Design of the HIV Prevention Trials Network (HPTN) Protocol 054: A cluster randomized crossover trial to evaluate combined access to Nevirapine in developing countries

HPTN054 is a cluster randomized trial designed to compare two approaches to providing single dose nevirapine to HIV-seropositive mothers and their infants to prevent mother-to-child transmission of HIV in resource limited settings. A number of challenging issues arose during the design of this trial. Most importantly, the need to achieve high participation rates among pregnant, HIV-seropositive women in selected prenatal care clinics led us to develop a method of collecting anonymous and unlinked information on a key surrogate endpoint instead of pursuing linked and identified information on a clinical endpoint. In addition, since group counseling is the standard model for prenatal care in sub-Saharan Africa, the prenatal care clinic serves as the unit of randomization. However, constraints on the number of suitable clinics and other logistical difficulties necessitated a unique type of hybrid parallel/stepped wedge cluster randomized design in which some clinics cross over between the two treatment modalities and some do not. We describe the design for the HPTN054 trial with an emphasis on the logistic and statistical features that allowed us to address these issues. We also provide some general statistical results that are useful for computing power in parallel, crossover, stepped wedge or mixed designs of cluster randomized trials

Primary HIV-1 Infection Among Infants in sub-Saharan Africa: HPTN 024.

Our objectives were to assess clinical signs and diagnoses associated with primary HIV-1 infection among infants. We analyzed data from a clinical trial (HIV Prevention Trials Network Protocol 024) in sub-Saharan Africa. Study visits were conducted at birth, at 4-6 weeks, and at 3, 6, 9, and 12 months. The study population comprised live born, singleton, first-born infants of HIV-1-infected women with negative HIV-1 RNA assays who were still breastfeeding at 4-6 weeks. Of 1317 HIV-1-exposed infants, 84 became HIV-1 infected after 4-6 weeks and 1233 remained uninfected. There were 102 primary and 5650 nonprimary infection visits. The most common signs were cough and diarrhea, and the most common diagnoses were malaria and pneumonia. Primary infection was associated with significantly increased odds of diarrhea [odds ratio (OR) = 2.4], pneumonia (OR = 3.5), otitis media (OR = 3.1), and oral thrush (OR = 2.9). For the clinical signs and diagnoses evaluated, sensitivity was low (1%-16.7%) and specificity was high (88.2%-99%). Positive predictive values ranged from 0.1%-1.4%. Negative predictive values ranged from 28.0%-51.1%. Certain clinical signs and diagnoses, although more common during primary HIV-1 infection, had low sensitivity and high specificity. Efforts to expand access to laboratory assays for the diagnosis of primary HIV-1 infection among infants of HIV-1-infected women should be emphasized

Treatment of trichomoniasis in pregnancy in sub-Saharan Africa does not appear to be associated with low birth weight or preterm birth

Objectives. To determine whether treatment of trichomoniasis increases the risk of prematurity. Design. Sub-analysis of a randomised trial. Setting. We analysed data from HPTN 024, a randomised trial of antenatal and intrapartum antibiotics to reduce chorioamnionitis-related perinatal HIV transmission. Subjects. Pregnant women from four sites in Africa. Outcome measures. Gestational age at the time of delivery or mean birth weight. Results. Of 2 428 women-infant pairs included, 428 (18%) had trichomoniasis at enrolment. There were no differences in infant age or birth weight between women with or without trichomoniasis. By randomisation group, there were no differences in gestational age at birth or birth weight. Of the 428 women diagnosed with trichomoniasis, 365 (83%) received antibiotics and 63 (15%) did not. In analysis of actual use of antibiotics, women with trichomoniasis who received no treatment were more likely to deliver a preterm infant when the symphysis-fundal height was used to estimate gestational age (36% v. 23%; p=0.03), but not when the Ballard score was used (16% v. 21%; p=0.41). There were no differences in mean birth weight between groups. Conclusions. In pregnant women in sub-Saharan Africa, most of whom were HIV-infected, neither trichomoniasis nor its treatment appears to influence the risk of preterm birth or a low-birth-weight infant

Risk Factors for Late Postnatal Transmission of Human Immunodeficiency Virus Type 1 in Sub-Saharan Africa

We conducted secondary data analyses of a clinical trial (HIVNET 024) to assess risk factors for late postnatal transmission (LPT) of HIV-1 through breastfeeding

Population Attributable Fractions for Late Postnatal Mother-to-Child Transmission of HIV-1 in Sub-Saharan Africa

Assess population attributable fractions (PAFs) for late postnatal transmission (LPT) of human immunodeficiency virus-1 (HIV-1) in a cohort of HIV-1-exposed infants

