FebriDx host-response point-of-care testing improves patient triage for coronavirus disease 2019 (COVID-19) in the emergency department

Although we had all hoped we might not reach this pandemic point again, much of the world is seeing rising numbers of coronavirus disease 2019 (COVID-19) cases. Healthcare systems across the United States and elsewhere are strained, and the findings of Mansbridge et al1 regarding the use of FebriDx (Lumos Diagnostics, Sarasota, FL) in the emergency department (ED) to quickly separate patients infected with severe acute respiratory coronavirus virus 2 (SARS-CoV-2) from other patients provides us with a welcome tool in our hospital management of COVID-19. The SARS-CoV-2 omicron variant is ∼3.3 times more transmissible than the previous delta variant, and it has created a surge that has overwhelmed hospitals worldwide since November 2021.2,3 The United States is now recording >800,000 COVID-19 cases per day, and this is likely an underestimate given the high number of rapid tests being performed outside healthcare settings that report results.4 Although many of these cases are asymptomatic or mild and do not prompt a visit to the ED, many of them aremore severe, and do. Additionally, when the community prevalence of the disease is high, the number of people incidentally infected with severe acute respiratory coronavirus virus 2 (SARSCoV-2) that need to visit the ED for other reasons is high as well. The influx of COVID-19 patients into EDs during the current omicron surge has exacerbated the long-standing problem of ED overcrowding.5 Burnt-out healthcare workers and those who may be absent due to quarantine, isolation, or caring for a child whose school has been canceled lead to shortages of staff.6,7 This shortage frequently results in insufficient capacity to open certain areas of the ED where isolation rooms might exist. Nationwide, this situation has led to EDs to resort to using hallway spaces for patient care.8,9 Patients may wait anywhere from 2 to 6 hours before seeing a provider and continue to receive care in those spots even longer. Those who need to be admitted remain in the ED while waiting for inpatient hospital beds to become available and, in some hospitals, admitted patients are being boarded in the ED for days due to a lack of beds elsewhere. Unfortunately, the symptoms of SARS-CoV-2 are protean and not easily distinguished from other disease entities. Thus, patients with mixed infection status may be placed in stretchers near each other. Consistently wearing a mask for long periods of time while in this setting can be very challenging for patients, particularly those who are very ill. All these factors make preventing nosocomial transmission challenging, particularly in high-prevalence areas, as we are seeing throughout much of the United States. For example, in New York City at the peak of the omicron surge, 31% of patients tested for SARS-CoV-2 were positive.10 Quickly identifying and isolating patients with COVID-19 individually or in cohorts could dramatically reduce nosocomial transmission in the ED. However, we cannot rely on methods used earlier in the pandemic, such as temperature checks and symptom screeners, which have proven to be largely ineffective.11,12 Even more advanced clinical algorithms that incorporate laboratory and imaging data are not very accurate in determining the likelihood of a patient having COVID-19.13 This situation is expected to be evenmore prevalent with the omicron variant, given the high number of asymptomatic patients.14 By contrast, rapid point-of-care tests (POCTs), with their turnaround time of 10–15 minutes, may be used to quickly identify and isolate patients with COVID-19.15 In their manuscript, Mansbridge et al1 studied the use of 1 POCT, the lateral flow assay FebriDx, which has been designed to distinguish between bacterial and viral illnesses. They studied its utilization in a high prevalence setting, similar to circumstances we are now seeing in some areas of the United States during the omicron surge, and they found it to be useful in decreasing time spent in high-risk, cohorted areas of the ED, among patients who were triaged there due to concern for COVID-19. Although FebriDx currently has not been approved by the US Food and Drug Administration for use in the United States, other point-of-care (POC) lateral-flow assays have been approved, particularly various antigen tests. This class of tests has similarly been shown to have a high sensitivity and negative predictive value in detecting infectious virus,16–18 and these test may be considered for use in a manner similar to FebriDx. The SARS-CoV-2 antigen test has an advantage over assays that are less specific in detecting a particular virus. As the prevalence of respiratory viruses other than SARS-CoV-2 increases, a SARS-CoV-2 antigen test would allow for more accurate placement of patients in cohorts. Another major advantage of using rapid POC assays, either antigen or antiviral host-response tests, during the initial ED visit is that they are less likely than PCR testing to pick up residual virus from a prior infection in patients who have recovered from Author for correspondence: Elissa M. Schechter-Perkins, E-mail: elissa.perkins@bmc. org Cite this article: DiLorenzo MA and Schechter-Perkins EM. (2022). FebriDx hostresponse point-of-care testing improves patient triage for coronavirus disease 2019 (COVID-19) in the emergency department. Infection Control & Hospital Epidemiology, 43: 1049–1050, https://doi.org/10.1017/ice.2022.29