Can we use temperature measurements to identify pre-symptomatic SARS-CoV-2 infection in nursing home residents?

BACKGROUND: COVID-19 has had a severe impact on morbidity and mortality among nursing home (NH) residents. Earlier detection of SARS-CoV-2 may position us to better mitigate the risk of spread. Both asymptomatic and pre-symptomatic transmission are common in outbreaks, and threshold temperatures, such as 38C, for screening for infection could miss timely detection in the majority of residents. We hypothesized that in long-term care residents, temperature trends with SARS-CoV-2 infection could identify infection in pre-symptomatic individuals earlier than standard screening. METHODS: We conducted a retrospective cohort study using electronic health records in 6176 residents of the VA NHs who underwent SARS-CoV-2 testing triggered by symptoms. We collected information about age and other demographics, baseline temperature, and specific comorbidities. We created standardized definitions, and a hypothetical model to test measures of temperature variation and compare outcomes to the VA standard of care. RESULTS: We showed that a change from baseline of 0.4C identified 47% of NH residents who became SARS-CoV-2 positive, earlier than standard testing by an average of 42.2 h. Temperature variability of 0.5C over 3 days when paired with a 37.2C temperature cutoff identified 55% of NH residents who became SARS-CoV-2 positive earlier than the standard of care testing by an average of 44.4 h. A change from baseline temperature of 0.4C when combined with temperature variability of 0.7C over 3 days identified 52% of NH residents who became SARS-CoV-2 positive, earlier than standard testing by an average of 40 h, and by more than 3 days in 22% of the residents. This earlier detection comes at the expense of triggering 57,793 tests, as compared to the number of trigger tests ordered in the VA system of 40,691. CONCLUSIONS: Our model suggests that early temperature trends with SARS-CoV-2 infection may identify infection in pre-symptomatic long-term care residents.

Dementia prevalence, a contextual factor associated with SARS-CoV-2 in veterans affairs community living centers.

BACKGROUND: Alzheimer's disease and related dementias (ADRD) impact the diagnosis and infection control of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in nursing homes (NH) by influencing the behavior of residents and their caregivers. Health system data show an association between ADRD and SARS-CoV-2. Whether this association is present in NH populations remains unknown. How increased SARS-CoV-2 risk among residents with ADRD impacts the greater NH population also remains unknown. METHODS: This retrospective cohort study used electronic health record data on Veterans residing in 133 Veterans Affairs Community Living Centers (CLC) and 15 spinal cord injury units from March 1, 2020 to December 13, 2020. We measured ADRD using diagnostic codes 12 months before an index SARS-CoV-2 test date for each resident. We used Poisson regression to determine the relative risk of SARS-CoV-2 for the highest quartile of facility ADRD prevalence versus the lowest, stratifying by individual ADRD status, and adjusting for covariates, with and without a random intercept to account for facility clustering. RESULTS: Across the study period, 15,043 residents resided in CLCs, 1952 (13.0%) had SARS-CoV-2, and 8067 (53.6%) had ADRD. There was an estimated 60% increased risk of SARS-CoV-2 in facilities with highest dementia prevalence versus lowest (relative risk, 1.6 [95% confidence interval 0.95, 2.7]). CONCLUSIONS: CLC residents had a greater likelihood of SARS-CoV-2 infection in facilities with greater ADRD prevalence. Facility characteristics other than ADRD prevalence may account for this association.

The effect of age on fever response among nursing home residents with SARS-COV-2 infection.

Over 15,000 veterans in 135 VA nursing homes were systematically tested for SARS-CoV-2 and had daily temperatures assessed from March to August, 2020. Lower baseline temperatures, and in SARS-CoV-2+ , lower maximum temperatures were observed with advancing age. Clinicians should be aware of the potential diminished fever response in the elderly with SARS-CoV-2.

Can we clinically identify pre-symptomatic and asymptomatic COVID-19?

OBJECTIVES: COVID-19 has had a severe impact on morbidity and mortality among nursing home (NH) residents. Earlier detection of SARS-CoV-2 may position us to better mitigate risk of spread. Both asymptomatic or pre-symptomatic transmission are common in outbreaks, and threshold temperatures, such as 38C, for screening for infection could miss timely detection in the majority. DESIGN: Retrospective cohort study using electronic health records. METHODS: We hypothesized that in long-term care residents, temperature trends with SARS-CoV-2 infection could identify infection in pre-symptomatic and asymptomatic individuals earlier. We collected information about age and other demographics, baseline temperature, and specific comorbidities. We created standardized definitions, and an alternative hypothetical model to test measures of temperature variation and compare outcomes to the VA reality. SETTINGS AND PARTICIPANTS: Our subjects were 6,176 residents of the VA NHs who underwent SARS-CoV-2 trigger testing. RESULTS: We showed that a change from baseline of >0.4C identifies 47% of the SARS-CoV-2 positive NH residents early, and achieves earlier detection by 42.2 hours. Range improves early detection to 55% when paired with a 37.2C cutoff, and achieves earlier detection by 44.4 hours. Temperature elevation >0.4C from baseline, when combined with a 0.7C range, would detect 52% early, leading to earlier detection by more than 3 days in 22% of the residents. This earlier detection comes at the expense of triggering 57,793 tests, as compared to the number of trigger tests ordered in the VA system of 40,691. CONCLUSION AND IMPLICATIONS: Our model suggests that current clinical screening for SARS-CoV-2 in NHs can be substantially improved upon by triggering testing using a patient-derived baseline temperature with a 0.4C degree relative elevation or temperature variability of 0.7C trigger threshold for SARS-CoV2 testing. Such triggers could be automated in facilities that track temperatures in their electronic records.