Development of methods for cross-sectional HIV incidence estimation in a large, community randomized trial.

BACKGROUND: Accurate methods of HIV incidence determination are critically needed to monitor the epidemic and determine the population level impact of prevention trials. One such trial, Project Accept, a Phase III, community-randomized trial, evaluated the impact of enhanced, community-based voluntary counseling and testing on population-level HIV incidence. The primary endpoint of the trial was based on a single, cross-sectional, post-intervention HIV incidence assessment. METHODS AND FINDINGS: Test performance of HIV incidence determination was evaluated for 403 multi-assay algorithms [MAAs] that included the BED capture immunoassay [BED-CEIA] alone, an avidity assay alone, and combinations of these assays at different cutoff values with and without CD4 and viral load testing on samples from seven African cohorts (5,325 samples from 3,436 individuals with known duration of HIV infection [1 month to >10 years]). The mean window period (average time individuals appear positive for a given algorithm) and performance in estimating an incidence estimate (in terms of bias and variance) of these MAAs were evaluated in three simulated epidemic scenarios (stable, emerging and waning). The power of different test methods to detect a 35% reduction in incidence in the matched communities of Project Accept was also assessed. A MAA was identified that included BED-CEIA, the avidity assay, CD4 cell count, and viral load that had a window period of 259 days, accurately estimated HIV incidence in all three epidemic settings and provided sufficient power to detect an intervention effect in Project Accept. CONCLUSIONS: In a Southern African setting, HIV incidence estimates and intervention effects can be accurately estimated from cross-sectional surveys using a MAA. The improved accuracy in cross-sectional incidence testing that a MAA provides is a powerful tool for HIV surveillance and program evaluation.

Antibody maturation and viral diversification in HIV-infected women.

INTRODUCTION: The Post-exposure Prophylaxis in Infants (PEPI)-Malawi trial evaluated infant antiretroviral regimens for prevention of post-natal HIV transmission. A multi-assay algorithm (MAA) that includes the BED capture immunoassay, an avidity assay, CD4 cell count, and viral load was used to identify women who were vs. were not recently infected at the time of enrollment (MAA recent, N = 73; MAA non-recent, N = 2,488); a subset of the women in the MAA non-recent group known to have been HIV infected for at least 2 years before enrollment (known non-recent, N = 54). Antibody maturation and viral diversification were examined in these women. METHODS: Samples collected at enrollment (N = 2,561) and 12-24 months later (N = 1,306) were available for serologic analysis using the BED and avidity assays. A subset of those samples was used for analysis of viral diversity, which was performed using a high resolution melting (HRM) diversity assay. Viral diversity analysis was performed using all available samples from women in the MAA recent group (61 enrollment samples, 38 follow-up samples) and the known non-recent group (43 enrollment samples, 22 follow-up samples). Diversity data from PEPI-Malawi were also compared to similar data from 169 adults in the United States (US) with known recent infection (N = 102) and known non-recent infection (N = 67). RESULTS: In PEPI-Malawi, results from the BED and avidity assays increased over time in the MAA recent group, but did not change significantly in the MAA non-recent group. At enrollment, HIV diversity was lower in the MAA recent group than in the known non-recent group. HRM diversity assay results from women in PEPI-Malawi were similar to those from adults in the US with known duration of HIV infection. CONCLUSIONS: Antibody maturation and HIV diversification patterns in African women provide additional support for use of the MAA to identify populations with recent HIV infection.

Vitamin D levels in Malawian infants from birth to 24 months.

We measured longitudinal levels of vitamin D in unsupplemented Malawian infants at 0 (birth), 2, 12, 15, 18 and 24 months of age. Matched maternal plasma and breast milk vitamin D(2) and D(3) levels were also measured at delivery and 2 months postpartum. Vitamin D was measured using isotope-dilution liquid chromatography tandem-mass spectrometry. Vitamin D(3) levels in children were 36% of adult levels at birth, 60% of adult levels at age 2 months, and at par with adult levels by 12 months of age. This adult-equivalent level is subsequently maintained through age 24 months and consisted of a 98% molar ratio of vitamin D(3). Vitamin D levels in breast milk were below the limit of detection, 0.1 ng/ml. Breast milk of unsupplemented Malawian mothers is a poor source of vitamin D.

