Table 2 Overall proportion of HCW with (a) detectable antibodies, (b) history of past positive rRT-PCR, (c) Positive rRT-PCR at study recruitment, and (d) Cumulative prevalence of infection (past/current rRT-PCR and/or antibodies).

From: Seroprevalence of antibodies against SARS-CoV-2 among health care workers in a large Spanish reference hospital

 nTotal% (95% CI)Not previously diagnosed as COVID-19 by rRT-PCR (n (%))COVID19-symptoms reporteda n (%)
Seropositive to SARS CoV-2 Antibodies (IgA and/or IgM and/or IgG)545789.3% (7.1–12.0)21 (38.9%)10 (47.6%)
Positive rRT-PCR at study recruitmentb155762.6% (1.5–4.3)6 (42.9%)3 (50.0%)
Any evidence of past/current infection by rRT-PCR of serology6557811.2% (8.8–14.1)26 (40.0%)12 (46.2%)
  1. aAmong those not previously diagnosed as COVID-19 (from previous column).
  2. bResults of 42 of the 578 rRT-PCRs done were invalid (Ct ≥ 40 for RNase P).