The ability of SARS-CoV-2 to spread rapidly among residents and staff in congregate settings poses a major infection control challenge. In a study conducted in 9 long-term care facilities in Pasadena, California in April 2020, the findings demonstrated a high proportion of asymptomatic infection, even within moderately affected facilities, and support the use of mass testing-based strategies in concert with symptom screening. Data from the facility wide screenings indicate that the rate of asymptomatic infection among staff, on average, was 1 in 4, and among residents was 1 in 2.
Early in the COVID-19 pandemic, the supply of both nasopharyngeal swabs and test kits for SARS-CoV-2 RT-PCR testing in the United States was extremely limited and made available only for symptomatic persons meeting certain criteria determined by the Centers for Disease Control and Prevention (CDC). Diagnostic testing remained limited for many weeks, and LTCFs relied on symptom screening to exclude potentially infectious staff from work. On March 30, CDC published a change for the COVID-19 period of exposure risk from onset of symptoms to 48 hours before symptom onset. This change meant that symptom screening alone could be insufficient in protecting LTCF residents from contracting COVID-19 from asymptomatic, but infectious, staff, and studies have suggested a role for asymptomatic transmission in COVID-19 outbreaks.
The findings demonstrate a high prevalence of both symptomatic and asymptomatic COVID-19 infection among residents and staff in 9 LTCFs. The lead epidemiologist for the study indicated that long-term care facilities should include both mass testing-based strategies and symptom screening. Most of us are following CMS and CDC guidance regarding testing. If you aren’t sure you are meeting the guidelines, consider going to the CDC website and review what is recommended today. Remember, things are changing daily so stay well, stay safe and of course stay tuned!