SARS-CoV-2 Seroprevalence in Healthcare Workers from the Three Teaching Hospitals in Abidjan (Cote D’ivoire) during Pandemic Waves of 2022

Abstract

Background: In view of the concern about the nosocomial character of SARS-CoV-2 known for its high variability and its strong ability to spread, this study was conducted to assess the immunogenicity status through the seroprevalence of COVID -19 among healthcare workers in the three University hospitals of Abidjan (Cocody, Angré, Treichville). Methodology: On a sample of 275 healthcare workers randomly chosen from the different professional strata taking into account the levels of risk intensity of contamination according to services and workstations, we measured total antibodies IgG / IgM and antibodies (neutralizing) anti RBD IgG of SARS-CoV-2 using the following kits respectively: Diagnostics Evolution CHORUS Diesse® Ref 81401 SARS-CoV-2 IgM and 81400 SARS-CoV-2 IgG and Diagnostics Evolution CHORUS Diesse® Ref 81408 SARS- CoV-2 Neutralyzing Ab by a technique based on double enzyme fluorescence labeling (ELFA – Enzyme Linked Fluorescence Assay) which combines a two-step sandwich enzyme immunoassay method with fluorescence detection. Results: The predominantly female study population was characterized by young age with rates of vaccination coverage and history of COVID-19 infection, which  amount to 65,96% and 50,4% respectively. Among these health agents of which 44.1% and 46.16% worked in a context of intermediate level of risk contamination, considering respectively the department and the workstation, a very strong immunization was noted with a high seroprevalence at 93.5% of the population having produced total antibodies of IgG isotype but no IgM while 6.5% produced both IgG and IgM anti-SARS-CoV-2. Regarding anti-RBD neutralizing antibodies, 99.6% of agents are carriers. Conclusion: This strong immunization is the response both to the vaccine, whose coverage is quite broad, and to the history of contact with the virus circulating in the population. This degree of protection obtained among healthcare workers, can be considered as collective immunity, and should be reassuring.