High Burden of Morbidity and Mortality but Not Growth Failure in Infants Exposed to but Uninfected with Human Immunodeficiency Virus in Tanzania

Characterization of longitudinal nasopharyngeal microbiome patterns in maternally HIV-exposed Zambian infants

Background

Previous studies of infants born to HIV-positive mothers have linked HIV exposure to poor outcomes from gastrointestinal and respiratory illnesses, and to overall increased mortality rates. The mechanism behind this is unknown, but it is possible that differences in the nasopharyngeal (NP) microbiome between infants who are HIV-unexposed or HIV-exposed could play a role in perpetuating some outcomes.

Methods

We conducted a longitudinal analysis of 170 NP swabs of healthy infants who are HIV-exposed (n=10) infants and their HIV(+) mothers, and infants who are HIV-unexposed, uninfected (HUU; n=10) .and their HIV(-) mothers. These swabs were identified from a sample library collected in Lusaka, Zambia between 2015 and 2016. Using 16S rRNA gene sequencing, we characterized the maturation of the microbiome over the first 14 weeks of life to determine what quantifiable differences exist between HIV-exposed and HUU infants, and what patterns are reflected in the mothers' NP microbiomes.

Results

In both HIV-exposed and HUU infants, Staphylococcus and Corynebacterium began as primary colonizers of the NP microbiome but were in time replaced by Dolosigranulum, Streptococcus, Moraxella and Haemophilus. When evaluating the interaction between HIV exposure status and time of sampling among infants, the microbe Staphylococcus haemolyticus showed a distinctive high association with HIV exposure at birth. When comparing infants to their mothers with paired analyses, HIV-exposed infants' NP microbiome composition was only slightly different from their HIV(+) mothers at birth or 14 weeks, including in their carriage of S. pneumoniae, H. influenzae, and S. haemolyticus.

Conclusions

Our analyses indicate that the HIV-exposed infants in our study exhibit subtle differences in the NP microbial composition throughout the sampling interval. Given our results and the sampling limitations of our study, we believe that further research must be conducted in order to confidently understand the relationship between HIV exposure and infants' NP microbiomes.

The safety and immunogenicity of vaccines administered to pregnant women living with HIV: a systematic review and meta-analysis

Background

Human Immunodeficiency Virus (HIV)-exposed uninfected (HEU) infants have a higher burden of infectious diseases related morbidity and mortality compared with HIV-unexposed uninfected (HUU). Immunization of pregnant women living with HIV (PWLWH) could reduce the severity and burden of infectious diseases for HEU in early infancy.

Methods

We conducted a systematic review of safety and immunogenicity of vaccines administered to PWLWH and meta-analyses to test the overall effect of immunogenicity comparing pregnant women without HIV (PWWH) to PWLWH. We searched MEDLINE, Embase, Web of Science, Virtual Health Library and Cochrane databases in accordance with PRISMA guidelines for randomized controlled trials and observational studies. Review articles, case series, conference abstracts, and animal studies were excluded. Studies were included from inception to 6th September 2023, with no language restrictions. Random effects meta-analyses were performed for immunogenicity using Review manager (RevMan) analysis software version 5.4.1, Geometric Mean Titer (GMT) values were transformed to obtain the mean and standard deviation within RevMan, the effect size was computed and reported as mean difference with respective 95% confidence intervals. The review was registered with PROSPERO CRD42021289081.

Findings

We included 12 articles, comprising 3744 pregnant women, 1714 were PWLWH given either influenza, pneumococcal or an investigational Group B streptococcal (GBS) vaccine. Five studies described safety outcomes, and no increase in adverse events was reported in PWLWH compared to PWWH. The GMT increase from baseline to 28-35 weeks post vaccination in HA units ranged from 12.4 (95% CI: 9.84-14.9) to 238.8 (95% CI: 0.35-477.9). Meta-analyses of influenza vaccines showed the pooled geometric mean difference in Hemagglutination Inhibition (HAI) titers post vaccination was 56.01 (95% CI: 45.01-67.01), p < 0.001. The increase was less in PWLWH when compared with PWWH: -141.76 (95% CI: -194.96, -88.55), p < 0.001.

Interpretation

There are limited data on the safety and immunogenicity of vaccines given to PWLWH making policy consideration in this group difficult when new vaccines are introduced. With new vaccines on the horizon, PWLWH need to be included in studies to promote vaccine confidence for this special population.

Funding

This work was funded by Medical Research Council Joint Clinical Trials Round 9 [MR/T004983/1].

Zinc supplementation for preventing mortality, morbidity, and growth failure in children aged 6 months to 12 years

BACKGROUND

Zinc deficiency is prevalent in low- and middle-income countries, and is considered a significant risk factor for morbidity, mortality, and linear growth failure. The effectiveness of preventive zinc supplementation in reducing prevalence of zinc deficiency needs to be assessed.

OBJECTIVES

To assess the effects of zinc supplementation for preventing mortality and morbidity, and for promoting growth, in children aged 6 months to 12 years.

SEARCH METHODS

A previous version of this review was published in 2014. In this update, we searched CENTRAL, MEDLINE, Embase, five other databases, and one trials register up to February 2022, together with reference checking and contact with study authors to identify additional studies.

SELECTION CRITERIA

Randomized controlled trials (RCTs) of preventive zinc supplementation in children aged 6 months to 12 years compared with no intervention, a placebo, or a waiting list control. We excluded hospitalized children and children with chronic diseases or conditions. We excluded food fortification or intake, sprinkles, and therapeutic interventions.

