In utero and intra-partum HIV-1 transmission and acute HIV-1 infection during pregnancy: using the BED capture enzyme-immunoassay as a surrogate marker for acute infection

Incident HIV acquisition among pregnant women in Botswana: findings from the Tsepamo birth outcomes surveillance study

INTRODUCTION

In Botswana, where almost all pregnant women known to have HIV receive antiretroviral therapy, a large proportion of vertical HIV transmission may occur among women with incident undiagnosed HIV infection during pregnancy. Botswana guidelines recommend repeat HIV testing every 3 months in pregnancy, with at least one test in the third trimester. We evaluated the rate of repeat HIV testing, calculated HIV incidence during pregnancy and estimated missed seroconversions.

METHODS

In the Botswana Tsepamo Study, we abstracted HIV test dates and results from obstetric records of all women who delivered at maternity wards in 18 communities between 7th May 2017 and 20th August 2021. We defined seroconversion as an initial negative/indeterminate HIV test in pregnancy followed by a positive test during pregnancy/at delivery. The incidence rate (IR) of seroconversion was calculated among women with > = 2 known test dates. Missed seroconversions were estimated among women without a test in the third trimester by applying the IR to the time after the last HIV test until delivery.

RESULTS

Among 103,529 women delivering in the study period testing negative at the first test and with known conception and HIV test dates, 29,085 (28%) were tested in one trimester of pregnancy, 73,156 (71%) were tested in ≥ 2 trimesters of pregnancy and 9628 (9%) had a test in all trimesters. A total of 78,162 (75%) women had a third-trimester test. There were 223 seroconversions (2.58/1000 pregnancies, 0.26%) among those with ≥ 2 known HIV test dates, yielding an IR of 0.69/100 person-years. Among 25,289 women who did not have a test in the third trimester, we estimate approximately 58 seroconversions may have been missed during pregnancy due to a lack of repeat testing. Factors associated with seroconversion during pregnancy included younger age, less education and not being married.

CONCLUSIONS

More than two-thirds of women had repeat HIV testing in pregnancy and HIV incidence was low. However, an estimated 21% of seroconversions in pregnancy were likely missed due to a lack of re-testing. To reach the goal of zero new paediatric HIV infections, Botswana will need to intensify repeat HIV testing in the third trimester of pregnancy.

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.

Optimizing HIV retesting during pregnancy and postpartum in four countries: a cost-effectiveness analysis

INTRODUCTION

HIV retesting during late pregnancy and breastfeeding can help detect new maternal infections and prevent mother-to-child HIV transmission (MTCT), but the optimal timing and cost-effectiveness of maternal retesting remain uncertain.

METHODS

We constructed deterministic models to assess the health and economic impact of maternal HIV retesting on a hypothetical population of pregnant women, following initial testing in pregnancy, on MTCT in four countries: South Africa and Kenya (high/intermediate HIV prevalence), and Colombia and Ukraine (low HIV prevalence). We evaluated six scenarios with varying retesting frequencies from late in antenatal care (ANC) through nine months postpartum. We compared strategies using incremental cost-effectiveness ratios (ICERs) over a 20-year time horizon using country-specific thresholds.

RESULTS

We found maternal retesting once in late ANC with catch-up testing through six weeks postpartum was cost-effective in Kenya (ICER = $166 per DALY averted) and South Africa (ICER=$289 per DALY averted). This strategy prevented 19% (Kenya) and 12% (South Africa) of infant HIV infections. Adding one or two additional retests postpartum provided smaller benefits (1 to 2 percentage point increase in infections averted versus one retest). Adding three retests during the postpartum period averted additional infections (1 to 3 percentage point increase in infections averted versus one retest) but ICERs ($7639 and in Kenya and $11 985 in South Africa) greatly exceeded the cost-effectiveness thresholds. In Colombia and Ukraine, all retesting strategies exceeded the cost-effectiveness threshold and prevented few infant infections (up to 31 and 5 infections, respectively).

CONCLUSIONS

In high HIV burden settings with MTCT rates similar to those seen in Kenya and South Africa, HIV retesting once in late ANC, with subsequent intervention, is the most cost-effective strategy for preventing infant HIV infections. In these settings, two HIV retests postpartum marginally reduced MTCT and were less costly than adding three retests. Retesting in low-burden settings with MTCT rates similar to Colombia and Ukraine was not cost-effective at any time point due to very low HIV prevalence and limited breastfeeding.

HIV in pregnancy - An update

Human immunodeficiency virus (HIV) is an infection with a global prevalence and currently no cure or vaccine. Women living with HIV who become pregnant or who acquire the virus during pregnancy are at risk of both maternal and perinatal morbidity and mortality mainly if the virus is poorly controlled. Furthermore, there is a risk of vertical transmission to the fetus during pregnancy labour and postpartum through breastfeeding.

Appropriate management must be instituted to reduce the consequences of HIV in pregnancy, ideally starting with preconception counselling and planning pregnancies when the viral load is minimum. During pregnancy, an appropriate combined anti-retroviral (cART) medication is mandatory with very close monitoring of the viral load, cluster of differentiation 4 (CD4) cell counts, blood counts, liver and kidney function tests.

