Higher SARS-CoV-2 seroprevalence in workers with lower socioeconomic status in Cape Town, South Africa.
Journal
PloS one
ISSN: 1932-6203
Titre abrégé: PLoS One
Pays: United States
ID NLM: 101285081
Informations de publication
Date de publication:
2021
2021
Historique:
received:
11
01
2021
accepted:
12
02
2021
entrez:
25
2
2021
pubmed:
26
2
2021
medline:
10
3
2021
Statut:
epublish
Résumé
Inequality is rife throughout South Africa. The first wave of COVID-19 may have affected people in lower socioeconomic groups worse than the affluent. The SARS-CoV-2 seroprevalence and the specificity of anti-SARS-CoV-2 antibody tests in South Africa is not known. We tested 405 volunteers representing all socioeconomic strata from the workforce of a popular shopping and tourist complex in central Cape Town with the Abbott SARS-CoV-2 IgG assay. We assessed the association between antibody positivity and COVID-19 symptom status, medical history, and sociodemographic variables. We tested 137 serum samples from healthy controls collected in Cape Town prior to the COVID-19 pandemic, to confirm the specificity of the assay in the local population. Of the 405 volunteers tested one month after the first peak of the epidemic in Cape Town, 96(23.7%) were SARS-CoV-2 IgG positive. Of those who tested positive, 46(47.9%) reported no symptoms of COVID-19 in the previous 6 months. Seropositivity was significantly associated with living in informal housing, residing in a subdistrict with low income-per household, and having a low-earning occupation. The specificity of the assay was 98.54%(95%CI 94.82%-99.82%) in the pre-COVID controls. There is a high background seroprevalence in Cape Town, particularly in people of lower socioeconomic status. Almost half of cases are asymptomatic, and therefore undiagnosed by local testing strategies. These results cannot be explained by low assay specificity.
Sections du résumé
BACKGROUND
Inequality is rife throughout South Africa. The first wave of COVID-19 may have affected people in lower socioeconomic groups worse than the affluent. The SARS-CoV-2 seroprevalence and the specificity of anti-SARS-CoV-2 antibody tests in South Africa is not known.
METHODS
We tested 405 volunteers representing all socioeconomic strata from the workforce of a popular shopping and tourist complex in central Cape Town with the Abbott SARS-CoV-2 IgG assay. We assessed the association between antibody positivity and COVID-19 symptom status, medical history, and sociodemographic variables. We tested 137 serum samples from healthy controls collected in Cape Town prior to the COVID-19 pandemic, to confirm the specificity of the assay in the local population.
RESULTS
Of the 405 volunteers tested one month after the first peak of the epidemic in Cape Town, 96(23.7%) were SARS-CoV-2 IgG positive. Of those who tested positive, 46(47.9%) reported no symptoms of COVID-19 in the previous 6 months. Seropositivity was significantly associated with living in informal housing, residing in a subdistrict with low income-per household, and having a low-earning occupation. The specificity of the assay was 98.54%(95%CI 94.82%-99.82%) in the pre-COVID controls.
CONCLUSIONS
There is a high background seroprevalence in Cape Town, particularly in people of lower socioeconomic status. Almost half of cases are asymptomatic, and therefore undiagnosed by local testing strategies. These results cannot be explained by low assay specificity.
Identifiants
pubmed: 33630977
doi: 10.1371/journal.pone.0247852
pii: PONE-D-21-00967
pmc: PMC7906413
doi:
Types de publication
Journal Article
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM
Pagination
e0247852Déclaration de conflit d'intérêts
The authors have declared that no competing interests exist.
Références
Afr J Prim Health Care Fam Med. 2020 Oct 02;12(1):e1-e3
pubmed: 33054266
J Clin Microbiol. 2020 Jul 23;58(8):
pubmed: 32513859
Lancet Infect Dis. 2020 Aug 4;:
pubmed: 32763195
N Engl J Med. 2020 Oct 29;383(18):1724-1734
pubmed: 32871063
Lancet. 2020 Aug 1;396(10247):313-319
pubmed: 32534626
J Clin Microbiol. 2020 Jul 23;58(8):
pubmed: 32381641
Lancet Infect Dis. 2020 Dec;20(12):1390-1400
pubmed: 32979318
Science. 2021 Jan 1;371(6524):79-82
pubmed: 33177105
Ann Epidemiol. 2020 Aug;48:23-29.e4
pubmed: 32648546
EClinicalMedicine. 2020 Aug;25:100466
pubmed: 32840492
BMC Med. 2020 Sep 4;18(1):271
pubmed: 32883276
Int J Infect Dis. 2021 Jan;102:577-583
pubmed: 33176202
Ann Intern Med. 2020 Aug 18;173(4):262-267
pubmed: 32422057
Sci Rep. 2020 Oct 15;10(1):17458
pubmed: 33060704
Int J Epidemiol. 2021 Jan 12;:
pubmed: 33434269
Lancet. 2020 Aug 22;396(10250):535-544
pubmed: 32645347
J Infect. 2020 Dec;81(6):e7-e9
pubmed: 32739487
J Hosp Infect. 2021 Jan 7;110:60-66
pubmed: 33422589
J Med Virol. 2021 Feb;93(2):916-923
pubmed: 32710669
Nat Hum Behav. 2020 Dec;4(12):1294-1302
pubmed: 33144713