Temperature and oxygen saturation in skilled nursing facility residents positive for SARS-CoV-2 prior to symptom onset

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) spreads rapidly amongst residents of skilled nursing facilities (SNFs). The rapid transmission dynamics and high morbidity and mortality that occur in SNFs emphasize the need for early detection of cases. We hypothesized that residents of SNFs infected with SARS-CoV-2 would demonstrate an acute change in either temperature or oxygen saturation (SpO₂ ) prior to symptom onset. The Minnesota Department of Health (MDH) conducted a retrospective analysis of both temperature and SpO₂ at two separate SNFs to assess the utility of these quantitative markers to identify SARS-CoV-2 infection prior to the development of symptoms.

A retrospective analysis was conducted of 165 individuals positive for SARS-CoV-2 who were residents of SNFs that experienced coronavirus disease 2019 (COVID-19) outbreaks during April-June 2020 in a metropolitan area of Minnesota. Age, sex, symptomology, temperature and SpO₂ values, date of symptom onset, and date of positive SARS-CoV-2 test were analyzed. Temperature and SpO₂ values for the period 14 days before and after the date of initial positive test were included. Descriptive analyses evaluated changes in temperature and SpO₂ , defined as either exceeding a set threshold or demonstrating an acute change between consecutive measurements.

Two (1%) residents had a temperature value ≥100°F, and 30 (18%) had at least one value ≥99°F within 14 days before symptom development. One hundred and sixteen residents (70%) had at least one SpO₂ value ≤94%, while 131 (80%) had an acute decrease in SpO₂ of ≥3% between consecutive values in the 14 days prior to symptom onset.

Our results suggest that acute change in SpO₂ might be useful in the identification of SARS-CoV-2 infection prior to the development of symptoms among residents living in SNFs. Facilities may consider adding SpO₂ to daily temperature and symptom screening checklists to improve early detection of residents of SNFs infected with SARS-CoV-2.