Host factors that influence mother-to-child transmission of HIV-1: genetics, coinfections, behavior and nutrition

Correlates of mother-to child-transmission of HIV infection in a tertiary hospital in Ebonyi state, Nigeria

BACKGROUND

Nigeria has the largest global burden of HIV new infections in children despite global and national concerted efforts at the reduction of mother-to-child transmission of HIV. The goal of this study was to determine the associations between maternal characteristics, practices and mother-to-child transmission of HIV infection among mothers living with HIV.

METHODS

This is a hospital-based descriptive cross-sectional study. Information was obtained using interviewer-administered questionnaire from the 240 participants. Data were analyzed with SPSS version 26, and P < 0.05 was considered statistically significant.

RESULTS

Out of the 240 mothers recruited, 129 (53.8%) were within 25-35 years of age, with a mean age of 31.08 ± 5.65. A total of 35 (14.6%) of the participants had at least a child with HIV infection. Maternal ART status before childbirth (AOR = 0.02, 95%CI = 0.01-0.05, P = < 0 .001) was the singular determinant of having a child with HIV infection. Mothers who delivered outside the health facility were about four-fold at risk of having an infected child (AOR = 3.89, 95%CI = 1.82-8.50, P = 0.070).

CONCLUSION

The prevalence rate of mother-to-child transmission of HIV is high. Routine HIV testing services and the provision of accessible and affordable reproductive health services are recommended for all women of childbearing age.

In Utero Mother-to-Child Transmission of HIV-1 and the Associated Factors in Rwanda, Africa

Mother-to-child transmission (MTCT) of HIV-1 and associated mortality continue to occur at unacceptably high rates, despite the extensive rollout and implementation of Prevention of Mother-to-Child Transmission (PMTCT) Programs, including the modified versions of Option B and B+ in 2010 and 2012, respectively. Maternal HIV viral load (VL) and socio-behavioral factors sustaining MTCT in Rwanda remain largely unexplored. The study examined the effects of socio-behavioral factors on maternal VL and their contribution to in utero transmission of HIV-1 in the context of Rwanda's HIV epidemic. A prospective cohort study was conducted in 862 mother-baby pairs enrolled in 10 PMTCT clinics in Rwanda. VL was determined on plasma and Dried Blood Spots samples, whereas HIV DNA PCR was performed to determine in utero MTCT of HIV of the babies immediately at birth and then at 3 weeks, 4 weeks, 6 months, and 18 months, together with HIV antibody testing to determine other forms of MTCT of HIV. Quantitative data on socio-behavioral factors were collected through a structured questionnaire. Linear regression and univariate analysis of variances using SPSS 25.0 were used to test the hypotheses. We found 22/862 (2.55%) cases of in utero transmission and a total of 32/862 (3.7%) cases of MTCT of HIV-1 over 18 study months. Maternal VL at delivery was significantly associated with the risk of in utero transmission of HIV-1. Socio-behavioral factors associated with elevated maternal VL at delivery included alcohol, smoking, multiple sexual partners, mothers' income, being a casual laborer, and distance to health care services. We report an MTCT rate of 3.7% in our study population over the 18 months, higher than the national average of 1.5%, the majority of which occurred in utero. MTCT cases were attributable to failure to suppress maternal VL.

HIV prevalence among children admitted with severe acute malnutrition and associated factors with mother-to-child HIV transmission at Mulago Hospital, Uganda: A mixed methods study

BACKGROUND

Despite global efforts to eliminate mother-to-child-transmission of HIV (MTCT), many children continue to become infected. We determined the prevalence of HIV among children with severe acute malnutrition (SAM) and that of their mothers, at admission to Mwanamugimu Nutrition Unit, Mulago Hospital, Uganda. We also assessed child factors associated with HIV-infection, and explored factors leading to HIV-infection among a subset of the mother-child dyads that tested positive.

