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Topics in Antiviral Medicine ; 30(1 SUPPL):300-301, 2022.
Article in English | EMBASE | ID: covidwho-1880872


Background: South Africa is one of the African countries most affected by the COVID-19 pandemic. SARS-CoV-2 seroprevalence surveys provide valuable epidemiological information given the existence of asymptomatic cases. We report the findings of the first nationwide household-based population estimates of SARS-CoV-2 seroprevalence among people aged 12 years and older in South Africa. Methods: The survey used a cross-sectional multi-stage stratified cluster design undertaken over two separate time periods (November 2020-February 2021 and April-June 2021) which coincided with the second and third waves of the pandemic in South Africa. The Abbott® and Euroimmun® ani-SARS CoV-2 antibody assays were used to test for SARS-CoV-2 antibodies, the latter being the final result. The survey data was weighted with final individual weights benchmarked against 2020 mid-year population estimates by age, race, sex, and province. Frequencies were used to describe characteristics of the study population and SARS-CoV-2 seroprevalence. Bivariate and multivariate logistics regression analysis were used to identify factors associated with SARS-CoV-2 seropositivity. Results: 13640 participants gave a blood sample. The SARS-CoV-2 seroprevalence using the Euroimmun assay was 19.6% (95% CI 17.9-21.3) over the study period, translating to an estimated 8 675 265 (95% CI 7 508 393-9 842 137) estimated infections among people aged 12 years and older across South Africa by June 2021. Seroprevalence was higher in the Free State (26.8%), and Eastern Cape (26.0%) provinces (Figure). Increased odds of seropositivity were associated with prior PCR testing [aOR=1.29 (95% CI: 0.99-1.66)], being female [aOR=1.28 (95% CI 1.00-1.64), p=0.048] and hypertension, [aOR=1.28 (95% CI 1.00-1.640, p=0.048]. Conclusion: These findings highlight the burden of infection in South Africa by June 2021, and support testing strategies that focus on individuals with known exposure or symptoms since universal testing is not feasible. Females and younger people were more likely to be infected suggesting need for additional strategies targeting these populations. The estimated number of infections was 6.5 times higher than the number of SARS-CoV-2 cases reported nationally, suggesting that the country's testing strategy and capacity partly explain the dynamics of the pandemic. It is therefore essential to bolster testing capacity and to rapidly scale up vaccinations in order to contain the spread of the virus in the country.

Topics in Antiviral Medicine ; 30(1 SUPPL):332, 2022.
Article in English | EMBASE | ID: covidwho-1880610


Background: Accurate and reliable serological assays are essential for epidemiological surveillance of SARS-CoV-2. Several commercial anti-SARS assays are available and use cases for serological testing includes surveillance. However, there is growing evidence of varying performance of SARS-CoV-2 assays dependent of their format. We compare the performance of 3 different assays used in a national serosurvey undertaken between April and June 2021, in South Africa before widescale vaccination roll out. Methods: Venous blood samples from participants ≥12 years were transported under cold chain to a central testing laboratory within 24 hours of collection. Samples were tested for SARS CoV-2 antibodies with the Abbott nucleocapsid (NC)-based Architect anti-SARS CoV-2 chemiluminescent microparticle immunoassay (CMIA), the EuroImmun Spike (S)-based assay and the Roche total IgG NC-based Elecsys Anti-SARS-CoV-2 electrochemiluminescence immunoassay (ECLIA) on the Cobas e411 platform. We compared antibody detection proportions. Results: 8146 participants (median age 40 years, IQR 26-55) 5.6% of whom reported ≥1 SARS-CoV-2 symptom in the preceding 3 months gave a blood sample. Samples were tested on the Abbott assay with different cut-offs:-15.5% tested positive at the 1.40 cut-off and 26.8% at the 0.49 lower cut-off. 21.6% of the samples tested positive on the Euroimmun and 39.0% tested positive on the Roche assay (Table). 286 samples were from respondents self-reporting a prior positive PCR test, and among them 149(52.1%), 156(54.6%), and 206(72.3%) were positive on the Abbott (1.40 cut-off), Euroimmun and Roche assays respectively. 116/286(40.6%) of these were positive on all three assays and with 21(7.3%) positive on Roche only. 224/286(78.3%) of those reporting prior PCR test positivity were positive at the lower Abbott cut-off, with 47(16.4%) positive on Abbott only. Conclusion: These samples collected before wide scale vaccination roll out in South Africa show variable performance of these assays with the Roche NC assay detecting more infections that both the Abbott NC assay(0.40 cut-off) and the Euroimmun S assay.This could be reflective of seroreversion previously reported with Abbott and Euroimmun, and the greater sensitivity of Roche assay targeting the more abundant NC as an epitope. Use of direct, double Antigen-sandwich-based assays that are stable and have increased sensitivity over time may be optimal to detect both natural and vaccine-induced immunity in serosurveys.

Transplantation ; 105(7):S95-S95, 2021.
Article in English | Web of Science | ID: covidwho-1431471
Transplantation ; 105(7 SUPPL 1):S95, 2021.
Article in English | EMBASE | ID: covidwho-1306078


Introduction: The Covid-19 pandemic has placed many of our services under greater strain, raising challenges to maintain monitoring protocol and continuity of care for children and families. Social distancing measures were introduced in the UK in March 2020. Virtual clinics were identified as a potential way forward to ensure patient management was at the forefront of our care. Aim: To describe our experience of supporting children and families following intestinal transplant during a global pandemic. Method 1. All calls and emails reviewed from Nurse Led telephone advice service (March 2020 - January 2021) and key concerns identified. Discuss the need for face to face (F2F) appointments and admissions if circumstances require. • Virtual clinic platforms like Accurx, Zoom and Microsoft teams were used. Results: Increased telephone calls to our nurse led telephone advice service for reassurance and families' desire for information on shielding and safety within hospital environments. Providing information leaflets on accessing different platforms for virtual clinics has been essential to increase engagement to new systems. Initial feedback from the families was that virtual clinics/information sessions can feel overwhelming and distant. Reassuring patients and families has been essential for the MDT to acknowledge this while helping them develop new strategies to cope with the changes and challenges faced.Signposting families to support networks to manage their anxiety through practical support and providing up to date information. Enabling families to sign consent forms for transplant in collaboration with local teams. Discussion: Children and families were reassured that virtual clinics provide the same opportunities to discuss their child's/young person's clinical needs as well as emotional support. Involvement of MDT team members e.g. Clinical Psychologist, Dietitian in virtual clinic platforms restored confidence in families about our holistic delivery of care. Virtual clinics helped in reducing social and welfare issues for many families. Conclusion: New virtual technology has been embraced by families and many are keen to continue with a combination of virtual and F2F appointments in the future. Virtual clinics and information sessions can offer greater access and convenience to patients and their families, many of whom travel great distances to attend hospital appointments.