Why are smell tests being proposed over temperature checks at workplaces?
Why are smell tests being proposed over temperature checks at workplaces?
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While many businesses and public spaces have begun using temperature checks as a way to try to identify people who might be infected with COVID-19, several studies have proposed that using a smell test in addition to a thermometer check may be a more accurate way of detecting potential cases. The reasons for this are numerous, and are mostly due to concerns about the effectiveness of temperature checks. Some of these issues include: - The fact that many people with COVID-19 never develop any symptoms such as fevers; - People with fevers might not have the virus at all and could have any number of other illnesses; - Infrared/non-contact thermometers are often inaccurate and operating errors may occur; and - People who take over-the-counter medication for fevers might be ill but will not present with a fever. Using a temperature check alone is not an effective strategy to detect COVID-19 infections at public sites. On the other hand, the potential benefits of a smell test are numerous, as the loss of smell— also called 'anosmia'—is relatively unique to COVID-19, whereas fevers are common symptoms in many illnesses. For instance, a recent preprint study (awaiting peer-review) showed that COVID-19 patients were 27 times more likely to have lost their sense of smell than people without the virus, but only 2.6 times more likely to have fever or chills than those without the virus. Another study demonstrated that people with a loss of smell are "more than 10 times more likely to have COVID-19 than other causes of infection," according to Dr. Carol Yan, making it a more accurate marker for COVID-19 than a fever would likely be, as they have many other causes and are associated with many other illnesses. Reasons like this are why many health experts believe that a combination of a smell test in addition to temperature checks could more accurately test and identify people for COVID-19.
While many businesses and public spaces have begun using temperature checks as a way to try to identify people who might be infected with COVID-19, several studies have proposed that using a smell test in addition to a thermometer check may be a more accurate way of detecting potential cases. The reasons for this are numerous, and are mostly due to concerns about the effectiveness of temperature checks. Some of these issues include: - The fact that many people with COVID-19 never develop any symptoms such as fevers; - People with fevers might not have the virus at all and could have any number of other illnesses; - Infrared/non-contact thermometers are often inaccurate and operating errors may occur; and - People who take over-the-counter medication for fevers might be ill but will not present with a fever. Using a temperature check alone is not an effective strategy to detect COVID-19 infections at public sites. On the other hand, the potential benefits of a smell test are numerous, as the loss of smell— also called 'anosmia'—is relatively unique to COVID-19, whereas fevers are common symptoms in many illnesses. For instance, a recent preprint study (awaiting peer-review) showed that COVID-19 patients were 27 times more likely to have lost their sense of smell than people without the virus, but only 2.6 times more likely to have fever or chills than those without the virus. Another study demonstrated that people with a loss of smell are "more than 10 times more likely to have COVID-19 than other causes of infection," according to Dr. Carol Yan, making it a more accurate marker for COVID-19 than a fever would likely be, as they have many other causes and are associated with many other illnesses. Reasons like this are why many health experts believe that a combination of a smell test in addition to temperature checks could more accurately test and identify people for COVID-19.
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What our experts say
While many businesses and public spaces have begun using temperature checks as a way to try to identify people who might be infected with COVID-19, several studies have proposed that using a smell test in addition to a thermometer check may be a more accurate way of detecting potential cases. The reasons for this are numerous, and are mostly due to concerns about the effectiveness of temperature checks. Some of these issues include: - The fact that many people with COVID-19 never develop any symptoms such as fevers; - People with fevers might not have the virus at all and could have any number of other illnesses; - Infrared/non-contact thermometers are often inaccurate and operating errors may occur; and - People who take over-the-counter medication for fevers might be ill but will not present with a fever. Using a temperature check alone is not an effective strategy to detect COVID-19 infections at public sites. On the other hand, the potential benefits of a smell test are numerous, as the loss of smell— also called 'anosmia'—is relatively unique to COVID-19, whereas fevers are common symptoms in many illnesses.
For instance, a recent preprint study (awaiting peer-review) showed that COVID-19 patients were 27 times more likely to have lost their sense of smell than people without the virus, but only 2.6 times more likely to have fever or chills than those without the virus. Another study demonstrated that people with a loss of smell are "more than 10 times more likely to have COVID-19 than other causes of infection," according to Dr. Carol Yan, making it a more accurate marker for COVID-19 than a fever would likely be, as they have many other causes and are associated with many other illnesses. Reasons like this are why many health experts believe that a combination of a smell test in addition to temperature checks could more accurately test and identify people for COVID-19.
