Seroprevalence of IgG antibodies against severe acute respiratory syndrome coronavirus 2 and associated risk factors in blood donors

Abstract

Objective: To determine the seroprevalence of SARS-CoV-2 immunoglobulin G (IgG) antibody and identify risk factors among blood donors.

Methodology: This cross-sectional study was conducted at the Armed Forces Institute of transfusion (AFIT), from July to October, 2020. A total of 900 blood donors were enrolled according to the calculated sample size. Sociodemographic, behavioral and clinical data were collected through a preformed questionnaire. Seroprevalence of SARS-CoV-2 IgG antibody was detected using indirect enzyme linked immunosorbent assay (ELISA) of Vircell COVID 19.

Results: Out of a total 900 donors, 180 (20%) were found out to be positive for SARS- CoV-2 antibodies. Of these 180 SARS-CoV-2 IgG positive cases, asymptomatic donors were 140 (77.7%) whereas 60 (33.7%) were symptomatic. Respiratory symptoms were most common and gastrointestinal were least common among seropositive donors respectively. None of the ELISA IgG negative samples were found to be positive for SARS-CoV-2 RNA by RT-PCR.

Conclusion: A high seroprevalence of SARS-CoV-2 IgG antibody reflected a great extent of spread virus in blood donor population.