DATA COLLECTION AND ANALYSIS

Two review authors screened studies, extracted data, and assessed the risk of bias. We contacted study authors for missing information and used GRADE to assess the certainty of evidence. The primary outcomes of this review were all-cause mortality; and cause-specific mortality, due to all-cause diarrhea, lower respiratory tract infection (LRTI, including pneumonia), and malaria. We also collected information on a number of secondary outcomes, such as those related to diarrhea and LRTI morbidity, growth outcomes and serum levels of micronutrients, and adverse events.

MAIN RESULTS

We included 16 new studies in this review, resulting in a total of 96 RCTs with 219,584 eligible participants. The included studies were conducted in 34 countries; 87 of them in low- or middle-income countries. Most of the children included in this review were under five years of age. The intervention was delivered most commonly in the form of syrup as zinc sulfate, and the most common dose was between 10 mg and 15 mg daily. The median duration of follow-up was 26 weeks. We did not consider that the evidence for the key analyses of morbidity and mortality outcomes was affected by risk of bias. High-certainty evidence showed little to no difference in all-cause mortality with preventive zinc supplementation compared to no zinc (risk ratio (RR) 0.93, 95% confidence interval (CI) 0.84 to 1.03; 16 studies, 17 comparisons, 143,474 participants). Moderate-certainty evidence showed that preventive zinc supplementation compared to no zinc likely results in little to no difference in mortality due to all-cause diarrhea (RR 0.95, 95% CI 0.69 to 1.31; 4 studies, 132,321 participants); but probably reduces mortality due to LRTI (RR 0.86, 95% CI 0.64 to 1.15; 3 studies, 132,063 participants) and mortality due to malaria (RR 0.90, 95% CI 0.77 to 1.06; 2 studies, 42,818 participants); however, the confidence intervals around the summary estimates for these outcomes were wide, and we could not rule out a possibility of increased risk of mortality. Preventive zinc supplementation likely reduces the incidence of all-cause diarrhea (RR 0.91, 95% CI 0.90 to 0.93; 39 studies, 19,468 participants; moderate-certainty evidence) but results in little to no difference in morbidity due to LRTI (RR 1.01, 95% CI 0.95 to 1.08; 19 studies, 10,555 participants; high-certainty evidence) compared to no zinc. There was moderate-certainty evidence that preventive zinc supplementation likely leads to a slight increase in height (standardized mean difference (SMD) 0.12, 95% CI 0.09 to 0.14; 74 studies, 20,720 participants). Zinc supplementation was associated with an increase in the number of participants with at least one vomiting episode (RR 1.29, 95% CI 1.14 to 1.46; 5 studies, 35,192 participants; high-certainty evidence). We report a number of other outcomes, including the effect of zinc supplementation on weight and serum markers such as zinc, hemoglobin, iron, copper, etc. We also performed a number of subgroup analyses and there was a consistent finding for a number of outcomes that co-supplementation of zinc with iron decreased the beneficial effect of zinc.

AUTHORS' CONCLUSIONS

Even though we included 16 new studies in this update, the overall conclusions of the review remain unchanged. Zinc supplementation might help prevent episodes of diarrhea and improve growth slightly, particularly in children aged 6 months to 12 years of age. The benefits of preventive zinc supplementation may outweigh the harms in regions where the risk of zinc deficiency is relatively high.

Characterization of longitudinal nasopharyngeal microbiome patterns in maternally HIV-exposed Zambian infants

Background: Previous studies of infants born to HIV-positive mothers have linked HIV exposure to poor outcomes from gastrointestinal and respiratory illnesses, and to overall increased mortality rates. The mechanism behind this is unknown, but it is possible that differences in the nasopharyngeal (NP) microbiome between HIV-unexposed and HIV-exposed infants could play a role in perpetuating some outcomes. Methods: We conducted a longitudinal analysis of 170 NP swabs of healthy HIV-exposed, uninfected (HEU; n=10) infants and their HIV(+) mothers and HIV-unexposed, uninfected (HUU; n=10) infants and their HIV(-) mothers. These swabs were identified from a sample library collected in Lusaka, Zambia between 2015 and 2016. Using 16S rRNA gene sequencing, we characterized the maturation of the microbiome over the first 14 weeks of life to determine what quantifiable differences exist between HEU and HUU infants, and what patterns are reflected in the mothers' NP microbiomes. Results: In both HEU and HUU infants, Staphylococcus and Corynebacterium began as primary colonizers of the NP microbiome but were in time replaced by Dolosigranulum, Streptococcus, Moraxella and Haemophilus. When studying differences between infants, the microbe Staphylococcus haemolyticus indicated a distinctive high association with HIV exposure at birth, even when accounting for the interaction between HIV exposure status and time of sampling. When comparing infants to their mothers with paired analyses, HEU infants’ NP microbiome composition was only slightly different from their HIV(+) mothers at birth or 14 weeks, including in their carriage of S. pneumoniae, H. influenzae, and S. haemolyticus. Conclusions: Our analyses indicate that the HEU infants in our study exhibit subtle differences in the NP microbial composition throughout the sampling interval. Given our results and the sampling limitations of our study, we believe that further research must be conducted in order to confidently understand the relationship between HIV exposure and infants’ NP microbiomes.

