Treatment Failures and Excess Mortality Among HIV-Exposed, Uninfected Children With Pneumonia

Maternal breastfeeding and education impact infant growth and development more than in-utero HIV/antiretroviral therapy exposure in context of universal antiretroviral therapy

BACKGROUND

Exposure to HIV and antiretroviral therapy (ART) in utero may influence infant growth and development. Most available evidence predates adoption of universal ART (Option B+ ART regimens). In a recent cohort, we compared growth and development in HIV-exposed uninfected (HEU) to HIV-unexposed (HUU) infants.

DESIGN

Prospective cohort study: data from Impact of Maternal HIV on Mycobacterium Tuberculosis Infection among Peripartum Women and their Infants (MiTIPS) in Western Kenya.

METHODS

Women were enrolled during pregnancy. Mother-infant pairs were followed until 24 months postpartum. We used multivariable linear mixed-effects models to compare growth rates [weight-for-age z score (WAZ) and height-for-age z score (HAZ)] and multivariable linear regression to compare overall development between HEU and HUU children.

RESULTS

About 51.8% (184/355) of the infants were HEU, 3.9% low birthweight (<2.5 kg), and 8.5% preterm (<37 gestational weeks). During pregnancy, all mothers of HEU received ART; 67.9% started ART prepregnancy, and 87.3% received 3TC/FTC, TDF, and EFV. In longitudinal analyses, HEU children did not differ significantly from HUU in growth or development ( P  > 0.05 for all). In the combined HEU/HUU cohort, higher maternal education was associated with significantly better growth and development: WAZ [ β  = 0.18 (95% CI 0.01-0.34)], HAZ [ β  = 0.26 (95% CI 0.04-0.48)], and development [ β  = 0.24 (95% CI 0.02-0.46)]. Breastfeeding was associated with significantly better HAZ [ β =0.42 (95% CI 0.19-0.66)] and development [ β  =0.31 (95% CI 0.08-0.53)].

CONCLUSION

HEU children in the setting of universal maternal ART had a similar growth trajectory and development to HUU children. Breastfeeding and maternal education improved children's weight, height, and overall development irrespective of maternal HIV status.

What are the risk factors for death among children with pneumonia in low- and middle-income countries? A systematic review

Background

Knowledge of the risk factors for and causes of treatment failure and mortality in childhood pneumonia is important for prevention, diagnosis, and treatment at an individual and population level. This review aimed to identify the most important risk factors for mortality among children aged under ten years with pneumonia.

Methods

We systematically searched MEDLINE, EMBASE, and PubMed for observational and interventional studies reporting risk factors for mortality in children (aged two months to nine years) in low- and middle-income countries (LMICs). We screened articles according to specified inclusion and exclusion criteria, assessed risk of bias using the EPHPP framework, and extracted data on demographic, clinical, and laboratory risk factors for death. We synthesized data descriptively and using Forest plots and did not attempt meta-analysis due to the heterogeneity in study design, definitions, and populations.

Findings

We included 143 studies in this review. Hypoxaemia (low blood oxygen level), decreased conscious state, severe acute malnutrition, and the presence of an underlying chronic condition were the risk factors most strongly and consistently associated with increased mortality in children with pneumonia. Additional important clinical factors that were associated with mortality in the majority of studies included particular clinical signs (cyanosis, pallor, tachypnoea, chest indrawing, convulsions, diarrhoea), chronic comorbidities (anaemia, HIV infection, congenital heart disease, heart failure), as well as other non-severe forms of malnutrition. Important demographic factors associated with mortality in the majority of studies included age <12 months and inadequate immunisation. Important laboratory and investigation findings associated with mortality in the majority of studies included: confirmed Pneumocystis jirovecii pneumonia (PJP), consolidation on chest x-ray, pleural effusion on chest x-ray, and leukopenia. Several other demographic, clinical and laboratory findings were associated with mortality less consistently or in a small numbers of studies.

Conclusions

Risk assessment for children with pneumonia should include routine evaluation for hypoxaemia (pulse oximetry), decreased conscious state (e.g. AVPU), malnutrition (severe, moderate, and stunting), and the presence of an underlying chronic condition as these are strongly and consistently associated with increased mortality. Other potentially useful risk factors include the presence of pallor or anaemia, chest indrawing, young age (<12 months), inadequate immunisation, and leukopenia.

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.

HIV exposure and its association with paediatric ICU outcomes in children admitted with severe pneumonia at Chris Hani Baragwanath Academic Hospital, South Africa

Background. Pneumonia is one of the leading causes of under-5 death in South Africa and accounts for a substantial burden of paediatric intensive care unit (PICU) admissions. However, little is known about PICU outcomes in HIV-exposed uninfected (HIV-EU) children with pneumonia, despite the growing size of this vulnerable population.Objectives. To determine whether HIV exposure without infection is an independent risk factor for mortality and morbidity in childrenadmitted to PICU with pneumonia.Methods. This retrospective review included all patients with pneumonia admitted to the PICU at Chris Hani Baragwanath AcademicHospital between 1 January 2013 and 31 December 2014. Patients were classified as HIV-unexposed (HIV-U), HIV-EU and HIV-infected.Medical records were reviewed to determine survival to PICU discharge, duration of PICU admission and duration of mechanicalventilation. Survival analysis was used to determine the association between HIV infection/exposure with mortality, and linear regression was used to examine the association with length of stay and duration of mechanical ventilation. This study included 107 patients: 54 were HIV-U; 28 were HIV-EU; 23 HIV-positive; and 2 had an unknown HIV status.Results. Overall, 84% (n=90) survived to PICU discharge, with no difference in survival based on HIV infection or exposure. Both HIV-EUand HIV-U children had significantly shorter PICU admissions and fewer days of mechanical ventilation compared with HIV-infectedchildren (p=0.011 and p=0.004, respectively).Conclusion. HIV-EU children behaved similarly to HIV-U children in terms of mortality, duration of PICU admission and length ofmechanical ventilation. HIV infection was associated with prolonged length of mechanical ventilation and ICU stay but not increasedmortality

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.

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.

Prevalence of hypoxaemia in children with pneumonia in low-income and middle-income countries: a systematic review and meta-analysis

BACKGROUND

Pneumonia accounts for around 15% of all deaths of children younger than 5 years globally. Most happen in resource-constrained settings and are potentially preventable. Hypoxaemia is one of the strongest predictors of these deaths. We present an updated estimate of hypoxaemia prevalence among children with pneumonia in low-income and middle-income countries.

METHODS

We conducted a systematic review using the following key concepts "children under five years of age" AND "pneumonia" AND "hypoxaemia" AND "low- and middle-income countries" by searching in 11 bibliographic databases and citation indices. We included all articles published between Nov 1, 2008, and Oct 8, 2021, based on observational studies and control arms of randomised and non-randomised controlled trials. We excluded protocol papers, articles reporting hypoxaemia prevalence based on less than 100 pneumonia cases, and articles published before 2008 from the review. Quality appraisal was done with the Joanna Briggs Institute tools. We reported pooled prevalence of hypoxaemia (SpO2 <90%) by classification of clinical severity and by clinical settings by use of the random-effects meta-analysis models. We combined our estimate of the pooled prevalence of pneumonia with a previously published estimate of the number of children admitted to hospital due to pneumonia annually to calculate the total annual number of children admitted to hospital with hypoxaemic pneumonia.

