Rates of Hospitalization and Infection-Related Hospitalization Among Human Immunodeficiency Virus (HIV)-Exposed Uninfected Children Compared to HIV-Unexposed Uninfected Children in the United States, 2007-2016

Risk and rates of hospitalisation in young children: A prospective study of a South African birth cohort

Children in sub-Saharan Africa (SSA) are disproportionately affected by morbidity and mortality. There is also a growing vulnerable population of children who are HIV-exposed uninfected (HEU). Understanding reasons and risk factors for early-life child hospitalisation will help optimise interventions to improve health outcomes. We investigated hospitalisations from birth to two years in a South African birth cohort study. Mother-child pairs in the Drakenstein Child Health Study were followed from birth to two years with active surveillance for hospital admission and investigation of aetiology and outcome. Incidence, duration, cause, and factors associated with child hospitalisation were investigated, and compared between HEU and HIV-unexposed uninfected (HUU) children. Of 1136 children (247 HEU; 889 HUU), 314 (28%) children were hospitalised in 430 episodes despite >98% childhood vaccination coverage. The highest hospitalisation rate was from 0-6 months, decreasing thereafter; 20% (84/430) of hospitalisations occurred in neonates at birth. Amongst hospitalisations subsequent to discharge after birth, 83% (288/346) had an infectious cause; lower respiratory tract infection (LRTI) was the most common cause (49%;169/346) with respiratory syncytial virus (RSV) responsible for 31% of LRTIs; from 0-6 months, RSV-LRTI accounted for 22% (36/164) of all-cause hospitalisations. HIV exposure was associated with increased incidence rates of hospitalisation in infants (IRR 1.63 [95% CI 1.29-2.05]) and longer hospital admission (p = 0.004). Prematurity (HR 2.82 [95% CI 2.28-3.49]), delayed infant vaccinations (HR 1.43 [95% CI 1.12-1.82]), or raised maternal HIV viral load in HEU infants were risk factors for hospitalisation; breastfeeding was protective (HR 0.69 [95% CI 0.53-0.90]). In conclusion, children in SSA experience high rates of hospitalisation in early life. Infectious causes, especially RSV-LRTI, underly most hospital admissions. HEU children are at greater risk of hospitalisation in infancy compared to HUU children. Available strategies such as promoting breastfeeding, timely vaccination, and optimising antenatal maternal HIV care should be strengthened. New interventions to prevent RSV may have additional impact in reducing hospitalisation.

Attention and neurodevelopment in young children who are HIV-exposed uninfected

ABSTRACTChildren HIV-exposed, uninfected (CHEU) are at risk for compromised developmental outcomes. Attention is important for behavioural, cognitive and academic skills, yet has not been thoroughly investigated compared to children HIV-unexposed uninfected (CHUU). Fifty-five CHEU and 51 CHUU children were recruited at 5.5 years of age. Measures of inattention (IA), hyperactivity/impulsivity (HI) and total scores were collected using the parent-reported ADHD-Rating-Scale-IV. Measures of intelligence, visuomotor skills, academics and adaptive functioning were obtained. Analyses of between-group differences were performed as were correlational and multiple regression models, accounting for maternal education, employment and delivery type. Few children met clinical cut-offs for probable ADHD (3.6% CHEU, 2.0% CHUU), and no group differences in measures of IA, HI and combined scores were found. CHEU scored significantly lower than CHUU on intelligence, visuomotor function, academic skills and aspects of adaptive behaviour, though within age expectations. Lower Full-Scale IQ and Processing Speed were associated with higher IA in CHEU and lower adaptive functioning with higher IA in CHUU. Across both groups, children of unemployed mothers had more HI symptoms. CHEU were not at increased risk for attention difficulties at 5.5 years of age. Maternal employment status highlights the contribution of sociodemographic factors in shaping behaviour and neurodevelopment.

Setting the research agenda: involving parents in research on children who are HIV-free

INTRODUCTION

There is growing interest in health, developmental and survival outcomes of children who are born HIV-free to women living with HIV (children born HIV-free). To date, the research agenda has been largely determined by researchers, funders and policy makers, with limited involvement of parents, who are key stakeholders. Researchers at UCL Great Ormond Street Institute of Child Health in partnership with community-based organisation 4M Network of Mentor Mothers conducted two workshops with parents in March 2022 to establish research priorities for children born HIV-free, and key considerations for methodological approaches both to research and engagement with the affected communities.

