ABSTRACT
Objective: Evaluate the impact of the timing of SARS-CoV-2 infection on pregnancy outcomes in a low-middle income setting. Design: two parallel, observational studies. Setting and population: pregnant women or women presenting for labour, enrolled between April-September 2020, in South Africa. Methods: i) longitudinal follow-up study of symptomatic or asymptomatic pregnant women investigated for SARS-CoV-2 infection antenatally, ii) cross-sectional study of SARS-CoV-2 infection at time of labour. SARS-CoV-2 infection was investigated by nucleic acid amplification test (NAAT). Main Outcome Measures: association of SARS-CoV-2 infection on nasal swab and birth outcomes. Results: Antenatally, 793 women were tested for SARS-CoV-2. Overall SARS-CoV-2 infection was confirmed in 138 women, including 119/275 with symptomatic illness (COVID-19) and 19/518 asymptomatic women; 493 women were asymptomatic and SARS-CoV-2 non-reactive. Women with COVID-19 were 1.66-times (95%CI: 1.02, 1.71) more likely to have a low-birthweight newborn (30%) compared to asymptomatic women without SARS-CoV-2 (21%). Overall, 3117 women were tested for SARS-CoV-2 infection at delivery, including 1560 healthy women with an uncomplicated term delivery. Adverse birth outcomes or pregnancy-related complications were not associated with infection at delivery. Among women with SARS-CoV-2 infection at delivery, NAAT was reactive on 6/98 of maternal blood samples, 8/93 of cord-blood, 14/54 of placentas and 3/22 of nasopharyngeal swabs from newborns collected within 72-hours of birth. Conclusions: Antenatal, but not intrapartum, SARS-CoV-2 infection was associated with low-birthweight delivery. Maternal infection at the time of labour was associated with in utero foetal and placental infection, and possible vertical and/or horizontal viral transfer to the newborn.
Subject(s)
COVID-19 , Placenta Diseases , InfectionsABSTRACT
Background: Healthcare workers (HCWs) are at high risk for SARS-CoV-2 infection. We investigated the burden of SARS-CoV-2 infection in a longitudinal cohort of frontline HCWs in South Africa from April to September 2020.Methods: HCWs working in five departments at Chris Hani Baragwanath Academic Hospital were followed-up weekly, independent of clinical symptomatology, during the first wave of the COVID-19 pandemic and tested for SARS-CoV-2 infection by polymerase chain reaction (PCR). Furthermore, paired sera collected at enrolment and end of surveillance were tested for IgG to receptor binding domain of the spike protein to evaluate for sero-response.Findings: Overall 137 (34·6%) of 396 enrolled HCWs had PCR-confirmed SARS-CoV-2 infection (132·1 [95%CI: 111·8, 156·2] per 1,000 person-months), and an additional 27 only showed sero-response at the end of follow-up. HCWs in the Internal Medicine department had the highest rate of SARS-CoV-2 infection (61·7%; 103/167), with HCWs from other departments (27·5%; 63/229) experiencing 70% lower odds of infection (adjust odds ratio 0·29 [95%CI: 0·17, 0·49]) in multivariable analysis. Among SARS-CoV-2 PCR-confirmed cases, 14 (10·4%) HCWs remained asymptomatic, 41 (30·4%) were pre-symptomatic and 80 (59·3%) were symptomatic. Symptomatic cases compared to asymptomatic had lower PCR cycle threshold values at diagnosis (24·2 vs. 28·9) and longer duration of PCR-positivity (18·9 vs. 13·0 days).Interpretation: The high rates of SARS-CoV-2 infection among HCWs in a relatively well-resourced middle-income setting attest to the threat that the COVID-19 pandemic poses to health care systems.Funding: This study was supported by the European & Developing Countries Clinical Trials Partnership (grant number RIA2020EF-3020) and The Bill & Melinda Gates Foundation (grant number INV018148_2020). There was also partial support from the Department of Science and Technology and National Research Foundation: South African Research Chair Initiative in Vaccine Preventable Diseases; and the South African Medical Research Council.Conflict of Interest: MCN has received grant support from the Bill & Melinda Gates Foundation, MedImmune and Pfizer outside the submitted work; has received honoraria from Pfizer and Sanofi Pasteur outside the submitted work. CLC has received grant support from the Bill & Melinda Gates Foundation, Pfizer and IMPRINT outside the submitted work; has received honoraria from Pfizer outside the submitted work. SAM has received grant support from the Bill & Melinda Gates Foundation, Pfizer, GlaxoSmithKline, Minervax and Novavx outside the submitted work; personal fees from Bill & Melinda Gates Foundation outside the submitted work. All other authors have nothing to disclose.Ethical Approval: The study was approved by the Human Research Ethics Committee of the University of the Witwatersrand (reference number 200405) and conducted in accordance with Good Clinical Practice guidelines. All study participants provided written informed consent.