FINDINGS

We identified 2825 unique records from the databases, of which 57 studies met the eligibility criteria: 26 from Africa, 23 from Asia, five from South America, and four from multiple continents. The prevalence of hypoxaemia was 31% (95% CI 26-36; 101 775 children) among all children with WHO-classified pneumonia, 41% (33-49; 30 483 children) among those with very severe or severe pneumonia, and 8% (3-16; 2395 children) among those with non-severe pneumonia. The prevalence was much higher in studies conducted in emergency and inpatient settings than in studies conducted in outpatient settings. In 2019, we estimated that over 7 million children (95% CI 5-8 million) were admitted to hospital with hypoxaemic pneumonia. The studies included in this systematic review had high τ2 (ie, 0·17), indicating a high level of heterogeneity between studies, and a high I2 value (ie, 99·6%), indicating that the heterogeneity was not due to chance. This study is registered with PROSPERO, CRD42019126207.

INTERPRETATION

The high prevalence of hypoxaemia among children with severe pneumonia, particularly among children who have been admitted to hospital, emphasises the importance of overall oxygen security within the health systems of low-income and middle-income countries, particularly in the context of the COVID-19 pandemic. Even among children with non-severe pneumonia that is managed in outpatient and community settings, the high prevalence emphasises the importance of rapid identification of hypoxaemia at the first point of contact and referral for appropriate oxygen therapy.

FUNDING

UK National Institute for Health Research (Global Health Research Unit on Respiratory Health [RESPIRE]; 16/136/109).

The effects of exposure to HIV in neonates at a referral hospital in South Africa

Background

Fewer infants are infected with HIV through mother-to-child transmission, making HIV-exposed but uninfected (HEU) infants a growing population. HIV-exposure seems to affect immunology, early growth and development, and is associated with higher morbidity and mortality rates. Currently, there is a lack of information regarding the clinical effects of HIV-exposure during the neonatal period.

Objectives

To identify a possible difference in mortality and common neonatal morbidities in HEU neonates compared to HIV-unexposed neonates.

Methods

This was a retrospective, descriptive study of all neonates admitted to the neonatal unit at Charlotte Maxeke Johannesburg Academic Hospital between 1 January 2017 and 31 December 2018. HEU neonates were compared to HIV-unexposed neonates.

Results

There were 3236 neonates included, where 855 neonates were HEU. The HEU neonates had significantly lower birth weight and gestational age. The HEU neonates had higher rates of neonatal sepsis (19.8% vs 14.2%, OR 1.49, p <  0.001), specifically for late onset sepsis, and required more respiratory support. NCPAP and invasive ventilation was more common in the HEU group (36.3% vs 31.3% required NCPAP, p = 0.008, and 20.1% vs 15,0% required invasive ventilation, p <  0.001). Chronic lung disease was more common among HIV-exposed neonates (12.2% vs 8.7%, OR 1.46, p = 0.003). The difference in mortality rates between the study groups was not significant (10.8% of HEU neonates and 13.3% of HIV-unexposed).

Conclusions

HEU neonates had higher rates of neonatal sepsis, particularly late-onset sepsis, required more respiratory support and had higher rates of chronic lung disease. Mortality of HEU neonates was not different HIV-unexposed neonates.

Epidemiology of Human Metapneumovirus-associated Lower Respiratory Tract Infections in African Children: Systematic Review and Meta-analysis

BACKGROUND

Human metapneumovirus (hMPV) has been associated with upper and lower respiratory tract infections (LRTI) in children and adults. This systematic review evaluated the epidemiology of hMPV-associated LRTI, including severe acute respiratory infection (SARI) hospitalization or clinically diagnosed severe pneumonia, in African children under 5 years of age.

METHODS

We searched Science Direct, PubMed, Cochrane Central, Scopus, and WHO regional databases using the terms "("Human metapneumovirus" AND "Africa") OR ("hMPV" AND "Africa")" up to September 17, 2020. Other sources included ClinicalTrials.gov to obtain unpublished data. Studies were included if children were less than 5 years of age and hospitalized with hMPV-associated LRTI, SARI or if clinically diagnosed with severe pneumonia in the community. The main outcomes were prevalence of hMPV identified among children with hospitalized LRTI or SARI. We further calculated odds ratios for hMPV in cases with LRTI compared with non-LRTI controls. Pooled results were calculated using a random-effects model.

RESULTS

Thirty studies were eligible for inclusion in the review. The prevalence of hMPV-LRTI/SARI among hospitalized and severe pneumonia cases was 4.7% [95% confidence interval (CI): 3.9-5.6, I2 = 95.0]. The case-control studies indicated that hMPV was 2.0-fold (95% CI: 0.9-4.4) more likely to be identified in LRTI cases (10.3%) than controls (6.0%). Three of 5 studies reported hMPV-associated LRTI case fatality risk, with a pooled estimate of 1.3% (95% CI: 0.3-2.9; I2 = 49).

CONCLUSIONS

hMPV was associated with approximately 5% of LRTI/SARI hospitalizations or severe pneumonia cases in Africa.

A Tale of 2 Pneumos: The Impact of Human Immunodeficiency Virus Exposure or Infection Status on Pediatric Nasopharyngeal Carriage of Streptococcus pneumoniae and Pneumocystis jiroveci: A Nested Case Control Analysis From the Pneumonia Etiology Research In Child Health Study

BACKGROUND

The majority of pediatric human immunodeficiency virus (HIV) cases in Africa reflect maternal-to-child transmission. HIV exposed but uninfected (HEU) children have increased rates of morbidity and mortality when compared to HIV unexposed and uninfected (HUU) children. The mechanisms behind these unexpected trends are only partially understood but could be explained by the differences in the immune response to infections triggered by an altered immune system state.

METHODS

Using quantitative reverse transcription polymerase chain reaction, we compared the nasopharyngeal carriage prevalence and density of Streptococcus pneumoniae (SP) and Pneumocystis jirovecii (PJ) between children living with HIV and HEU or HUU cases (pneumonia) and controls (without pneumonia).

RESULTS

The cohort included 1154 children (555 cases and 599 matched controls). The SP carriage prevalence rates were similar between cases and controls. Among SP carriers with pneumonia, carriage density was increased among children living with HIV, versus HEU or HUU children (15.8, 4.7, and 3.6 × 105 copies/mL, respectively). The rate of PJ carriage was significantly higher among children living with HIV than among HEU and HUU children (31%, 15%, and 10%, respectively; P < .05), as was carriage density (63.9, 20.9, and 4.8 × 103 copies/mL, respectively; P < .05).