DISCUSSION

When exploring research on children born HIV-free, we consider the following: what aspects of current research are aligned with women and parents' priorities, what is missing and what approaches would be preferred. A holistic approach to research on children born HIV-free should be prioritised, focussing on a breadth of outcomes and how they intersect. Secondary use of existing data sources should be maximised to facilitate this, with a view of monitoring the long-term effects of fetal antiretroviral drug exposure alongside other key health and developmental outcomes. Involving and engaging with parents, and children where possible, must be at the heart of research design to maximise relevance and impact of findings for the affected communities. Potential barriers to engaging with individuals who were children born HIV-free include parental disclosure and individuals not identifying as a child born HIV-free to a mother living with HIV. Stigma-free language must be incorporated into the vocabulary of researchers and other stakeholders, avoiding reference to exposure; we propose the term "children born HIV-free."

CONCLUSIONS

Mothers and parents living with HIV should be involved in research about their children born HIV-free and are key in identifying research priorities so that findings may translate into an impact on their children's health and wellbeing. Meaningful involvement of women living with HIV through trusted community partners is an effective mechanism by which to elicit views on research about their children.

Facteurs associés à la létalité chez les patients hospitalisés pour le VIH avancé

CONTEXT

A unit supported by Médecins Sans Frontières (MSF) cares for patients with advanced HIV at Donka National Hospital, Conakry, Guinea.

OBJECTIVE

To determine the factors associated with the occurrence of death in patients hospitalised in the unit between 2017 and 2021.

DESIGN

This was a retrospective analysis of routine data from patients hospitalised with advanced HIV.

RESULTS

A total of 3,718 patients were included, with a median age of 40 years (IQR 33-51), of whom 2,241 (60.3%) were women. The mean mortality rate was 33.6% (n = 1,240), down from 40% in 2017 to 29% in 2021, but this was not statistically significant. The period most at risk of death was the first 25 days of hospitalisation. Among these patients, TB (43.8%) and toxoplasmosis (11.4%) were the most frequent diagnoses. After multivariate analysis using Cox regression, the factors associated with death were age 25-49 years (adjusted hazard ratio [aHR] 1.60; P = 0.002) or ≥50 years (aHR 1.80; P < 0.001), the presence of respiratory (aHR 1.23; P = 0.001) or abdominal symptoms (aHR 1.26; P < 0.001) and readmission (aHR 0.54; P < 0.001).

CONCLUSION

Patients aged 25-49 years or older, or those presenting with respiratory or abdominal signs require increased surveillance, as they are at the greatest risk of dying from the disease, especially during the first 25 days of hospitalisation.

Rates of Seroprotection against Vaccine-Preventable Infectious Diseases in HIV-Exposed and -Unexposed Malawian Infants

BACKGROUND

The evaluation of seroprotection rates against vaccine-preventable infectious diseases allows for the identification of risk populations. HIV-exposed infants, even if not infected with HIV, have higher morbidity and mortality in comparison to unexposed counterparts. The aim of this study was to compare the specific IgG levels against Haemophilus influenzae type-B (HiB), Hepatitis-B (HBV), and Streptococcus pneumoniae (Spn) in two groups of infants (HIV-exposed and HIV-unexposed) living in Malawi.

METHODS

Blood samples from 62 infants, 49 HIV-exposed, uninfected (HEU), and born to women living with HIV and 13 HIV-unexposed and uninfected (HUU), were collected at 6 months, and specific IgG levels were determined using ELISA tests.

RESULTS

The antibody levels against HiB, HBV, and Spn were similar in the two groups. At six months, all HUU infants and 81.6% of HEU infants showed seroprotective levels against HiB, while a percentage of protection varying from 80.6 to 84.6% was observed for HBV and Spn regardless of HIV exposure. Only 59.2% of HEU and 69.2% of HUU infants showed antibody protection against all three pathogens.

CONCLUSIONS

These results indicate similar rates of seroprotection among HEU and HUU infants but also suggest that a consistent fraction of infants received incomplete vaccinations. Strategies to enforce participation in immunization programs in Malawi should be a health priority.

Risk and rates of hospitalisation in young children: a prospective study of a South African birth cohort

Introduction

Children in sub-Saharan Africa (SSA) are disproportionately affected by morbidity and mortality; there is also a growing vulnerable population of children who are HIV-exposed uninfected (HEU). Understanding reasons and risk factors for early-life child hospitalisation will help optimise interventions to improve health outcomes. We investigated hospitalisations from birth to two years in a South African birth cohort.

