The Role of Staff in Transmission of SARS-CoV-2 in Long-term Care Facilities

• Type of Material: Article
• Authors: Carly Adams, Emory University; Allison Chamberlain, Emory University; Yuke Wang, Emory University; Mallory Hazell, Fulton County Board of Health; Sarita Shah, Emory University; David Holland, Emory University; Fazle Khan, Fulton County Board of Health; Neel Gandhi, Emory University; Scott Fridkin, Emory University; Jon Zelner, University of Michigan; Benjamin Lopman, Emory University
• Language: English
• Date: 2022-09-01
• Publisher: LIPPINCOTT WILLIAMS & WILKINS
• Publication Version: Final Published Version
• Copyright Statement: © 2022 The Author(s). Published by Wolters Kluwer Health, Inc.
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1097/EDE.0000000000001510
• Title of Journal or Parent Work: EPIDEMIOLOGY
• Volume: 33
• Issue: 5
• Start Page: 669
• End Page: 677
• Grant/Funding Information: N.R.G. was supported by grant K24AI114444 from the US National Institutes of Health. J.Z. was supported by award 1 U01 IP001138-01 from the Centers for Disease Control and Prevention. A.C., S.S., and N.R.G. were supported by the Fulton County Board of Health.; This work was supported by grant R01 HS025987 from the Agency for Healthcare Research and Quality, grant 2032084 from the National Science Foundation (2032084), and the Emory Covid-19 Response Collaborative (funded by a Robert W. Woodruff Foundation grant).
• Keywords: Public, Environmental & Occupational Health; GEORGIA; transmission; MEMBERS; long-term care; SARS-CoV-2; Science & Technology; COVID-19; Life Sciences & Biomedicine; RESIDENTS; NURSING-HOMES; reproduction number
• Research Categories: Health Sciences, Medicine and Surgery

Abstract

Background: US long-term care facilities (LTCFs) have experienced a disproportionate burden of COVID-19 morbidity and mortality. Methods: We examined SARS-CoV-2 transmission among residents and staff in 60 LTCFs in Fulton County, Georgia, from March 2020 to September 2021. Using the Wallinga-Teunis method to estimate the time-varying reproduction number, R(t), and linear-mixed regression models, we examined associations between case characteristics and R(t). Results: Case counts, outbreak size and duration, and R(t) declined rapidly and remained low after vaccines were first distributed to LTCFs in December 2020, despite increases in community incidence in summer 2021. Staff cases were more infectious than resident cases (average individual reproduction number, Ri= 0.6 [95% confidence intervals [CI] = 0.4, 0.7] and 0.1 [95% CI = 0.1, 0.2], respectively). Unvaccinated resident cases were more infectious than vaccinated resident cases (Ri= 0.5 [95% CI = 0.4, 0.6] and 0.2 [95% CI = 0.0, 0.8], respectively), but estimates were imprecise. Conclusions: COVID-19 vaccines slowed transmission and contributed to reduced caseload in LTCFs. However, due to data limitations, we were unable to determine whether breakthrough vaccinated cases were less infectious than unvaccinated cases. Staff cases were six times more infectious than resident cases, consistent with the hypothesis that staff were the primary drivers of SARS-CoV-2 transmission in LTCFs.