CONCLUSIONS

Carriage prevalences and densities for SP and PJ show different kinetics in terms of their relationship with HIV exposure and clinical status, particularly for Pneumocystis jirovecii. This supports the theory that the increased morbidity and mortality observed among HEU children may reflect deficits not just in humoral immunity but in cell-mediated immunity as well.

Umbilical cord interleukin-6 predicts outcome in very low birthweight infants in a high HIV-burden setting: a prospective cohort study

OBJECTIVES

South Africa has a double burden of high neonatal mortality and maternal HIV prevalence. Common to both is a proinflammatory in utero and perinatal milieu. The aim of this study was to determine cytokine profiles in HIV exposed (HE) and HIV unexposed (HU) very low birthweight (VLBW) infants and to determine whether these were associated with predischarge outcomes.

DESIGN

Single-centre, prospective cohort study conducted from 1 June 2017 to 31 January 2019.

PATIENTS

Inborn infants with birth weight of <1500 g were enrolled and cord blood was collected for interleukin (IL)-6 and tumour necrosis factor alpha (TNF-α) assays. Participants provided informed consent and ethics approval was obtained.

OUTCOME MEASURES

The primary outcome was umbilical cord cytokine levels according to maternal HIV status. Secondary outcomes included death and/or serious neonatal infection, necrotising enterocolitis, intraventricular haemorrhage, periventricular leucomalacia, chronic lung disease and haemodynamically significant patent ductus arteriosus before discharge.

RESULTS

A total of 279 cases were included with 269 cytokine assays performed on 122 HEs and 147 HUs. Median IL-6 levels were 53.0 pg/mL in HEs and 21.0 pg/mL in HUs (p=0.07). Median TNF-α levels were 7.2 pg/mL in HEs and 6.5 pg/mL in HUs (p=0.6). There was significantly more late-onset sepsis in the HE group compared with the HU group (41.2% vs 27.9%) (p=0.03). IL-6 levels were significantly higher for those with any adverse outcome (p=0.006) and death and/or any adverse outcome (p=0.0001). TNF-α levels did not differ according to predischarge outcomes.

CONCLUSION

There is no significant difference in IL-6 and TNF-α levels in cord blood of HE compared with HU VLBWs. However, IL-6 levels are significantly higher in VLBWs with adverse predischarge outcomes, and VLBW HEs are at increased risk of adverse predischarge outcomes compared with HUs, particularly late-onset sepsis.

Contemporary Issues in Pregnancy (and Offspring) in the Current HIV Era

PURPOSE OF REVIEW

Although antiretroviral therapy (ART) has dramatically reduced mother to child transmission of HIV, data continue to mount that infants exposed to HIV in utero but are not infected (HEU) have serious negative health consequences compared to unexposed infants. This review evaluates recent literature on contemporary issues related to complications seen in pregnant women with HIV and their offspring.

RECENT FINDINGS

Current studies show that HEU infants are at a high risk of adverse outcomes, including premature birth, poor growth, neurodevelopmental impairment, immune dysfunction, infectious morbidity, and death. Etiologies for the observed clinical events and subclinical alterations are complex and multifactorial, and the long-term consequences of many findings are yet unknown. HEU infants have an unacceptable rate of morbidity and mortality from perinatal HIV and ART exposure, even in the modern ART era. Continual monitoring and reporting is imperative to protect this vulnerable population in our everchanging landscape of HIV treatment and prevention.

Peripheral blood mononuclear cell transcriptomes reveal an over-representation of down-regulated genes associated with immunity in HIV-exposed uninfected infants

HIV-exposed uninfected (HEU) infants are disproportionately at a higher risk of morbidity and mortality, as compared to HIV-unexposed uninfected (HUU) infants. Here, we used transcriptional profiling of peripheral blood mononuclear cells to determine immunological signatures of in utero HIV exposure. We identified 262 differentially expressed genes (DEGs) in HEU compared to HUU infants. Weighted gene co-expression network analysis (WGCNA) identified six modules that had significant associations with clinical traits. Functional enrichment analysis on both DEGs and the six significantly associated modules revealed an enrichment of G-protein coupled receptors and the immune system, specifically affecting neutrophil function and antibacterial responses. Additionally, malaria pathogenicity genes (thrombospondin 1-(THBS 1), interleukin 6 (IL6), and arginine decarboxylase 2 (ADC2)) were down-regulated. Of interest, the down-regulated immunity genes were positively correlated to the expression of epigenetic factors of the histone family and high-mobility group protein B2 (HMGB2), suggesting their role in the dysregulation of the HEU transcriptional landscape. Overall, we show that genes primarily associated with neutrophil mediated immunity were repressed in the HEU infants. Our results suggest that this could be a contributing factor to the increased susceptibility to bacterial infections associated with higher morbidity and mortality commonly reported in HEU infants.

Childhood pneumonia in low-and-middle-income countries: An update

OBJECTIVES

To review epidemiology, aetiology and management of childhood pneumonia in low-and-middle-income countries.

DESIGN

Review of published English literature between 2013 and 2019.

RESULTS

Pneumonia remains a major cause of morbidity and mortality. Risk factors include young age, malnutrition, immunosuppression, tobacco smoke or air pollution exposure. Better methods for specimen collection and molecular diagnostics have improved microbiological diagnosis, indicating that pneumonia results from several organisms interacting. Induced sputum increases microbiologic yield for Bordetella pertussis or Mycobacterium tuberculosis, which has been associated with pneumonia in high TB prevalence areas. The proportion of cases due to Streptococcus pneumoniae and Haemophilus influenzae b has declined with new conjugate vaccines; Staphylococcus aureus and H. influenzae non-type b are the commonest bacterial pathogens; viruses are the most common pathogens. Effective interventions comprise antibiotics, oxygen and non-invasive ventilation. New vaccines have reduced severity and incidence of disease, but disparities exist in uptake.

CONCLUSION

Morbidity and mortality from childhood pneumonia has decreased but a considerable preventable burden remains. Widespread implementation of available, effective interventions and development of novel strategies are needed.

Case fatality rate and viral aetiologies of acute respiratory tract infections in HIV positive and negative people in Africa: The VARIAFRICA-HIV systematic review and meta-analysis

BACKGROUND

To set priorities for efficient control of acute respiratory tract infection (ARTI) in Africa, it is necessary to have accurate estimate of its burden, especially among HIV-infected populations.

OBJECTIVES

To compare case fatality rate (CFR) and viral aetiologies of ARTI between HIV-positive and HIV-negative populations in Africa.

STUDY DESIGN

We searched PubMed, EMBASE, Web of Knowledge, Africa Journal Online, and Global Index Medicus to identify studies published from January 2000 to April 2018. Random-effect meta-analysis method was used to assess association (pooled weighted odds ratios (OR) with 95% confidence interval (CI)).

