Geographical Profiles of COVID-19 Outbreak in Tokyo: An Analysis of the Primary Care Clinic–Based Point-of-Care Antibody Testing

• Published in: Journal of primary care & community health Vol. 11; p. 2150132720942695
• Main Authors: Takita, Morihito, Matsumura, Tomoko, Yamamoto, Kana, Yamashita, Erika, Hosoda, Kazutaka, Hamaki, Tamae, Kusumi, Eiji
• Format: Journal Article
• Language: English
• Published: Los Angeles, CA SAGE Publications 2020; SAGE PUBLICATIONS, INC; SAGE Publishing
• Subjects: Adolescent; Adult; Antibodies, Viral - blood; Betacoronavirus - immunology; Chemical analysis; Classification; Clinical Laboratory Techniques; Coronavirus Infections - diagnosis; Coronavirus Infections - epidemiology; Coronaviruses; COVID-19; COVID-19 Testing; Disease Outbreaks; Female; Humans; Immunity; Immunoglobulin G - blood; Male; Middle Aged; Pandemics; Pilot Studies; Pneumonia, Viral - diagnosis; Pneumonia, Viral - epidemiology; Point-of-Care Systems; Primary care; Primary Health Care; Residence; Residence Characteristics - statistics & numerical data; SARS-CoV-2; Seroepidemiologic Studies; Severe acute respiratory syndrome; Severe acute respiratory syndrome coronavirus 2; Tokyo - epidemiology; Triage; Young Adult; Tokyo; COVID-19; point-of-care testing; contagion; seroprevalence; antibody test; community health
• ISSN: 2150-1327; 2150-1319; 2150-1327
• DOI: 10.1177/2150132720942695

Introduction: The primary care clinic plays a major role in triage for coronavirus disease 2019 (COVID-19), where seroprevalence in the setting of primary care clinic remains less clear. As a point-of-care immunodiagnostic test for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the serosurvey represents an alternative to the polymerase chain reaction (PCR) test to measure the magnitude of COVID-19 outbreak in the communities lacking sufficient diagnostic capability for PCR testing. Methods: We assessed seropositivity for the SARS-CoV-2 IgG between April 21 and May 20, 2020, at 2 primary care clinics in Tokyo, Japan. Results: The overall positive percentage of SARS-CoV-2 IgG was 3.83% (95% confidence interval [CI]: 2.76-5.16) for the entire cohort (n = 1071). The 23 special wards of central Tokyo exhibited a significantly higher prevalence compared with the other areas of Tokyo after classification by residence (P = .02, 4.68% [3.08-6.79] vs 1.83 [0.68-3.95] in central and suburban Tokyo, respectively). In central Tokyo, the southern area showed the highest seroprevalence compared with the other areas (7.92% [3.48-15.01]), corresponding to the cumulative number of confirmed COVID-19 patients by PCR test reported by the Tokyo Metropolitan Government. Conclusion: The seroprevalence surveyed in this study was too low for herd immunity, suggesting the need for robust disease control and prevention. A regional-level approach, rather than state- or prefectural-level, could be of importance in ascertaining detailed profiles of the COVID-19 outbreak.