Predictors of SARS-CoV-2 Positivity Based on RT-PCR Swab Tests at a Drive-Through Outpatient Clinic for COVID-19 Screening in Japan

Predictors of SARS-CoV-2 Positivity Based on RT-PCR Swab Tests at a Drive-Through Outpatient Clinic for COVID-19 Screening in Japan

Tadashi Ishii,¹ Shigeki Kushimoto,² Yukio Katori,³ Shigeo Kure,⁴ Kaoru Igarashi,⁵ Motoo Fujita,⁶ Shin Takayama,¹ Michiaki Abe,¹ Junichi Tanaka,¹ Akiko Kikuchi,¹ Yoshiko Abe,¹ Hiroyuki Imai,⁷ Yohei Inaba,⁸ Yoko Iwamatsu-Kobayashi,⁹ Takashi Nishioka,¹⁰ Ko Onodera¹¹ and Tetsuya Akaishi¹

¹Department of Education and Support for Regional Medicine, Tohoku University Hospital, Sendai, Miyagi, Japan
²Division of Emergency and Critical Care Medicine, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
³Department of Otolaryngology-Head and Neck Surgery, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
⁴Department of Pediatrics, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
⁵Division of Craniofacial Anomalies, Tohoku University Graduate School of Dentistry, Sendai, Miyagi, Japan
⁶Department of Emergency and Critical Care Medicine, Tohoku University Hospital, Sendai, Miyagi, Japan
⁷Clinical Skills Laboratory, Tohoku University School of Medicine, Sendai, Miyagi, Japan
⁸Department of Radiation Disaster Medicine, International Research Institute of Disaster Science, Tohoku University, Sendai, Miyagi, Japan
⁹Department of Dental Infection Control, Tohoku University Hospital, Sendai, Miyagi, Japan
¹⁰Liaison Center for Innovative Dentistry, Tohoku University Graduate School of Dentistry, Sendai, Miyagi, Japan
¹¹Department of General Practitioner Development, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan

In response to the COVID-19 pandemic caused by SARS-CoV-2 in 2020, we conducted drive-through nasopharyngeal swab testing for COVID-19 in Sendai city, Japan, since April 2020. All tested individuals were judged in advance by public health centers for the necessity of undergoing the test with possible contact history and/or symptoms suggestive of COVID-19. In this study, to identify the predictors of SARS-CoV-2 test positivity for more efficient and evidenced selection of suspected individuals, we enrolled 3,540 consecutive individuals, tested in the first 7 months of the testing program, with data regarding to the history of close contact with COVID-19 patients, including those involved in cluster outbreaks. This cohort included 284 foreign students (257 males and 27 females) from a vocational school involved in the largest cluster outbreak in the area. Close contact history was present in 952 (26.9%) of the participants. The reverse transcription-polymerase chain reaction (RT-PCR) test results showed that 164 participants (4.6%) were positive and 3,376 participants (95.4%) were negative for the SARS-CoV-2 nucleocapsid gene (N2). In the univariate and multivariate analyses, history of close contact with COVID-19 patients, higher age, cough symptoms, and non-native ethnicity were predictors for SARS-CoV-2 test positivity. However, the significance of age and foreign nationality disappeared or declined upon excluding the foreign students from the aforementioned largest cluster outbreak. In conclusion, a history of close contact with COVID-19 patients and the presence of cough symptoms are significant predictors of SARS-CoV-2 test positivity.

Keywords —— coronavirus disease 2019 (COVID-19); drive-through; nasopharyngeal swab test; reverse transcription polymerase chain reaction (RT-PCR); SARS-CoV-2

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Tohoku J. Exp. Med 2021 February, 253(2), 101-108.

Correspondence: Tetsuya Akaishi, Department of Education and Support for Regional Medicine, Tohoku University Hospital, 1-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8574, Japan.

e-mail: t-akaishi@med.tohoku.ac.jp