RESULTS

A total of 36 studies (126,526 participants) were included. CFR was significantly higher in patients with HIV than in HIV-negative controls (OR 4.10, 95%CI: 2.63-6.27, I²: 93.7%). The risk was significantly higher among children ≤5 years (OR 5.51, 95%CI 2.83-10.74) compared to people aged >5 years (OR 1.48, 95%CI 1.17-1.89); p = 0.0002. There was no difference between children (15 years) and adults and between regions of Africa. There was no difference for viral respiratory aetiologies (Enterovirus, Adenovirus, Bocavirus, Coronavirus, Metapneumovirus, Parainfluenza, Influenza, and Respiratory Syncytial Virus) of ARTI between HIV-positive and HIV-negative people, except for Rhinovirus where being HIV-negative was associated with Rhinovirus (OR 0.70; 95%CI 0.51-0.97, I²: 63.4%).

CONCLUSIONS

This study shows an increased risk of deaths among HIV-infected individuals with ARTI, however with no difference in viral aetiologies compared to HIV-negative individuals in Africa. ARTI deserves more attention from HIV health-care providers for efficient control. Specific strategies are needed for HIV-positive children under 5.

Predictors of Poor Outcomes Among Infants With Respiratory Syncytial Virus-associated Acute Lower Respiratory Infection in Botswana

Among children 1-23 months of age with respiratory syncytial virus-associated acute lower respiratory infection in Botswana, young age (<6 months), household use of wood as a cooking fuel, moderate or severe malnutrition and oxygen saturation <90% on room air were independent predictors of clinical nonresponse at 48 hours. Among HIV-uninfected infants less than six months of age, HIV exposure was associated with a higher risk of in-hospital mortality.

Lower Respiratory Tract Infections in Children in a Well-vaccinated South African Birth Cohort: Spectrum of Disease and Risk Factors

Background

Childhood lower respiratory tract infections (LRTIs) cause substantial morbidity and under-5 child mortality. The epidemiology of LRTI is changing in low- and middle-income countries with expanding access to conjugate vaccines, yet there are few data on the incidence and risk factors for LRTI in these settings.

Methods

A prospective birth cohort enrolled mother–infant pairs in 2 communities near Cape Town, South Africa. Active surveillance for LRTI was performed for the first 2 years of life over 4 respiratory seasons. Comprehensive data collection of risk factors was done through 2 years of life. World Health Organization definitions were used to classify clinical LRTI and chest radiographs.

Results

From March 2012 to February 2017, 1143 children were enrolled and followed until 2 years of age. Thirty-two percent of children were exposed to antenatal maternal smoking; 15% were born at low birth weights. Seven hundred ninety-five LRTI events occurred in 429 children by February 2017; incidence of LRTI was 0.51 and 0.25 episodes per child-year in the first and second years of life, respectively. Human immunodeficiency virus (HIV)–exposed, uninfected infants (vs HIV-unexposed infants) were at increased risk of hospitalized LRTI in the first 6 months of life. In regression models, male sex, low birth weight, and maternal smoking were independent risk factors for both ambulatory and hospitalized LRTI; delayed or incomplete vaccination was associated with hospitalized LRTI.

Conclusions

LRTI incidence was high in the first year of life, with substantial morbidity. Strategies to ameliorate harmful exposures are needed to reduce LRTI burden in vulnerable populations.

HIV-Exposed Uninfected Infants Have Increased Regulatory T Cells That Correlate With Decreased T Cell Function

Background: HIV-exposed uninfected infants (HEU) are at higher risk of severe infections, hospitalizations and death compared with HIV-unexposed uninfected infants (HUU), but the immune deficit underlying it is not known. To address this gap, we investigated T cell functionality and its relationship to phenotypic profiles of T cells and antigen presenting cells (APC) in HEU and HUU.

Methods: Blood mononuclear cells from 55 HEU and 16 HUU were stimulated with Staphylococcal Enterotoxin B (SEB) or mock for 72 h, and tested by flow cytometry for proliferation and expression of Th1, Th2, and regulatory (Treg) markers. In parallel, cells were phenotypically assessed for differentiation profiles of Treg, conventional T cell (Tconv) and APC in unstimulated cells.

Results: HEU had lower CD4+ functional responses to SEB/mock and similar CD8+ responses compared with HUU. In the phenotypic T cell panel, HEU showed higher proportions of CD4+ and CD8+ Treg expressing IL10, FOXP3, and CD25; higher effector Tconv and Treg; and lower naïve and CD4+TGFβ+ Treg compared with HUU. In the phenotypic APC panel, HEU showed higher proportions of CD1c+ cDC2, CD123+ pDC, CD16+ inflammatory monocytes and cDC and higher expression of CD103 on CD1c-CD123-CD16-cDC1 compared with HUU. Regression analyses adjusted for HIV exposure and multiple comparisons showed that higher CD8+IL10+ and CD8+FOXP3+ Treg in unstimulated cells were associated with lower CD8+ T cell functional responses to SEB/mock. Functionality was not affected by Tconv differentiation, but higher APC activation in aggregate was associated with higher CD8+IL10+ Treg responses to SEB.

Conclusions: T cell functionality was decreased in HEU compared with HUU. High CD8+ Treg proportions were the most important predictors of decreased T cell functionality in HEU and HUU.

Infectious Morbidity, Mortality and Nutrition in HIV-exposed, Uninfected, Formula-fed Infants: Results From the HPTN 040/PACTG 1043 Trial

BACKGROUND

HIV-exposed uninfected (HEU) infants are a growing population with potentially poor health outcomes. We evaluated morbidity and mortality in HEU formula-fed infants enrolled in the NICHD HPTN 040/PACTG 1043 trial.

METHODS

Infectious morbidity, mortality and undernutrition were evaluated within a cohort of 1000 HEU infants enrolled between April 2004 and April 2010 in Brazil (n = 766) and South Africa (n = 234) as part of the NICHD/HPTN 040 trial of 3 different antiretroviral regimens to decrease intrapartum HIV vertical transmission.

RESULTS

Twenty-three percent of infants had at least 1 infectious serious adverse effect. Infants born to mothers with <12 years of education [adjusted odds ratio (AOR), 2.6; 95% confidence interval [CI], 1.2-5.9), with maternal viral load of >1,000,000 copies/mL at delivery (AOR, 9.9; 95% CI, 1.6-63.1) were more likely to have infectious serious adverse effects. At 6 months, the infant mortality rate per 1000 live births overall was 22 ± 2.6, 9.1 ± 1.8 in Brazil and 64.1 ± 3 in South Africa. Undernutrition and stunting peaked at 1 month of age with 18% having a weight-for-age Z score ≤-2, and 22% with height for Z score ≤-2. The likelihood of infant mortality was greater among infants born in South Africa compared with Brazil (AOR, 6.2; 95% CI, 2.5-15.8), high maternal viral load (AOR, 1.7; 95% CI, 1.01-2.9) and birth weight-for-age Z score ≤-2 (AOR, 5.2; 95% CI, 1.8-14.8).

CONCLUSIONS

There were high rates of undernutrition, stunting and infectious serious adverse effect in this study's formula-fed HEU population. Suppressing maternal HIV viral load during the peripartum period may be a modifiable risk factor to decrease infant mortality.

