Drug resistance and coreceptor usage in HIV type 1 subtype C-infected children initiating or failing highly active antiretroviral therapy in South Africa

HIV-1 drug resistance monitoring in resource-poor settings is crucial due to limited drug alternatives. Recent reports of the increased prevalence of CXCR4 usage in subtype C infections may have implications for CCR5 antagonists in therapy. We investigated the prevalence of drug resistance mutations and CXCR4 coreceptor utilization of viruses from HIV-1 subtype C-infected children. Fifty-one children with virological failure during highly active antiretroviral therapy (HAART) and 43 HAART-naive children were recruited. Drug resistance genotyping and coreceptor utilization assessment by phenotypic and genotypic methods were performed. At least one significant drug resistance mutation was present in 85.4% of HAART-failing children. Thymidine analogue mutations (TAMs) were detected in 58.5% of HAART-failing children and 39.0% had ≥3 TAMs. CXCR4 (X4) or dual (R5X4)/mixed (R5, X4) (D/M)-tropic viruses were found in 54.3% of HAART-failing and 9.4% of HAART-naive children (p<0.0001); however, the HAART-failing children were significantly older (p<0.0001). In multivariate logistic regression, significant predictors of CXCR4 usage included antiretroviral treatment, older age, and lower percent CD4(+) T cell counts. The majority of genotypic prediction tools had low sensitivity (≤65.0%) and high specificity (≥87.5%) for predicting CXCR4 usage. Extensive drug resistance, including the high percentage of TAMs found, may compromise future drug choices for children, highlighting the need for improved treatment monitoring and adherence counseling. Additionally, the increased prevalence of X4/D/M viruses in HAART-failing children suggests limited use of CCR5 antagonists in salvage therapy. Enhanced genotypic prediction tools are needed as current tools are not sensitive enough for predicting CXCR4 usage.     

Assisted reproductive technologies in Africa: first results from the African Network and Registry for Assisted Reproductive Technology, 2013

Research question

What were utilization, outcomes and practices in assisted reproductive technology (ART) in Africa in 2013?

Development and validation of the HIV adolescent readiness for transition scale (HARTS) in South Africa

IntroductionAdolescents living with perinatally acquired HIV have low rates of retention in care and viral suppression after the transition from paediatric to adult care. In this study, we developed and validated a tool to identify adolescent transition readiness.MethodsWe developed the HIV Adolescent Readiness for Transition Scale (HARTS) from June 2016 to May 2019 by iteratively adapting existing transition readiness scales for other chronic illnesses by conducting focus groups with 11 healthcare providers and 20 adolescents in South Africa. We administered a preliminary questionnaire to 131 adolescents to determine psychometric properties and assess test–retest variability. We used confirmatory factor analysis to verify the proposed scale structure using the underlying variable approach. We correlated responses to self‐described transition readiness and age using linear regression. We subsequently validated the scale by prospectively administering it to 199 adolescents in a second South African setting before their transition. We then used multivariable logistic regression to assess the effects of the HARTS and relevant socio‐behavioural covariates on viral suppression one year after transition.ResultsWe identified four domains relevant to transition readiness: disclosure, health navigation, self‐advocacy and health literacy. Fifteen questions with a significant factor loading of 0.3 to 0.9 were identified. No significant test–retest variability was seen among 10% of participants. Positive correlations with self‐described transition readiness were significant with the overall HARTS and domains of health navigation, self‐advocacy and health literacy. In the prospective analysis, for adolescents not using drugs, each 10‐point increase in the HARTS was associated with 0.62 odds of viral failure (95% CI 0.45 to 0.86; p = 0.004). The individual domains of self‐advocacy (AOR 0.56; 95% CI 0.33 to 0.94; p = 0.029), disclosure (AOR 0.02; 95% CI 0.01 to 0.25; p = 0.002), health navigation (AOR 0.51; 95%CI 0.25 to 1.02; p = 0.056) and health literacy (AOR 0.37; 95% CI 0.10 to 1.30; p = 0.121) were associated with viral failure adjusting for age at antiretroviral therapy initiation, ART regimen, sex, disclosure status, and alcohol use in both analyses.ConclusionsThe HARTS is a validated scale that can be used to identify which adolescents may require additional interventions prior to transitioning to adult care to improve viral suppression after transition.     

Development of a transition readiness score for adolescents living with perinatally-acquired HIV and transitioning to adult care

AIDS and Behavior - We created a transition readiness score for adolescents with perinatally-acquired HIV as they transition from pediatric to adult care. Of the 199 adolescents who transitioned to...     

