IgG Neutralizing Antibodies to SARS-CoV-2 Among Healthcare Workers Who Frequently Encountered Patients with COVID-19

Introduction: Since the Severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) first emerged in Wuhan, on 12 December 2019, it has spread rapidly across the world and developed into a pandemic. As healthcare workers are frequently in contact with Coronavirus disease-2019 (COVID-19) patients, they can be affected more often than the general population. In this study we aimed to investigate the SARS-CoV-2 seroprevalence and the IgG antibody levels among healthcare workers who frequently encountered COVID-19 patients in our hospital. Materials and Methods: In total, 182 healthcare workers were identified from database and their data was retrospectively analyzed. Participants with previous PCR positivity, pregnant, autoimmune disease history or immunosuppressive treatment history were excluded. Participants were grouped depending on their frequency of contact with COVID-19 patients (high and medium risk). All the samples were tested simultaneously for anti-SARS-CoV-2-IgG antibodies by the ELISA method. A chi-square test was used to compare categorical variables. A t-test and an ANOVA test were carried out to where appropriate. Results: Serological testing of 182 HCWs exposed to SARS-CoV-2 patients illustrated that 13.2% of them (24 out of 182) might have experienced an asymptomatic or subclinical SARS-CoV-2 infection. High risk participants, anosmia, and ageusia were statistically significant risk factors. The rate of detection of antibody positivity among doctors (p=0.030) and patients with anosmia, and ageusia (p=0.047) were found significantly higher than the others. In addition, SARS-CoV-2 antibody ratio results were found significantly higher in the groups of high risk participants (p=0.046), patients with clinical signs (p=0.008), myalgia (p=0.039), anosmia, and ageusia (p=0.025), respectively. Conclusion: Our study showed that serological testing is useful for determining asymptomatic or subclinical infections prevelance of SARS-CoV-2 among those with close contact with COVID-19 patients. Serological tests can be helpful determining the prevelance COVID-19 infection, especially among the HCWs.