Factors Associated with Lower Respiratory Tract Infections in HIV-Exposed Uninfected Infants

To identify factors that predispose human immunodeficiency virus (HIV)-exposed uninfected infants (HEUs) to higher incidence of severe infections, hospitalization, and death in the first 6-24 months of life compared with HEUs with and without lower respiratory tract infection (LRTI) in the first 6 months of life. Nested case-control study of 107 LRTI+ infants enrolled in the International Site Development Initiative (NISDI) Perinatal and Longitudinal Study in Latin American Countries (LILAC) studies with and 140 LRTI- in the first 6 months, matched by date and place of birth. Infants and mothers had plasma antibodies measured against respiratory syncytial virus (RSV), parainfluenza (PIV) 1, 2, 3, influenza, and pneumococcus 1, 5, 6B, and 14. Compared with LRTI-, mothers of LRTI+ HEUs had lower years of education, lower CD4⁺ cells, and higher HIV plasma viral load at delivery, but similar use of antiretrovirals and cotrimoxazole and other sociodemographic characteristics. LRTI+ and LRTI- HEUs had similar demographic and hematological characteristics and antibody concentrations against respiratory pathogens at birth. At 6 months, the rates of seroconversions to respiratory pathogens and antibody responses to tetanus vaccine were also similar. However, antibody concentrations to RSV were significantly higher in LRTI+ compared with LRTI- HEUs and marginally higher to PIV1. Maternal factors associated with advanced HIV disease, but unrelated to the use of antiretrovirals, cotrimoxazole, or the level of maternal antibodies against respiratory pathogens, contribute to the increased risk of LRTI in HEUs. In HEUs, antiretroviral and cotrimoxazole use, exposure to respiratory pathogens and humoral immune responses were not associated with the incidence of LRTI.

Investigating Mediators of the Poor Pneumonia Outcomes of Human Immunodeficiency Virus-Exposed but Uninfected Children

BACKGROUND

Human immunodeficiency virus-exposed but uninfected (HIV-EU) children have a higher mortality rate than the children of HIV-negative mothers (HIV-unexposed). Causal mediators of the poor health outcomes of HIV-EU children remain poorly defined.

METHODS

We conducted a hospital-based prospective cohort study of children aged 1 to 23 months with clinically defined pneumonia. The children were recruited at a referral hospital in Gaborone, Botswana, between April 2012 and June 2016. The primary outcome, treatment failure at 48 hours, was assessed by an investigator blinded to the children's HIV-exposure status. We examined associations between HIV exposure and pneumonia outcomes in HIV-uninfected children. We next determined whether the effect of HIV exposure on outcomes was mediated by low-birth-weight status, nonbreastfeeding, malnutrition, in utero exposure to combination antiretroviral therapy, or pneumonia severity.

RESULTS

A total of 352 HIV-uninfected children were included in these analyses, including 245 (70%) HIV-unexposed and 107 (30%) HIV-EU children. Their median age was 7.4 months, and 57% were male. Treatment failure occurred in 111 (32%) children, and 19 (5.4%) children died. HIV-EU children were more likely to fail treatment (risk ratio [RR], 1.57 [95% confidence interval (CI), 1.19-2.07]; P = .002) and had a higher in-hospital mortality rate (RR, 4.50 [95% CI, 1.86-10.85]; P = .001) than HIV-unexposed children. Nonbreastfeeding mediated 47% of the effect of HIV exposure on the risk of in-hospital death.

CONCLUSIONS

HIV-EU children have worse pneumonia outcomes than HIV-unexposed children. Nonbreastfeeding mediates nearly half of the effect of HIV exposure on pneumonia mortality. Our findings provide additional evidence for a mortality benefit of breastfeeding by HIV-EU children.

The Nasopharyngeal Microbiota of Children With Respiratory Infections in Botswana

BACKGROUND

Nearly half of child pneumonia deaths occur in sub-Saharan Africa. Microbial communities in the nasopharynx are a reservoir for pneumonia pathogens and remain poorly described in African children.

METHODS

Nasopharyngeal swabs were collected from children with pneumonia (N = 204), children with upper respiratory infection symptoms (N = 55) and healthy children (N = 60) in Botswana between April 2012 and April 2014. We sequenced the V3 region of the bacterial 16S ribosomal RNA gene and used partitioning around medoids to cluster samples into microbiota biotypes. We then used multivariable logistic regression to examine whether microbiota biotypes were associated with pneumonia and upper respiratory infection symptoms.

RESULTS

Mean ages of children with pneumonia, children with upper respiratory infection symptoms and healthy children were 8.2, 11.4 and 8.0 months, respectively. Clustering of nasopharyngeal microbiota identified 5 distinct biotypes: Corynebacterium/Dolosigranulum-dominant (23%), Haemophilus-dominant (11%), Moraxella-dominant (24%), Staphylococcus-dominant (13%) and Streptococcus-dominant (28%). The Haemophilus-dominant [odds ratio (OR): 13.55; 95% confidence interval (CI): 2.10-87.26], the Staphylococcus-dominant (OR: 8.27; 95% CI: 2.13-32.14) and the Streptococcus-dominant (OR: 39.97; 95% CI: 6.63-241.00) biotypes were associated with pneumonia. The Moraxella-dominant (OR: 3.71; 95% CI: 1.09-12.64) and Streptococcus-dominant (OR: 12.26; 95% CI: 1.81-83.06) biotypes were associated with upper respiratory infection symptoms. In children with pneumonia, HIV infection was associated with a lower relative abundance of Dolosigranulum (P = 0.03).

CONCLUSIONS

Pneumonia and upper respiratory infection symptoms are associated with distinct nasopharyngeal microbiota biotypes in African children. A lower abundance of the commensal genus Dolosigranulum may contribute to the higher pneumonia risk of HIV-infected children.

Health and survival of HIV perinatally exposed but uninfected children born to HIV-infected mothers

PURPOSE OF REVIEW

The number of HIV-exposed but uninfected (HEU) infants exposed to both HIV and multiple antiretroviral drugs in utero and during prolonged breastfeeding is increasing in low-income countries where HIV prevalence is the highest. We review recent evidence on the effects of perinatal/postnatal exposure to maternal HIV and combined antiretroviral therapy (cART) on health outcomes of HEU children (mitochondrial and metabolic toxicity, adverse pregnancy outcomes, neurodevelopment, growth, infectious morbidity, and mortality).

RECENT FINDINGS

Several studies have reported ART-associated mitochondrial toxicity and metabolic disorders with conflicting results on adverse pregnancy outcomes, underscoring the need to conduct further investigations on these questions. Studies about congenital abnormalities report no significant differences between HEU exposed to ART and HIV-unexposed (HUU) children. Updated French data showed no significant difference in cancer incidence between HEU cART-exposed children and the general paediatric population. Furthermore, HEU children exposed to maternal cART have modest but significant impairment of development and a higher risk of growth impairment. Finally, HEU have higher risks of infections (mainly low respiratory tract infections and diarrhoea) and malaria than HUU children, particularly in children not breastfed or after early weaning. Higher mortality risk from infectious disease is reported in HEU compared to HUU children.