Planning delivery should not be different in women on cART and suppressed viral loads. However, special care must be taken to limit vertical transmission in those who present late and in whom viral load is unknown or not controlled at the time of delivery.

Breastfeeding remains a potential source of infection for the baby and is being discouraged in high-income countries for women living with HIV; however, in low-income countries, the recommendation is exclusive breastfeeding. If breastfeeding must happen, it is best when viral load is suppressed, and cART continued until weaning.

Serodiscordant couples present unique problems, and their management should begin with the planning of pregnancy. Emphasis should be on taking steps to prevent HIV transmission to the negative partner and vertical transmission to the new-born.

Mistakes from the HIV pandemic should inform the COVID-19 response for maternal and newborn care

BACKGROUND

In an effort to prevent infants being infected with SARS-CoV-2, some governments, professional organisations, and health facilities are instituting policies that isolate newborns from their mothers and otherwise prevent or impede breastfeeding.

WEIGHING OF RISKS IS NECESSARY IN POLICY DEVELOPMENT

Such policies are risky as was shown in the early response to the HIV pandemic where efforts to prevent mother to child transmission by replacing breastfeeding with infant formula feeding ultimately resulted in more infant deaths. In the COVID-19 pandemic, the risk of maternal SARS-CoV-2 transmission needs to be weighed against the protection skin-to-skin contact, maternal proximity, and breastfeeding affords infants.

CONCLUSION

Policy makers and practitioners need to learn from the mistakes of the HIV pandemic and not undermine breastfeeding in the COVID-19 pandemic. It is clear that in order to maximise infant health and wellbeing, COVID-19 policies should support skin-to-skin contact, maternal proximity, and breastfeeding.

HIV testing of male partners of pregnant women in Porto Alegre, Brazil: a potential strategy for reduction of HIV seroconversion during pregnancy

Pregnant women have a significantly higher risk of HIV acquisition during gestation than their non-pregnant counterparts due to behavioral and biological factors. Acute seroconversion during gestation results in increased HIV mother-to-child transmission rates and has been identified as a major public health challenge. In order to address potential HIV seroconversion in our pregnant patients, we conducted a prospective cohort study to evaluate the acceptability of offering HIV testing to sexual partners of HIV-negative pregnant women receiving antenatal care at two hospitals in Porto Alegre, Brazil. Over a 14-month study period, HIV-negative pregnant women at two hospital-based clinic sites were encouraged to bring their stable sexual partner for HIV voluntary counseling and testing during prenatal care. Women were re-interviewed following delivery to measure success of the intervention. Of the 1223 HIV-negative pregnant women enrolled in the study, 663 (54%) of their male sexual partners received HIV testing during antenatal care and 4 (0.6%) were diagnosed with HIV infection. A total of 645 women were interviewed at the time of delivery, with 620 (97%) confirming that HIV testing was suggested to their partner. The most common reason provided by women as to why partners did not come for testing was work (69%) and lack of perceived risk (14%). Independent predictors of successful partner testing included being white (odds ratio [OR] 1.59, 95% confidence interval [CI] 1.18-2.12), married (OR 1.78, 95% CI 1.08-2.94), having an older age of sexual debut (OR 0.94, 95% CI 0.9-0.98), and being recruited at Hospital Conceiçao (OR 2.1, 95% CI 1.52-2.88). We conclude that HIV partner testing during prenatal care is acceptable, rendering this intervention attractive to public health programs targeting prevention of sexually transmitted infections.

Recent HIV-1 infection: identification of individuals with high viral load setpoint in a voluntary counselling and testing centre in rural Mozambique

Background

Identification of recent HIV-infections is important for describing the HIV epidemic and compiling HIV-RNA-setpoint data for future HIV intervention trials. We conducted a study to characterize recent infections, and HIV-RNA-setpoint within the adult population presenting at a voluntary counselling and testing centre (VCT) in southern Mozambique.

Methods

All adults attending the Manhiça District-Hospital VCT between April and October 2009 were recruited if they had at least one positive rapid HIV-serology test. Patients were screened for recent HIV-1 infection by BED-CEIA HIV-incidence test. Clinical examination, assessment of HIV-RNA and CD4 cell counts were performed at enrollment, 4 and 10 months.

Results

Of the 492 participants included in this study, the prevalence of recent infections as defined by BED-CEIA test, CD4 counts >200 cells/µl and HIV-RNA >400 copies/mL, was 11.58% (57/492; 95% CI 8.89–14.74). Due to heterogeneity in HIV-RNA levels in recently infected patients, individuals were categorized as having “high” HIV-RNA load if their HIV-RNA level was above the median (4.98 log₁₀ copies/mL) at diagnosis. The “high” HIV-RNA group sustained a significantly higher HIV-viral load at all visits with a median HIV-RNA setpoint of 5.22 log₁₀ copies/mL (IQR 5.18–5.47) as compared to the median of 4.15 log₁₀ copies/ml (IQR 3.37–4.43) for the other patients (p = 0.0001).

Conclusion

The low proportion of recent HIV-infections among HIV-seropositive VCT clients suggests that most of this population attends the VCT at later stages of HIV/AIDS. Characterization of HIV-RNA-setpoint may serve to identify recently infected individuals maintaining HIV viral load>5 log10 copies/mL as candidates for antiretroviral treatment as prevention interventions.