Vitamin D3 supplementation during pregnancy and lactation for women living with HIV in Tanzania: A randomized controlled trial

BACKGROUND

Observational studies suggest that vitamin D deficiency among people living with HIV is associated with a greater risk of disease progression and death. Low levels of vitamin D in pregnancy are also associated with poor fetal and infant growth. Therefore, vitamin D supplementation may improve clinical outcomes for pregnant women living with HIV and improve fetal and postnatal growth for their infants.

METHODS AND FINDINGS

We conducted a randomized, triple-blind, placebo-controlled trial of vitamin D3 supplementation among pregnant and lactating women living with HIV in Dar es Salaam, Tanzania (ClinicalTrials.gov NCT02305927). Participants were randomized with 1:1 allocation stratified by study clinic to receive either daily 3,000 IU vitamin D3 supplements or matching placebo supplements from the second trimester of pregnancy (12-27 weeks) until 1 year postpartum. The primary outcomes were (i) maternal HIV progression or death, (ii) small-for-gestational-age (SGA) live births (<10th percentile), and (iii) infant stunting at 1 year of age (length-for-age z-score < -2). We also examined the effect of vitamin D3 supplementation on secondary maternal and infant health outcomes, maternal and infant serum 25-hydroxyvitamin D (25[OH]D) concentrations, and maternal hypercalcemia. An intent-to-treat analysis was used as the primary analytic approach. We enrolled 2,300 pregnant women between June 15, 2015, and April 17, 2018, and follow-up of mothers and infants was completed on October 20, 2019. There were 1,148 pregnant women randomly assigned to the vitamin D3 group, and 1,152 to the placebo group. The proportion of mothers lost to follow-up at 1 year postpartum was 6.6% in the vitamin D3 group (83 of 1,148) and 6.6% in the placebo group (76 of 1,152). The proportion of children lost to follow-up at 1 year of age was 5.5% in the vitamin D3 group (59 of 1,074 live births) and 5.2% in the placebo group (57 of 1,093 live births). There was no difference in the risk of maternal HIV progression or death, with 166 events during 1,461 person-years of follow-up in the vitamin D3 group and 141 events during 1,469 person-years of follow-up in the placebo group (hazard ratio 1.21, 95% CI 0.97 to 1.52, p = 0.09). There was no difference in the risk of SGA birth between the vitamin D3 (229 SGA births among 1,070 live births) and placebo groups (236 SGA births among 1,091 live births) (relative risk 1.03, 95% CI 0.87 to 1.22, p = 0.70). There was also no difference in the risk of infant stunting at 1 year of age between the vitamin D3 (407 events among 867 infants) and placebo groups (413 events among 873 infants) (relative risk 1.00, 95% CI 0.92 to 1.10, p = 0.95). In terms of adverse events, no cases of maternal hypercalcemia were identified. One hypersensitivity reaction to the trial supplements occurred for a pregnant woman in the placebo group. A limitation of our study is that our findings may not be generalizable to HIV-negative pregnant women or contexts where severe vitamin D deficiency is prevalent.

CONCLUSIONS

The trial findings do not support routine vitamin D supplementation for pregnant and lactating women living with HIV in Tanzania.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02305927.

The Etiology of Pneumonia in HIV-uninfected South African Children: Findings From the Pneumonia Etiology Research for Child Health (PERCH) Study

BACKGROUND

Pneumonia is the major contributor to under 5 childhood mortality globally. We evaluated the etiology of pneumonia amongst HIV-uninfected South African children enrolled into the Pneumonia Etiology Research for Child Health case-control study.

METHODS

Cases, 1-59 months of age hospitalized with World Health Organization clinically defined severe/very severe pneumonia, were frequency-matched by age and season to community controls. Nasopharyngeal-oropharyngeal swabs were analyzed using polymerase chain reaction for 33 respiratory pathogens, and whole blood was tested for pneumococcal autolysin. Cases were also tested for Mycobacterium tuberculosis. Population etiologic fractions (EF) of pneumonia with radiologic evidence of consolidation/infiltrate were derived for each pathogen through Bayesian analysis.

RESULTS

Of the 805 HIV-uninfected cases enrolled based on clinical criteria, radiologically confirmed pneumonia was evident in 165 HIV-exposed, -uninfected, and 246 HIV-unexposed children. In HIV-exposed and HIV-unexposed children, respiratory syncytial virus was the most important pathogen with EFs of 31.6% [95% credible interval (CrI), 24.8%-38.8%] and 36.4% (95% CrI, 30.5%-43.1%), respectively. M. tuberculosis contributed EFs of 11.6% (95% CrI, 6.1%-18.8%) in HIV-exposed and 8.3% (95% CrI, 4.5%-13.8%) in HIV-unexposed children, including an EF of 16.3% (95% CrI, 6.1%-33.3%) in HIV-exposed children ≥12 months of age. Bacteremia (3.0% vs. 1.6%) and case fatality risk (3.6% vs. 3.7%) were similar in HIV-exposed and HIV-unexposed children.

CONCLUSIONS

Vaccination strategies targeting respiratory syncytial virus should be prioritized for prevention of pneumonia in children. Furthermore, interventions are required to address the high burden of tuberculosis in the pathogenesis of acute community-acquired pneumonia in settings such as ours.