SUMMARY

As we move toward the elimination of mother-to-child transmission of HIV, HEU children are an emerging population whose health outcomes remain to be fully described. Future large cohorts of HEU children using careful comparison groups of HUU in the post-ART era are needed to better understand their long-term health outcomes.

Excess respiratory viral infections and low antibody responses among HIV-exposed, uninfected infants

OBJECTIVE

HIV-exposed uninfected (HEUs) infants have frequent severe infection, hospitalization, and death. We performed a serologic investigation to determine the role of common childhood respiratory pathogens in the excess incidence of infections in HEUs.

DESIGN

Prospective cohort study of mother-infant pairs.

METHODS

Among 247 HEUs and 88 HIV-unexposed uninfected (HUU) infant-mother pairs, we measured maternal antibodies to respiratory syncytial virus (RSV) and pneumococcus (PNC 1, 5, 6B, 14); infant antibodies to RSV, influenza A (flu), parainfluenza viruses (1, 2, 3), and PNC 1, 5, 6B, and 14 were measured at 0 and 6 months, and antitetanus antibodies at 6 months.

RESULTS

HIV-infected mothers had higher RSV and lower PNC antibody concentrations at delivery than uninfected mothers. Transplacental transfer of maternal antibodies, particularly for RSV, was lower in HEUs compared with HUUs. At birth, HEUs had higher concentrations of anti-RSV antibodies than HUUs, but lower antibodies to the other respiratory agents. At 6 months, HEUs had significantly higher proportions of seroconversions and higher antibody concentrations against parainfluenza viruses 1, 2, and 3. There were no significant differences in seroconversions to flu and RSV, but antibody concentrations to RSV were six-fold lower in HEUs versus HUUs at 6 months. Antibody responses to at least two doses of tetanus vaccine were also six-fold lower in HEUs compared with HUUs.

CONCLUSION

Six-month-old HEUs had a higher incidence of respiratory viral infections than HUUs. In addition to the low passive protection from maternal antibodies, low antibody responses of HEUs may contribute to increased morbidity and mortality.

A Prospective Cohort Study of Common Childhood Infections in South African HIV-exposed Uninfected and HIV-unexposed Infants

BACKGROUND

Much evidence of HIV-exposed uninfected (HEU) infant infectious morbidity predates availability of maternal combination antiretroviral therapy and does not control for universal risk factors (preterm birth, low birth weight, suboptimal breastfeeding and poverty).

METHODS

This prospective cohort study identified HIV-infected and HIV-uninfected mothers and their newborns from South African community midwife unit. The primary outcome, infectious cause hospitalization or death before 6 months of age, was compared between HEU and HIV-unexposed (HU) infants and classified for type and severity using validated study-specific case definitions. Adjusted odds ratios (aORs) were calculated by logistic regression including stratified analyses conditioned on breastfeeding.

RESULTS

One hundred and seventy-six (94 HEU and 82 HU) mother-infant pairs were analyzed. HIV-infected mothers were older (median, 27.8 vs. 24.7 years; P < 0.01) and HU infants more often breastfed (81/82 vs. 35/94; P < 0.001). Groups were similar for maternal education, antenatal course, household characteristics, birth weight, gestational age and immunizations. The primary outcome occurred in 17 (18%) HEU and 10 (12%) HU infants [aOR, 1.45; 95% confidence interval (CI): 0.44-4.55]. In stratified analysis restricted to breastfed infants, the aOR for hospitalization due to very severe infection or death was 4.2 (95% CI: 1.00-19.2; P = 0.05) for HEU infants. Hospitalization for diarrhea was more common in HEU than HU infants [8/94 (8.5%) vs. 1/82 (1.2%); P = 0.04].

CONCLUSION

The difference between HEU and HU infants in the probability of infectious cause hospitalization or death in the first 6 months of life was not significant. However, among breastfed infants, severe infectious morbidity occurred more often in HEU than HU infants.

Maternal HIV and Paediatric Lung Health

With improved prevention of mother to child transmission of HIV, paediatric HIV disease is less common. However, the number of HIV exposed but uninfected infants is growing. Exposure to maternal HIV impacts infant respiratory health through an increase in known risk factors such as increased preterm birth and low birth weight, suboptimal breastfeeding, increased psychosocial stressors and increased exposure to infective pathogens. Exposure to the HIV virus and altered maternal immune environment result in immunologic changes in the infant that may contribute to respiratory disease risk. HIV exposed infants are at increased risk for severe pneumonia with poorer outcomes compared to unexposed infants. Maternal ART and optimal nutrition, including breastfeeding in high infective disease burden settings, reduce morbidity and mortality in HIV exposed infants and should be prioritized. The impact of exposure to maternal HIV on normal lung growth and risk for chronic respiratory disease is unknown and warrants further investigation.

Predicting Hospitalised Paediatric Pneumonia Mortality Risk: An External Validation of RISC and mRISC, and Local Tool Development (RISC-Malawi) from Malawi

BACKGROUND

Pneumonia is the leading infectious cause of under-5 mortality in sub-Saharan Africa. Clinical prediction tools may aide case classification, triage, and allocation of hospital resources. We performed an external validation of two published prediction tools and compared this to a locally developed tool to identify children admitted with pneumonia at increased risk for in-hospital mortality in Malawi.

METHODS

We retrospectively analyzed the performance of the Respiratory Index of Severity in Children (RISC) and modified RISC (mRISC) scores in a child pneumonia dataset prospectively collected during routine care at seven hospitals in Malawi between 2011-2014. RISC has both an HIV-infected and HIV-uninfected tool. A local score (RISC-Malawi) was developed using multivariable logistic regression with missing data multiply imputed using chained equations. Score performances were assessed using c-statistics, sensitivity, specificity, positive predictive value, negative predictive value, and likelihood statistics.

RESULTS

16,475 in-patient pneumonia episodes were recorded (case-fatality rate (CFR): 3.2%), 9,533 with complete data (CFR: 2.0%). The c-statistic for the RISC (HIV-uninfected) score, used to assess its ability to differentiate between children who survived to discharge and those that died, was 0.72. The RISC-Malawi score, using mid-upper arm circumference as an indicator of malnutrition severity, had a c-statistic of 0.79. We were unable to perform a comprehensive external validation of RISC (HIV-infected) and mRISC as both scores include parameters that were not routinely documented variables in our dataset.

CONCLUSION

In our population of Malawian children with WHO-defined pneumonia, the RISC (HIV-uninfected) score identified those at high risk for in-hospital mortality. However the refinement of parameters and resultant creation of RISC-Malawi improved performance. Next steps include prospectively studying both scores to determine if incorporation into routine care delivery can have a meaningful impact on in-hospital CFRs of children with WHO-defined pneumonia.

Risk Factors for Presumed Bacterial Pneumonia Among HIV-uninfected Children Hospitalized in Soweto, South Africa

BACKGROUND

Pneumonia is a leading cause of child morbidity and death. Data on risk factors can guide prevention efforts. Within a study on pneumococcal conjugate vaccine effectiveness, we investigated risk factors for presumed bacterial pneumonia (PBP).

