This study found that than half of skilled nursing facility residents with positive COVID-19 tests were asymptomatic at the time of testing and most likely contributed to transmission.

Researchers assessed the transmission and adequacy of symptom-based screening to identify infections of COVID-19 in nursing facility residents. They conducted two point-prevalence surveys a week apart, in which consenting participants were tested for infections with PCR. Asymptomatic residents who tested positive were checked again a week later.

Twenty-three days after the first positive test, 64% tested positive for COVID-19. Among 76 residents who participated in the study, 63% tested positive. Of the 48 positive residents

• 56% were asymptomatic at the time of testing
• 50% subsequently developed symptoms (median 4 days)
• Viable virus was recovered from 35%.

As of April 3, of the 57 residents with COVID-19, 11 had been hospitalized (3 in ICU) and 15 had died (mortality 26%).