METHODOLOGY

We conducted a cross-sectional evaluation within the REDMOTHIV (Reduce mortality in HIV) clinical trial that investigated strategies to reduce mortality among HIV-infected and HIV-exposed children admitted with SAM at the Nutrition Unit. From June 2021 to December 2022, we consecutively tested children aged 1 month to 5 years with SAM for HIV, and the mothers who were available, using rapid antibody testing upon admission to the unit. HIV-antibody positive children under 18 months of age had a confirmatory HIV-DNA PCR test done. In-depth interviews (IDIs) were conducted with mothers of HIV positive dyads, to explore the individual, relationship, social and structural factors associated with MTCT, until data saturation. Quantitative data was analyzed using descriptive statistics and logistic regression in STATAv14, while a content thematic approach was used to analyze qualitative data.

RESULTS

Of 797 children tested, 463(58.1%) were male and 630(79.1%) were ≤18months of age; 76 (9.5%) tested positive. Of 709 mothers, median (IQR) age 26 (22, 30) years, 188(26.5%) were HIV positive. Sixty six of the 188 mother-infant pairs with HIV exposure tested positive for HIV, an MTCT rate of 35.1% (66/188). Child age >18 months was marginally associated with HIV-infection (crude OR = 1.87,95% CI: 1.11-3.12, p-value = 0.02; adjusted OR = 1.72, 95% CI: 0.96, 3.09, p-value = 0.068). The IDIs from 16 mothers revealed associated factors with HIV transmission at multiple levels. Individual level factors: inadequate information regarding prevention of MTCT(PMTCT), limited perception of HIV risk, and fear of antiretroviral drugs (ARVs). Relationship level factors: lack of family support and unfaithfulness (infidelity) among sexual partners. Health facility level factors: negative attitude of health workers and missed opportunities for HIV testing. Community level factors: poverty and health service disruptions due to the COVID-19 pandemic.

CONCLUSION

In this era of universal antiretroviral therapy for PMTCT, a 10% HIV prevalence among severely malnourished children is substantially high. To eliminate vertical HIV transmission, more efforts are needed to address challenges mothers living with HIV face intrinsically and within their families, communities and at health facilities.

Final HIV status outcome for HIV-exposed infants at 18 months of age in nine states and the Federal Capital Territory, Nigeria

Introduction

While antiretroviral therapy (ART) coverage for pregnant women has undergone steady scale-up, Nigeria’s final mother- to-child transmission of HIV (MTCT) rate remains unacceptably high at 10%. This study aimed to determine final outcomes (MTCT rates) and their correlates among HIV-exposed infants (HEI) in nine states and the Federal Capital Territory, Nigeria.

Methods

This retrospective, cross-sectional study was conducted at 96 primary, secondary and tertiary health facilities supported by the Institute of Human Virology Nigeria. Data was abstracted for a birth cohort of HEI born between October 30, 2014 and April 30, 2015 whose 18–24 month final outcome was assessed by October 30, 2016. Only infants with a six-week first DNA PCR result, and a rapid HIV antibody test result at age 18 to 24 months were included. Multivariate logistic regression (adjusted odds ratios [aORs]) evaluated for predictors of HIV positivity at ≥18 months.

Results

After testing at ≥18 months, 68 (2.8%) of the 2,405 exposed infants in the birth cohort were HIV-positive. After a minimum of 18 months of follow-up, 51 (75%) HIV-positive infants were alive on ART; 7 (10%) had died, 5 (7.3%) were lost to follow-up and 5 (7.3%) were transferred out. Rural maternal residence, lack of maternal ART/ARV prophylaxis, mixed infant feeding and infant birth weight less than 2.5 kg correlated with an HIV-positive status for infant final outcomes.

Conclusion

The final HIV positivity rate of 2.8% is encouraging, but is not population-based. Nevertheless, supported by our findings, we recommend continued programmatic focus on early access to quality prenatal care and maternal ART for pregnant women, especially for women living with HIV in rural areas. Furthermore, implementation of nationwide sensitization and education on six-months’ exclusive infant breastfeeding with concurrent maternal ART should be strengthened and sustained to reduce MTCT rates.