METHODS

PBP cases were human immunodeficiency virus (HIV) uninfected children with lower respiratory tract infection and consolidation on chest radiograph or nonconsolidated infiltrate with C-reactive protein ≥40 mg/L hospitalized at Chris Hani Baragwanath Academic Hospital (CHBAH) in Soweto. Age-matched community controls were identified using CHBAH birth records ±1 week of case birth date. Data were analyzed using conditional logistic regression.

RESULTS

A total of 889 PBP cases (median age 9 months) were matched to 2628 controls. Crowding was a significant risk factor among well-nourished children (adjusted odds ratio [aOR]: 2.29, 95% confidence interval [CI]: 1.89-2.78), but not in those with low weight-for-age. Malnutrition was associated with PBP; strength of association was highest in the absence of crowding (aOR: 6.68, 95% CI: 4.74-9.42). Exclusive breastfeeding was protective only among HIV-unexposed children (aOR: 0.65, 95% CI: 0.54-0.78). Self-reported maternal HIV infection was a risk factor among children exclusively breastfeed up to 4 months (aOR: 2.33, 95% CI: 1.53-3.55). Having indoor tap water was protective (aOR: 0.65, 95% CI: 0.54-0.78), whereas a primary care giver who smoked was a risk factor (aOR: 5.15, 95% CI: 2.94-9.03).

CONCLUSIONS

Our findings confirm several known pneumonia risk factors and highlight complex interactions between factors, including HIV exposure, breastfeeding, malnutrition and crowding. Improved housing, reduced secondhand smoke exposure and HIV prevention among women of reproductive age could lessen the child pneumonia burden.

A meta-analysis assessing all-cause mortality in HIV-exposed uninfected compared with HIV-unexposed uninfected infants and children

OBJECTIVE

Conduct a meta-analysis examining differential all-cause mortality rates between HIV-exposed uninfected (HEU) infants and children as compared with their HIV-unexposed uninfected (HUU) counterparts.

DESIGN

Meta-analysis summarizing the difference in mortality between HEU and HUU infants and children. Reviewed studies comparing children in the two groups for all-cause mortality, in any setting, from 1994 to 2016 from six databases.

METHODS

Meta-analyses were done estimating overall mortality comparing the two groups, stratified by duration of follow-up time from birth (0-12, 12-24 and >24 months) and by year enrollment ended in each study: less than 2002 compared with at least 2002, when single-dose nevirapine for prevention of mother-to-child transmission (PMTCT) commenced in low-income and middle-income countries.

RESULTS

Included 22 studies, for a total of 29 212 study participants [n = 8840 (30.3%) HEU; n = 20 372 (37.7%) HUU]. Random effects models showed HEU had a more than 70% increased risk of mortality vs. HUU. Stratifying by age showed that HEU vs. HUU had a significant 60-70% increased risk of death at every age strata. There was a significant 70% increase in the risk of mortality between groups before the implementation of PMTCT, which remained after 2002 [risk ratio: 1.46; 95% confidence interval (CI): 1.14-1.87], when the availability of PMTCT services was widespread, suggesting that prenatal antiretroviral therapy, and healthier mothers, does not fully eliminate this increased risk in mortality.

CONCLUSION

We show a consistent increase risk of mortality for HEU vs. HUU infants and children. Longitudinal research is needed to elucidate underlying mechanisms, such as maternal and infant health status and breast feeding practices, which may help explain these differences in mortality.

Linking Susceptibility to Infectious Diseases to Immune System Abnormalities among HIV-Exposed Uninfected Infants

HIV-exposed uninfected (HEU) infants experience increased overall mortality from infectious causes when compared to HIV-unexposed uninfected (HU) infants. This is the case in both the resource-rich and resource-limited settings. Here, we explore the concept that specific types of infectious diseases that are more common among HEU infants could provide clues as to the potential underlying immunological abnormalities. The most commonly reported infections in HEU vs. HU infants are caused by encapsulated bacteria, suggesting the existence of a less effective humoral (antibody, complement) immune response. Decreased transplacental transfer of protective maternal antibodies has consistently been observed among HEU newborns, suggesting that this may indeed be one of the key drivers of their susceptibility to infections with encapsulated bacteria. Reassuringly, HEU humoral response to vaccination appears to be well conserved. While there appears to be an increase in overall incidence of acute viral infections, no specific pattern of acute viral infections has emerged; and although there is evidence of increased chronic viral infection from perinatal transmission of hepatitis C and cytomegalovirus, no data exist to suggest an increase in adverse outcomes. Thus, no firm conclusions about antiviral effector mechanisms can be drawn. However, the most unusual of reported infections among the HEU have been opportunistic infections, suggesting the possibility of underlying defects in CD4 helper T cells and overall immune regulatory function. This may relate to the observation that the immunological profile of HEUs indicates a more activated T cell profile as well as a more inflammatory innate immune response. However, both of these observations appear transient, marked in early infancy, but no longer evident later in life. The causes of these early-life changes in immune profiles are likely multifactorial and may be related to in utero exposure to HIV, but also to increased environmental exposure to pathogens from sicker household contacts, in utero and postnatal antiretroviral drug exposure, and, in certain circumstances, differences in mode of feeding. The relative importance of each of these factors will be important to delineate in an attempt to identify those HEU at highest risk of adverse outcomes for targeted interventions.

HIV-exposed children account for more than half of 24-month mortality in Botswana

Background

The contribution of HIV-exposure to childhood mortality in a setting with widespread antiretroviral treatment (ART) availability has not been determined.

Methods

From January 2012 to March 2013, mothers were enrolled within 48 h of delivery at 5 government postpartum wards in Botswana. Participants were followed by phone 1–3 monthly for 24 months. Risk factors for 24-month survival were assessed by Cox proportional hazards modeling.

Results

Three thousand mothers (1499 HIV-infected) and their 3033 children (1515 HIV-exposed) were enrolled. During pregnancy 58 % received three-drug ART, 23 % received zidovudine alone, 11 % received no antiretrovirals (8 % unknown); 2.1 % of children were HIV-infected by 24 months. Vital status at 24 months was known for 3018 (99.5 %) children; 106 (3.5 %) died including 12 (38 %) HIV-infected, 70 (4.7 %) HIV-exposed uninfected, and 24 (1.6 %) HIV-unexposed. Risk factors for mortality were child HIV-infection (aHR 22.6, 95 % CI 10.7, 47.5 %), child HIV-exposure (aHR 2.7, 95 % CI 1.7, 4.5) and maternal death (aHR 8.9, 95 % CI 2.1, 37.1). Replacement feeding predicted mortality when modeled separately from HIV-exposure (aHR 2.3, 95 % CI 1.5, 3.6), but colinearity with HIV-exposure status precluded investigation of its independent effect. Applied at the population level (26 % maternal HIV prevalence), an estimated 52 % of child mortality occurs among HIV-exposed or HIV-infected children.