Methods

Mother-child pairs in the Drakenstein Child Health Study were followed from birth to two years with active surveillance for hospital admission and investigation of aetiology and outcome. Incidence, duration, cause, and factors associated with child hospitalisation were investigated, and compared between HEU and HIV-unexposed uninfected (HUU) children.

Results

Of 1136 children (247 HEU; 889 HUU), 314 (28%) children were hospitalised in 430 episodes despite >98% childhood vaccination coverage. The highest hospitalisation rate was from 0-6 months, decreasing thereafter; 20% (84/430) of hospitalisations occurred in neonates at birth. Amongst hospitalisations subsequent to discharge after birth, 83% (288/346) had an infectious cause; lower respiratory tract infection (LRTI) was the most common cause (49%;169/346) with respiratory syncytial virus (RSV) responsible for 31% of LRTIs; from 0-6 months, RSV-LRTI accounted for 22% (36/164) of all-cause hospitalisations. HIV exposure was a risk factor for hospitalisation in infants (IRR 1.63 [95% CI 1.29-2.05]) and longer hospital admission (p=0.004). Prematurity (HR 2.82 [95% CI 2.28-3.49]), delayed infant vaccinations (1.43 [1.12-1.82]), or raised maternal HIV viral load in HEU infants were risk factors; breastfeeding was protective (0.69 [0.53-0.90]).

Conclusion

Children in SSA continue to experience high rates of hospitalisation in early life. Infectious causes, especially RSV-LRTI, underly most hospital admissions. HEU children are at particular risk in infancy. Available strategies such as promoting breastfeeding, timely vaccination, and optimising antenatal maternal HIV care should be strengthened. New interventions to prevent RSV may have a large additional impact in reducing hospitalisation.

Maternal HIV infection drives altered placental Mtb-specific antibody transfer

Introduction

Placental transfer of maternal antibodies is essential for neonatal immunity over the first months of life. In the setting of maternal HIV infection, HIV-exposed uninfected (HEU) infants are at higher risk of developing severe infections, including active tuberculosis (TB). Given our emerging appreciation for the potential role of antibodies in the control of Mycobacterium tuberculosis (Mtb), the bacteria that causes TB, here we aimed to determine whether maternal HIV status altered the quality of Mtb-specific placental antibody transfer.

Methods

Antigen-specific antibody systems serology was performed to comprehensively characterize the Mtb-specific humoral immune response in maternal and umbilical cord blood from HIV infected and uninfected pregnant people in Uganda.

Results

Significant differences were noted in overall antibody profiles in HIV positive and negative maternal plasma, resulting in heterogeneous transfer of Mtb-specific antibodies. Altered antibody transfer in HIV infected dyads was associated with impaired binding to IgG Fc-receptors, which was directly linked to HIV viral loads and CD4 counts.

Conclusions

These results highlight the importance of maternal HIV status on antibody transfer, providing clues related to alterations in transferred maternal immunity that may render HEU infants more vulnerable to TB than their HIV-unexposed peers.

Unique Profile of Inflammation and Immune Activation in Pregnant People With HIV in the United States

BACKGROUND

Little is known about inflammation/immune activation during pregnancy in people with HIV (PWH) and growth in their children who are HIV-exposed and uninfected (CHEU).

METHODS

Using data from the Pediatric HIV/AIDS Cohort Study and an HIV-seronegative comparison group, we assessed associations of (1) HIV status, mode of HIV acquisition (perinatally vs nonperinatally acquired), and type of antiretroviral therapy (ART) with inflammation/immune activation in pregnancy; and (2) inflammation/immune activation in pregnancy with growth of CHEU at 12 months. Interleukin 6 (IL-6), high-sensitivity C-reactive protein (hs-CRP), soluble(s) TNF-α receptor 1 and 2 (sTNFR1, sTNFR2), sCD14, and sCD163 were measured between 13 and 27 weeks' gestation. Linear regression models were fit to estimate differences between groups for each log-transformed biomarker, adjusted for confounders.

RESULTS

Pregnant PWH (188 total, 39 perinatally acquired, 149 nonperinatally acquired) and 76 HIV-seronegative persons were included. PWH had higher IL-6, sTNFR1, sCD14, and sCD163 and lower sTNFR2 compared to HIV-seronegative persons in adjusted models. Among PWH, sCD163 was higher in those with perinatally versus nonperinatally acquired HIV and on PI-based versus INSTI-based ART. Higher maternal concentrations of IL-6, sTNFR2, and hs-CRP were associated with poorer growth at 12 months.

