SARS-CoV-2 seroprevalence in three Kenyan health and demographic surveillance sites, December 2020-May 2021.
Journal
PLOS global public health
ISSN: 2767-3375
Titre abrégé: PLOS Glob Public Health
Pays: United States
ID NLM: 9918283779606676
Informations de publication
Date de publication:
2022
2022
Historique:
received:
15
02
2022
accepted:
12
07
2022
entrez:
24
3
2023
pubmed:
25
3
2023
medline:
25
3
2023
Statut:
epublish
Résumé
Most of the studies that have informed the public health response to the COVID-19 pandemic in Kenya have relied on samples that are not representative of the general population. We conducted population-based serosurveys at three Health and Demographic Surveillance Systems (HDSSs) to determine the cumulative incidence of infection with SARS-CoV-2. We selected random age-stratified population-based samples at HDSSs in Kisumu, Nairobi and Kilifi, in Kenya. Blood samples were collected from participants between 01 Dec 2020 and 27 May 2021. No participant had received a COVID-19 vaccine. We tested for IgG antibodies to SARS-CoV-2 spike protein using ELISA. Locally-validated assay sensitivity and specificity were 93% (95% CI 88-96%) and 99% (95% CI 98-99.5%), respectively. We adjusted prevalence estimates using classical methods and Bayesian modelling to account for the sampling scheme and assay performance. We recruited 2,559 individuals from the three HDSS sites, median age (IQR) 27 (10-78) years and 52% were female. Seroprevalence at all three sites rose steadily during the study period. In Kisumu, Nairobi and Kilifi, seroprevalences (95% CI) at the beginning of the study were 36.0% (28.2-44.4%), 32.4% (23.1-42.4%), and 14.5% (9.1-21%), and respectively; at the end they were 42.0% (34.7-50.0%), 50.2% (39.7-61.1%), and 24.7% (17.5-32.6%), respectively. Seroprevalence was substantially lower among children (<16 years) than among adults at all three sites (p≤0.001). By May 2021 in three broadly representative populations of unvaccinated individuals in Kenya, seroprevalence of anti-SARS-CoV-2 IgG was 25-50%. There was wide variation in cumulative incidence by location and age.
Sections du résumé
BACKGROUND
BACKGROUND
Most of the studies that have informed the public health response to the COVID-19 pandemic in Kenya have relied on samples that are not representative of the general population. We conducted population-based serosurveys at three Health and Demographic Surveillance Systems (HDSSs) to determine the cumulative incidence of infection with SARS-CoV-2.
METHODS
METHODS
We selected random age-stratified population-based samples at HDSSs in Kisumu, Nairobi and Kilifi, in Kenya. Blood samples were collected from participants between 01 Dec 2020 and 27 May 2021. No participant had received a COVID-19 vaccine. We tested for IgG antibodies to SARS-CoV-2 spike protein using ELISA. Locally-validated assay sensitivity and specificity were 93% (95% CI 88-96%) and 99% (95% CI 98-99.5%), respectively. We adjusted prevalence estimates using classical methods and Bayesian modelling to account for the sampling scheme and assay performance.
RESULTS
RESULTS
We recruited 2,559 individuals from the three HDSS sites, median age (IQR) 27 (10-78) years and 52% were female. Seroprevalence at all three sites rose steadily during the study period. In Kisumu, Nairobi and Kilifi, seroprevalences (95% CI) at the beginning of the study were 36.0% (28.2-44.4%), 32.4% (23.1-42.4%), and 14.5% (9.1-21%), and respectively; at the end they were 42.0% (34.7-50.0%), 50.2% (39.7-61.1%), and 24.7% (17.5-32.6%), respectively. Seroprevalence was substantially lower among children (<16 years) than among adults at all three sites (p≤0.001).
CONCLUSION
CONCLUSIONS
By May 2021 in three broadly representative populations of unvaccinated individuals in Kenya, seroprevalence of anti-SARS-CoV-2 IgG was 25-50%. There was wide variation in cumulative incidence by location and age.
Identifiants
pubmed: 36962821
doi: 10.1371/journal.pgph.0000883
pii: PGPH-D-22-00247
pmc: PMC10021917
doi:
Types de publication
Journal Article
Langues
eng
Pagination
e0000883Subventions
Organisme : Wellcome Trust
ID : 214320
Pays : United Kingdom
Organisme : Medical Research Council
ID : MR/S005293/1
Pays : United Kingdom
Informations de copyright
Copyright: © 2022 Etyang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Déclaration de conflit d'intérêts
The authors have declared that no competing interests exist.
Références
Emerg Infect Dis. 2021 Jun;27(6):1598-1606
pubmed: 34013872
Int J Epidemiol. 2012 Jun;41(3):650-7
pubmed: 22544844
Nat Med. 2020 Jul;26(7):1033-1036
pubmed: 32398876
Science. 2021 Jan 1;371(6524):27-28
pubmed: 33384364
Nat Immunol. 2021 Jan;22(1):25-31
pubmed: 33154590
EClinicalMedicine. 2021 Nov;41:101172
pubmed: 34723165
Nat Commun. 2021 Oct 26;12(1):6196
pubmed: 34702829
Science. 2021 Jan 1;371(6524):79-82
pubmed: 33177105
Emerg Infect Dis. 2021 Dec;27(12):3020-3029
pubmed: 34477548
Int J Epidemiol. 2015 Apr;44(2):462-71
pubmed: 25596586
Science. 2021 Nov 19;374(6570):989-994
pubmed: 34618602
J Clin Virol. 2022 Jan;146:105061
pubmed: 34973474
Nat Commun. 2021 Jun 25;12(1):3966
pubmed: 34172732
Clin Infect Dis. 2022 Jan 29;74(2):288-293
pubmed: 33893491
JAMA. 2021 Oct 12;326(14):1436-1438
pubmed: 34473191
Clin Infect Dis. 2019 Oct 9;69(Suppl 4):S274-S279
pubmed: 31598663
Open Forum Infect Dis. 2021 Jun 12;8(7):ofab314
pubmed: 34660838
Lancet Glob Health. 2021 Nov;9(11):e1517-e1527
pubmed: 34678196
PLoS One. 2022 Oct 14;17(10):e0265478
pubmed: 36240176
Int J Infect Dis. 2021 Nov;112:25-34
pubmed: 34481966
F1000Res. 2021 Aug 26;10:853
pubmed: 35528961
Am J Epidemiol. 1978 Jan;107(1):71-6
pubmed: 623091