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.

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.

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.

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.

Initiation of antiretroviral treatment in women after delivery can induce multiclass drug resistance in breastfeeding HIV-infected infants.

BACKGROUND: The World Health Organization currently recommends initiation of highly active antiretroviral therapy (HAART) for human immunodeficiency virus (HIV)-infected lactating women with CD4+ cell counts <350 cells/µL or stage 3 or 4 disease. We analyzed antiretroviral drug resistance in HIV-infected infants in the Post Exposure Prophylaxis of Infants trial whose mothers initiated HAART postpartum (with a regimen of nevirapine [NVP], stavudine, and lamivudine). Infants in the trial received single-dose NVP and a week of zidovudine (ZDV) at birth; some infants also received extended daily NVP prophylaxis, with or without extended ZDV prophylaxis. METHODS: We analyzed drug resistance in plasma samples collected from all HIV-infected infants whose mothers started HAART in the first postpartum year. Resistance testing was performed using the first plasma sample collected within 6 months after maternal HAART initiation. Categorical variables were compared by exact or trend tests; continuous variables were compared using rank-sum tests. RESULTS: Multiclass resistance (MCR) was detected in HIV from 11 (29.7%) of 37 infants. Infants were more likely to develop MCR infection if their mothers initiated HAART earlier in the postpartum period (by 14 weeks vs after 14 weeks and up to 6 months vs after 6 months, P = .0009), or if the mother was exclusively breastfeeding at the time of HAART initiation (exclusive breastfeeding vs mixed feeding vs no breastfeeding, P = .003). CONCLUSIONS: Postpartum maternal HAART initiation was associated with acquisition of MCR in HIV-infected breastfeeding infants. The risk was higher among infants whose mothers initiated HAART closer to the time of delivery or were still exclusively breastfeeding when they first reported HAART use.

Postexposure prophylaxis of breastfeeding HIV-exposed infants with antiretroviral drugs to age 14 weeks: updated efficacy results of the PEPI-Malawi trial.

BACKGROUND: This analysis updates and extends efficacy estimates of the PEPI-Malawi trial through age 24 months at study completion in September 2009. METHODS: Infants of breastfeeding HIV-infected women were randomized at birth to the following: (1) single-dose nevirapine (NVP) + 1-week zidovudine (ZDV) (control); (2) control + extended daily NVP (ExtNVP) through 14 weeks; (3) control + extended daily NVP + ZDV (ExtNVP/ZDV) through 14 weeks. We estimated rates of HIV infection, death and HIV infection, or death using Kaplan-Meier analysis. RESULTS: This analysis includes 3126 infants uninfected at birth as follows: 1004 control, 1071 ExtNVP, and 1051 ExtNVP/ZDV. By 9 months, HIV infection rates were 5.0% in ExtNVP, 6.0% in ExtNVP/ZDV, and 11.1% in control (P < 0.001 comparing extended regimens with control). At age 24 months, HIV infection rates had risen to ~11% in the extended arms compared with 15.6% in the controls (P < 0.05). The rates of HIV infection or death were also significantly lower in extended arms. There were no differences in severe adverse events with the exception of higher possibly related events in the ExtNVP/ZDV arm. CONCLUSIONS: Daily infant antiretroviral prophylaxis reduces postnatal HIV infection by ~70% during the period of prophylaxis. But continued HIV transmission after prophylaxis stops suggests more prolonged infant prophylaxis is needed.

Frequency of gastroenteritis and gastroenteritis-associated mortality with early weaning in HIV-1-uninfected children born to HIV-infected women in Malawi.

