Effects of the COVID-19 pandemic on early infant diagnosis of HIV in Cape Town, South Africa.

Background: In South Africa, infants who are HIV-exposed are tested for HIV at birth and 10 weeks of age. The COVID-19 pandemic lockdown restrictions resulted in reduced access to healthcare services and uncertain impact on early infant HIV testing. Objectives: To describe the effects of the COVID-19 pandemic lockdown restrictions on early infant HIV testing and diagnosis in Cape Town, South Africa. Method: This retrospective cohort study compares HIV-exposed infants born during the first COVID-19 pandemic lockdown (2020) to those born in the same period the year before (2019). Laboratory and other data were abstracted from the Provincial Health Data Centre. Results: A total of 2888 infants were included: 1474 born in 2020 and 1413 in 2019. Compared to 2019, there was an increase in the 10-week HIV polymerase chain reaction (PCR) uptake in 2020 (71% vs. 60%, P < 0.001). There was also an increase in the proportion of infants who demised without 10-week testing or were lost to follow-up in 2020 compared to 2019 (8% vs. 5%, P = 0.017). Differences detected in birth HIV PCR positivity rates between the two groups (1.1% vs. 0.5%, P = 0.17) did not reach statistical significance; however, a significant increase in vertical transmission of HIV by 10 weeks old was found in the 2020 cohort (1.2% vs. 0.5%. P = 0.046). Conclusion: Vertical transmission of HIV at 10 weeks increased in the Cape Town Metropolitan during the initial COVID-19 lockdown. There was also an increase in the proportion of deaths without testing by 10 weeks in the 2020 group.

Factors associated with vertical transmission of HIV in the Western Cape, South Africa: a retrospective cohort analysis.

INTRODUCTION: Monitoring mother-infant pairs with HIV exposure is needed to assess the effectiveness of vertical transmission (VT) prevention programmes and progress towards VT elimination. METHODS: We used routinely collected data on infants with HIV exposure, born May 2018-April 2021 in the Western Cape, South Africa, with follow-up through mid-2022. We assessed the proportion of infants diagnosed with HIV at birth (≤7 days), 10 weeks (>1 to 14 weeks) and >14 weeks as proxies for intrauterine, intrapartum/early breastfeeding and late breastfeeding transmission, respectively. We used mixed-effects Poisson regression to assess factors associated with VT in mothers known with HIV by delivery. RESULTS: We included 50,461 infants born to mothers known with HIV by delivery. HIV was diagnosed in 894 (1.8%) infants. Among mothers, 51% started antiretroviral treatment (ART) before and 27% during pregnancy; 17% restarted during pregnancy after ≥6 months interruption; and 6% had no recorded ART during pregnancy. Most pregnancy ART regimens included non-nucleoside reverse transcriptase inhibitors (83%). Of mothers with available results (90% with viral load [VL]; 70% with CD4), VL nearest delivery was <100 copies/ml in 78% and CD4 count ≥350 cells/µl in 62%. HIV-PCR results were available for 86%, 67% and 48% of eligible infants at birth, 10 weeks and >14 weeks. Among these infants, 0.9%, 0.4% and 1.5% were diagnosed positive at birth, 10 weeks and >14 weeks, respectively. Among infants diagnosed with HIV, 43%, 16% and 41% were diagnosed at these respective time periods. Among mothers with VL<100, 100-999, 1000-99,000 and ≥100,000 copies/ml nearest delivery, infant HIV diagnosis incidence was 0.4%, 2.3%, 6.6% and 18.4%, respectively. Increased VT was strongly associated with recent elevated maternal VL with a seven-fold increased rate with even modestly elevated VL (100-999 vs. <100 copies/ml). VT was also associated with unknown/low maternal CD4, maternal age <20 years, no antenatal ART, later maternal ART start/restart in pregnancy and ART gaps. CONCLUSIONS: Despite high maternal ART coverage and routine postnatal prophylaxis, ongoing VT remains a concern. Timing of infant HIV diagnoses suggests intrapartum and/or breastfeeding transmission in nearly 60%. Interventions to ensure retention on ART and sustained maternal viral suppression are needed to reduce VT.

Association between tuberculosis and pregnancy outcomes: a retrospective cohort study of women in Cape Town, South Africa.