CONCLUSIONS

Maternal HIV status is associated with a distinct profile of inflammation/immune activation during pregnancy, which may influence child growth.

Children who are HIV-exposed and uninfected: evidence for action

Prior to widespread availability of antiretroviral therapy (ART) in sub-Saharan Africa, children who were HIV-exposed but uninfected (HEU) had increased mortality, morbidity and undernutrition compared with children who were HIV-unexposed. Scale-up of ART has led to impressive declines in vertical HIV transmission, but over 15 million children are now HEU, 90% of whom live in sub-Saharan Africa. There are ongoing health disparities among children who are HEU, with higher mortality, morbidity and stunting and modest impairments in early child development, which collectively hamper health and human capital in high prevalence countries. The underlying causes are multifactorial and include exposure to HIV, co-infections and a skewed antenatal inflammatory milieu, particularly if mothers start ART once they have advanced disease, as well as socioeconomic risk factors, which may cluster in HIV-affected households. Improving maternal health through early and sustained ART, ensuring optimal breastfeeding, and implementing evidence-based priority interventions for all children in areas of high HIV prevalence, will likely improve outcomes. A more comprehensive intervention package based on the Nurturing Care Framework may have particular benefits for children who are HEU, to close health gaps and ensure that the next generation of HIV-free children survive and thrive, and lead healthy and productive lives.

Immune and Metabolic Alterations in Children with Perinatal HIV Exposure

With the global rollout of mother-to-child prevention programs for women living with HIV, vertical transmission has been all but eliminated in many countries. However, the number of children who are exposed in utero to HIV and antiretroviral therapy (ART) is ever-increasing. These children who are HIV-exposed-but-uninfected (CHEU) are now well recognized as having persistent health disparities compared to children who are HIV-unexposed-and-uninfected (CHUU). Differences reported between these two groups include immune dysfunction and higher levels of inflammation, cognitive and metabolic abnormalities, as well as increased morbidity and mortality in CHEU. The reasons for these disparities remain largely unknown. The present review focuses on a proposed link between immunometabolic aberrations and clinical pathologies observed in the rapidly expanding CHEU population. By drawing attention, firstly, to the significance of the immune and metabolic alterations observed in these children, and secondly, the impact of their healthcare requirements, particularly in low- and middle-income countries, this review aims to sensitize healthcare workers and policymakers about the long-term risks of in utero exposure to HIV and ART.

Risk factors for stunting in children who are HIV-exposed and uninfected after Option B+ implementation in Malawi

Evidence suggests children HIV-exposed and uninfected (CHEU) experience poor growth. We analysed child anthropometrics and explored factors associated with stunting among Malawian CHEU. Mothers with HIV and their infants HIV-exposed were enroled in a nationally representative prospective cohort within the National Evaluation of Malawi's Prevention of Mother-to-Child HIV Transmission Programme after Option B+ implementation (2014-2018). Anthropometry was measured at enrolment (age 1-6 months), visit 1 (approximately 12 months), and visit 2 (approximately 24 months). Weight-for-age (WAZ) and length-for-age (LAZ) z-scores were calculated using World Health Organization Growth Standards; underweight and stunting were defined as WAZ and LAZ more than 2 standard deviations below the reference median. Multivariable logistic regression restricted to CHEU aged 24 months (±3 months) was used to identify factors associated with stunting. Among 1211 CHEU, 562/1211 attended visit 2, of which 529 were aged 24 months (±3 months) and were included. At age 24 months, 40.4% of CHEU were stunted and/or underweight, respectively. In multi-variable analysis, adjusting for child age and sex, the odds of stunting were higher among CHEU with infectious disease diagnosis compared to those with no diagnosis (adjusted odds ratio = 3.35 [95% confidence interval: 1.82-6.17]), which was modified by co-trimoxazole prophylaxis (p = 0.028). Infant low birthweight was associated with an increased odds of stunting; optimal feeding and maternal employment were correlated with reduced odds. This is one of the first studies examining CHEU growth since Option B+. Interventions to improve linear growth among CHEU should address their multi-faceted health risks, alongside maternal ART prescription, and follow-up of mother-child pairs.