Fetal-maternal surgery for spina bifida in a HIV-infected mother

INTRODUCTION

In select cases, in utero surgery for MMC leads to better outcomes than postnatal repair. However, maternal HIV infection constitutes a formal exclusion criterion due to the potential of vertical HIV transmission. Encouraged by a previous case of a successful fetal spina bifida repair in a Hepatitis Bs antigen positive woman, a plan was devised allowing for fetal surgery.

CASE REPORT

In utero MMC repair was performed although the mother was HIV-infected. To minimize the risk of in utero HIV transmission, the mother was treated by HAART throughout gestation as well as intravenous zidovudine administration during maternal-fetal surgery. The mother tolerated all procedures very well without any sequelae. The currently 20 month-old toddler, is HIV negative and has significantly benefitted from fetal surgery.

DISCUSSION/CONCLUSION

This case shows that maternal HIV is not a priori a diagnosis that excludes fetal surgery. Rather, it might be a surrogate for moving towards personalized medicine and away from applying too rigorous exclusion criteria in the selection of candidates for maternal-fetal surgery.

Mother-to-child transmission of HIV infection and its associated factors in the district of Bilene, Gaza Province-Mozambique

Background

Mother-to-child transmission of HIV infection is a significant problem in Mozambique. This study aims to determine the risk factors associated with mother-to-child transmission of HIV in rural Mozambique.

Methods

Retrospective case-control study in a rural area of Bilene District, on the coast of southern Mozambique, performed from January 2017 to June 2018. The analysis considered the clinical data of HIV exposed children with definitive HIV positive results and their respective infected mothers (cases), and the data of HIV exposed children with definitive HIV negative results and their respective infected mothers (controls) registered in At Risk Child Clinics from 1st January 2017 to 30th June 2018 at the Macia and Praia de Bilene health facilities in Bilene district, Gaza province–Mozambique.

Results

Ninety pregnant women with HIV were involved in the study, including 30 who had transmitted the infection to their children and 60 who had not. Statistical analysis, adjusted for maternal age and gestational age at first antenatal care visit, showed that independent risk factors for transmission were gestational age at first visit (adjusted odds ratio [aOR] 1.19, 95% confidence interval [CI] 1.05–1.36), non-adherence to combination antiretroviral therapy (56.7% vs. 5%; aOR 14.12, 95% CI 3.15–63.41); a viral load of 1000 copies/mL or more (90% vs. 5%; aOR: 156, 95% CI 22.91–1,062) and female sex of the neonate (80% vs. 51.7%; aOR: 4.43, 95% CI 1.33–15.87).

Conclusion

A high viral load and non-adherence to antiretroviral therapy are important predictors of mother-to-child HIV transmission.

HIV in pregnancy: Mother-to-child transmission, pharmacotherapy, and toxicity

An estimated 1.3 million pregnant women were living with HIV in 2018. HIV infection is associated with adverse pregnancy outcomes and all HIV-positive pregnant women, regardless of their clinical stage, should receive a combination of antiretroviral drugs to suppress maternal viral load and prevent vertical fetal infection. Although antiretroviral treatment in pregnant women has undoubtedly minimized mother-to-child transmission of HIV, several uncertainties remain. For example, while pregnancy is accompanied by changes in pharmacokinetic parameters, relevant data from clinical studies are lacking. Similarly, long-term adverse effects of exposure to antiretrovirals on fetuses have not been studied in detail. Here, we review current knowledge on HIV effects on the placenta and developing fetus, recommended antiretroviral regimens, and pharmacokinetic considerations with particular focus on placental transport. We also discuss recent advances in antiretroviral research and potential effects of antiretroviral treatment on placental/fetal development and programming.

HIV-1 at the placenta: immune correlates of protection and infection

PURPOSE OF REVIEW

Mother-to-child transmission (MTCT) of HIV-1 remains a significant global health concern despite implementation of maternal combination antiretroviral therapy for treatment as prevention to offset transmission. The risk of in-utero HIV-1 transmission in the absence of interventions is ∼7%. This low rate of transmission points to innate and adaptive mechanisms to restrict lentiviral infection within the placenta.

