a function of infant and maternal characteristics.

RESULTS

By 6 months after birth, a fifth of infants had WAZ <-2, 19% had an LAZ <-2, and 29% had a WLZ <-2. WLZ and WAZ were significantly lower in HIV-infected infants than in uninfected infants by 3 months of age and LAZ by 6 months of age (P<0.001). The risk of WAZ falling <-2 was associated with decreasing maternal CD4 cell count (adj. HR for CD4 cell count <200 cells/μl: 1.64; 95% CI: 1.10-2.43), premature birth (adj. HR: 2.82; 95% CI: 2.06-3.86) and formula feeding (adj. HR: 3.35; 95% CI: 1.64-6.85). The risk of LAZ falling <-2 was associated with increasingly lower maternal age (adj. HR for<20 years: 0.54; 95% CI: 0.31-0.96), lower maternal CD4 cell count (adj. HR for CD4 cell count <200 cells/μl: 1.72; 95% CI: 1.14-2.59), premature birth (adj. HR: 2.37; 95% CI: 1.70-3.30) and formula feeding (adj. HR: 4.22; 95% CI: 1.85-9.62). The risk of WLZ falling <-2 was significantly associated with infant HIV infection (adj. HR: 1.64; 95% CI: 1.16-2.32) and formula feeding (adj. HR: 1.78; 95% CI: 1.11-2.83). The risk of WAZ and LAZ falling <-2 was more than two times greater for HIV-infected infants than for uninfected infants with gastrointestinal infections.

CONCLUSIONS

HIV-infected infants were more likely to be stunted and wasted than uninfected infants, which often occurred within 3 months after birth. Infants who were born to mothers with advanced HIV disease, formula-fed and co-infected with HIV and gastrointestinal infections were at greater risk for growth disturbances. Further interventions are needed to promptly initiate both HIV-infected mothers and infants on appropriate antiretroviral therapy and nutritional supplementation.

Slower clearance of nevirapine resistant virus in infants failing extended nevirapine prophylaxis for prevention of mother-to-child HIV transmission

Nevirapine resistance mutations arise commonly following single or extended-dose nevirapine (ED-NVP) prophylaxis to prevent mother-to-child transmission (PMTCT) of human immunodeficiency virus (HIV), but decay within 6-12 months of single-dose exposure. Use of ED-NVP prophylaxis in infants is expected to rise, but data on decay of nevirapine resistance mutations in infants in whom ED-NVP failed remain limited. We assessed, in Ethiopian infants participating in the Six-Week Extended Nevirapine (SWEN) Trial, the prevalence and persistence of nevirapine resistance mutations at 6 and 12 months following single-dose or up to 6 weeks of ED-NVP, and correlated their presence with the timing of infection and the type of resistance mutations. Standard population genotyping followed by high-throughput cloning were done on dried blood spot samples collected during the trial. More infants who received ED-NVP had nevirapine resistance detected by standard population genotyping (high frequencies) at age 6 months compared with those who received single-dose nevirapine (SD-NVP) (58% of 24 vs. 26% of 19, respectively; p = 0.06). Moreover, 56% of ED-NVP-exposed infants with nevirapine resistance at age 6 months still had nevirapine resistance mutations present at high frequencies at age 1 year. Infants infected before 6 weeks of age who received either SD- or ED-NVP were more likely to have Y181C or K103N; these mutations were also more likely to persist at high frequencies through 1 year of age. HIV-infected infants in whom ED-NVP prophylaxis fails are likely to experience delayed clearance of nevirapine-resistant virus in the first year of life, which in turn places them at risk for early selection of multidrug-resistant HIV after initial therapy with nonnucleoside reverse transcriptase inhibitor-based regimens.

The infant feeding choices and experiences of women living with HIV in Kinshasa, Democratic Republic of Congo

HIV transmission through breastfeeding is a significant public health challenge. While breastfeeding provides important nutrition, and results in reduced morbidity and mortality, there is a risk of HIV transmission through breastfeeding. International prevention of mother-to-child transmission (PMTCT) guidelines recommend exclusive breastfeeding for six months among HIV-infected women on antiretroviral therapy. Promoting exclusive feeding has proved difficult in settings where mixed feeding is a cultural norm. Understanding the factors that influence HIV infected women's infant feeding choices and practices is critical to promoting adherence to PMTCT guidelines. We conducted in-depth interviews with 40 HIV+ pregnant and post-partum women in Kinshasa, Democratic Republic of Congo to understand their infant feeding experiences. Interviews were conducted in Lingala, and transcribed and translated into French for analysis. Deductive and inductive codes were applied, and matrices were created to facilitate cross-case analysis. Women had limited understanding of the specific mechanisms through which their infant feeding practices influenced HIV transmission risk. Clinical staff was the primary source of women's knowledge of HIV mother-to-child-transmission. Among the 24 post-partum women in the sample, seven women adhered to exclusive breastfeeding and two women to exclusive formula feeding for at least six months. Women's beliefs and awareness about HIV transmission through breastfeeding, as well as the information and support from clinical staff and other members of their support networks positively influenced their exclusive feeding. Common barriers to exclusive feeding included financial constraints, breast health problems, misinformation about HIV transmission, local norms, and prior feeding experiences. Health care workers play a key role in providing correct information on PMTCT and supporting women's infant feeding choices to adhere to guidelines of exclusive infant feeding. Optimizing provider-patient communication and creating a supportive environment surrounding infant feeding is critical.