Role of Inflammation in Virus Pathogenesis during Pregnancy

Viral infections during pregnancy lead to a spectrum of maternal and fetal outcomes, ranging from asymptomatic disease to more critical conditions presenting with severe maternal morbidity, stillbirth, preterm birth, intrauterine growth restriction, and fetal congenital anomalies, either apparent at birth or later in life. In this article, we review the pathogenesis of several viral infections that are particularly relevant in the context of pregnancy and intrauterine inflammation. Understanding the diverse mechanisms employed by viral pathogens as well as the repertoire of immune responses induced in the mother may help to establish novel therapeutic options to attenuate changes in the maternal-fetal interface and prevent adverse pregnancy outcomes.

Identifying Infants and Young Children at Risk of Unplanned Hospital Admissions and Clinic Visits in Dar es Salaam, Tanzania

BACKGROUND

Pediatric inpatient mortality rates are as high as 11% in parts of sub-Saharan Africa. Unscheduled clinic visits also burden children in sub-Saharan Africa. Our objective was to identify factors associated with hospital admissions and unscheduled clinic visits among Tanzanian children < 24 months of age.

METHODS

We conducted a secondary analysis of 2 trials conducted in Dar es Salaam, Tanzania. We performed univariate and Poisson multivariable regression analyses to identify factors associated with hospital admissions and unscheduled clinic visits.

RESULTS

Of 4784 children < 24 months of age, 293 (6.1%) were hospitalized at least once and 1308 (27.3%) had ≥ 1 unscheduled clinic visit. Infants and children who were exposed to but HIV-negative had increased risk of hospital admission [adjusted risk ratios (aRR): 3.67; 95% CI: 2.45-5.50; P < 0.001] compared with HIV-unexposed children. Those who were HIV-positive had even higher risk of hospital admission compared with those not exposed to HIV (aRR: 10.87; 95% CI: 7.01-16.89; P < 0.001). Birth weight and breast-feeding status were not associated with increased risk of hospital admission. Children with Apgar scores < 7 (aRR: 1.32; 95% CI: 1.03-1.69; P = 0.001), not exclusively breast-fed up to 6 months of age (aRR: 1.34; 95% CI: 1.12-1.60; P = 0.001), and who were HIV-exposed and HIV-negative (aRR: 2.35; 95% CI: 2.08-2.66; P < 0.001) or HIV-positive (aRR: 3.02; 95% CI: 2.52-3.61; P < 0.001) had higher risk of unscheduled clinic visits.

CONCLUSIONS

Exposure to HIV and being HIV-positive were associated with the greatest risk for hospital admission and unplanned clinic visits among infants and children in Tanzania. Targeting these vulnerable populations in interventional studies may reduce morbidity.

Correlates of loss to follow-up and missed diagnosis among HIV-exposed infants throughout the breastfeeding period in southern Mozambique

Introduction

Complete follow-up of human immunodeficiency virus (HIV)-exposed infants (HEI) is crucial for a successful prevention of mother-to-child HIV transmission. This study analyzed the HEI follow-up and factors associated with loss to follow-up (LTFU) in southern Mozambique.

Methods

This retrospective cohort study used the data of HEI enrolled between June 2017 and June 2018, followed-up for 18 months. The outcomes were the proportion of infants with completed follow-up and a definitive diagnosis, and the presence of clinical events. Kaplan–Meier survival analysis was used to calculate the cumulative probability of LTFU and of clinical events. Factors associated with LTFU and clinical events were analyzed using Cox regression to calculate the hazard ratio (HR) and adjusted HR (AHR), with a 95% confidence interval (CI) and a significance cutoff of p<0.05.

Results

1413 infants were enrolled (49% males) at a median age of 32 days (IQR 31–41); the median follow-up time was 12 months (IQR 8.2–14.2); 1129 (80%) completed follow-up and had a definitive diagnosis, 58 (4%) were HIV-positive, 225 (16%) were LTFU; 266 (19%) presented a clinical event. Factors associated with LTFU were: age >2 months at entry (AHR, 1.58; 95% CI, 1.12–2.23), non-exclusive breastfeeding (AHR, 1.44; 95% CI, 1.01–2.06), poor cotrimoxazole adherence (AHR, 3.42; 95% CI, 1.59–7.35), and clinical events (AHR, 0.51; 95% CI, 0.34–0.77). Factors associated with clinical events were: malnutrition (AHR, 10.06; 95% CI, 5.92–17.09), non-exclusive breastfeeding (AHR, 1.98; 95% CI, 1.34–2.93), no nevirapine prophylaxis (AHR, 1.67; 95% CI, 1.18–2.36), and poor cotrimoxazole adherence (AHR, 2.62; 95% CI, 1.10–6.22).

Conclusion

The high rate of HEI LTFU, associated with delayed linkage to postnatal care, poor prophylaxis adherence, non-exclusive breastfeeding, indicates the need to design a differentiated service delivery model that is tailored to the mothers’ and infants’ specific needs.

Differences in Growth of HIV-exposed Uninfected Infants in Ethiopia According to Timing of In-utero Antiretroviral Therapy Exposure

BACKGROUND

There are concerns about the adverse effect of in-utero exposure to antiretroviral therapy (ART) on the growth of HIV exposed-uninfected (HEU) infants. We compared growth of HEU-infants according to the timing and type of ART exposure.

METHODS

A retrospective cohort study was conducted by abstracting clinical data from HIV-infected mothers and HEU-infants in Addis Ababa, Ethiopia between February 2013 and October 2016. Mixed-effects linear models were used to compare changes in weight and length and cox proportional hazard models were used to evaluate stunting (length-for-age z score <-2.0) and underweight (weight-for-age z score <-2.0).