Transcriptome dynamics of CD4⁺ T cells during malaria maps gradual transit from effector to memory

The dynamics of CD4⁺ T cell memory development remain to be examined at genome scale. In malaria-endemic regions, antimalarial chemoprevention protects long after its cessation and associates with effects on CD4⁺ T cells. We applied single-cell RNA sequencing and computational modelling to track memory development during Plasmodium infection and treatment. In the absence of central memory precursors, two trajectories developed as T helper 1 (T_H1) and follicular helper T (T_(FH)) transcriptomes contracted and partially coalesced over three weeks. Progeny of single clones populated T_H1 and T_(FH) trajectories, and fate-mapping suggested that there was minimal lineage plasticity. Relationships between T_(FH) and central memory were revealed, with antimalarials modulating these responses and boosting T_H1 recall. Finally, single-cell epigenomics confirmed that heterogeneity among effectors was partially reset in memory. Thus, the effector-to-memory transition in CD4⁺ T cells is gradual during malaria and is modulated by antiparasitic drugs. Graphical user interfaces are presented for examining gene-expression dynamics and gene–gene correlations (http://haquelab.mdhs.unimelb.edu.au/cd4_memory/)

Morbidity and Mortality Among a Cohort of Human Immunodeficiency Virus Type 1-Infected and Uninfected Pregnant Women and Their Infants From Malawi, Zambia, and Tanzania

Morbidity and mortality patterns among pregnant women and their infants (before antiretroviral therapy was widely available) determines HIV-1 diagnostic, monitoring, and care interventions

Selected hematologic and biochemical measurements in African HIV-infected and uninfected pregnant women and their infants: the HIV Prevention Trials Network 024 protocol

Reference values for hematological and biochemical assays in pregnant women and in newborn infants are based primarily on Caucasian populations. Normative data are limited for populations in sub-Saharan Africa, especially comparing women with and without HIV infection, and comparing infants with and without HIV infection or HIV exposure. We determined HIV status and selected hematological and biochemical measurements in women at 20-24 weeks and at 36 weeks gestation, and in infants at birth and 4-6 weeks of age. All were recruited within a randomized clinical trial of antibiotics to prevent chorioamnionitis-associated mother-to-child transmission of HIV (HPTN024). We report nearly complete laboratory data on 2,292 HIV-infected and 367 HIV-uninfected pregnant African women who were representative of the public clinics from which the women were recruited. Nearly all the HIV-infected mothers received nevirapine prophylaxis at the time of labor, as did their infants after birth (always within 72 hours of birth, but typically within just a few hours at the four study sites in Malawi (2 sites), Tanzania, and Zambia. HIV-infected pregnant women had lower red blood cell counts, hemoglobin, hematocrit, and white blood cell counts than HIV-uninfected women. Platelet and monocyte counts were higher among HIV-infected women at both time points. At the 4-6-week visit, HIV-infected infants had lower hemoglobin, hematocrit and white blood cell counts than uninfected infants. Platelet counts were lower in HIV-infected infants than HIV-uninfected infants, both at birth and at 4-6 weeks of age. At 4-6 weeks, HIV-infected infants had higher alanine aminotransferase measures than uninfected infants. Normative data in pregnant African women and their newborn infants are needed to guide the large-scale HIV care and treatment programs being scaled up throughout the continent. These laboratory measures will help interpret clinical data and assist in patient monitoring in a sub-Saharan Africa context

Transcriptome dynamics of CD4⁺ T cells during malaria maps gradual transit from effector to memory

The dynamics of CD4⁺ T cell memory development remain to be examined at genome scale. In malaria-endemic regions, antimalarial chemoprevention protects long after its cessation and associates with effects on CD4⁺ T cells. We applied single-cell RNA sequencing and computational modelling to track memory development during Plasmodium infection and treatment. In the absence of central memory precursors, two trajectories developed as T helper 1 (T_H1) and follicular helper T (T_(FH)) transcriptomes contracted and partially coalesced over three weeks. Progeny of single clones populated T_H1 and T_(FH) trajectories, and fate-mapping suggested that there was minimal lineage plasticity. Relationships between T_(FH) and central memory were revealed, with antimalarials modulating these responses and boosting T_H1 recall. Finally, single-cell epigenomics confirmed that heterogeneity among effectors was partially reset in memory. Thus, the effector-to-memory transition in CD4⁺ T cells is gradual during malaria and is modulated by antiparasitic drugs. Graphical user interfaces are presented for examining gene-expression dynamics and gene–gene correlations (http://haquelab.mdhs.unimelb.edu.au/cd4_memory/)