A new study in JAMA Internal Medicine examines COVID-19 prevalence in a single Seattle-area combined assisted and independent care facility, and shows that symptomatic surveillance alone does not provide an accurate picture of COVID-19 prevalence in that setting. While many residents complained of COVID-19 symptoms, few had the virus when tested twice over a period of weeks.
The facility featured independent apartments, common spaces (including a shared library), and more intensive assisted-care rooms. After two residents in the facility were hospitalized with COVID-19, a total of 142 residents and staff exposed to those cases were tested for the virus using real-time reverse transcription polymerase chain reaction (PCR) assays.
Three asymptomatic infected residents (4%) and 2 symptomatic infected staff were identified; 1 week later, 1 additional asymptomatic infected resident was found, the authors said. Despite the test results, 41% of residents self-reported symptoms of COVID-19.
The authors explain the low prevalence of COVID-19 by the individual apartments used by many residents, and the rapid testing of staff and residents within 5 days of the first case identification.
"The low prevalence of SARS-CoV-2 detection among residents and staff … demonstrates a hopeful message: that adherence to strict hygiene and social distancing strategies may be effective in preventing widespread SARS-CoV-2 transmission in senior independent/assisted living communities," the authors concluded.
In an accompanying commentary, a group of researchers from the University of Michigan said the study was evidence that self-reporting of symptoms had low positive predictive value for COVID-19 infection rates.
"These findings illustrate the myriad challenges of symptom-based testing for an infection that has nonspecific protean manifestations and a wide range of clinical severity," they wrote.
Rapid testing to stop outbreaks
Meanwhile, a study today in Morbidity and Mortality Weekly Reports also shows that rapid testing contained a COVID-19 outbreak in a long-term care facility for veterans in Los Angeles. Like the Seattle study, the skilled nursing facility (SNF) identified two residents with COVID-19 on Mar 28.
From Mar 29 through Apr 23 staff and residents were tested multiple times for the virus using PCR testing. Nineteen of 99 (19%) residents and eight of 136 (6%) staff members had positive test results for SARS-CoV-2 during Mar 28–Apr 10; no further resident cases were identified on subsequent testing on April 13, April 22, and April 23, the authors said. Fourteen of the 19 residents with COVID-19 were asymptomatic at the time of testing.
Eight of the asymptomatic positives were later classified as presymptomatic, and one patient subsequently died. All infected residents were housed in isolation upon positive test results.
"This report demonstrates the high prevalence of asymptomatic SARS-CoV-2 infection that can occur in SNFs, highlighting the potential for widespread transmission among residents and staff members before illness is recognized and demonstrating the utility of universal RT-PCR testing for COVID-19 after case identification in this setting," the authors concluded.
Infection control lacking
In related news, a new Government Accountability Office (GAO) report published this week said infection control protocols were lacking in nursing homes and assisted living facilities before the pandemic.
Approximately 1.4 million Americans are residents of these 15,500 facilities, and 82% of facilities were cited for infection prevention and control deficiencies at least one time from 2013 through 2017.
For their report, the GAO analyzed data from the Centers for Medicare & Medicaid Services (CMS) showing that infection prevention and control deficiencies were the most common type of deficiency cited in surveyed nursing homes.