Conclusions

In a programmatic setting with high maternal HIV prevalence and widespread maternal and child ART availability, HIV-exposed and HIV-infected children still account for most deaths at 24 months. Lack of breastfeeding was a likely contributor to excess mortality among HIV-exposed children.

Pattern of Infectious Morbidity in HIV-Exposed Uninfected Infants and Children

Background

Almost 30% of children in Southern Africa are HIV exposed but uninfected (HEU) and experience exposures that could increase vulnerability to infectious diseases compared to HIV unexposed (HU) children. The mechanisms of HEU infant vulnerability remain ill-defined. This review seeks to appraise the existing clinical evidence of the pattern of HEU infant infectious morbidity to aid understanding of the potential mechanism of susceptibility.

Methods

A systematic search was conducted of scientific literature databases and conference proceedings up to December 2015 for studies comparing adequately defined HEU (in whom HIV-infection had been excluded through age-appropriate testing) and HU infants for all-cause mortality, all-cause hospitalization, or an infection-related morbidity. The systematic review was complemented by a narrative review of additional studies detailing the pattern of infectious morbidity experienced by HEU children without comparison to HU children or without conclusive exclusion of HIV-infection in HIV-exposed infants.

Results

Only 3 of 22 eligible identified studies were designed to primarily compare HEU and HU infants for infectious morbidity. Fourteen were conducted prior to 2009 in the context of limited antiretroviral interventions. Three patterns emerge: (1) causes of morbidity and mortality in HEU infants are consistent with the common causes of childhood morbidity and mortality (pneumonia, diarrheal disease, and bacterial sepsis) but occur with greater severity in HEU infants resulting in higher mortality, more frequent hospitalization, and more severe manifestations of disease; (2) the greatest relative difference between HEU and HU infants in morbidity and mortality occurs beyond the neonatal period, during mid-infancy, having waned by the second year of life; and (3) HEU infants are at greater risk than HU infants for invasive streptococcal infections specifically Group B Streptococcus and Streptococcus pneumonia.

Conclusion

To definitively understand HEU infant infectious morbidity risk, substantially larger prospective studies with appropriate HU infant comparison groups are necessary. HEU children would benefit from collaboration among researchers to achieve the quality of evidence required to improve HEU infant outcomes globally. HEU infant health and well-being, beyond avoiding HIV-infection, deserves a more prominent position in the local and international HIV research agendas.

HIV-exposed, uninfected infants: new global challenges in the era of paediatric HIV elimination

The number of infants infected with HIV is declining with the rise in interventions for the elimination of paediatric HIV infection, but the number of uninfected infants exposed to HIV through their HIV-infected mothers is increasing. Interest in the health outcomes of HIV-exposed, uninfected infants has grown in the past decade, with several studies suggesting that these infants have increased mortality rates, increased infectious morbidity, and impaired growth compared with HIV-unexposed infants. However, heterogeneous results might reflect the inherent challenges in studies of HIV-exposed, uninfected infants, which need large populations with appropriate, contemporaneous comparison groups and repeated HIV testing throughout the period of breastfeeding. We review the effects of HIV exposure on mortality, morbidity, and growth, discuss the immunological abnormalities identified so far, and provide an overview of interventions that could be effective in this susceptible population. As the number of infants infected with HIV declines, the health needs of HIV-exposed, uninfected infants should be prioritised further, to ensure that post-2015 Sustainable Development Goals are achieved.

Chest Radiographic Findings and Outcomes of Pneumonia Among Children in Botswana

BACKGROUND

Chest radiography is increasingly used to diagnose pneumonia in low-income and middle-income countries. Few studies examined whether chest radiographic findings predict outcomes of children with clinically suspected pneumonia in these settings.

METHODS

This is a hospital-based, prospective cohort study of children 1-23 months of age meeting clinical criteria for pneumonia in Botswana. Chest radiographs were reviewed by 2 pediatric radiologists to generate a consensus interpretation using standardized World Health Organization criteria. We assessed whether final chest radiograph classification was associated with our primary outcome, treatment failure at 48 hours, and secondary outcomes.

RESULTS

From April 2012 to November 2014, we enrolled 249 children with evaluable chest radiographs. Median age was 6.1 months, and 58% were male. Chest radiograph classifications were primary endpoint pneumonia (35%), other infiltrate/abnormality (42%) or no significant pathology (22%). The prevalence of endpoint consolidation was higher in children with HIV infection (P = 0.0005), whereas endpoint pleural effusions were more frequent among children with moderate or severe malnutrition (P = 0.0003). Ninety-one (37%) children failed treatment, and 12 (4.8%) children died. Primary endpoint pneumonia was associated with an increased risk of treatment failure at 48 hours (P = 0.002), a requirement for more days of respiratory support (P = 0.002) and a longer length of stay (P = 0.0003) compared with no significant pathology. Primary endpoint pneumonia also predicted a higher risk of treatment failure than other infiltrate/abnormality (P = 0.004).

CONCLUSIONS

Chest radiograph provides useful prognostic information for children meeting clinical criteria for pneumonia in Botswana. These findings highlight the potential benefit of expanded global access to diagnostic radiology services.

Association of respiratory viruses with outcomes of severe childhood pneumonia in Botswana

BACKGROUND

The highest incidence of childhood acute lower respiratory tract infection (ALRI) is in low- and middle-income countries. Few studies examined whether detection of respiratory viruses predicts ALRI outcomes in these settings.

METHODS

We conducted prospective cohort and case-control studies of children 1-23 months of age in Botswana. Cases met clinical criteria for pneumonia and were recruited within six hours of presentation to a referral hospital. Controls were children without pneumonia matched to cases by primary care clinic and date of enrollment. Nasopharyngeal specimens were tested for respiratory viruses using polymerase chain reaction. We compared detection rates of specific viruses in matched case-control pairs. We examined the effect of respiratory syncytial virus (RSV) and other respiratory viruses on pneumonia outcomes.

RESULTS

Between April 2012 and August 2014, we enrolled 310 cases, of which 133 had matched controls. Median ages of cases and controls were 6.1 and 6.4 months, respectively. One or more viruses were detected from 75% of cases and 34% of controls. RSV and human metapneumovirus were more frequent among cases than controls, but only enterovirus/rhinovirus was detected from asymptomatic controls. Compared with non-RSV viruses, RSV was associated with an increased risk of treatment failure at 48 hours [risk ratio (RR): 1.85; 95% confidence interval (CI): 1.20, 2.84], more days of respiratory support [mean difference (MD): 1.26 days; 95% CI: 0.30, 2.22 days], and longer duration of hospitalization [MD: 1.35 days; 95% CI: 0.20, 2.50 days], but lower in-hospital mortality [RR: 0.09; 95% CI: 0.01, 0.80] in children with pneumonia.

CONCLUSIONS

Respiratory viruses were detected from most children hospitalized with ALRI in Botswana, but only RSV and human metapneumovirus were more frequent than among children without ALRI. Detection of RSV from children with ALRI predicted a protracted illness course but lower mortality compared with non-RSV viruses.