Long-Term Comparison of 7 SARS-CoV-2 Antibody Assays in the North Zealand Covid-19 Cohort.

BACKGROUND: Throughout the coronavirus disease 2019 (Covid-19) pandemic numerous severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody assays have been approved through Emergency Use Authorization and require further evaluation of sensitivity and specificity in clinical laboratory settings prior to implementation. METHODS: We included 1733 samples from 375 PCR-confirmed SARS-CoV-2-positive individuals of the North Zealand Covid-19 Cohort in an 8-month period. We investigated diagnostic sensitivity and specificity against consensus and PCR and interassay agreement over time for 5 SARS-CoV-2 immunoassays [Roche-nucleocapsid (NC)-total, Roche-receptor binding domain (RBD)-total, Siemens-RBD-IgG, Siemens-RBD-total, Thermo Fisher Scientific (TFS)-RBD-IgG] commercially available on automated platforms and 2 ELISA assays (TFS-RBD-total, Wantai-RBD-total). RESULTS: Early interassay discrepancy in up to 49% of samples decreased steadily during the first 18 days. By day 18, all assays had reached a plateau between 82.3% and 90.5% seropositivity compared to PCR. Assays ranked by closest agreement with the consensus model beyond day 18 (sensitivity/specificity against consensus) were as follows: Roche-RBD-total, 99.8%/100.0%; Wantai-RBD-total, 99.8%/99.7%; Roche-NC-total, 97.8%/100.0%; Siemens-RBD-total, 98.0%/98.7%; TFS-RBD-total, 96.9%/99.7%; TFS-RBD-IgG, 91.5%/100.0%; and Siemens-RBD-IgG, 94.6%/89.9%. We found that 7.8% of PCR-positive patients remained seronegative in all assays throughout the study. CONCLUSIONS: All included assays had sensitivities against consensus >90% past day 18. For the current recommended use of antibody assays to detect former, undocumented Covid-19, our data suggest the use of total antibody assays rather than IgG-specific assays due to higher long-term sensitivity. Finally, a nonresponding subpopulation of 7.8% in our cohort with persistent seronegative results raises concern of a possible substantial number of people with continued low protection following natural SARS-CoV-2 infection.

[The attitude of doctors and nurses towards reporting and handling errors and adverse events]. / Laegers og sygeplejerskers holdninger til rapportering og håndtering af fejl og andre utilsigtede haendelser.

INTRODUCTION: Few studies have been published about the attitudes of doctors and nurses towards reporting and handling adverse events. However, knowledge about staff attitudes is relevant and may be essential to dealing with potential problems and barriers that staff might have, as well as to supporting cultural change in relation to reporting and learning. MATERIALS AND METHODS: From February to March 2002, a questionnaire comprising 133 questions was distributed to 4019 doctors and nurses in four counties in Denmark. This paper deals with only a subset of the results of the survey. RESULTS: Responses were obtained from 703 doctors and 881 nurses, yielding an overall response rate of 51%. Statistical analysis was performed with non-parametric tests (Mann-Whitney, Kruskal-Wallis). The survey shows large differences in attitudes among different staff groups towards reporting adverse events, and errors, in their reasons for not reporting and their degree of distress at the prospect of making mistakes. Doctors are more reluctant (34%) than nurses (21%) to bring up adverse events and errors, indicating as their main reasons: lack of tradition, fear of the press, and the risk of being reprimanded. In contrast to consultants, "non-consultants" (staff specialists and junior doctors), and especially the female members of this group, show a greater agreement with each of the proposed reasons. The thought that one may cause injury to a patient induces 35% of "non-consultants" to consider giving up their job "now and then/often". DISCUSSION: Efforts to improve patient safety culture can become more effective via knowledge about similarities and differences among staff groups that have been uncovered in this survey.