BACKGROUND: Tuberculosis (TB) remains a leading cause of mortality among women of childbearing age and a significant contributor to maternal mortality. Pregnant women with TB are at high risk of adverse pregnancy outcomes. This study aimed to determine risk factors for an adverse pregnancy outcome among pregnant women diagnosed with TB. METHODS: Using TB programmatic data, this retrospective cohort analysis included all women who were routinely diagnosed with TB in the public sector between October 2018 and March 2020 in two health subdistricts of Cape Town, and who were documented to be pregnant during their TB episode. Adverse pregnancy outcome was defined as either a live birth of an infant weighing <2500 g and/or with a gestation period <37 weeks or as stillbirth, miscarriage, termination of pregnancy, maternal or early neonatal death. Demographics, TB and pregnancy characteristics were described by HIV status. Logistic regression was used to determine risk factors for adverse pregnancy outcome. RESULTS: Of 248 pregnant women, half (52%) were living with HIV; all were on antiretroviral therapy at the time of their TB diagnosis. Pregnancy outcomes were documented in 215 (87%) women, of whom 74 (34%) had an adverse pregnancy outcome. Being older (35-44 years vs 25-34 years (adjusted OR (aOR): 3.99; 95% CI: 1.37 to 11.57), living with HIV (aOR: 2.72; 95% CI: 0.99 to 4.63), having an unfavourable TB outcome (aOR: 2.29; 95% CI: 1.03 to 5.08) and having presented to antenatal services ≤1 month prior to delivery (aOR: 10.57; 95% CI: 4.01 to 27.89) were associated with higher odds of an adverse pregnancy outcome. CONCLUSIONS: Pregnancy outcomes among women with TB were poor, irrespective of HIV status. Pregnant women with TB are a complex population who need additional support prior to, during and after TB treatment to improve TB treatment and pregnancy outcomes. Pregnancy status should be considered for inclusion in TB registries.

Maternal and birth outcomes in pregnant people with and without HIV in the Western Cape, South Africa.

INTRODUCTION: We evaluated associations of HIV and antiretroviral therapy (ART) with birth and maternal outcomes at a province-wide-level in the Western Cape, South Africa, in a recent cohort before dolutegravir-based first-line ART implementation. METHODS: This retrospective cohort study included pregnant people delivering in 2018-2019 with data in the Western Cape Provincial Health Data Centre which integrates individual-level data on all public sector patients from multiple electronic platforms using unique identifiers. Adverse birth outcomes (stillbirth, low birth weight (LBW), very LBW (VLBW)) and maternal outcomes (early and late pregnancy-related deaths, early and late hospitalizations) were compared by HIV/ART status and adjusted prevalence ratios (aPRs) calculated using log-binomial regression. RESULTS: Overall 171,960 pregnant people and their singleton newborns were included, 19% (N = 32 015) identified with HIV. Amongst pregnant people with HIV (PPHIV), 60% (N = 19 157) were on ART preconception, 29% (N = 9276) initiated ART during pregnancy and 11% (N = 3582) had no ART. Adjusted for maternal age, multiparity, hypertensive disorders and residential district, stillbirths were higher only for PPHIV not on ART [aPR 1.31 (95%CI 1.04-1.66)] compared to those without HIV. However, LBW and VLBW were higher among all PPHIV, with aPRs of 1.11-1.22 for LBW and 1.14-1.54 for VLBW. Pregnancy-initiated ART was associated with early pregnancy-related death (aPR 3.21; 95%CI 1.55-6.65), and HIV with or without ART was associated with late pregnancy-related death (aPRs 7.89-9.01). CONCLUSIONS: Even in the universal ART era, PPHIV experienced higher rates of LBW and VLBW newborns, and higher late pregnancy-related death regardless of ART status than pregnant people without HIV.

Change in HIV-related characteristics of children hospitalised with infectious diseases in Western Cape, South Africa, 2008-2021: a time trend analysis.