BACKGROUND: We assessed gastroenteritis (GE) burden in 2 randomized trials conducted in Malawi to reduce postnatal HIV transmission before and after World Health Organization recommendations regarding exclusive breastfeeding for HIV-exposed infants were adopted. The 2 trials were the nevirapine/AZT (NVAZ, 2000-2003 with prolonged breastfeeding) and the Postexposure Prophylaxis to the Infant (PEPI, 2004-2007 with breastfeeding cessation by 6 months). METHODS: From NVAZ and PEPI trials data, GE frequency through age 12 months among HIV-negative exposed infants was evaluated. Overall and GE-related cumulative mortality rates were estimated using Kaplan-Meier curves. RESULTS: The frequency of at least one GE-related hospitalization was greater in PEPI vs. NVAZ after age 6 months (respectively, 2.9% vs. 0.1%, at 7-9 months and 1.6% vs. 0.2% at 10-12 months, P < 0.001). Cumulative GE-related mortality was significantly higher in PEPI than in NVAZ after age 6 months; at ages 9 and 12 months GE-related mortality was 19 and 24 per 1000 infants in PEPI vs. 7 and 12 per 1000 infants in NVAZ (P = 0.0002). CONCLUSIONS: Early weaning was associated with increased risk of severe GE and GE-related mortality among HIV-exposed infants. Strategies are urgently needed which allow longer breastfeeding while reducing the risk of HIV breast milk transmission in resource-limited settings.

Postnatal HIV-1 transmission after cessation of infant extended antiretroviral prophylaxis and effect of maternal highly active antiretroviral therapy.

BACKGROUND: The association between postnatal human immunodeficiency virus type 1 (HIV-1) transmission and maternal highly active antiretroviral therapy (HAART) after infant extended antiretroviral prophylaxis was assessed. METHODS: A follow-up study was conducted for the Post-Exposure Prophylaxis of Infants trial in Blantyre, Malawi (PEPI-Malawi). In PEPI-Malawi, breast-feeding infants of HIV-infected women were randomized at birth to receive a either control regimen (single-dose nevirapine plus 1 week of zidovudine); the control regimen plus nevirapine to age 14 weeks; or the control regimen plus nevirapine and zidovudine to age 14 weeks. Infant HIV infection, maternal CD4 cell count, and HAART use were determined. Maternal HAART use was categorized as HAART eligible but untreated (CD4 cell count of <250 cells/microL, no HAART received), HAART eligible and treated (CD4 cell count of <250 cells/microL, HAART received), and HAART ineligible (CD4 cell count of 250 cells/microL). The incidence of HIV infection and the association between postnatal HIV transmission and maternal HAART were calculated among infants who were HIV negative at 14 weeks. RESULTS: Of 2318 infants, 130 (5.6%) acquired HIV infection, and 310 mothers (13.4%) received HAART. The rates of HIV transmission (in cases per 100 person-years) were as follows: for the HAART-eligible/untreated category, 10.56 (95% confidence interval [CI], 7.91-13.82); for the HAART-eligible/treated category, 1.79 (95% CI, 0.58-4.18); and for the HAART-ineligible category, 3.66 (95% CI, 2.86-4.61). The HIV transmission rate ratio for the HAART-eligible/treated category versus the HAART-eligible/untreated category, adjusted for infant prophylaxis, was 0.18 (95% CI, 0.07-0.44). CONCLUSIONS: Postnatal HIV transmission continues after cessation of infant prophylaxis. HAART-eligible women should start treatment early for their own health and to reduce postnatal HIV transmission to their infants.

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

BACKGROUND: Effective strategies are urgently needed to reduce mother-to-child transmission of human immunodeficiency virus type 1 (HIV-1) through breast-feeding in resource-limited settings. METHODS: Women with HIV-1 infection who were breast-feeding infants were enrolled in a randomized, phase 3 trial in Blantyre, Malawi. At birth, the infants were randomly assigned to one of three regimens: single-dose nevirapine plus 1 week of zidovudine (control regimen) or the control regimen plus daily extended prophylaxis either with nevirapine (extended nevirapine) or with nevirapine plus zidovudine (extended dual prophylaxis) until the age of 14 weeks. Using Kaplan-Meier analyses, we assessed the risk of HIV-1 infection among infants who were HIV-1-negative on DNA polymerase-chain-reaction assay at birth. RESULTS: Among 3016 infants in the study, the control group had consistently higher rates of HIV-1 infection from the age of 6 weeks through 18 months. At 9 months, the estimated rate of HIV-1 infection (the primary end point) was 10.6% in the control group, as compared with 5.2% in the extended-nevirapine group (P<0.001) and 6.4% in the extended-dual-prophylaxis group (P=0.002). There were no significant differences between the two extended-prophylaxis groups. The frequency of breast-feeding did not differ significantly among the study groups. Infants receiving extended dual prophylaxis had a significant increase in the number of adverse events (primarily neutropenia) that were deemed to be possibly related to a study drug. CONCLUSIONS: Extended prophylaxis with nevirapine or with nevirapine and zidovudine for the first 14 weeks of life significantly reduced postnatal HIV-1 infection in 9-month-old infants. (ClinicalTrials.gov number, NCT00115648.)

