Quantitative SARS-CoV-2 Antibody Screening of Healthcare Workers in the Southern Part of Kyoto City During the COVID-19 Pre-pandemic Period

Abstract

Background: The coronavirus disease-2019 (COVID-19) pandemic is associated with a heavy burden on the mental and physical health of patients, regional healthcare resources, and global economic activity. While understanding of the incidence and case-fatality rates has increased, there are limited data concerning seroprevalence of antibodies against the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) in healthcare workers during the pre-pandemic period. This study aimed to quantitatively evaluate seroprevalence of SARS-CoV-2 antibodies in healthcare workers in the southern part of Kyoto city, Japan.Methods: We prospectively recruited healthcare workers from a single hospital between April 10 and April 20, 2020. We collected serum samples from these participants and quantitatively evaluated SARS-CoV-2 IgG antibody levels using enzyme-linked immunosorbent assays.Results: Five (5.4%), 15 (16.3%), and 72 (78.3%) participants showed positive, borderline, and negative serum SARS-CoV-2 IgG antibody status, respectively. We found the mean titer associated with each antibody status (overall, positive, borderline, and negative) was clearly differentiated. Participants working at the otolaryngology department and/or with a history of seasonal common cold symptoms had a significantly higher SARS-CoV-2 IgG antibody titer (p = 0.046, p = 0.046, respectively).Conclusions: Five (5.4%) and 15 (16.3%) participants tested positive and borderline, respectively, for SARS-CoV-2 IgG antibody during the COVID-19 pre-pandemic period. These rates were higher than expected, based on government situation reports. These findings suggest that COVID-19 had already spread within the southern part of Kyoto city at the early stage of the pandemic.

Low prevalence of SARS‐CoV‐2 specific antibodies among endoscopists and their assistants in a university hospital in Tochigi prefecture–A single‐center study

“…Currently, the seroprevalence of SARS‐CoV‐2 antibodies was reported to be 0.07%–6.25% among HCWs in Japan. 5 , 6 , 7 , 8 , 9 , 10 These studies also showed that the seroprevalence in HCWs did not differ between high‐ and low‐risk groups. Since seroprevalence largely depends on the assays used, we performed four assays to facilitate comparison with other studies.…”

“…Indeed, SARS‐CoV‐2 infection of HCWs who work in endoscopy units was found to be 4.3% (42/968) in Northern Italy, an endemic area, 3 and 14% (10/73) in Egypt, where the cumulative number of patients with COVID‐19 was equivalent to that of Japan. 4 Although the seroprevalence of SARS‐CoV‐2 antibodies among HCWs was reported to be 0.07%–6.25% in Japan, 5 , 6 , 7 , 8 , 9 , 10 there are few data on the seroprevalence of SARS‐CoV‐2 antibodies among HCWs in endoscopy units. This study was undertaken to investigate the seroprevalence of SARS‐CoV‐2 antibodies among HCWs who practice and support gastrointestinal endoscopy.…”

Deployment of COVID-19 diagnostic testing: challenges and key considerations for the future

“…28 Whilst NAATs are capable of diagnosing current infection, antibody testing identifies exposure to the pathogen over the patient's lifetime, supporting diagnosis later during the disease course. 29 Antibody testing aids our understanding of COVID-19 and our immune response, [30][31][32][33] the spread of infection, 14,[34][35][36] and, more recently, our response to vaccine administration and long-term efficacy. 37…”

Choice of SARS-CoV-2 diagnostic test: challenges and key considerations for the future

“…While NAATs are capable of diagnosing current infection, antibody testing identifies exposure to the pathogen over the patient’s lifetime, supporting diagnosis later during the disease course [ 30 ]. Antibody testing aids our understanding of SARS-CoV-2 infection and our immune response [ 31–34 ], the spread of infection [ 14 , 35–37 ], and, more recently, our response to vaccine administration and long-term efficacy [ 38 ]. However, as there is a delay between infection and antibody development and the presence of antibodies following recovery from infection is anticipated, recent guidance notes that antibody testing does not replace virologic testing to establish the presence or absence of acute SARS-CoV-2 infection in the majority of settings [ 39 ].…”