INTRODUCTION: With the scaling up of vertical HIV transmission prevention programmes, the HIV-related population profile of children in South Africa has shifted. We described temporal changes in HIV-related characteristics of children, aged ≤3 years (up to the third birthday), with infectious disease hospitalisations across the Western Cape province. METHODS: We used routinely collected electronic data to identify children born in the Western Cape with infectious disease hospital records for lower respiratory tract infections, diarrhoea, meningitis and tuberculous meningitis, from 2008 to 2021. Linked maternal and child unique identifiers were used to extract pregnancy, HIV-related, laboratory, pharmacy and hospitalisation data. We described temporal changes in child HIV exposure and acquisition status, timing of maternal HIV diagnosis and antiretroviral therapy (ART) start, infant exposure to maternal ART and timing thereof, and maternal CD4 and HIV viral load closest to delivery. We used logistic and multinomial regression to assess changes in characteristics between the Pre-Option B+ (2008-2013), Option B+ (2013-2016) and Universal ART periods (2016-2021). RESULTS: Among 52,811 children aged ≤3 years with hospitalisations, the proportion living with HIV dreased from 7.0% (2008) to 1.1% (2021), while those exposed to HIV and uninfected increased from 14.0% (2008) to 16.1% (2021) with a peak of 18.3% in 2017. Among mothers with HIV (n = 9873), the proportion diagnosed with HIV and starting ART before pregnancy increased from 20.2% to 69.2% and 5.8% to 59.0%, respectively, between 2008 and 2021. Children hospitalised during the Universal ART period had eight times higher odds (Odds Ratio: 8.41; 95% CI: 7.36-9.61) of exposure to maternal ART versus children admitted Pre-Option B+. Among mothers of children exposed to HIV and uninfected with CD4 records (n = 7523), the proportion with CD4 <350 cells/µl decreased from 90.6% (2008) to 27.8% (2021). CONCLUSIONS: In recent years, among children hospitalised with infectious diseases, there were fewer children with perinatally acquired HIV, while an increased proportion of those without HIV acquisition are exposed to maternal HIV and ART. There is a need to look beyond paediatric HIV prevalence and consider child exposure to HIV and ART among children without HIV, when assessing the HIV epidemic's impact on child health services.

Hypertensive disorders of pregnancy and HIV: analysis of a province-wide cohort during 2018 and 2019.

OBJECTIVE: We evaluated the prevalence of de novo hypertensive disorders of pregnancy (dnHDP) in pregnant people with HIV (PPHIV) in the Western Cape Province, South Africa in 2018-2019 by HIV and antiretroviral therapy (ART) status. METHODS: All people with a pregnancy outcome from 1 January 2018 to 31 December 2019 in the Western Cape Provincial Health Data Centre (WCPHDC) were included. The WCPHDC integrates data from multiple electronic platforms according to unique identifiers. dnHDP was classified by ICD-10 code or first-time prescription of antihypertensive drugs less than 140 days before delivery. Pregnant people with preexisting hypertension without superimposed preeclampsia/eclampsia were not considered to have dnHDP. Adjusted prevalence ratios (aPR) for dnHDP by HIV/ART status were calculated using Poisson regression with robust variance. RESULTS: Among 180 553 pregnant people studied, 13 677 (7.6%) had dnHDP and 33 978 (18.8%) were PPHIV. Among PPHIV, 11.3% ( N  = 3827) had no evidence of ART, 59.7% ( N  = 20 283) initiated ART preconception and 29.0% ( N  = 9868) had ART initiated during pregnancy. Compared to those without HIV (7.7%), dnHDP prevalence was lower in PPHIV with preconception [6.9%; aPR 0.78; 95% confidence interval (CI) 0.74-0.83] or pregnancy-initiated ART (7.0%; aPR 0.83; 95% CI 0.75-0.92) and higher in PPHIV without ART (9.8%; aPR 1.17; 95% CI 1.06-1.29) adjusted for maternal age, multiparity, multigestation pregnancy and preexisting hypertension. ART duration by delivery of at least 100 weeks versus pregnancy-initiated ART of 20-<40 weeks was protective (aPR 0.88; 95% CI 0.78-0.98). CONCLUSIONS: In the context of universal ART, these findings are reassuring for most PPHIV. ART was not associated with increased dnHDP prevalence and longer ART duration was protective.

Determining antenatal medicine exposures in South African women: a comparison of three methods of ascertainment.

BACKGROUND: In the absence of clinical trials, data on the safety of medicine exposures in pregnancy are dependent on observational studies conducted after the agent has been licensed for use. This requires an accurate history of antenatal medicine use to determine potential risks. Medication use is commonly determined by self-report, clinician records, and electronic pharmacy data; different data sources may be more informative for different types of medication and resources may differ by setting. We compared three methods to determine antenatal medicine use (self-report, clinician records and electronic pharmacy dispensing records [EDR]) in women attending antenatal care at a primary care facility in Cape Town, South Africa in a setting with high HIV prevalence. METHODS: Structured, interview-administered questionnaires recorded self-reported medicine use. Data were collected from clinician records and EDR on the same participants. We determined agreement between these data sources using Cohen's kappa and, lacking a gold standard, used Latent Class Analysis to estimate sensitivity, specificity and positive predictive value (PPV) for each data source. RESULTS: Between 55% and 89% of 967 women had any medicine use documented depending on the data source (median number of medicines/participant = 5 [IQR 3-6]). Agreement between the datasets was poor regardless of class except for antiretroviral therapy (ART; kappa 0.6-0.71). Overall, agreement was better between the EDR and self-report than with either dataset and the clinician records. Sensitivity and PPV were higher for self-report and the EDR and were similar for the two. Self-report was the best source for over-the-counter, traditional and complementary medicines; clinician records for vaccines and supplements; and EDR for chronic medicines. CONCLUSIONS: Medicine use in pregnancy was common and no single data source included all the medicines used. ART was the most consistently reported across all three datasets but otherwise agreement between them was poor and dependent on class. Using a single data collection method will under-estimate medicine use in pregnancy and the choice of data source should be guided by the class of the agents being investigated.