RESULTS

A total of 624 HEU-infants were included in the analyses. Infants exposed to ART from conception had a lower rate of change in length [β = -0.54, 95% confidence interval (CI): -1.00 to -0.08] the first 3 months of life, as compared with infants exposed from late pregnancy. Risk of stunting was 51.9 per 100 person-years and risk of underweight was 26.7 per 100 person-years. Exposure to ART from conception was associated with a higher rate of stunting as compared with exposure from late pregnancy (adjusted hazard ratio = 1.95, 95% CI: 1.27-2.99). Infants born to mothers with advanced disease had a higher incidence of underweight compared with infants born to mothers with early-stage disease adjusted hazard ratio = 1.99, 95% CI: 1.32-3.03).

CONCLUSIONS

In HEU-infants, exposure to ART from conception was associated with decrease growth during early infancy and higher incidence of stunting compared with treatment exposure later in pregnancy. Close monitoring of HEU-infants' growth and prompt nutritional intervention is essential.

Maternal Immunization: Nature Meets Nurture

Vaccinating women in pregnancy (i.e., maternal immunization) has emerged as a promising tool to tackle infant morbidity and mortality worldwide. This approach nurtures a 'gift of nature,' whereby antibody is transferred from mother to fetus transplacentally during pregnancy, or postnatally in breast milk, thereby providing passive, antigen-specific protection against infections in the first few months of life, a period of increased immune vulnerability for the infant. In this review, we briefly summarize the rationale for maternal immunization programs and the landscape of vaccines currently in use or in the pipeline. We then direct the focus to the underlying biological phenomena, including the main mechanisms by which maternally derived antibody is transferred efficiently to the infant, at the placental interface or in breast milk; important research models and methodological approaches to interrogate these processes, particularly in the context of recent advances in systems vaccinology; the potential biological and clinical impact of high maternal antibody titres on neonatal ontogeny and subsequent infant vaccine responses; and key vaccine- and host-related factors influencing the maternal-infant dyad across different environments. Finally, we outline important gaps in knowledge and suggest future avenues of research on this topic, proposing potential strategies to ensure optimal testing, delivery and implementation of maternal vaccination programs worldwide.

Third Trimester Vitamin D Status Is Associated With Birth Outcomes and Linear Growth of HIV-Exposed Uninfected Infants in the United States

BACKGROUND

Vitamin D status in pregnancy may influence the risk of prematurity, birth size, and child postnatal growth, but few studies have examined the relationship among pregnant women living with HIV.

METHODS

We conducted a prospective cohort study of 257 HIV-infected mothers and their HIV-exposed uninfected infants who were enrolled in the 2009-2011 nutrition substudy of the Surveillance Monitoring for ART Toxicities (SMARTT) study. HIV-infected pregnant women had serum 25-hydroxyvitamin D (25(OH)D) assessed in the third trimester of pregnancy, and their infants' growth and neurodevelopment were evaluated at birth and approximately 1 year of age.

RESULTS

The mean third trimester serum 25(OH)D concentration was 35.4 ± 14.2 ng/mL with 15% of women classified as vitamin D deficient (<20 ng/mL) and 21% as insufficient (20-30 ng/mL). In multivariable models, third trimester vitamin D deficiency and insufficiency were associated with -273 g [95% confidence interval (CI): -450 to -97] and -203 g (95% CI: -370 to -35) lower birth weights compared with vitamin D sufficient women, respectively. Maternal vitamin D deficiency was also associated with shorter gestation (mean difference -0.65 weeks; 95% CI: -1.22 to -0.08) and lower infant length-for-age z-scores at 1 year of age (mean difference: -0.65; 95% CI: -1.18 to -0.13). We found no association of vitamin D status with infant neurodevelopment at 1 year of age.

CONCLUSION

Third trimester maternal vitamin D deficiency was associated with lower birth weight, shorter length of gestation, and reduced infant linear growth. Studies and trials of vitamin D supplementation in pregnancy for women living with HIV are warranted.

Comparison of 6-week PMTCT outcomes for HIV-exposed and HIV-unexposed infants in the era of lifelong ART: Results from an observational prospective cohort study

Background

Lifelong antiretroviral therapy (ART) reduces mother-to-child HIV transmission (MTCT) and improves maternal health. Data on the outcomes of HIV-exposed infants (HEI) compared to their unexposed counterparts in the era of universal ART is limited. We compared birth and 6-week outcomes among infants born to HIV-positive and HIV-negative women in Lesotho.

Methods

941 HIV-negative and 653 HIV-positive pregnant women were enrolled in an observational cohort to evaluate the effectiveness of prevention of mother-to-child HIV transmission (PMTCT) program after implementation of universal maternal ART in 14 health facilities. Pregnancy, delivery, birth, and 6-week data were collected through participant interviews and medical record review. DNA PCR testing for HEI was conducted within 2 weeks of birth and at around 6 weeks of age. Data were analysed to estimate the distribution of birth outcomes, mortality, HIV transmission and HIV-free survival at 6 weeks.

Results

HIV-positive women were older (mean age of 28.7 vs. 24.4 years) and presented for antenatal care earlier (mean gestational age of 23.0 weeks vs 25.3 weeks) than HIV-negative women. Prematurity was more frequent among HEI, 7.8% vs. 3.6%. There was no difference in rates of congenital anomalies between HEI (1.0%) and HIV-unexposed infants (HUI) (0.6%). Cumulative HIV transmission was 0.9% (N = 4/431) (95% CI:0.25–2.36) at birth and 1.0% (N = 6/583) (95% CI:0.38–2.23) at 6 weeks. Overall mortality, including stillbirths, was 5.2% and 6.0% by 6 weeks for HUI and HEI respectively. Among liveborn infants, 6-week HIV-free survival for HEI was 95.6% (95% CI:93.7–97.1) compared to 96.8% (95% CI:95.4–97.9) survival for HUI.

