The National Evaluation of Malawi's PMTCT Program (NEMAPP) study: 24-month HIV-exposed infant outcomes from a prospective cohort study

OBJECTIVES

Data on long-term HIV-free survival in breastfeeding, HIV-exposed infants (HEIs) are limited. The National Evaluation of Malawi's Prevention of Mother-to-Child Transmission (PMTCT) Program (NEMAPP), conducted between 2014 and 2018, evaluated mother-to-child transmission (MTCT) and infant outcomes up to 24 months postpartum.

METHODS

We enrolled a nationally representative cohort of HEIs at 54 health facilities across four regional strata in Malawi and used multivariable Cox regression analysis to investigate the risk of adverse outcomes (HIV transmission, infant death and loss to follow-up) to 24 months postpartum. Models, controlling for survey design, were fitted for the total cohort (n = 3462) and for a subcohort that received maternal viral load (VL) monitoring (n = 1282).

RESULTS

By 24 months, in 3462 HEIs, weighted cumulative MTCT was 4.9% [95% confidence interval (CI) 3.7-6.4%], 1.3% (95% CI 0.8-2.2%) of HEIs had died, 26.2% (95% CI 24.0-28.6%) had been lost to follow-up and 67.5% (95% CI 65.0-70.0%) were alive and HIV-free. Primiparity [weighted adjusted hazard ratio (aHR) 1.6; 95% CI 1.1-2.2; parity 2-3: weighted aHR 1.5; 95% CI 1.2-1.9], the mother not disclosing her HIV status to her partner (no disclosure: weighted aHR 1.3; 95% CI 1.1-1.6; no partner: weighted aHR 0.7; 95% CI 0.5-0.9), unknown maternal ART start (weighted aHR 2.0; 95% CI 1.0-3.9) and poor adherence (missed ≥ 2 days of ART in the last month: weighted aHR 1.7; 95% CI 1.2-2.2; not on ART: weighted aHR 1.7; 95% CI 1.0-2.7) were associated with adverse outcomes by 24 months. In the subcohort analysis, risk of HIV transmission or infant death was higher among HEIs whose mothers started ART post-conception (during pregnancy: weighted aHR 3.2; 95% CI 1.3-7.7; postpartum: weighted aHR 12.4; 95% CI 1.5-99.6) or when maternal viral load at enrolment was > 1000 HIV-1 RNA copies/mL (weighted aHR 15.7; 95% CI 7.8-31.3).

CONCLUSIONS

Infant positivity and infant mortality at 24 months were low for a breastfeeding population. Starting ART pre-conception had the greatest impact on HIV-free survival in HEIs. Further population-level reduction in MTCT may require additional intervention during breastfeeding for women new to PMTCT programmes. Pre-partum diagnosis and linkage to ART, followed by continuous engagement in care during breastfeeding can further reduce MTCT but are challenging to implement.

The systemic inflammatory landscape of COVID-19 in pregnancy: Extensive serum proteomic profiling of mother-infant dyads with in utero SARS-CoV-2

While pregnancy increases the risk for severe COVID-19, the clinical and immunological implications of COVID-19 on maternal-fetal health remain unknown. Here, we present the clinical and immunological landscapes of 93 COVID-19 mothers and 45 of their SARS-CoV-2-exposed infants through comprehensive serum proteomics profiling for >1,400 cytokines of their peripheral and cord blood specimens. Prenatal SARS-CoV-2 infection triggers NF-κB-dependent proinflammatory immune activation. Pregnant women with severe COVID-19 show increased inflammation and unique IFN-λ antiviral signaling, with elevated levels of IFNL1 and IFNLR1. Furthermore, SARS-CoV-2 infection re-shapes maternal immunity at delivery, altering the expression of pregnancy complication-associated cytokines, inducing MMP7, MDK, and ESM1 and reducing BGN and CD209. Finally, COVID-19-exposed infants exhibit induction of T cell-associated cytokines (IL33, NFATC3, and CCL21), while some undergo IL-1β/IL-18/CASP1 axis-driven neonatal respiratory distress despite birth at term. Our findings demonstrate COVID-19-induced immune rewiring in both mothers and neonates, warranting long-term clinical follow-up to mitigate potential health risks.

