Recent HIV infection among pregnant women in the 2017 antenatal sentinel cross-sectional survey, South Africa: Assay-based incidence measurement.

INTRODUCTION: New HIV infection during pre-conception and pregnancy is a significant contributor of mother-to-child transmission of HIV in South Africa. This study estimated HIV incidence (defined as new infection within the last one year from the time of the survey which included both new infections occurred during pregnancy or just before pregnancy) among pregnant women and described the characteristics of recently infected pregnant women at national level. METHODS: Between 1 October and 15 November 2017, we conducted a national cross-sectional survey among pregnant women aged 15-49 years old attending antenatal care at 1,595 public facilities. Blood specimens were collected from pregnant women and tested for HIV in a centralised laboratory. Plasma viral load and Limiting Antigen Avidity Enzyme Immunosorbent Assay (LAg) tests were further performed on HIV positive specimens to differentiate between recent and long-term infections. Recent infection was defined as infection that occurred within one year from the date of collection of blood specimen for the survey. Data on age, age of partner, and marital status were collected through interviews. Women whose specimens were classified as recent by LAg assay and with viral loads >1,000 copies/mL were considered as recently infected. The calculated proportion of HIV positive women with recent infection was adjusted for assay-specific parameters to estimate annual incidence. Survey multinomial logistic regression was used to examine factors associated with being recently infected using HIV negative women as a reference group. Age-disparate relationship was defined as having a partner 5 or more years older. RESULTS: Of 10,049 HIV positive participants with LAg and viral load data, 1.4% (136) were identified as recently infected. The annual HIV incidence was 1.5% (95% confidence interval (CI): 1.2-1.7). In multivariable analyses, being single (adjusted odds ratio, aOR: 3.4, 95% CI: 1.8-6.2) or cohabiting (aOR: 3.8, 95% CI: 1.8-7.7), compared to being married as well as being in an age-disparate relationship among young women (aOR: 3.1, 95% CI: 2.0-4.7; reference group: young women (15-24years) whose partners were not 5 years or more older) were associated with higher odds of recent infection. CONCLUSIONS: Compared to previous studies among pregnant women, the incidence estimated in this study was substantially lower. However, the UNAIDS target to reduce incidence by 75% by 2020 (which is equivalent to reducing incidence to <1%) has not been met. The implementation of HIV prevention and treatment interventions should be intensified, targeting young women engaged in age-disparate relationship and unmarried women to fast track progress towards the UNAIDS target.

Awareness of HIV-positive status and linkage to treatment prior to pregnancy in the "test and treat" era: A national antenatal sentinel survey, 2017, South Africa.

INTRODUCTION: Knowledge of HIV status in South Africa (SA) is reported to be 90% among people living with HIV. National level estimates could mask population-specific levels, which are critical to monitor program coverage and potential impact. Using data from the 2017 national antenatal sentinel survey, we assessed knowledge of HIV-positive status, initiation of antiretroviral therapy (ART), and socio-demographic characteristics associated with knowledge of HIV-positive status prior to the current pregnancy among women attending antenatal care. METHODS: Between 1 October and 15 November 2017, a nationally representative sample of 32,716 pregnant women were enrolled from 1,595 public health facilities selected from all districts of SA. Data on age, gravidity, knowledge of HIV-positive status and ART initiation prior to pregnancy were extracted from medical records. A blood sample was collected from each woman regardless of prior knowledge of HIV status or ART history, and tested for HIV in the laboratory. All HIV-positive pregnant women enrolled in the survey were eligible for inclusion in the analysis. Multivariable survey logistic regression was used to examine factors associated with knowledge of HIV-positive status prior to the current pregnancy. RESULTS: Of 10,065 eligible HIV-positive women, 60.8% (95% confidence interval (CI):59.9%-61.7%) knew their HIV status prior to the current pregnancy, of whom 91.1% (95% CI: 90.4%-91.7%) initiated ART prior to the current pregnancy. Knowledge of HIV-positive status was lower among adolescent girls and young women (15-24 years) (38.9%) and primigravid women (40.5%) compared with older women (35-49 years) (75.5%) and multigravid women (64.7%). In a multivariable analysis, significant effect modification was found between gravidity and age (P value = 0.047). Being in the age group 15-24 years compared to the age group 35-49 years decreased the odds of knowing HIV-positive status by 80% (adjusted odds ratio (AOR): 0.2, 95% CI:0.1-0.4) among primigravid women and by 60%(AOR: 0.4, 95% CI:0.3-0.4) among multigravid women. CONCLUSION: Knowledge of HIV-positive status prior to the current pregnancy fell short of the target of 90% among pregnant women living with HIV. This was especially low among adolescent girls and young women, highlighting the gap in youth friendly reproductive health and HIV testing services.