RECENT FINDINGS

Placental macrophages (Hofbauer cells) are key mediators in in-utero transmission of HIV-1. Hofbauer cells constitutively express elevated concentrations of regulatory cytokines, which inhibit HIV-1 replication in vitro, and possess intrinsic antiviral properties. Hofbauer cells sequester HIV-1 in intracellular compartments that can be accessed by HIV-1-specific antibodies and may occur in vivo to offset MTCT. Intriguingly, studies have reported strong associations between maternal human cytomegalovirus (HCMV) viremia and MTCT of HIV-1. HCMV infection at the placenta promotes inflammation, chronic villitis, and trophoblast damage, providing potential HIV-1 access into CD4CCR5 target cells. The placenta exhibits a variety of mechanisms to limit HIV-1 replication, yet viral-induced activation with maternal HCMV may override this protection to facilitate in-utero transmission of HIV-1.

SUMMARY

Understanding immune correlates of protection or transmission at the placenta during on-going HIV-1 exposure may contribute to understanding HIV pathogenesis and the development of effective immunotherapies.

African Lessons on Climate Change Risks for Agriculture

Climate change impact assessments on agriculture are subject to large uncertainties, as demonstrated in the present review of recent studies for Africa. There are multiple reasons for differences in projections, including uncertainties in greenhouse gas emissions and patterns of climate change; assumptions on future management, aggregation, and spatial extent; and methodological differences. Still, all projections agree that climate change poses a significant risk to African agriculture. Most projections also see the possibility of increasing agricultural production under climate change, especially if suitable adaptation measures are assumed. Climate change is not the only projected pressure on African agriculture, which struggles to meet demand today and may need to feed an additional one billion individuals by 2050. Development strategies are urgently needed, but they will need to consider future climate change and its inherent uncertainties. Science needs to show how existing synergies between climate change adaptation and development can be exploited.

The role of co-infections in mother-to-child transmission of HIV

In HIV-infected women, co-infections that target the placenta, fetal membranes, genital tract, and breast tissue, as well as systemic maternal and infant infections, have been shown to increase the risk for mother-to-child transmission of HIV (MTCT). Active co-infection stimulates the release of cytokines and inflammatory agents that enhance HIV replication locally or systemically and increase tissue permeability, which weakens natural defenses to MTCT. Many maternal or infant co-infections can affect MTCT of HIV, and particular ones, such as genital tract infection with herpes simplex virus, or systemic infections such as hepatitis B, can have substantial epidemiologic impact on MTCT. Screening and treatment for co-infections that can make infants susceptible to MTCT in utero, peripartum, or postpartum can help reduce the incidence of HIV infection among infants and improve the health of mothers and infants worldwide.

HIV-1 control in battlegrounds: important host genetic variations for HIV-1 mother-to-child transmission and progression to clinical pediatric AIDS

HIV-1 mother-to-child transmission (MTCT) is the passing of maternal HIV-1 to the offspring during pregnancy, labor and delivery, and/or breastfeeding. HIV-1 MTCT and the evolution to pediatric AIDS are multifactorial, dynamic and variable phenotypic conditions. Both genetic and nongenetic variables can influence susceptibility to HIV-1 MTCT or the rate of progression to clinical pediatric AIDS. In this review, we summarize the current state of knowledge about the roles of genetic variations seen in host immune response genes, and those that have been independently associated, mostly through population genetics of candidate genes, with interindividual susceptibility to HIV-1 MTCT, and progression to pediatric AIDS. We examine common and rare host genetic variations at coding and noncoding polymorphisms, whether functional or not, in agonists and antagonists of the immune response, which have been implicated in HIV-1 control in battlegrounds of cell entry, replication and evolution to AIDS. Further, we point to over 380 single-nucleotide polymorphisms, mostly within the HLA super region, recently identified in unbiased genome-wide association studies of HIV replication and evolution in adults, still unexplored in the context of HIV-1 MTCT, and which are likely to also influence susceptibility to pediatric HIV-1/AIDS.