Surveillance of asymptomatic persons, early social distancing, other infection control measures show positive outcome

A Covid-19 outbreak investigation at a Seattle independent and assisted living facility identified asymptomatic exposure and very low rates of SARS-CoV-2 infection overall, suggesting that adherence to social distancing and other infection control measures may be highly effective even in vulnerable populations.

The case series study of 142 older adult residents and staff exposed to Covid-19 by 2 residents who required hospitalization initially identified an additional 3 asymptomatic infected residents and 2 symptomatic infected staffers.

One week later, retesting identified 1 additional asymptomatic infected resident, and the assisted-living community did not experience a facility-wide outbreak.

Writing in JAMA Internal Medicine, Alison Roxby, MD, of the University of Washington, Seattle, and colleagues, noted that the finding of asymptomatic SARS-CoV-2 at the nursing home “signals the need for strategies beyond symptom screening, such as mask wearing of staff and facility-based surveillance testing.”

A total of 41% of the residents reported symptoms compatible with viral illness, but just 4% had positive test results.

“Asymptomatic and minimally symptomatic SARS-CoV-2 infection has been noted among younger populations, and this report confirms a report describing this among older adults including elders with multiple comorbidities,” they wrote.

Real-time PCR testing at the Seattle facility, which housed both independent-living older adults and those requiring assisted living arrangements, took place in March, during the time Covid-19 was raging in several Seattle-area nursing homes.

Life Care Center in suburban Kirkland, Washington experienced the first outbreak of Covid-19 in the nation in late February. The outbreak claimed the lives of roughly 40 residents and others affiliated with the facility.

The low rate of transmission at the congregant living facility examined by Roxby and colleagues may have been due, in part, to the fact that while the residents were elderly (mean age = 86), their overall functional status remained relatively good. A total of 83 resided in private apartments, and most were ambulatory. Low rates of renal disease and diabetes were also reported.

Staff and residents implemented strict isolation measures immediately after the first resident was found to be infected with SARS-CoV-2. These measures included shutting down of communal dining and library areas and stopping visitation.

Enhanced hygiene practices were implemented, and daily staff screening and temperature monitoring was implemented.

In an editorial published with the study, Grace Jeng, MD; John Mills, MD, and Pretti Malani, MD, of the University of Michigan, Ann Arbor, wrote that active surveillance allowed early detection of disease among infected residents who are asymptomatic or had atypical symptoms.

“If logically feasible, active surveillance can be vital to preventing Covid-19 in settings with high potential for person-to-person transmission, especially by asymptomatic individuals,” they wrote.

But they added that surveillance alone will not be effective unless it is paired with infection control measures.

“Early social distancing, including shutdown of communal areas, as well as enhanced environmental measures (cleaning and disinfection of high-touch surfaces and adequate access to hand hygiene) likely contributed to the lack of widespread transmission at the Seattle facility,” they wrote.

While the CDC recommends that nursing homes and other assisted living facilities enact strict isolation policies to protect residents and staff from Covid-19, the editorial writers noted that “residents cannot and should not be isolated from their loved ones indefinitely.”

With no end in sight to the pandemic, Pretti Malani told BreakingMED that she worries about the unintended consequences of restricting family access to elderly nursing home residents indefinitely.

“Restricting visitation is another tragedy of Covid-19, especially for older people in assisted living,” she said. “It is important to remember that families are often not just visiting, they are providing needed care such as combing hair or getting meds in order. They are keeping the residents engaged and active, which is so important.”

The infectious disease specialist said while increased isolation and inactivity may be necessary consequences of preventing Covid-19 in vulnerable, elderly populations, strategies are urgently needed to safely reunite residents with their loved ones and reintroduce communal activities.

“We are focusing on preventing infection, as we should be,” she said. “We can use common sense and public health principles to decrease risk, but we can’t eliminate it. And at some point we have to decide how much risk is acceptable. With the families in assisted living that is an immediate and very difficult challenge.”

  1. A Covid-19 outbreak investigation at a Seattle independent and assisted living facility identified asymptomatic exposure and very low rates of SARS-CoV-2 infection overall.

  2. The findings suggest that adherence to social distancing and other infection control measures may be highly effective even in vulnerable populations and that active testing was superior to symptom screening.

Salynn Boyles, Contributing Writer, BreakingMED™

Researcher Alexander Greninger reported receiving personal fees from Abbott Molecular unrelated to the study. No other researchers reported relevant disclosures.

Editorial writers Grace Jeng, John Mills, and Preeti Malani declared no conflicts of interest.

Cat ID: 125

Topic ID: 79,125,282,287,494,931,570,125,926,192,927,151,928,925,934