Viral suppression and factors associated with failure to achieve viral suppression among pregnant women in South Africa.

OBJECTIVE: To describe viral load levels among pregnant women and factors associated with failure to achieve viral suppression (viral load ≤50 copies/ml) during pregnancy. DESIGN: Between 1 October and 15 November 2017, a cross-sectional survey was conducted among 15-49-year-old pregnant women attending antenatal care (ANC) at 1595 nationally representative public facilities. METHODS: Blood specimens were taken from each pregnant woman and tested for HIV. Viral load testing was done on all HIV-positive specimens. Demographic and clinical data were extracted from medical records or self-reported. Survey logistic regression examined factors associated with failure to achieve viral suppression. RESULT: Of 10 052 HIV-positive participants with viral load data, 56.2% were virally suppressed. Participants initiating antiretroviral therapy (ART) prior to pregnancy had higher viral suppression (71.0%) by their third trimester compared with participants initiating ART during pregnancy (59.3%). Booking for ANC during the third trimester vs. earlier: [adjusted odds ratio (AOR) 1.8, 95% confidence interval (CI):1.4-2.3], low frequency of ANC visits (AOR for 2 ANC visits vs. ≥4 ANC visits: 2.0, 95% CI:1.7-2.4), delayed initiation of ART (AOR for ART initiated at the second trimester vs. before pregnancy:2.2, 95% CI:1.8-2.7), and younger age (AOR for 15-24 vs. 35-49 years: 1.4, 95% CI:1.2-1.8) were associated with failure to achieve viral suppression during the third trimester. CONCLUSION: Failure to achieve viral suppression was primarily associated with late ANC booking and late initiation of ART. Efforts to improve early ANC booking and early ART initiation in the general population would help improve viral suppression rates among pregnant women. In addition, the study found, despite initiating ART prior to pregnancy, more than one quarter of participants did not achieve viral suppression in their third trimester. This highlights the need to closely monitor viral load and strengthen counselling and support services for ART adherence.

Assessment of readiness to transition from antenatal HIV surveillance surveys to PMTCT programme data-based HIV surveillance in South Africa: The 2017 Antenatal Sentinel HIV Survey.

OBJECTIVE: South Africa has used antenatal HIV surveys for HIV surveillance in pregnant women since 1990. We assessed South Africa's readiness to transition to programme data based antenatal HIV surveillance with respect to PMTCT uptake, accuracy of point-of-care rapid testing (RT) and selection bias with using programme data in the context of the 2017 antenatal HIV survey. METHODS: Between 1 October and 15 November 2017, the national survey was conducted in 1,595 public antenatal facilities selected using stratified multistage cluster sampling method. Results of point-of-care RT were obtained from medical records. Blood samples were taken from eligible pregnant women and tested for HIV using immunoassays (IA) in the laboratory. Descriptive statistics were used to report on: PMTCT uptake; agreement between HIV point-of-care RT and laboratory-based HIV-1 IA; and selection bias associated with using programme data for surveillance. RESULTS: PMTCT HIV testing uptake was high (99.8%). The positive percent agreement (PPA) between RT and IA was lower than the World Health Organization (WHO) benchmark (97.6%) at 96.3% (95% confidence interval (CI): 95.9%-96.6%). The negative percent agreement was above the WHO benchmark (99.5%), at 99.7% (95% CI: 99.6%-99.7%) nationally. PPA markedly varied by province (92.9%-98.3%). Selection bias due to exclusion of participants with no RT results was within the recommended threshold at 0.3%. CONCLUSION: For the three components assessed, South Africa was close to meeting the WHO standard for transitioning to routine RT data for antenatal HIV surveillance. The wide variations in PPA across provinces should be addressed.