Cohort profile: the Western Cape Pregnancy Exposure Registry (WCPER).

PURPOSE: The Western Cape Pregnancy Exposure Registry (PER) was established at two public sector healthcare sentinel sites in the Western Cape province, South Africa, to provide ongoing surveillance of drug exposures in pregnancy and associations with pregnancy outcomes. PARTICIPANTS: Established in 2016, all women attending their first antenatal visit at primary care obstetric facilities were enrolled and followed to pregnancy outcome regardless of the site (ie, primary, secondary, tertiary facility). Routine operational obstetric and medical data are digitised from the clinical stationery at the healthcare facilities. Data collection has been integrated into existing services and information platforms and supports routine operations. The PER is situated within the Provincial Health Data Centre, an information exchange that harmonises and consolidates all health-related electronic data in the province. Data are contributed via linkage across a unique identifier. This relationship limits the missing data in the PER, allows validation and avoids misclassification in the population-level data set. FINDINGS TO DATE: Approximately 5000 and 3500 pregnant women enter the data set annually at the urban and rural sites, respectively. As of August 2021, >30 000 pregnancies have been recorded and outcomes have been determined for 93%. Analysis of key obstetric and neonatal health indicators derived from the PER are consistent with the aggregate data in the District Health Information System. FUTURE PLANS: This represents significant infrastructure, able to address clinical and epidemiological concerns in a low/middle-income setting.

Viral genome sequence datasets display pervasive evidence of strand-specific substitution biases that are best described using non-reversible nucleotide substitution models.

Background: The vast majority of phylogenetic trees are inferred from molecular sequence data (nucleotides or amino acids) using time-reversible evolutionary models which assume that, for any pair of nucleotide or amino acid characters, the relative rate of X to Y substitution is the same as the relative rate of Y to X substitution. However, this reversibility assumption is unlikely to accurately reflect the actual underlying biochemical and/or evolutionary processes that lead to the fixation of substitutions. Here, we use empirical viral genome sequence data to reveal that evolutionary non-reversibility is pervasive among most groups of viruses. Specifically, we consider two non-reversible nucleotide substitution models: (1) a 6-rate non-reversible model (NREV6) in which Watson-Crick complementary substitutions occur at identical relative rates and which might therefor be most applicable to analyzing the evolution of genomes where both complementary strands are subject to the same mutational processes (such as might be expected for double-stranded (ds) RNA or dsDNA genomes); and (2) a 12-rate non-reversible model (NREV12) in which all relative substitution types are free to occur at different rates and which might therefore be applicable to analyzing the evolution of genomes where the complementary genome strands are subject to different mutational processes (such as might be expected for viruses with single-stranded (ss) RNA or ssDNA genomes). Results: Using likelihood ratio and Akaike Information Criterion-based model tests, we show that, surprisingly, NREV12 provided a significantly better fit to 21/31 dsRNA and 20/30 dsDNA datasets than did the general time reversible (GTR) and NREV6 models with NREV6 providing a better fit than NREV12 and GTR in only 5/30 dsDNA and 2/31 dsRNA datasets. As expected, NREV12 provided a significantly better fit to 24/33 ssDNA and 40/47 ssRNA datasets. Next, we used simulations to show that increasing degrees of strand-specific substitution bias decrease the accuracy of phylogenetic inference irrespective of whether GTR or NREV12 is used to describe mutational processes. However, in cases where strand-specific substitution biases are extreme (such as in SARS-CoV-2 and Torque teno sus virus datasets) NREV12 tends to yield more accurate phylogenetic trees than those obtained using GTR. Conclusion: We show that NREV12 should, be seriously considered during the model selection phase of phylogenetic analyses involving viral genomic sequences.