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

Objectives: Gastrointestinal endoscopic procedures have a risk to transmit severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) through aerosols. Little information is available on the seroprevalence of SARS-CoV-2 antibodies among healthcare workers (HCWs) in endoscopy units. Thus, the seroprevalence was examined in HCWs who do and do not participate in gastrointestinal endoscopy.

Methods: A total of 382 HCWs at Jichi Medical University Hospital were enrolled in this study through March 2021. Among 382 HCWs, 63 are in the endoscopy unit. Serum antibody levels against SARS-CoV-2 were determined by immunochromatography, chemiluminescent immunoassay (CLIA), electric CLIA (ECLIA), and chemiluminescence microparticle immunoassay (CMIA). HCWs in the endoscopy unit underwent testing up to three times. We defined antibody-positive as when at least one test was positive.

Results: The seroprevalence of SARS-CoV-2 antibodies in 63 HCWs in the endoscopy unit was 0%-1.9%, 0%-1.7%, and 0%-1.7% during the first (Ap-May 2020), second (Jun-Nov 2020), and third intervals (Dec 2020-Mar 2021), respectively. This seroprevalence was comparable to that of other HCWs not involved with gastrointestinal endoscopy. Two HCWs in the endoscopy unit were positive for antibodies: one was ECLIA-positive and the another was CMIA-positive. The ECLIA-positive HCW was PCR negative and converted to negative for the second and third tests. Another HCW was CMIA-positive at all three evaluations and the titers were unchanged. No HCWs in the endoscopy unit contracted a SARS-CoV-2 infection.

Conclusions: The seroprevalence of SARS-CoV-2 antibodies was low among HCWs in the endoscopy unit through March 2021 (UMIN000039997).