Facility-Wide Testing for SARS-CoV-2 in Nursing Homes — SevenU.S. Jurisdictions March–June 2020

摘要

Undetected infection with SARS-CoV-2, the virus that causes coronavirus disease 2019(COVID-19) contributes to transmission in nursing homes, settings where large outbreakswith high resident mortality have occurred ( , ). Facility-wide testing of residents and health carepersonnel (HCP) can identify asymptomatic and presymptomatic infections and facilitateinfection prevention and control interventions ( – ). Seven state or local health departments conductedinitial facility-wide testing of residents and staff members in 288 nursing homes duringMarch 24–June 14, 2020. Two of the seven health departments conducted testing in195 nursing homes as part of facility-wide testing all nursing homes in their state,which were in low-incidence areas (i.e., the median preceding 14-day cumulativeincidence in the surrounding county for each jurisdiction was 19 and 38 cases per100,000 persons); 125 of the 195 nursing homes had not reported any COVID-19 casesbefore the testing. Ninety-five of 22,977 (0.4%) persons tested in 29 (23%) of these 125facilities had positive SARS-CoV-2 test results. The other five health departmentstargeted facility-wide testing to 93 nursing homes, where 13,443 persons were tested,and 1,619 (12%) had positive SARS-CoV-2 test results. In regression analyses among 88 ofthese nursing homes with a documented case before facility-wide testing occurred, eachadditional day between identification of the first case and completion of facility-widetesting was associated with identification of 1.3 additional cases. Among 62 facilitiesthat could differentiate results by resident and HCP status, an estimated 1.3 HCP caseswere identified for every three resident cases. Performing facility-wide testingimmediately after identification of a case commonly identifies additional unrecognizedcases and, therefore, might maximize the benefits of infection prevention and controlinterventions. In contrast, facility-wide testing in low-incidence areas without a casehas a lower proportion of test positivity; strategies are needed to further optimizetesting in these settings.