Late postnatal transmission of HIV-1 and associated factors.

BACKGROUND: The present study was undertaken to determine the risk and timing of late postnatal transmission (LPT) of human immunodeficiency virus type 1 (HIV-1). METHODS: Breast-fed infants previously enrolled in 2 trials of antiretroviral prophylaxis were monitored in Malawi. Kaplan-Meier and proportional hazard models assessed cumulative incidence and association of factors with LPT. RESULTS: Overall, 98 infants were HIV infected, and 1158 were uninfected. The cumulative risk of LPT at age 24 months was 9.68% (95% confidence interval, 7.80%-11.56%). The interval hazards at 1.5-6, 6-12, 12-18, and 18-24 months were 1.22%, 4.05%, 3.48%, and 1.27%, respectively. CONCLUSIONS: The risk of LPT beyond 6 months is substantial. Weaning at 6 months could prevent >85% of LPT.

Intermittent intravaginal antibiotic treatment of bacterial vaginosis in HIV-uninfected and -infected women: a randomized clinical trial.

OBJECTIVE: Assess efficacy of intermittent intravaginal metronidazole gel treatment in reducing frequency of bacterial vaginosis (BV). DESIGN: Randomized, double-masked, placebo-controlled phase 3 trial. SETTING: Postnatal and family planning clinics of the Queen Elizabeth Central Hospital and two health centers in Blantyre, Malawi. PARTICIPANTS: Nonpregnant HIV-uninfected and -infected women. INTERVENTION: Intravaginal metronidazole treatment and placebo gels provided at baseline and every 3 mo for 1 y. OUTCOME MEASURES: PRIMARY: Cross-sectional and longitudinal comparisons of BV frequency at baseline, 1 mo after product dispensation (post-treatment evaluation [PTE]), and every quarterly visit. Secondary: Effect of treatment on BV clearance and recurrence. RESULTS: BASELINE: 842 HIV-uninfected and 844 HIV-infected women were enrolled. The frequency of BV at baseline in treatment and placebo arms, respectively, was 45.9% and 46.8% among HIV-uninfected women, and 60.5% and 56.9% among HIV-infected women. PRIMARY OUTCOMES: At the PTEs the prevalence of BV was consistently lower in treatment than placebo arms irrespective of HIV status. The differences were statistically significant mainly in HIV-uninfected women. Prevalence of BV was also reduced over time in both treatment and placebo arms. In a multivariable analysis that controlled for other covariates, the effect of intravaginal metronidazole treatment gel compared with placebo was not substantial: adjusted relative risk (RR) 0.90, 95% confidence interval (CI) 0.83-0.97 in HIV-uninfected women and adjusted RR 0.95, 95% CI 0.89-1.01 in HIV-infected women. SECONDARY OUTCOMES: Intravaginal metronidazole treatment gel significantly increased BV clearance (adjusted hazard ratio [HR] 1.34, 95% CI 1.07-1.67 among HIV-uninfected women and adjusted HR 1.29, 95% CI 1.06-1.58 among HIV-infected women) but was not associated with decreased BV recurrence. SAFETY: No serious adverse events were related to use of intravaginal gels. CONCLUSION: Intermittent microbicide treatment with intravaginal gels is an innovative approach that can reduce the frequency of vaginal infections such as BV.

The impact of breastfeeding on the health of HIV-positive mothers and their children in sub-Saharan Africa.

