Serial Testing for SARS-CoV-2 and Virus Whole Genome Sequencing Inform Infection Risk at Two Skilled Nursing Facilities with COVID-19 Outbreaks - Minnesota, April-June 2020

MMWR Morb Mortal Wkly Rep. 2020 Sep 18;69(37):1288-1295. doi: 10.15585/mmwr.mm6937a3.


SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19), can spread rapidly in high-risk congregate settings such as skilled nursing facilities (SNFs) (1). In Minnesota, SNF-associated cases accounted for 3,950 (8%) of 48,711 COVID-19 cases reported through July 21, 2020; 35% of SNF-associated cases involved health care personnel (HCP*), including six deaths. Facility-wide, serial testing in SNFs has been used to identify residents with asymptomatic and presymptomatic SARS-CoV-2 infection to inform mitigation efforts, including cohorting of residents with positive test results and exclusion of infected HCP from the workplace (2,3). During April-June 2020, the Minnesota Department of Health (MDH), with CDC assistance, conducted weekly serial testing at two SNFs experiencing COVID-19 outbreaks. Among 259 tested residents, and 341 tested HCP, 64% and 33%, respectively, had positive reverse transcription-polymerase chain reaction (RT-PCR) SARS-CoV-2 test results. Continued SARS-CoV-2 transmission was potentially facilitated by lapses in infection prevention and control (IPC) practices, up to 12-day delays in receiving HCP test results (53%) at one facility, and incomplete HCP participation (71%). Genetic sequencing demonstrated that SARS-CoV-2 viral genomes from HCP and resident specimens were clustered by facility, suggesting facility-based transmission. Residents and HCP working in SNFs are at risk for infection with SARS-CoV-2. As part of comprehensive COVID-19 preparation and response, including early identification of cases, SNFs should conduct serial testing of residents and HCP, maximize HCP testing participation, ensure availability of personal protective equipment (PPE), and enhance IPC practices (4-5).

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Betacoronavirus / genetics
  • Betacoronavirus / isolation & purification
  • COVID-19
  • COVID-19 Testing
  • Clinical Laboratory Techniques / methods*
  • Coronavirus Infections / diagnosis*
  • Coronavirus Infections / epidemiology*
  • Disease Outbreaks*
  • Female
  • Genome, Viral / genetics
  • Humans
  • Male
  • Middle Aged
  • Minnesota / epidemiology
  • Pandemics
  • Pneumonia, Viral / diagnosis*
  • Pneumonia, Viral / epidemiology*
  • Risk Assessment
  • SARS-CoV-2
  • Skilled Nursing Facilities*
  • Whole Genome Sequencing
  • Young Adult