Cytomegalovirus Viremia Predicts Postdischarge Mortality in Kenyan HIV-Exposed Uninfected Children

BACKGROUND

Cytomegalovirus (CMV) viremia is associated with mortality in severely ill immunocompetent adults and hospitalized children with HIV (CWH). We measured CMV viremia in HIV-exposed and -unexposed Kenyan children aged 1-59 months discharged from hospital and determined its relationship with postdischarge mortality.

METHODS

CMV DNA levels were measured in plasma from 1024 children (97 of which were HIV exposed uninfected [HEU], and 15 CWH). Poisson and Cox proportional hazards regression models were used to identify correlates of CMV viremia ≥ 1000 IU/mL 
and estimate associations with 6-month mortality, respectively.

RESULTS

CMV viremia was detected in 31% of children, with levels ≥ 1000 IU/mL in 5.8%. HIV infection, age < 2 years, breastfeeding, and midupper arm circumference < 12.5 cm were associated with CMV viremia ≥ 1000 IU/mL. Among HEU children, CMV ≥ 1000 IU/mL (hazard ratio [HR] = 32.0; 95% confidence interval [CI], 2.9-354.0; P = .005) and each 1-log increase in CMV viral load (HR = 5.04; 95% CI, 1.7-14.6; P = .003) were associated with increased risk of mortality. CMV viremia was not significantly associated with mortality in HIV-unexposed children.

CONCLUSIONS

CMV levels at hospital postdischarge predict increased risk of 6-month mortality in Kenyan HEU children. CMV suppression may be a novel target to reduce mortality in HEU children.

CLINICAL TRIAL REGISTRATION

NCT02414399.

Altered Maternal Antibody Profiles in Women With Human Immunodeficiency Virus Drive Changes in Transplacental Antibody Transfer

BACKGROUND

Human immunodeficiency virus (HIV)-exposed, uninfected (HEU) children have a higher risk of severe infection, but the causes are poorly understood. Emerging data point to altered antibody transfer in women with HIV (WHIV); however, specific perturbations and the influence of antiretroviral therapy (ART) and HIV viremia remain unclear.

METHODS

We evaluated antigen-specific transplacental antibody transfer across 14 antigens in paired maternal and umbilical cord plasma from 352 Ugandan women; 176 were WHIV taking ART. We measured antigen-specific immunoglobulin G (IgG) sub-class (IgG1, 2, 3, 4) levels and antibody Fcγ receptor (FcγRn, 2a, 2b, 3a, 3b) binding profiles. We used partial least squares discrimi-nant analysis to define antigen-specific transplacental antibody transfer features.

RESULTS

Global antibody transfer patterns were similar by maternal HIV serostatus, pointing to effective placental function in WHIV. However, HEU umbilical cord antibody profiles were altered, driven by perturbed WHIV seroprofiles, with higher levels of herpesvirus antibodies (P < .01 for Epstein-Barr virus, herpes simplex virus) and lower levels of classic vaccine-induced antibodies (P < .01 for tetanus, polio, Haemophilus influenzae type b), suggesting that umbilical cord antibody profile differences arise from imbalanced WHIV immunity. Abnormal WHIV antibody profiles were associated with HIV viremia, lower CD4 count, and postconception ART initiation (P = .01).

CONCLUSIONS

Perturbed immune-dominance profiles in WHIV shift the balance of immunity delivered to neonates. Perturbed HIV-associated maternal antibody profiles are a key determinant of com-promised neonatal immunity. Maternal vaccination interventions may promote transfer of relevant, effective antibodies to protect HEU children against early-life infections.

HIV-Infektion und -Exposition bei Kindern und Jugendlichen

Hintergrund

Seit 1997 steht mit den antiretroviralen, kombinierbaren Wirkstoffen eine effektive Prävention und Behandlung einer Infektion mit dem „human immunodeficiency virus“ (HIV) zur Verfügung.

Fragestellung

Was wurde in dieser Zeit durch die Transmissionsprophylaxe und Behandlung der HIV-Infektion bei Kindern in Deutschland erreicht?

Material und Methoden

Darstellung der Entwicklung der Transmissionsprophylaxe und der epidemiologischen Erhebungen des Robert Koch-Instituts, Darstellung der Arzneimittelentwicklung und der Leitlinien zur antiretroviralen Therapie (ART) bei Kindern und Jugendlichen, Vorstellung von Erhebungen der deutschen Kinder-HIV-Kohorte („German pediatric and adolescent HIV cohort“, GEPIC).

