Hospital-Wide SARS-CoV-2 seroprevalence in health care workers in a Spanish teaching hospital.

INTRODUCTION: Hospital-wide SARS-CoV-2 seroprevalence is rarely explored and can identify areas of unexpected risk. We determined the seroprevalence against SARS-CoV-2 in all health care workers (HCW) at a hospital. METHODS: Cross-sectional study (14-27/04/2020). We determined SARS-CoV-2 IgG by ELISA in all HCW including external workers of a teaching hospital in Madrid. They were classified by professional category, working area, and risk for SARS-CoV-2 exposure. RESULTS: Among 2919 HCW, 2590 (88,7%) were evaluated. The mean age was 43.8 years (SD 11.1), and 73.9% were females. Globally, 818 (31.6%) workers were IgG positive with no differences for age, sex or previous diseases. Of these, 48.5% did not report previous symptoms. Seropositivity was more frequent in high- (33.1%) and medium- (33.8%) than in low-risk areas (25.8%, p=0.007), but not for hospitalization areas attending COVID-19 and non-COVID-19 patients (35.5 vs 38.3% p>0.05). HWC with a previous SARS-CoV2 PCR-positive test were IgG seropositive in 90.8%. By multivariate logistic regression analysis seropositivity was significantly associated with being physicians (OR 2.37, CI95% 1.61-3.49), nurses (OR 1.67, CI95% 1.14-2.46), nurse assistants (OR 1.84, CI95% 1.24-2.73), HCW working at COVID-19 hospitalization areas (OR 1.71, CI95% 1.22-2.40), non-COVID-19 hospitalization areas (OR 1.88, CI95% 1.30-2.73), and at the Emergency Room (OR 1.51, CI95% 1.01-2.27). CONCLUSIONS: Seroprevalence uncovered a high rate of infection previously unnoticed among HCW. Patients not suspected of having COVID-19 as well as asymptomatic HCW may be a relevant source for nosocomial SARS-CoV-2 transmission.

Hospital-Wide SARS-CoV-2 seroprevalence in health care workers in a Spanish teaching hospital / Seroprevalencia frente a SARS-CoV-2 en 2.590 trabajadores de un hospital universitario español

Introduction: Hospital-wide SARS-CoV-2 seroprevalence is rarely explored and can identify areas of unexpected risk. We determined the seroprevalence against SARS-CoV-2 in all health care workers (HCW) at a hospital. Methods: Cross-sectional study (14-27/04/2020). We determined SARS-CoV-2 IgG by ELISA in all HCW including external workers of a teaching hospital in Madrid. They were classified by professional category, working area, and risk for SARS-CoV-2 exposure. Results: Among 2919 HCW, 2590 (88,7%) were evaluated. The mean age was 43.8 years (SD 11.1), and 73.9% were females. Globally, 818 (31.6%) workers were IgG positive with no differences for age, sex or previous diseases. Of these, 48.5% did not report previous symptoms. Seropositivity was more frequent in high- (33.1%) and medium- (33.8%) than in low-risk areas (25.8%, p=0.007), but not for hospitalization areas attending COVID-19 and non-COVID-19 patients (35.5 vs 38.3% p>0.05). HWC with a previous SARS-CoV2 PCR-positive test were IgG seropositive in 90.8%. By multivariate logistic regression analysis seropositivity was significantly associated with being physicians (OR 2.37, CI95% 1.61–3.49), nurses (OR 1.67, CI95% 1.14–2.46), nurse assistants (OR 1.84, CI95% 1.24–2.73), HCW working at COVID-19 hospitalization areas (OR 1.71, CI95% 1.22–2.40), non-COVID-19 hospitalization areas (OR 1.88, CI95% 1.30–2.73), and at the Emergency Room (OR 1.51, CI95% 1.01–2.27). Conclusions: Seroprevalence uncovered a high rate of infection previously unnoticed among HCW. Patients not suspected of having COVID-19 as well as asymptomatic HCW may be a relevant source for nosocomial SARS-CoV-2 transmission.(AU)