Conclusions

Implementation of universal maternal ART lowers MTCT at 6 weeks of age with no differences in congenital anomalies or early mortality between HIV exposed Infants and HIV unexposed infants. However, HIV exposed infants continue to have high rates of prematurity despite improved maternal health on ART.

Fc Characteristics Mediate Selective Placental Transfer of IgG in HIV-Infected Women

The placental transfer of maternal IgG is critical for infant protection against infectious pathogens. However, factors that modulate the placental transfer of IgG remain largely undefined. HIV-infected women have impaired placental IgG transfer, presenting a unique "disruption model" to define factors that modulate placental IgG transfer. We measured the placental transfer efficiency of maternal HIV and pathogen-specific IgG in US and Malawian HIV-infected mothers and their HIV-exposed uninfected and infected infants. We examined the role of maternal HIV disease progression, infant factors, placental Fc receptor expression, IgG subclass, and glycan signatures and their association with placental IgG transfer efficiency. Maternal IgG characteristics, such as binding to placentally expressed Fc receptors FcγRIIa and FcγRIIIa, and Fc region glycan profiles were associated with placental IgG transfer efficiency. Our findings suggest that Fc region characteristics modulate the selective placental transfer of IgG, with implications for maternal vaccine design and infant health.

Experiences of Fetal or Infant Loss among Tanzanian Women in HIV Care

This study examined the impact of fetal or infant loss on HIV care engagement. We conducted semi-structured interviews with 15 HIV-infected women who experienced fetal or infant loss while enrolled in prevention of mother-to-child transmission (PMTCT) services in Tanzania. Women attributed the loss to delays in receiving healthcare. Provider communication about the cause of the loss was poor, and women reported substantial distress related to the loss. One-fifth reported gaps in HIV care or disengagement from care following their loss. Loss of a fetus or infant is not uncommon in HIV endemic settings, and should be integrated into PMTCT guidelines.

Compromised Growth Among HIV-exposed Uninfected Compared With Unexposed Children in Nigeria

BACKGROUND

HIV-exposed but uninfected (HEU) children may be at an increased risk of impaired growth when compared with their HIV-unexposed and uninfected (HUU) counterparts. We compared the growth patterns of HEU to HUU children in Nigeria.

METHODS

Pregnant women with and without HIV infection were enrolled at the Plateau State Specialist Hospital, Jos, Nigeria. Infants born to these mothers were recruited at birth and the mother-infant pairs followed up for 18 months. Weight, length and head circumference of the infants were measured at each visit. Age- and sex-standardized Z scores were generated for each anthropometric measure using the World Health Organization Child Growth Standards. Children with length-for-age, weight-for-age and weight-for-length Z scores <-2 were classified as stunted, underweight and wasted, respectively.

RESULTS

Of 415 children (307 HEU and 108 HUU) recruited for this study, 117 (28.4%), 9 (2.2%) and 32 (7.8%) infants were stunted, underweight and wasted, respectively, at birth. In a multivariable longitudinal analysis, the odds of stunting were higher among HEU as compared with HUU children [adjusted odds ratio: 2.4 (95% confidence interval: 1.4-4.1)]. Similarly, odds of being underweight were higher among the HEU children [adjusted odds ratio: 1.6 (95% confidence interval: 1.1-2.2)].

CONCLUSIONS

Linear and ponderal growth were more impaired among HEU as compared with HUU children in Nigeria during the first 18 months of life. Further studies are needed to explore the causal basis for these differences.

"If I don't have children, they will know that I'm sick": fertility desires of women and men living with HIV in Iringa, Tanzania

As safer conception services are expanded and integrated into HIV care systems, these services will need to address cultural, social, economic and medical concerns of women and men living with HIV. We conducted interviews with 30 HIV-positive women, 30 HIV-positive men, and 30 healthcare providers that examined factors specific to the experience of living with HIV that influence fertility desires in Iringa, Tanzania. HIV-related factors fell under five themes: knowing one could prevent mother-to-child transmission; reaching an ideal family size in the context of HIV-related infant mortality; concealing one's HIV status; being able to provide for children; and managing HIV disease progression. Integration of safer conception counseling that includes locally-tailored messaging around desired family size, health risks, stigma and financial considerations into safer conception services will help people living with HIV reach their reproductive goals, while reducing the risks of HIV transmission.

Pediatric Neurodevelopmental Functioning After In Utero Exposure to Triple-NRTI vs. Dual-NRTI + PI ART in a Randomized Trial, Botswana

BACKGROUND

In utero exposure to nucleoside reverse transcriptase inhibitor (NRTI)-containing antiretroviral treatment (ART) regimens may be associated with poor neurodevelopmental functioning in children of HIV-infected mothers. We investigated neurodevelopmental outcomes of HIV-exposed uninfected (HEU) children of HIV-infected women enrolled in a randomized trial of abacavir/zidovudine/lamivudine (triple-NRTI regimen) vs. lopinavir/ritonavir/zidovudine/lamivudine [dual-NRTI + protease inhibitor (PI) regimen].

SETTING

The Mma Bana randomized trial was conducted in urban and rural sites in Botswana.

