Presymptomatic SARS-CoV-2 Infections and Transmission in a Skilled Nursing Facility

Abstract

BACKGROUNDSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can spread rapidly within skilled nursing facilities. After identification of a case of Covid-19 in a skilled nursing facility, we assessed transmission and evaluated the adequacy of symptom-based screening to identify infections in residents. METHODSWe conducted two serial point-prevalence surveys, 1 week apart, in which assenting residents of the facility underwent nasopharyngeal and oropharyngeal testing for SARS-CoV-2, including real-time reverse-transcriptase polymerase chain reaction (rRT-PCR), viral culture, and sequencing. Symptoms that had been present during the preceding 14 days were recorded. Asymptomatic residents who tested positive were reassessed 7 days later. Residents with SARS-CoV-2 infection were categorized as symptomatic with typical symptoms (fever, cough, or shortness of breath), symptomatic with only atypical symptoms, presymptomatic, or asymptomatic. RESULTSTwenty-three days after the first positive test result in a resident at this skilled nursing facility, 57 of 89 residents (64%) tested positive for SARS-CoV-2. Among 76 residents who participated in point-prevalence surveys, 48 (63%) tested positive. Of these 48 residents, 27 (56%) were asymptomatic at the time of testing; 24 subsequently developed symptoms (median time to onset, 4 days). Samples from these 24 presymptomatic residents had a median rRT-PCR cycle threshold value of 23.1, and viable virus was recovered from 17 residents. As of April 3, of the 57 residents with SARS-CoV-2 infection, 11 had been hospitalized (3 in the intensive care unit) and 15 had died (mortality, 26%). Of the 34 residents whose specimens were sequenced, 27 (79%) had sequences that fit into two clusters with a difference of one nucleotide. CONCLUSIONSRapid and widespread transmission of SARS-CoV-2 was demonstrated in this skilled nursing facility. More than half of residents with positive test results were asymptomatic at the time of testing and most likely contributed to transmission. Infection-control strategies focused solely on symptomatic residents were not sufficient to prevent transmission after SARS-CoV-2 introduction into this facility.

Quantitative COVID-19 infectiousness estimate correlating with viral shedding and culturability suggests 68% pre-symptomatic transmissions

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COVID-19 in Correctional and Detention Facilities — United States, February–April 2020

“…Although symptom screening is important, an investigation of a COVID-19 outbreak in a skilled nursing facility found that approximately one half of cases identified through facilitywide testing were among asymptomatic and presymptomatic persons, who likely contributed to transmission (4). These data indicate that symptom screening alone is inadequate to promptly identify and isolate infected persons in congregate settings such as correctional and detention facilities.…”

COVID-19: it is time to balance infection management and person-centered care to maintain mental health of people living in German nursing homes

“…The reported figures from official statistics as well as recent research show the widespread transmission of SARS-CoV-2 and the high lethality of COVID-19 in nursing home residents (Arons et al, 2020). Moreover, more than half of the residents with a positive COVID-19 diagnosis are asymptomatic at the time of testing.…”

“…These asymptomatic cases very likely contribute to the transmission of the virus. Therefore, broad and frequent testing of all nursing home residents and their caregivers is recommended (Arons et al, 2020;Centers for Disease Control and Prevention, 2020). In addition, sufficient personal protective equipment is needed for nursing home staff and also for relatives and friends of residents.…”