Introducción: Los estudios de seroprevalencia frente a SARS-CoV-2 en los trabajadores sanitarios (TS) permiten identificar áreas de riesgo inesperado en los hospitales. Métodos: Estudio transversal (14-27/04/2020). Se determinó IgG frente a SARS-CoV-2 mediante ELISA en todos los TS, incluidos los externos, de un hospital universitario de Madrid. Se clasificaron por categoría profesional, área de trabajo y riesgo de exposición al SARS-CoV-2. Resultados: Entre 2.919 TS, se evaluaron 2.590 (88,7%); edad media 43,8años (DE11,1) y 73,9% mujeres. Globalmente, 818 (31,6%) trabajadores tuvieron IgG positiva, sin diferencias por edad, sexo o enfermedades previas. De estos, el 48,5% no comunicaron síntomas previos. La seropositividad fue más frecuente en las áreas de alto (33,1%) y medio (33,8%) que en las de bajo riesgo (25,8%, p=0,007), pero similar en las áreas de hospitalización que atendían a pacientes con y sin COVID-19 (35,5 vs 38,3%, p>0,05). El 90,8% de los TS con PCR previa positiva frente a SARS-CoV-2 tuvieron IgG positiva. Por análisis multivariante, la seropositividad se asoció con ser médico (OR2,37, IC95%: 1,61-3,49), enfermero (OR1,67, IC95%: 1,14-2,46), auxiliar de enfermería (OR1,84, IC95%: 1,24-2,73), trabajar en áreas de hospitalización COVID-19 (OR1,71, IC95%: 1,22-2,40) y no COVID-19 (OR1,88, IC95%: 1,30-2,73) y en Urgencias (OR1,51, IC95%: 1,01-2,27). Conclusiones: El estudio de seroprevalencia desveló una alta tasa de infección que pasó desapercibida entre los trabajadores sanitarios. Los pacientes sin sospecha clínica de COVID-19 y los trabajadores sanitarios asintomáticos pueden ser una fuente importante de transmisión nosocomial del SARS-CoV-2.(AU)

Hospital-Wide SARS-CoV-2 seroprevalence in health care workers in a Spanish teaching hospital.

INTRODUCTION: Hospital-wide SARS-CoV-2 seroprevalence is rarely explored and can identify areas of unexpected risk. We determined the seroprevalence against SARS-CoV-2 in all health care workers (HCW) at a hospital. METHODS: Cross-sectional study (14-27/04/2020). We determined SARS-CoV-2 IgG by ELISA in all HCW including external workers of a teaching hospital in Madrid. They were classified by professional category, working area, and risk for SARS-CoV-2 exposure. RESULTS: Among 2919 HCW, 2590 (88,7%) were evaluated. The mean age was 43.8 years (SD 11.1), and 73.9% were females. Globally, 818 (31.6%) workers were IgG positive with no differences for age, sex or previous diseases. Of these, 48.5% did not report previous symptoms. Seropositivity was more frequent in high- (33.1%) and medium- (33.8%) than in low-risk areas (25.8%, p=0.007), but not for hospitalization areas attending COVID-19 and non-COVID-19 patients (35.5 vs 38.3% p>0.05). HWC with a previous SARS-CoV2 PCR-positive test were IgG seropositive in 90.8%. By multivariate logistic regression analysis seropositivity was significantly associated with being physicians (OR 2.37, CI95% 1.61-3.49), nurses (OR 1.67, CI95% 1.14-2.46), nurse assistants (OR 1.84, CI95% 1.24-2.73), HCW working at COVID-19 hospitalization areas (OR 1.71, CI95% 1.22-2.40), non-COVID-19 hospitalization areas (OR 1.88, CI95% 1.30-2.73), and at the Emergency Room (OR 1.51, CI95% 1.01-2.27). CONCLUSIONS: Seroprevalence uncovered a high rate of infection previously unnoticed among HCW. Patients not suspected of having COVID-19 as well as asymptomatic HCW may be a relevant source for nosocomial SARS-CoV-2 transmission.