METHODS

The Mma Bana study randomized HIV-infected pregnant women with CD4 ≥200 cells per mm to a triple-NRTI vs. dual-NRTI + PI regimen from 26- to 34-week gestation through planned weaning at 6-month postpartum. Partway through the study, neurodevelopmental assessments were added at 24 months of age, including the Developmental Milestones Checklist, the Bayley Scales of Infant and Toddler Development third edition, Ten Questions Questionnaire, and Profile of Social Emotional Development. We evaluated differences in mean scores between the 2 arms using unadjusted and adjusted linear regression.

RESULTS

A total of 197 HEU infants (48% male) completed a neurodevelopmental assessment (101 in triple-NRTI arm and 96 in dual-NRTI + PI-exposed arm). Mean values for all neurodevelopmental outcomes were similar for children of mothers randomized to either ART regimen, with no significant differences in either unadjusted or adjusted models (estimated effect sizes ranging from -0.12 to 0.14).

CONCLUSIONS

Neurodevelopmental outcomes in 24-month-old HEU children of HIV-infected mothers with baseline CD4 ≥200 were similar in those randomized to a dual-NRTI + PI-based vs. a triple-NRTI-based ART regimen, suggestive of lack of short-term toxicity. Monitoring of long-term toxicity and newer regimens is warranted.

Biomarkers of Systemic Inflammation and Growth in Early Infancy are Associated with Stunting in Young Tanzanian Children

Stunting can afflict up to one-third of children in resource-constrained countries. We hypothesized that low-grade systemic inflammation (defined as elevations in serum C-reactive protein or alpha-1-acid glycoprotein) in infancy suppresses the growth hormone–insulin-like growth factor (IGF) axis and is associated with subsequent stunting. Blood samples of 590 children from periurban Dar es Salaam, Tanzania, were obtained at 6 weeks and 6 months of age as part of a randomized controlled trial. Primary outcomes were stunting, underweight, and wasting (defined as length-for-age, weight-for-age and weight-for-length z-scores < −2) between randomization and endline (18 months after randomization). Cox proportional hazards models were constructed to estimate hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) of time to first stunting, underweight, and wasting as outcomes, with measures of systemic inflammation, insulin-like growth factor-1 (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3) as exposures, adjusting for numerous demographic and clinical variables. The incidences of subsequent stunting, underweight, and wasting were 26%, 20%, and 18%, respectively. In multivariate analyses, systemic inflammation at 6 weeks of age was significantly associated with stunting (HR: 2.14, 95% CI: 1.23, 3.72; p = 0.002). Children with higher levels of IGF-1 at 6 weeks were less likely to become stunted (HR: 0.58, 95% CI: 0.37, 0.93; p for trend = 0.019); a similar trend was noted in children with higher levels of IGF-1 at 6 months of age (HR: 0.50, 95% CI: 0.22, 1.12; p for trend = 0.07). Systemic inflammation occurs as early as 6 weeks of age and is associated with the risk of future stunting among Tanzanian children.

Safety and Immunogenicity of Measles Vaccination in HIV-Infected and HIV-Exposed Uninfected Children: A Systematic Review and Meta-Analysis

BACKGROUND

HIV-infected and HIV-exposed uninfected (HEU) children have an increased risk of measles that may be due to altered immune responses or suboptimal timing of measles vaccination. We aimed to evaluate the safety and immunogenicity of measles vaccination in HIV-infected and HEU children.

METHODS

For this systematic review and meta-analysis, we searched PubMed, Embase, Cochrane Library, CINAHL, Global Health Library and IndMED on May 9, 2018. Studies were included if they reported on safety or seroresponse (either seroprotection/seropositivity/seroconversion) after measles vaccination in HIV-infected or HEU children. We calculated pooled estimates to compare immunogenicity outcomes between HIV-infected, HEU and HIV-unexposed children, using risk ratios [RRs] (with 95%CIs). PROSPERO registration number: CRD42017057411.

FINDINGS

Seventy-one studies met the inclusion criteria (15,363 children). Twenty-eight studies reported on safety; vaccine-associated adverse events and deaths were uncommon. Sixty-two studies reported on immunogenicity, 27 were included in the meta-analysis. HIV-infected children had lower seroresponse rates after primary vaccination compared with HIV-unexposed (RR 0.74; 95%CI: 0.61-0.90, I 2  = 85.9%) and HEU children (0.78; 0.69-0.88, I 2  = 77.1%), which was mitigated by antiretroviral therapy and time interval between vaccination and serology. HEU and HIV-unexposed children had similar seroresponses. Vaccination at 6-months resulted in similar proportions of HIV-infected children having seroresponse compared with HIV-unexposed (0.96; 0.77-1.19) and HEU children (1.00; 0.73-1.37, I 2  = 63.7%).

INTERPRETATION

Primary measles vaccination at 6-months of age may provide protection against measles during early infancy in settings with high prevalence of maternal HIV-infection, however, further studies are needed to evaluate this strategy in HEU children and HIV-infected children receiving antiretroviral therapy.

FUNDING

South African Research Chairs Initiative of the Department of Science and Technology and National Research Foundation in Vaccine Preventable Diseases; Medical Research Council: Respiratory and Meningeal Pathogens Research Unit.