While many businesses and public spaces have begun using temperature checks as a way to try to identify people who might be infected with COVID-19, several studies have proposed that using a smell test in addition to a thermometer check may be a more accurate way of detecting potential cases. The reasons for this are numerous, and are mostly due to concerns about the effectiveness of temperature checks. Some of these issues include: - The fact that many people with COVID-19 never develop any symptoms such as fevers; - People with fevers might not have the virus at all and could have any number of other illnesses; - Infrared/non-contact thermometers are often inaccurate and operating errors may occur; and - People who take over-the-counter medication for fevers might be ill but will not present with a fever. Using a temperature check alone is not an effective strategy to detect COVID-19 infections at public sites. On the other hand, the potential benefits of a smell test are numerous, as the loss of smell— also called 'anosmia'—is relatively unique to COVID-19, whereas fevers are common symptoms in many illnesses.
For instance, a recent preprint study (awaiting peer-review) showed that COVID-19 patients were 27 times more likely to have lost their sense of smell than people without the virus, but only 2.6 times more likely to have fever or chills than those without the virus. Another study demonstrated that people with a loss of smell are "more than 10 times more likely to have COVID-19 than other causes of infection," according to Dr. Carol Yan, making it a more accurate marker for COVID-19 than a fever would likely be, as they have many other causes and are associated with many other illnesses. Reasons like this are why many health experts believe that a combination of a smell test in addition to temperature checks could more accurately test and identify people for COVID-19.
Context and background
There is growing interest in smell tests to supplement temperature testing during the current pandemic. Loss of smell, also called anosmia, is one of the possible symptoms of COVID-19. In some patients who have tested positive for COVID-19, loss of smell is the only reported symptom. The potential for a smell test serving as a better diagnostic for COVID-19 may lie in anosmia's unique link to COVID-19. Dr. Andrew Badley of the Mayo Clinic further explains this point as he stated “My impression is that anosmia is an earlier symptom of Covid-19 relative to fever, and some infected people can have anosmia and nothing else. So it’s potentially a more sensitive screen for asymptomatic patients.”
Additionally, temperature checks can be insufficient for screening because patients with COVID-19 may not have a fever, and there are other health conditions that can cause a fever. Loss of smell is more unique to COVID-19. While smell tests can be helpful to add to temperature screenings at workplaces, schools, airports, restaurants and other locations, it is important to remember that infected people can still transmit COVID-19 without showing any symptoms like fever or loss of smell.
There is growing interest in smell tests to supplement temperature testing during the current pandemic. Loss of smell, also called anosmia, is one of the possible symptoms of COVID-19. In some patients who have tested positive for COVID-19, loss of smell is the only reported symptom. The potential for a smell test serving as a better diagnostic for COVID-19 may lie in anosmia's unique link to COVID-19. Dr. Andrew Badley of the Mayo Clinic further explains this point as he stated “My impression is that anosmia is an earlier symptom of Covid-19 relative to fever, and some infected people can have anosmia and nothing else. So it’s potentially a more sensitive screen for asymptomatic patients.”
Additionally, temperature checks can be insufficient for screening because patients with COVID-19 may not have a fever, and there are other health conditions that can cause a fever. Loss of smell is more unique to COVID-19. While smell tests can be helpful to add to temperature screenings at workplaces, schools, airports, restaurants and other locations, it is important to remember that infected people can still transmit COVID-19 without showing any symptoms like fever or loss of smell.
Resources
- COVID‑19 Strategy Update 14 April 2020 (WHO)
- General Business Frequently Asked Questions (U.S. CDC)
- Employers Rush to Adopt Virus Screening. The Tools May Not Help Much. (NYT)
- Augmented Curation of Clinical Notes from a Massive EHR System Reveals Symptoms of Impending COVID-19 Diagnosis (medRxiv)
- Self‐reported olfactory loss associates with outpatient clinical course in COVID‐19 (IFAR)
- The implications of silent transmission for the control of COVID-19 outbreaks (PNAS)
- Fever checks are a flawed way to flag Covid-19 cases. Experts say smell tests might help (STAT News)
- COVID‑19 Strategy Update 14 April 2020 (WHO)
- General Business Frequently Asked Questions (U.S. CDC)
- Employers Rush to Adopt Virus Screening. The Tools May Not Help Much. (NYT)
- Augmented Curation of Clinical Notes from a Massive EHR System Reveals Symptoms of Impending COVID-19 Diagnosis (medRxiv)
- Self‐reported olfactory loss associates with outpatient clinical course in COVID‐19 (IFAR)
- The implications of silent transmission for the control of COVID-19 outbreaks (PNAS)
- Fever checks are a flawed way to flag Covid-19 cases. Experts say smell tests might help (STAT News)
