Table 1.
Country | SARS-CoV-2 serology assay | Period of sampling | Study sample size (no. tested) | Age range (years) | Seroprevalence estimate (% seropositive, 95% CI) | Reference |
---|---|---|---|---|---|---|
Slovenia | Euroimmun ELISA; Roche Elecsys-N and Elecsys-S ECLIA |
20 April to 1 May (first round); 17 October to 10 November 2020 (second round) | 1316 (first round) 1211 (second round) |
0–99 | First round (April 2020): 0.87% (95% HDI 0.40%–1.38%); Second round (October/November 2020): unadjusted lower limit of seroprevalence on 11 November 2020: 4.06% (95% HDI 2.97%–5.16%) and unadjusted upper limit of seroprevalence on 3 October 2020: 4.29% (95% HDI 3.18%–5.47%) |
Maver and Oštrbenk Valenčak et al., 2020 [6] |
Iceland | Roche Elecsys-N ECLIA; Wantai ELISA |
3 April to 8 July 2020 | 30 576: a) 1237 recovered b) 4222 quarantined c) 23 452 unknown exposure |
ND | Overall seroprevalence estimate for Iceland: 0.9% (95% CI 0.8%–0.9%) a) recovered persons: 91.1% (95% CI 89.4%–92.6%) b) quarantined persons: 2.3% (95% CI 1.9%–2.8%) c) persons with unknown exposure: 0.3% (95% CI 0.2%–0.4%) |
Gudbjartsson et al., 2020 [7] |
Spain | Orient Gene Biotech POCT; Abbott IgG CLIA |
27 April to 11 May 2020 | 51 958 | <1 to >90 | POCT: 5.0% (95% CI 4.7%–5.4%); Abbott: 4.6% (95% CI 4.3%–5.0%), with a specificity–sensitivity range of 3.7% (95% CI 3.3%–4.0%; both tests positive) to 6.2% (95% CI 5.8%–6.6%; either test positive) | Pollán et al., 2020 [8] |
USA (Indiana) | CLIA (not specifically defined) | 25–29 April 2020 | 3629 | ≥12 | 1.01% (95% CI 0.76%–1.45%); estimated overall population SARS-CoV-2 prevalence of active or current infection: 2.79% (95% CI 2.02%–3.70%) | Menachemi et al., 2020 [9] |
USA (Los Angeles County, CA) | Premier Biotech POCT | 10–14 April 2020 | 863 | ≥18 | 4.06% (exact binomial CI, 2.84%–5.60%); adjusted unweighted and weighted seroprevalence: 4.34% (bootstrap CI, 2.76%–6.07%) and 4.65% (bootstrap CI, 2.52%–7.07%) | Sood et al., 2020 [10] |
Switzerland (Geneva) | Euroimmun ELISA | 6 April to 9 May 2020 | 2766 (1339 households in 5 weeks) | ≥5 | 1st to 5th week, respectively: 4.8% (95% CI 2.4%–8.0%, n = 341); 8.5% (95% CI 5.9%–11.4%, n = 469); 10.9% (95% CI 7.9%–14.4%, n = 577); 6.6% (95% CI 4.3%–9.4%, n = 604); 10.8% (95% CI 8.2%–13.9%, n = 775) | Stringhini et al., 2020 [4] |
India | Kavach ELISA; Euroimmun ELISA | 11 May to 4 June 2020 | 28 000 | ≥18 | 0.73% after adjusting for test performance (95% CI 0.34%–1.13%) | Muhrekar et al., 2020 [11] |
Faroe Islands | Wantai ELISA | 27 April to 1 May 2020 | 1075 | 0–100 | 0.6% (exact binomial 95% CI 0.2%–1.2%); 0.7% (bootstrap 95% CI 0.3%–1.3%) after adjustment for test sensitivity and specificity |
Petersen et al., 2020 [12] |
Brazil | Wondfo POCT | 14–21 May 2020; 4–7 June 2020 | 25 025 and 31 165 | ≥1 | Corrected prevalence estimates: 1.6% (95% CI 1.4%–1.8%) in the first survey and 2.8% (95% CI 2.5%–3.1%) in the second; city-level prevalence ranged from 0 to 25.4% in both surveys | Hallal et al., 2020 [13] |
Iran | Pishtaz Teb ELISA | 17 April to 2 June 2020 | 3530 from the general population, 5372 from a high-risk group | ND | Overall population weight-adjusted and test performance-adjusted seroprevalence: 17.1% (95% CI 14.6%–19.5%); in the high-risk population: 20.0% (95% CI 18.5%–21.7%) | Poustchi et al., 2020 [14] |
Netherlands | Laboratory-developed immunoassay | 31 March to 11 May 2020 | 3207 | 2–90 | Overall weighted seroprevalence: 2.8% (95% CI 2.1%–3.7%) | Vos et al., 2020 [15] |
Italy (northeast region) | Abbott Architect CLIA | 5–15 May 2020 | 6075 | >10 | 23.1% (95% CI 22.0%–24.1%) | Stefanelli et al., 2020 [16] |
China | Innovita colloidal gold detection kit | 6 March to 3 May 2020 | 63 107: Hubei 49 257; other 29 provinces 13 850 | 17–63 | All of China: 0.74%; Wuhan: 1.68%; Hubei province without Wuhan: 0.59%; other 29 provinces: 0.38% | Duan et al., 2021 [17] |
Abbreviations: CLIA, chemiluminescent microparticle immunoassay; ECLIA, electrochemiluminescence assay; ELISA, enzyme-linked immunosorbent assay; HDI, high-density interval; ND, no data; POCT, point-of-care test; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.
Non-peer-reviewed seroprevalence surveys with results deposited in open-access preprint repositories or posted at websites and those performed retrospectively on residual serum samples were not considered eligible. A more detailed summary of each study is provided in the Supplementary material (Table S6).