Ergebnisse

Die Einführung der HIV-Testung Schwangerer hat die regelmäßige ART HIV-positiver Schwangerer und die Einführung von transmissionsmindernden Maßnahmen möglich gemacht. Damit konnte das Risiko der vertikalen Transmission von ca. 30 % auf < 1 % gesenkt werden. Gegenwärtig wird untersucht, ob HIV-exponierte Kinder ohne Risiko gestillt werden können. Die ART bei Kindern hat die Überlebensraten sowie die körperliche und die kognitive Entwicklung HIV-positiver Kinder entscheidend verbessert. Neue Wirkstoffe haben ein günstigeres Nebenwirkungsprofil. In Deutschland konnten die WHO-Ziele, bei 90 % der Kinder eine vollständige Suppression der Viruslast zu erzielen, erreicht werden. Späte Diagnosen sind bei Kindern und Jugendlichen weiterhin mit schweren Infektionen verbunden. Die HIV-Infektion ist weiterhin eine Erkrankung mit Stigma geblieben und wird deswegen meist gegenüber den Kindern und ihrer Umwelt geheim gehalten.

Schlussfolgerung

Mit der jetzt möglichen Transmissionsprophylaxe und Therapie gelingt es, Transmissionen weitgehend zu verhindern und HIV-positiven Kindern bei frühzeitiger Diagnose ein weitgehend gesundes Leben zu ermöglichen. Das Ziel, dass Kinder ihre Krankheit ohne Angst kennen und nennen können, ist nach wie vor nicht erreicht.

Evolution of the Gut Microbiome in HIV-Exposed Uninfected and Unexposed Infants during the First Year of Life

HIV-exposed uninfected infants (HEU) have abnormal immunologic functions and increased infectious morbidity in the first 6 months of life, which gradually decreases thereafter. The mechanisms underlying HEU immune dysfunctions are unknown. We hypothesized that unique characteristics of the HEU gut microbiota associated with maternal HIV status may underlie the HEU immunologic dysfunctions. We characterized the infant gut, maternal gut, and breast milk microbiomes of mother-infant pairs, including 123 with HEU and 117 with HIV-uninfected infants (HUU), from South Africa. Pan-bacterial 16S rRNA gene sequencing was performed on (i) infant stool at 6, 28, and 62 weeks; (ii) maternal stool at delivery and 62 weeks; and (iii) breast milk at 6 weeks. Infant gut alpha and beta diversities were similar between groups. Microbial composition significantly differed, including 12 genera, 5 families and 1 phylum at 6 weeks; 12 genera and 2 families at 28 weeks; and 2 genera and 2 families at 62 weeks of life. Maternal gut microbiomes significantly differed in beta diversity and microbial composition, and breast milk microbiomes differed in microbial composition only. Infant gut microbiotas extensively overlapped with maternal gut and minimally with breast milk microbiotas. Nevertheless, exclusively breastfed HEU and HUU had less divergent microbiomes than nonexclusively breastfed infants. Feeding pattern and maternal gut microbiome imprint the HEU gut microbiome. Compared to HUU, the HEU gut microbiome prominently differs in early infancy, including increased abundance of taxa previously observed to be present in excess in adults with HIV. The HEU and HUU gut microbiome compositions converge over time, mirroring the kinetics of HEU infectious morbidity risk.

Standardized Definitions of In Utero Human Immunodeficiency Virus and Antiretroviral Drug Exposure Among Children

In countries with high human immunodeficiency virus (HIV) prevalence, up to 30% of pregnant women are living with HIV, with fetal exposure to both HIV and antiretroviral therapy during pregnancy. In addition, pregnant women without HIV but at high risk of HIV acquisition are increasingly receiving HIV preexposure antiretroviral prophylaxis (PrEP). Investments are being made to establish and follow cohorts of children to evaluate the long-term effects of in utero HIV and antiretroviral exposure. Agreement on a key set of definitions for relevant exposures and outcomes is important both for interpreting individual study results and for comparisons across cohorts. Harmonized definitions of in utero HIV and antiretroviral drug (maternal treatment or PrEP) exposure will also facilitate improved classification of these exposures in future observational studies and clinical trials. The proposed definitions offer a uniform approach to facilitate the consistent description and estimation of effects of HIV and antiretroviral exposures on key child health outcomes.

