SARS-CoV-2 Infection among Medical Institution Faculty and Healthcare Workers in Tokyo, Japan

Nishimura, Tomoyasu; Uwamino, Yoshifumi; Uno, Shunsuke; Kashimura, Shoko; Shiraki, Toshikimi; Kurafuji, Toshinobu; Morita, Maasa; Noguchi, Masayo; Azegami, Tatsuhiko; Yamada-Goto, Nobuko; Murai-Takeda, Ayano; Yokoyama, Hirokazu; Kuwabara, Kazuyo; Kato, Suzuka; Matsumoto, Minako; Hirata, Aya; Iida, Miho; Harada, Sei; Ishizaka, Tamami; Misawa, Kana; Murata, Mitsuru; Saya, Hideyuki; Amagai, Masayuki; Kitagawa, Yuko; Takeuchi, Tsutomu; Mori, Masaaki; Takebayashi, Toru; Hasegawa, Naoki

OBJECTIVE: To consider effective measures against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in medical institutions, this study estimated the SARS-CoV-2 infection rate among healthcare workers (HCWs) in Tokyo, Japan, and determined the specific findings for mild coronavirus disease 2019 (COVID-19) cases. METHODS: This study analyzed the results of serologic tests to detect immunoglobulin G antibodies against SARS-CoV-2 and evaluated the demographic and clinical characteristics of the faculty and HCWs at a Tokyo medical institution in August 2020. The demographic and clinical characteristics of participants with antibody-positive results were compared to those of participants with antibody-negative results. MATERIALS: This study recruited 2,341 faculty and HCWs at a Tokyo medical institution, 21 of whom had a COVID-19 history. RESULTS: Of the 2,320 participants without a COVID-19 history, 20 (0.862%) had positive serologic test results. A fever and dysgeusia or dysosmia occurred with greater frequency among the participants with positive test results than in those with negative results [odds ratio (OR), 5.475; 95% confidence interval (CI), 1.960-15.293 and OR, 24.158; 95% CI, 2.693-216.720, respectively]. No significant difference was observed in the positivity rate between HCWs providing medical care for COVID-19 patients using adequate protection and other HCWs (OR, 2.514; 95% CI, 0.959-6.588). CONCLUSION: To reduce the risk of COVID-19 spread in medical institutions, faculty and HCWs should follow standard and necessary transmission-based precautions, and those with a fever and dysgeusia or dysosmia should excuse themselves from work as soon as possible.