National Coronavirus Antibody Survey (NCAS) 2020-21

Description:
Topics covered in the questionnaire are: household members and their characteristics, household income, availability of services, demographic information, medical history, health risk behaviours, symptom history, access to COVID-19 prevention measures, self-perceived risk, and travel habits or physical distancing.

A total of 10 109 VPs were approached to participate in the survey, of the 10 109 VPs approached, 5 580 agreed to participate, giving a household response rate of 55%. Of all the VPs approached, 43.1% refused to take part in the survey, and 1.6% of the valid VPs were unoccupied or empty.

A total of 16 646 individuals were eligible to participate in the study, of whom 90.87% agreed to be interviewed. Of those who were eligible, 81.9% completed the interview and provided blood specimens.

The data set available for dissemination contains 15 127 cases and 156 variables.
Abstract:
This dataset is a nationwide household-based population survey of SARS-CoV-2 seroprevalence in adolescents 12 years and older in South Africa. Data was collected on two separate rounds using a cross-sectional multi-stage stratified cluster survey design where SARS CoV-2 antibodies were tested first using the Abbott Architect anti-SARS CoV-2 immunoglobulin class G (IgG) chemiluminescent microparticle immunoassay with the final status determined by the Euroimmun Anti-SARS-CoV-2 ELISA (IgG) Euroimmun ® antibody assay. A subset of specimens positive on the Abbott ® assay were selected for analysis using a pseudotyped neutralization assay. Seroprevalence estimates presented are based on the Euroimmun ®assay. Summary statistics were used to describe SARS-CoV-2 Seroprevalence and characteristics of the study population. Bivariate and multivariate logistics regression analysis were used to identify factors associated with SARS-CoV-2 seropositivity.

In addition, among the samples tested for neutralization less than two thirds neutralized the D614G and the Beta strains, highlighting the importance of vaccination.