ABSTRACT
The aim of the work: To map the prevalence of antibodies against SARS-CoV-2 among employees of the Faculty Thomayer Hospital in Prague after the first wave of the covid-19 disease. A large number of people with proven covid-19 infection were treated and hospitalized in the first wave at the Thomayer University Hospital. Material and methods: Voluntary study based on questionnaire survey and determination of total antibodies (ECLIA, Roche) and individual classes of immunoglobulins (ELISA IgG and IgA, Euroimmun).
ABSTRACT
OBJECTIVES: To map the prevalence of SARS-CoV-2 antibodies in the staff of the Thomayer University Hospital in Prague following the first wave of COVID-19. The main reason was the large number of COVID-19 patients admitted to the Thomayer University Hospital with confirmed SARS-CoV-2 infection. MATERIAL AND METHODS: A volunteer study based on a questionnaire survey and determination of total antibodies (ECLIA, Roche) and individual classes of immunoglobulins (ELISA IgG and IgA, Euroimmun). RESULTS: The study involved 808 employees, 2/3 of whom were from clinical departments. Fifteen participants, predominantly nurses (n = 12), tested ECLIA positive for antibodies against SARS-CoV-2 and ELISA positive or borderline positive for IgG antibodies. Positive or borderline IgA antibodies were recorded in 12 subjects. Most of the positive study participants (n = 13) contracted the SARS-CoV-2 virus at the workplace after repeated contact with positive patients. Most subjects infected (n = 12) had a more severe course but did not require hospitalization. We detected only one asymptomatic antibody-positive person. CONCLUSIONS: After the first wave of COVID-19, SARS-CoV-2 antibodies were only demonstrated in 1.9% of the Thomayer University Hospital employees tested. In clinical departments, the positivity rate was 2.3%, and in non-clinical departments, it was only 0.5%. The low prevalence of antibodies points to the low number of infected hospital staff and a very good level of compliance with all public health and epidemiological measures.
Subject(s)
COVID-19 , Antibodies, Viral , COVID-19/epidemiology , Humans , Immunoglobulin A , Immunoglobulin G , Personnel, Hospital , Prevalence , SARS-CoV-2ABSTRACT
Objective: The aim of this study is to provide information on the comparison of the determination anti-SARS-CoV-2 antibodies by two differently designed assays, ECLIA (Roche Diagnostics) and ELISA (Euroimmun). Settings: Department of Clinical Biochemistry and Immunology Laboratory, Thomayer University Hospital Materials and Methods: We selected 134 serum samples from 90 patients, Thomayer Hospital staff, and convalescent plasma donors (33 PCR-negative and 57 PCR-positive) at various intervals from the onset of clinical symptoms (1-136 days). We examined anti-SARS-CoV-2 antibodies simultaneously by ELISA in the IgG and IgA classes (DSX) and ECLIA (Cobas e602) and statistically processed the results. By measuring control materials, positive and negative pools we evaluated selected analytical characteristics. Results: We found a high degree of agreement between ELISA and ECLIA. Specificity and sensitivity were very high in both tests, the sensitivity increasing with the distance from the beginning of the symptoms with a maximum of more than 20 days. For ECLIA, the sensitivity may be further increased by application an optimized cut-off. Antibodies persisted to a high degree after 60 days from the onset of symptoms, especially in the IgG class. Intermediate precision and repeatability suited clinical purposes. Conclusion: Both methods are very useful serological monitoring of the antibody response status to SARS-CoV-2 infection. ECLIA method using a highly immunogenic nucleocapsid antigen that captures high affinity antibodies of all classes is preferable for daily routine and the rapid screening. ELISA tests with a conservative spike protein can then be used to confirm and distinguish individual immunoglobulin classes.