Chembio DPP COVID-19 IgM/IgG Serological Testing: Laboratory Validation, Guidelines, and Recommendations.

Background: On January 30, 2020, WHO declared COVID-19 a pandemic. In this article we describe our experience at Richmond University Medical Center with Chembio serological IgM, IgG testing.

Methods: In this prospective cohort study of patients and hospital employees, we utilized Chembio COVID-19 IgM/IgG serological testing in addition to Cepheid RT-PCR analysis.

Results: We evaluated the performance of Chembio serological test for IgM and IgG as an employee screening tool in a community hospital setting. The total number of currently asymptomatic employees screened was 1,866 from the Richmond University Medical Center. The non-exposed group included 1,253 (67.1%) employees with no significant clinical history and non-reactive IgM and IgG antibodies. The convalescent group included 255 (13.7%) of the employees with elevation of IgG only, 18 (1%) employees with past history of positive PCR and COVID-19 who currently have non-reactive IgM and IgG antibodies or demonstrate elevated IgG only, followed by 3 employees (< 1%) with no past clinical history who demonstrated reactive IgM and IgG antibodies and negative follow up by PCR. The reported 14.9% exposure/convalescent rate is lower than the reported 20% by the Department of Health and Governor Andrew Cuomo and may represent a better utilization of personal protective equipment, better hand washing techniques, and better disinfection procedures combined with strict social distancing.

Conclusions: Chembio's performance is satisfactory; however, hospitals must design their own policies addressing: who needs to be screened and who will interpret the results as well as constructing management algorithms for employees with no previous history and current double positive antibodies.