Vitamin A supplements for reducing mother-to-child HIV transmission

BACKGROUND

Strategies to reduce the risk of mother-to-child transmission of the human immunodeficiency virus (HIV) include lifelong antiretroviral therapy (ART) for HIV-positive women, exclusive breastfeeding from birth for six weeks plus nevirapine or replacement feeding plus nevirapine from birth for four to six weeks, elective Caesarean section delivery, and avoiding giving children chewed food. In some settings, these interventions may not be practical, feasible, or affordable. Simple, inexpensive, and effective interventions (that could potentially be implemented even in the absence of prenatal HIV testing programmes) would be valuable. Vitamin A, which plays a role in immune function, is one low-cost intervention that has been suggested in such settings.

OBJECTIVES

To summarize the effects of giving vitamin A supplements to HIV-positive women during pregnancy and after delivery.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Embase, and the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) up to 25 August 2017, and checked the reference lists of relevant articles for eligible studies.

SELECTION CRITERIA

We included randomized controlled trials conducted in any setting that compared vitamin A supplements to placebo or no intervention among HIV-positive women during pregnancy or after delivery, or both.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed study eligibility and extracted data. We expressed study results as risk ratios (RR) or mean differences (MD) as appropriate, with their 95% confidence intervals (CI), and conducted random-effects meta-analyses. This is an update of a review last published in 2011.

MAIN RESULTS

Five trials met the inclusion criteria. These were conducted in Malawi, South Africa, Tanzania, and Zimbabwe between 1995 and 2005 and none of the participants received ART. Women allocated to intervention arms received vitamin A supplements at a variety of doses (daily during pregnancy; a single dose immediately after delivery, or daily doses during pregnancy plus a single dose after delivery). Women allocated to comparison arms received identical placebo (6601 women, 4 trials) or no intervention (697 women, 1 trial). Four trials (with 6995 women) had low risk of bias and one trial (with 303 women) had high risk of attrition bias.The trials show that giving vitamin A supplements to HIV-positive women during pregnancy, the immediate postpartum period, or both, probably has little or no effect on mother-to-child transmission of HIV (RR 1.07, 95% CI 0.91 to 1.26; 4428 women, 5 trials, moderate certainty evidence) and may have little or no effect on child death by two years of age (RR 1.06, 95% CI 0.92 to 1.22; 3883 women, 3 trials, low certainty evidence). However, giving vitamin A supplements during pregnancy may increase the mean birthweight (MD 34.12 g, 95% CI -12.79 to 81.02; 2181 women, 3 trials, low certainty evidence) and probably reduces the incidence of low birthweight (RR 0.78, 95% CI 0.63 to 0.97; 1819 women, 3 trials, moderate certainty evidence); but we do not know whether vitamin A supplements affect the risk of preterm delivery (1577 women, 2 trials), stillbirth (2335 women, 3 trials), or maternal death (1267 women, 2 trials).

AUTHORS' CONCLUSIONS

Antepartum or postpartum vitamin A supplementation, or both, probably has little or no effect on mother-to-child transmission of HIV in women living with HIV infection and not on antiretroviral drugs. The intervention has largely been superseded by ART which is widely available and effective in preventing vertical transmission.

Critical Role for Monocytes/Macrophages in Rapid Progression to AIDS in Pediatric Simian Immunodeficiency Virus-Infected Rhesus Macaques

Infant humans and rhesus macaques infected with the human or simian immunodeficiency virus (HIV or SIV), respectively, express higher viral loads and progress more rapidly to AIDS than infected adults. Activated memory CD4+ T cells in intestinal tissues are major primary target cells for SIV/HIV infection, and massive depletion of these cells is considered a major cause of immunodeficiency. Monocytes and macrophages are important cells of innate immunity and also are targets of HIV/SIV infection. We reported previously that a high peripheral blood monocyte turnover rate was predictive for the onset of disease progression to AIDS in SIV-infected adult macaques. The purpose of this study was to determine if earlier or higher infection of monocytes/macrophages contributes to the more rapid progression to AIDS in infants. We observed that uninfected infant rhesus macaques exhibited higher physiologic baseline monocyte turnover than adults. Early after SIV infection, the monocyte turnover further increased, and it remained high during progression to AIDS. A high percentage of terminal deoxynucleotidyltransferase dUTP nick end label (TUNEL)-positive macrophages in the lymph nodes (LNs) and intestine corresponded with an increasing number of macrophages derived from circulating monocytes (bromodeoxyuridine positive [BrdU+] CD163+), suggesting that the increased blood monocyte turnover was required to rapidly replenish destroyed tissue macrophages. Immunofluorescence analysis further demonstrated that macrophages were a significant portion of the virus-producing cells found in LNs, intestinal tissues, and lungs. The higher baseline monocyte turnover in infant macaques and subsequent macrophage damage by SIV infection may help explain the basis of more rapid disease progression to AIDS in infants.IMPORTANCE HIV infection progresses much more rapidly in pediatric cases than in adults; however, the mechanism for this difference is unclear. Using the rhesus macaque model, this work was performed to address why infants infected with SIV progress more quickly to AIDS than do adults. Earlier we reported that in adult rhesus macaques, increasing monocyte turnover reflected tissue macrophage damage by SIV and was predictive of terminal disease progression to AIDS. Here we report that uninfected infant rhesus macaques exhibited a higher physiological baseline monocyte turnover rate than adults. Furthermore, once infected with SIV, infants displayed further increased monocyte turnover that may have facilitated the accelerated progression to AIDS. These results support a role for monocytes and macrophages in the pathogenesis of SIV/HIV and begin to explain why infants are more prone to rapid disease progression.