Impaired functionality of antigen presenting cells in HIV- exposed uninfected infants in the first six months of life

HIV-exposed uninfected infants (HEU) have increased morbidity and mortality due to infections in the first 6 months of life that tapers down to 2 years of life. The underlying immunologic defects remain undefined. We investigated antigen-presenting cells (APC) by comparing the phenotype of unstimulated APC, responses to toll-like receptor (TLR) stimulation, and ability to activate natural killer (NK) cells in 24 HEU and 64 HIV-unexposed infants (HUU) at 1-2 days of life (birth) and 28 HEU and 45 HUU at 6 months of life. At birth, unstimulated APC showed higher levels of activation and cytokine production in HEU than HUU and stimulation with TLR agonists revealed lower expression of inflammatory cytokines and activation markers, but similar expression of IL10 regulatory cytokine, in APC from HEU compared to HUU. Differences were still present at 6 months of life. From birth to 6 months, APC underwent extensive phenotypic and functional changes in HUU and minimal changes in HEU. TLR stimulation also generated lower NK cell expression of CD69 and/or IFNγ in HEU compared with HUU at birth and 6 months. In vitro experiments showed that NK IFNγ expression depended on APC cytokine secretion in response to TLR stimulation. Ex vivo IL10 supplementation decreased APC-mediated NK cell activation measured by IFNγ expression. We conclude that APC maturation was stunted or delayed in the first 6 months of life in HEU compared with HUU. Deficient inflammatory APC responses and/or the imbalance between inflammatory and regulatory responses in HEU may play an important role in their increased susceptibility to severe infections.

Higher Hospitalization Rates in Children Born HIV-exposed Uninfected in British Columbia, Canada, Between 1990 and 2012

BACKGROUND

Compared with children who are HIV-unexposed and uninfected (CHUU), children who are HIV-exposed and uninfected (CHEU) experience more clinical complications. We investigated hospitalizations among CHEU by antenatal antiretroviral therapy (ART) exposure, in British Columbia, Canada.

METHODS

This retrospective controlled cohort study used administrative health data from 1990 to 2012. CHEU and CHUU were matched 1:3 for age, sex and maternal geographical area of residence. We determined adjusted odds ratios (aORs) via conditional logistic regression, adjusting for maternal risk factors.

RESULTS

A total of 446 CHEU and 1333 CHUU were included. Compared with CHUU, more CHEU experienced one or more lifetime hospitalization (47.3% vs. 29.8%), one or more neonatal hospitalization (40.4% vs. 27.6%), and any intensive care unit admission (28.5% vs. 9.2%). In adjusted analyses, CHEU experienced higher odds of any lifetime hospitalization (aOR 2.30, 95% confidence interval 1.81-2.91) and neonatal hospitalization (aOR 2.14, 95% confidence interval 1.68-2.73), compared with CHUU. There was, however, no difference in infection-related hospitalizations (9.0% vs. 7.5%), which were primarily respiratory tract infections among both CHEU and CHUU. CHEU whose mothers-initiated ART preconception showed lower odds of infection-related hospitalizations than children whose mothers initiated ART during pregnancy or received no ART.

CONCLUSIONS

CHEU experienced increased odds of hospitalization relative to CHUU. A substantial number of CHEU hospitalizations occurred within the neonatal period and were ICU admissions. Initiating ART preconception may reduce the risk of infection-related hospitalizations. These findings reinforce the benefit of ART in pregnancy and the need for ongoing pediatric care to reduce hospitalizations.

Increased infectious-cause hospitalization among infants who are HIV-exposed uninfected compared with HIV-unexposed

OBJECTIVES

Increased risk of morbidity and hospitalization has been observed in children who are HIV-exposed uninfected (HEU) compared with HIV-unexposed uninfected (HUU). Studies in the era of universal maternal antiretroviral treatment (ART) are limited.

DESIGN

Prospective cohort.

METHODS

We investigated hospitalization between 29 days and 12 months of life in a South African cohort of infants born between February 2017 and January 2019 (HEU = 455; HUU = 458). All mothers known with HIV during pregnancy received ART. We reviewed hospital records and classified and graded infectious diagnoses using a standardized tool. We examined factors associated with infectious-cause hospitalization using mixed-effects Poisson regression.

RESULTS

Infants HEU vs. HUU had higher all-cause and infectious-cause hospitalization (13 vs. 7%, P = 0.004 and 10 vs. 6%, P = 0.014, respectively). Infectious causes accounted for most hospitalizations (77%). More infants HEU were hospitalized with severe or very severe infections than those HUU (9 vs. 6%; P = 0.031). Mortality (<1%) did not differ between groups. HIV exposure was a significant risk factor for infectious-cause hospitalization [adjusted incidence rate ratios (aIRRs) = 2.8; 95% confidence interval (CI) 1.5-5.4]. Although increased incidence of preterm birth (14 vs. 10%; P < 0.05) and shorter duration of breastfeeding (44 vs. 68% breastfed for ≥3 months, P < 0.001) among infants HEU vs. HUU contributed to increased hospitalization, they did not account for all the increased risk.

