Nursing homes that conducted more frequent staff surveillance testing experienced significantly lower rates of COVID-19 infections and deaths among residents, according to a study published Wednesday in the New England Journal of Medicine.
The findings suggest that frequent staff testing can protect vulnerable populations during a pandemic.
U.S. nursing homes employ 1.7 million staff and house 4 million residents. While constituting only 2% of the U.S. population, nursing home residents represented 20% of COVID-19 deaths through 2021. The Centers for Disease Control and Prevention (CDC) had recommended that facilities in high COVID-19 transmission areas perform routine staff screening tests up to twice weekly. While test shortages initially made this difficult to achieve, the government prioritized nursing homes for distribution; by August 2020, rapid COVID-19 tests were widely available at these facilities.
To quantify the effect of these tests, the team compiled a database that tracked more than 90 million COVID-19 test results for staff in 13,433 skilled nursing facilities from 2020 to 2022. The primary data source was the Centers for Medicare and Medicaid Services COVID-19 Nursing Home Database. The team separated their analysis into three timeframes: before COVID-19 vaccines were available; after vaccines became available, but before the Omicron variant appeared; and during the Omicron wave.
During outbreaks, high testing frequency (1.7 COVID tests per week, per staff) was associated with fewer resident cases and deaths compared to low testing frequency (0.6 per week). This difference was particularly pronounced during the pre-vaccine period, when high-testing facilities had almost 25% fewer deaths. Based on their data, the researchers projected that had all facilities performed one additional test per staff member per week during the pre-vaccine phase of the pandemic, 30% of resident cases and 26% of resident deaths could have been prevented.
For nursing homes that used rapid, point-of-care tests, faster results were also associated with fewer resident deaths. Before vaccines, the difference between receiving results in under two days versus more than three days was associated with 13% fewer cases and 28% fewer deaths.
Surveillance testing was less associated with COVID-19 cases or deaths during the post-vaccine/pre-Omicron phase, when nursing home staff and residents were prioritized for vaccines that were highly effective at preventing both infections and severe disease. However, during the Omicron wave, frequent surveillance testing was associated with fewer resident cases but no difference in deaths, a finding consistent with the reduction in vaccine efficacy for preventing COVID-19 infections.
“Testing is a key part of any infectious disease response, surveillance testing in particular,” University of Rochester assistant professor Brian McGarry, PhD, lead author, said in a statement. “This research demonstrates that frequent COVID surveillance testing protected nursing home residents and undoubtedly saved lives by detecting more infected staff, and disrupting potential viral transmission chains … particularly before the availability of vaccines.”