Cytomegalovirus-Specific T Cell Epitope Recognition in Congenital Cytomegalovirus Mother-Infant Pairs

Background: Congenital cytomegalovirus (cCMV) infection is the most common infection acquired before birth and from which about 20% of infants develop permanent neurodevelopmental effects regardless of presence or absence of symptoms at birth. Viral escape from host immune control may be a mechanism of CMV transmission and infant disease severity. We sought to identify and compare CMV epitopes recognized by mother-infant pairs. We also hypothesized that if immune escape were occurring, then one pattern of longitudinal CD8 T cell responses restricted by shared HLA alleles would be maternal loss (by viral escape) and infant gain (by viral reversion to wildtype) of CMV epitope recognition. Methods: The study population consisted of 6 women with primary CMV infection during pregnancy and their infants with cCMV infection. CMV UL83 and UL123 peptides with known or predicted restriction by maternal MHC class I alleles were identified, and a subset was selected for testing based on several criteria. Maternal or infant cells were stimulated with CMV peptides in the IFN-γ ELISpot assay. Results: Overall, 14 of 25 (56%; 8 UL83 and 6 UL123) peptides recognized by mother-infant pairs were not previously reported as CD8 T cell epitopes. Of three pairs with longitudinal samples, one showed maternal loss and infant gain of responses to a CMV epitope restricted by a shared HLA allele. Conclusions: CD8 T cell responses to multiple novel CMV epitopes were identified, particularly in infants. Moreover, the hypothesized pattern of CMV immune escape was observed in one mother-infant pair. These findings emphasize that knowledge of paired CMV epitope recognition allows exploration of viral immune escape that may operate within the maternal-fetal system. Our work provides rationale for future studies of this potential mechanism of CMV transmission during pregnancy or clinical outcomes of infants with cCMV infection.

Retention of mothers and infants in the prevention of mother-to-child transmission of HIV programme is associated with individual and facility-level factors in Rwanda

Objectives

Investigate levels of retention at specified time periods along the prevention of mother-to-child transmission (PMTCT) cascade among mother-infant pairs as well as individual- and facility-level factors associated with retention.

Methods

A retrospective cohort of HIV-positive pregnant women and their infants attending five health centres from November 2010 to February 2012 in the Option B programme in Rwanda was established. Data were collected from several health registers and patient follow-up files. Additionally, informant interviews were conducted to ascertain health facility characteristics. Generalized estimating equation methods and modelling were utilized to estimate the number of mothers attending each antenatal care visit and assess factors associated with retention.

Results

Data from 457 pregnant women and 462 infants were collected at five different health centres (three urban and two rural facilities). Retention at 30 days after registration and retention at 6 weeks, 3, 6, 9 and 12 months post-delivery were analyzed. Based on an analytical sample of 348, we found that 58% of women and 81% of infants were retained in care within the same health facility at 12 months post-delivery, respectively. However, for mother-infant paired mothers, retention at 12 months was 74% and 79% for their infants. Loss to facility occurred early, with 26% to 33% being lost within 30 days post-registration. In a multivariable model retention was associated with being married, adjusted relative risk (ARR): 1.26, (95% confidence intervals: 1.11, 1.43); antiretroviral therapy eligible, ARR: 1.39, (1.12, 1.73) and CD4 count per 50 mm³, ARR: 1.02, (1.01, 1.03).

Conclusions

These findings demonstrate varying retention levels among mother-infant pairs along the PMTCT cascade in addition to potential determinants of retention to such programmes. Unmarried, apparently healthy, HIV-positive pregnant women need additional support for programme retention. With the significantly increased workload resulting from lifelong antiretroviral treatment for all HIV-positive pregnant women, strategies need to be developed to identify, provide support and trace these women at risk of loss to follow-up. This study provides further evidence for the need for such a targeted supportive approach.

Temporal Changes in Pneumococcal Colonization in HIV-infected and HIV-uninfected Mother-Child Pairs Following Transitioning From 7-valent to 13-valent Pneumococcal Conjugate Vaccine, Soweto, South Africa

BACKGROUND

We investigated the impact of infant pneumococcal conjugate vaccine (PCV) immunization on pneumococcal colonization among human immunodeficiency virus (HIV)-infected and HIV-uninfected mother-child pairs.

METHODS

Pneumococcal colonization was assessed in May 2010-February 2011 (period 1; 7-valent PCV era) and May 2012-April 2013 (period 2; 13-valent PCV era). Standard microbiological methods were used for pneumococcus isolation and serotyping.

RESULTS

In children 0-12 years, PCV13-serotype colonization decreased from period 1 to period 2 among HIV-uninfected (adjusted odds ratio [OR], 0.32; 95% confidence interval [CI], .25-.40) and HIV-infected children (adjusted OR, 0.37; 95% CI, .28-.49), while there was an increase in nonvaccine serotype colonization. Decreases in PCV13-serotype colonization were observed in HIV-uninfected women (adjusted OR, 0.44; 95% CI, .23-.81), with a similar trend in HIV-infected women. HIV-infected compared to -uninfected women had higher prevalence of overall (20.5% vs 9.7% in period 1; 13.8% vs 9.7% in period 2) and PCV13-serotype colonization (8.7% vs 5.4% in period 1; 4.8% vs 2.0% in period 2), P < .04 for all observations.

CONCLUSIONS

Targeted PCV vaccination of African infants in a setting with high HIV prevalence was associated with PCV13-serotype colonization reduction, including among unvaccinated HIV-infected women.