CONCLUSION

Infectious-cause hospitalization incidence was higher among infants HEU vs. HUU, likely partly because of higher incidence of preterm birth and lower breastfeeding rates among infants HEU. The increased infectious disease burden in HEU infants has important implications for health services in sub-Saharan Africa.

Immunologic and Virologic Factors Associated With Hospitalization in Human Immunodeficiency Virus-Exposed, Uninfected Infants in the United States

BACKGROUND

Human immunodeficiency virus (HIV)-exposed, uninfected (HEU) infants experience higher rates of morbidity and mortality than HIV-unexposed, uninfected (HUU) infants. Few studies have examined whether particular infections and/or immune responses are associated with hospitalization among HEU infants born in the United States.

METHODS

We evaluated a subset of HEU infants enrolled in the International Maternal Pediatric Adolescent AIDS Clinical Trials Group P1025 and/or Pediatric HIV/AIDS Cohort Study Surveillance Monitoring for ART Toxicities studies. We determined seroconversion to 6 respiratory viruses and measured antibody concentrations to 9 vaccine antigens using quantitative ELISA or electrochemiluminescence. Multivariable modified Poisson regression models were fit to evaluate associations of seroconversion to each respiratory virus/family and antibody concentrations to vaccine antigens with risk of hospitalization in the first year of life. Antibody concentrations to vaccine antigens were compared between HEU infants and HUU infants from a single site using multivariable linear regression models.

RESULTS

Among 556 HEU infants, seroconversion to respiratory syncytial virus (RSV) and parainfluenza was associated with hospitalization (adjusted risk ratio, 1.95 [95% CI, 1.21-3.15] and 2.30 [1.42-3.73], respectively). Antibody concentrations to tetanus toxoid, pertussis, and pneumococcal vaccine antigens were higher among 525 HEU compared with 100 HUU infants. No associations were observed between antibody concentrations with any vaccine and hospitalization among HEU infants.

CONCLUSIONS

RSV and parainfluenza contribute to hospitalization among HEU infants in the first year of life. HEU infants demonstrate robust antibody responses to vaccine antigens; therefore, humoral immune defects likely do not explain the increased susceptibility to infection observed in this population.

Preterm birth and severe morbidity in hospitalized neonates who are HIV exposed and uninfected compared with HIV unexposed

OBJECTIVES

Infants who are HIV exposed but uninfected (HEU) compared with HIV unexposed uninfected (HUU) have an increased risk of adverse birth outcomes, morbidity and hospitalization. In the era of universal maternal antiretroviral treatment, there are few insights into patterns of neonatal morbidity specifically.

DESIGN

A prospective cohort study.

METHODS

We compared neonatal hospitalizations among infants who were HEU (n = 463) vs. HUU (n = 466) born between 2017 and 2019 to a cohort of pregnant women from a large antenatal clinic in South Africa. We examined maternal and infant factors associated with hospitalization using logistic regression.

RESULTS

Hospitalization rates were similar between neonates who were HEU and HUU (13 vs. 16%; P = 0.25). Overall, most hospitalizations occurred directly after birth (87%); infection-related causes were identified in 34%. The most common reason for hospitalization unrelated to infection was respiratory distress (25%). Very preterm birth (<32 weeks) (29 vs. 11%; P = 0.01) as well as very low birthweight (<1500 g) (34 vs. 16%; P = 0.02) occurred more frequently among hospitalized neonates who were HEU. Of those hospitalized, risk of intensive care unit (ICU) admission was higher in neonates who were HEU (53%) than HUU (27%) [risk ratio = 2.1; 95% confidence interval (95% CI) 1.3-3.3]. Adjusted for very preterm birth, the risk of ICU admission remained higher among neonates who were HEU (aRR = 1.8; 95% CI 1.1-2.9).

CONCLUSION

Neonates who were HEU (vs. HUU) did not have increased all-cause or infection-related hospitalization. However, very preterm birth, very low birthweight and ICU admission were more likely in hospitalized neonates who were HEU, indicating increased severity of neonatal morbidity.