Does Temperature Screening Work to Detect COVID?
Businesses and airports are starting to utilize devices to detect fevers to screen people for COVID-19 before entering buildings. Many new products are being developed to do this. The United States Food and Drug Administration (FDA) has recently updated their guidelines to include specifications for devices intended to be used to screen fevers (1). The FDA recommends that these telethermographic systems be used to screen for temperatures in areas with a large number of people where thermometer screening would be challenging, but that a positive result should be confirmed with a thermometer (1).
The Centers for Disease Control and Prevention (CDC) suggests that temperature screening is an optional method to screen for COVID-19 and gives advice on how to screen safely, especially when done individually (2). Temperatures can be checked using thermometers, including non-touch temperatures on the forehead, and telethermograms, using cameras from a distance. When screening temperatures using thermometers, the employee checking temperatures is at risk for exposure and of contaminating others if not very careful. It is important to sanitize thermometers between uses thoroughly and to utilize barriers and personal protective equipment (2). Telethermograms offer a way to screen temperatures remotely without the need for a staff member to be at risk of contracting and spreading COVID-19. Telethermograms have been used in hospitals, the military, airports, and warehouses (3,4). They have been used to screen for SARS, H1N1, and Ebola (5). Research suggests that telethermograms are useful in initial fever screening, especially when screening many people, but because some devices have a significant amount of false positives, they would need verification by thermometers (6–8). Additionally, implementing temperature checks reinforces the importance of monitoring symptoms and not coming in to work if they do not feel well. However, there is the risk that workers may take an antipyretic before coming to work to be allowed in.
When adding temperature screening to a business, there are some critical aspects to consider. These include what temperature will be considered a fever. A fever is defined as a temperature of 100.4˚F or higher by the CDC, but the employer should consider a lower temperature, depending on the accuracy of the thermometer (2). There should also be safety precautions in place if a person will be screening others’ temperatures. Additionally, a plan should be in place for employees with an elevated temperature, such as testing for COVID-19, if available, and instructions on when it will be safe to return to work. The employee should also be allowed to leave work without adverse consequences if they do have a fever and will need to stay out.
A fever is only one symptom of COVID-19. When screening for both fever and symptoms, one study found that only 40% of COVID-19 cases may be detected (9). Screening can be beneficial in identifying COVID-19, as even catching 1 case can prevent significant future disease, especially in a contained building. Therefore, it is still critical to maintain other preventive measures in addition to screening. This includes social distancing, strict hygiene measures, and limiting non-essential traveling. Incorporating each of these measures can significantly cut down the risk of the spread of COVID-19.
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