Next-generation point-of-care testing in pediatric human immunodeficiency virus infection facilitates diagnosis and monitoring of treatment

Point-of-care (PoC) testing facilitates early infant diagnosis (EID) and treatment initiation, which improves outcome. We present a field evaluation of a new PoC test (Cepheid Xpert® HIV-1 Qual XC RUO) to determine whether this test improves EID and assists the management of children living with human immunodeficiency virus (HIV) infection.We compared 2 PoC tests with the standard-of-care (SoC) test used to detect HIV infection from dry blood spots in newborn infants at high risk of in utero infection. We also evaluated the ability of the PoC tests to detect HIV total nucleic acid (TNA) in children living with HIV infection who had maintained undetectable plasma viremia following very early combination antiretroviral therapy (cART) initiation.Qualitative (Qual) detection of HIV using the Xpert® HIV-1 Qual XC RUO (“RUO”) and Xpert® HIV-1 Qual (“Qual”) PoC tests was compared in 224 infants with the SoC DBS Roche COBAS® HIV-1/HIV-2 qualitative test. The same 2 PoC tests were also evaluated in 35 older children who had initiated cART before 21 days of age and maintained undetectable plasma viremia for a mean of 25 months.No discrepancies were observed in detection of HIV infection via the 2 PoC tests or the SoC test in the 224 neonates studied, but only 95% of the SoC test results were generated compared with 100% of the PoC test results (P = .0009). The cycle threshold values for the research use only (RUO) assay were the lowest of the 3 assays (P < .0001 in each case). In 6 of the 35 early-treated aviremic children, HIV TNA was detected by RUO but not Qual.The RUO assay outperforms Qual in detecting HIV-1 infection. RUO would therefore potentially improve EID and assist in identifying cART-adherent early-treated children with the lowest HIV TNA levels and the highest HIV cure potential.     

Synergy between mannose-binding lectin gene polymorphisms and supplementation with vitamin A influences susceptibility to HIV infection in infants born to HIV-positive mothers

BACKGROUND: Mannose-binding lectin (MBL-2) allele variants are associated with deficiencies in innate immunity and have been found to be correlated with HIV infection in adults and children. OBJECTIVE: We tested whether MBL-2 variants among infants born to HIV-positive mothers have an increased susceptibility to HIV. DESIGN: MBL-2 allele variants were measured among 225 infants born to HIV-positive mothers enrolled in a trial in Durban, South Africa. Mothers of 108 infants were randomly assigned to receive vitamin A and beta-carotene supplementation and 117 to receive placebo. Infants were followed with regular HIV tests to determine rates of mother-to-child HIV transmission. RESULTS: A high proportion of infants were either homozygous (10.7%) or heterozygous (32.4%) for MBL-2 variants. MBL-2 variants within the placebo arm were associated with an increased risk of HIV transmission (odds ratio: 3.09; 95% CI: 1.21, 7.86); however, MBL-2 variants within the supplementation arm were not associated with an increased risk of transmission (P = 0.04; test of interaction). Among infants with MBL-2 variants, supplementation was associated with a decreased risk of HIV transmission (odds ratio: 0.37; 95% CI: 0.15, 0.91). CONCLUSION: We observed what appears to be a gene-environment interaction between MBL-2 variants and an intervention with vitamin A plus beta-carotene that is relevant to mother-to-child HIV transmission.     

Antiretroviral postnatal prophylaxis to prevent HIV vertical transmission: present and future strategies

Introduction

Maternal antiretroviral therapy (ART) with viral suppression prior to conception, during pregnancy and throughout the breastfeeding period accompanied by infant postnatal prophylaxis (PNP) forms the foundation of current approaches to preventing vertical HIV transmission. Unfortunately, infants continue to acquire HIV infections, with half of these infections occurring during breastfeeding. A consultative meeting of stakeholders was held to review the current state of PNP globally, including the implementation of WHO PNP guidelines in different settings and identifying the key factors affecting PNP uptake and impact, with an aim to optimize future innovative strategies.

Discussion

WHO PNP guidelines have been widely implemented with adaptations to the programme context. Some programmes with low rates of antenatal care attendance, maternal HIV testing, maternal ART coverage and viral load testing capacity have opted against risk-stratification and provide an enhanced PNP regimen for all infants exposed to HIV, while other programmes provide infant daily nevirapine antiretroviral (ARV) prophylaxis for an extended duration to cover transmission risk throughout the breastfeeding period. A simplified risk stratification approach may be more relevant for high-performing vertical transmission prevention programmes, while a simplified non-risk stratified approach may be more appropriate for sub-optimally performing programmes given implementation challenges. In settings with concentrated epidemics, where the epidemic is often driven by key populations, infants who are found to be exposed to HIV should be considered at high risk for HIV acquisition. All settings could benefit from newer technologies that promote retention during pregnancy and throughout the breastfeeding period. There are several challenges in enhanced and extended PNP implementation, including ARV stockouts, lack of appropriate formulations, lack of guidance on alternative ARV options for prophylaxis, poor adherence, poor documentation, inconsistent infant feeding practices and in inadequate retention throughout the duration of breastfeeding.

Conclusions

Tailoring PNP strategies to a programmatic context may improve access, adherence, retention and HIV-free outcomes of infants exposed to HIV. Newer ARV options and technologies that enable simplification of regimens, non-toxic potent agents and convenient administration, including longer-acting formulations, should be prioritized to optimize the effect of PNP in the prevention of vertical HIV transmission.