OBJECTIVE: We assessed the impact of breastfeeding by women infected with human immunodeficiency virus (HIV)-1 on their morbidity and risk of mortality and on the mortality of their children. METHODS: We analysed longitudinal data from two previous randomized clinical trials of mother-to-child transmission of HIV conducted between April 2000 and March 2003 in the Republic of Malawi, Africa. Mothers infected with HIV, and their newborns, were enrolled at the time of their child's birth; they then returned for follow-up visits when the child was aged 1 week, 6-8 weeks and then 3, 6, 9, 15, 18, 21 and 24 months. Patterns of breastfeeding (classified as exclusive, mixed or no breastfeeding), maternal morbidity and mortality, and mortality among their children were assessed at each visit. Descriptive and multivariate analyses were performed to determine the association between breastfeeding and maternal and infant outcomes. FINDINGS: A total of 2000 women infected with HIV were enrolled in the original studies. During the 2 years after birth, 44 (2.2%) mothers and 310 (15.5%) children died. (Multiple births were excluded.) The median duration of breastfeeding was 18 months (interquartile range (IQR)=9.0-22.5), exclusive breastfeeding 2 months (IQR=2-3) and mixed feeding 12 months (IQR=6-18). Breastfeeding patterns were not significantly associated with maternal mortality or morbidity after adjusting for maternal viral load and other covariates. Breastfeeding was associated with reduced mortality among infants and children: the adjusted hazard ratio for overall breastfeeding was 0.44 (95% confidence interval (CI)=0.28-0.70), for mixed feeding 0.45 (95% CI=0.28-0.71) and for exclusive breastfeeding 0.40 (95% CI=0.22-0.72). These protective effects were seen both in infants who were infected with HIV and those who were not. CONCLUSION: Breastfeeding by women infected with HIV was not associated with mortality or morbidity; it was associated with highly significant reductions in mortality among their children.

Development of nevirapine resistance in infants is reduced by use of infant-only single-dose nevirapine plus zidovudine postexposure prophylaxis for the prevention of mother-to-child transmission of HIV-1.

We analyzed the development of nevirapine (NVP) resistance in human immunodeficiency virus type 1 (HIV-1)-infected Malawian infants who received regimens containing single-dose NVP (SD-NVP) for the prevention of mother-to-child transmission (MTCT) of HIV-1. All infants received SD-NVP, and some randomly received zidovudine (ZDV) as well. Mothers did or did not receive SD-NVP on the basis of when they arrived at the hospital for delivery. In infants 6-8 weeks of age, NVP resistance was less frequent when infants had received SD-NVP plus ZDV and mothers had not received SD-NVP than when infants had received SD-NVP alone and mothers had received SD-NVP (4/15 [27%] vs. 20/23 [87%]; P < .001). The risk of MTCT of HIV-1 was comparable with these regimens. Infant-only prophylaxis also eliminates the development of NVP resistance in mothers.

Gender differences in perinatal HIV acquisition among African infants.

OBJECTIVE: We investigated gender-specific risks of mother-to-child transmission (MTCT) at birth and at 6 to 8 weeks among infants born to HIV-infected African women. DESIGN: Follow-up study of infants enrolled in 2 randomized, phase III, clinical trials to prevent MTCT, conducted in Blantyre, Malawi, in southeast Africa. METHODS: Infants were enrolled at birth and monitored postnatally, and their HIV status was assessed at birth and at 6 to 8 weeks (assessment beyond 6-8 weeks is ongoing). Statistical analyses were stratified according to gender, and comparisons were made with descriptive, univariate, and multivariate statistical tests. MTCT was estimated at birth and at 6 to 8 weeks among infants who were not infected at birth. RESULTS: Overall, 966 boys and 998 girls were enrolled. The rate of HIV transmission at birth was 9.5% (187 of 1964 infants). However, at birth significantly more girls (12.6%) than boys (6.3%) were infected with HIV. This association remained significant after controlling for maternal viral load and other factors. Among infants who were uninfected at birth, 8.7% (135 of 1554 infants) acquired HIV by 6 to 8 weeks; of these infants, more girls acquired HIV (10.0%), compared with boys (7.4%). CONCLUSIONS: Female infants may be more susceptible to HIV infection before birth and continuing after birth. Alternatively, in utero mortality rates of HIV-infected male infants may be disproportionately higher and thus more HIV-infected female infants are born. In areas of sub-Saharan Africa, where HIV infection rates are high among women of reproductive age, the magnitude of the gender transmission differences observed in this study could have clinical, preventive, and demographic implications.

