Are temperature checks an adequate screening tool for COVID-19?

Clinical Symptoms Infection and Spread Staying Safe

A: Unfortunately, no.

Being fever-free at the time of a temperature check is not a guarantee that a person doesn’t have COVID-19, nor that someone with COVID-19 won’t spread the infection to others.

Why is that?

The period of infectiousness for someone with COVID-19 (i.e., the window of time when someone can infect others) starts ~2 days BEFORE symptom onset, so individuals can have COVID-19 and spread the infection to others before developing a fever (or any other symptoms for that matter). Also important to note-not all individuals with COVID-19 will have a fever. Last, even if someone with COVID-19 no longer has a fever, if <10 days has passed since their symptoms started, they are still considered infectious.

So does temperature screening have any value?

Temperature checks will likely catch some of the people who have a fever at the time they are screened (and probably a few people that just happen to have an elevated temperature at that moment as well), but will miss those who have COVID-19 and don’t have a fever. A better scenario is one in which those who are experiencing ANY symptoms of COVID-19 (fever or otherwise) opt to (and importantly are enabled able to!) stay home from work, school or other activities, in the first place, instead of trying to rely on temperature checks on-site to identify those who are sick. For more info on what to do if you have COVID-19 symptoms, see here.

What measures should I focus on instead?

Given individuals can transmit SARS-CoV-2 to others, before they develop fever or other symptoms, a key question to consider in any scenario is, “What measures are being taken that serve to lower the likelihood that people will spread SARS-CoV-2 to others whether they currently have symptoms OR NOT?” Places that require face masks, maximize the ability for people to be physically distanced, make indoor air more like the outdoors (or moving activities outside to begin with), reduce the number of people gathered and limit the duration of time people spend in close contact are implementing measures that serve to help prevent the spread of SARS-CoV-2 from those who are infected, whether they know it yet or not. Temperature checks alone are unfortunately not adequate to identify all individuals who have COVID-19 nor prevent all those who are infected with SARS-CoV-2, from spreading it to others.

#clinicalsymptoms #Infection&Spread #stayingsafe

For a recent NYT article outlining the limitations of temperature screening for COVID-19, see here.

For another helpful previous post on use of temperature checks, see here.

For our previous post with handy timeline of the infectious period for COVID-19, see here.

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