Lack of Serologic Evidence of Infection Among Health Care Personnel and Other Contacts of First 2 Confirmed Patients With COVID-19 in Illinois, 2020. (January 2021)

• Record Type: Journal Article
• Authors: McPherson, Tristan D.; Ghinai, Isaac; Binder, Alison M.; Freeman, Brandi D.; Hoskin Snelling, Chantel; Hunter, Jennifer C.; Anderson, Kristin M.; Davenport, Polly; Rudd, Deborah L.; Zafer, Mujeeb; Christiansen, Demian; Joshi, Kiran; Rubin, Rachel; Black, Stephanie R.; Fricchione, Marielle J.; Pacilli, Massimo; Walblay, Kelly A.; Korpics, Jacqueline; Moeller, Darcie; Quartey-Kumapley, Pearl; Wang, Chen; Charles, E. Matt; Kauerauf, Judy; Patel, Megan T.; Disari, Vishal S.; Fischer, Marc; Jacobs, Max W.; Lester, Sandra N.; Midgley, Claire M.; Rasheed, Mohammed Ata Ur; Reese, Heather E.; Verani, Jennifer R.; Wallace, Megan; Watson, John T.; Thornburg, Natalie J.; Layden, Jennifer E.; Kirking, Hannah L.;
• Is Part Of: Public health reports. Volume 136:Number 1(2021)
• Page Start: 88
• Page End: 96
• Publication Date: 2021-01
• Subjects: COVID-19 -- SARS-CoV-2 -- antibodies -- serology -- epidemiology; Public health -- United States -- Periodicals; 614.0973
• DOI: 10.1177/0033354920966064
• Languages: English
• ISSNs: 0033-3549

Abstract

Objectives: Widespread global transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus causing coronavirus disease 2019 (COVID-19), continues. Many questions remain about asymptomatic or atypical infections and transmission dynamics. We used comprehensive contact tracing of the first 2 confirmed patients in Illinois with COVID-19 and serologic SARS-CoV-2 antibody testing to determine whether contacts had evidence of undetected COVID-19. Methods: Contacts were eligible for serologic follow-up if previously tested for COVID-19 during an initial investigation or had greater-risk exposures. Contacts completed a standardized questionnaire during the initial investigation. We classified exposure risk as high, medium, or low based on interactions with 2 index patients and use of personal protective equipment (PPE). Serologic testing used a SARS-CoV-2 spike enzyme-linked immunosorbent assay on serum specimens collected from participants approximately 6 weeks after initial exposure to either index patient. The 2 index patients provided serum specimens throughout their illness. We collected data on demographic, exposure, and epidemiologic characteristics. Results: Of 347 contacts, 110 were eligible for serologic follow-up; 59 (17% of all contacts) enrolled. Of these, 53 (90%) were health care personnel and 6 (10%) were community contacts. Seventeen (29%) reported high-risk exposures, 15 (25%) medium-risk, and 27 (46%) low-risk. No participant had evidence of SARS-CoV-2 antibodies. The 2 index patients had antibodies detected at dilutions >1:6400 within 4 weeks after symptom onset. Conclusions: In serologic follow-up of the first 2 known patients in Illinois with COVID-19, we found no secondary transmission among tested contacts. Lack of seroconversion among these contacts adds to our understanding of conditions (ie, use of PPE) under which SARS-CoV-2 infections might not result in transmission and demonstrates that SARS-CoV-2 antibody testing is a useful tool to verify epidemiologic findings.