Nonoxynol-9 100 mg gel: multi-site safety study from sub-Saharan Africa.

OBJECTIVES: To evaluate the safety of 100 mg nonoxynol-9 (N-9) gel, a vaginal microbicide, on the genital mucosa of women from Malawi and Zimbabwe in preparation for a phase III efficacy study. METHODS: HIV-uninfected women (180) were enrolled and randomized to either N-9 or placebo gel and instructed to insert gel into the vagina twice daily for 14 days. Follow up examinations were conducted at 7 and 14 days. RESULTS: The number of adverse events in the N-9 gel group was higher than in the placebo group (40% versus 13%; P < 0.01). Reported number of any genital symptoms was significantly higher in the N-9 group (38% N-9, 13% placebo; P = 0.01). The number of total epithelial disruptions was higher in the N-9 group (20% versus 3%; P < 0.01); however, the number of genital ulcers and abrasions in the N-9 group was low (2% and 3%, respectively) and not different from that in the placebo group (1% and 2%, respectively). CONCLUSIONS: N-9 gel 100 mg caused a significant increase in the rate of genital symptoms and epithelial disruptions compared with placebo. The clinical significance of these epithelial disruptions is unknown. Although these findings alone were not sufficient to cancel the planned phase III study, when considered together with the negative results from the COL-1492 effectiveness trial of 52.5 mg N-9 gel, the decision was made to cancel the planned phase III trial of 100 mg N-9 gel.

Nevirapine and zidovudine at birth to reduce perinatal transmission of HIV in an African setting: a randomized controlled trial.

CONTEXT: Antenatal counseling and human immunodeficiency virus (HIV) testing are not universal in Africa; thus, women often present in labor with unknown HIV status without receiving the HIVNET 012 nevirapine (NVP) regimen (a single oral dose of NVP to the mother at the start of labor and to the infant within 72 hours of birth). OBJECTIVE: To determine risk of mother-to-child transmission of HIV when either standard use of NVP alone or in combination with zidovudine (ZDV) was administered to infants of women tested at delivery. DESIGN, SETTING, AND PARTICIPANTS: A randomized, open-label, phase 3 trial conducted between April 1, 2000, and March 15, 2003, at 6 clinics in Blantyre, Malawi, Africa. The trial included all infants born to 894 women who were HIV positive, received NVP intrapartum, and were previously antiretroviral treatment-naive. Infants were randomly assigned to NVP (n = 448) and NVP plus ZDV (n = 446). Infants were enrolled at birth, observed at 6 to 8 weeks, and followed up through 3 to 18 months. The HIV status of 90% of all infants was established at 6 to 8 weeks. INTERVENTION: Mothers received a 200-mg single oral dose of NVP intrapartum and infants received either 2-mg/kg oral dose of NVP or NVP (same dose) plus 4 mg/kg of ZDV twice per day for a week. MAIN OUTCOME MEASURES: HIV infection of infant at birth and 6 to 8 weeks, and adverse events. RESULTS: The mother-to-child transmission of HIV at birth was 8.1% (36/445) in infants administered NVP only and 10.1% (45/444) in those administered NVP plus ZDV (P =.30). A life table estimate of transmission at 6 to 8 weeks was 14.1% (95% confidence interval [CI], 10.7%-17.4%) in infants who received NVP and 16.3% (95% CI, 12.7%-19.8%) in those who received NVP plus ZDV (P =.36). For infants not infected at birth and retested at 6 to 8 weeks, transmission was 6.5% (23/353) in those who received NVP only and 6.9% (25/363) in those who received NVP plus ZDV (P =.88). Almost all infants (99%-100%) were breastfed at 1 week and 6 to 8 weeks. Grades 3 and 4 adverse events were comparable; 4.9% (22/448) and 5.4% (24/446) in infants receiving NVP only and NVP plus ZDV, respectively (P =.76). CONCLUSIONS: The frequency of mother-to-child HIV transmission at 6 to 8 weeks in our 2 study groups was comparable with that observed for other perinatal HIV intervention studies among breastfeeding women in Africa. The safety of the regimen containing neonatal ZDV was similar to that of a standard NVP regimen.