Many schools and businesses are requiring people to stop to get their temperature checked before they're allowed inside, a precaution aimed to slow the spread of COVID-19. A recent study conducted by Natalie Lambert, PhD, questions whether that may be giving people a false sense of security.

After surveying about 4,000 people who have experienced COVID-19 symptoms, Lambert found that less than eight percent (7.7 percent) of survey respondents reported having a fever within the first ten days of getting sick. When factoring in the 40% of people who are asymptomatic, the survey results suggest that only 4.6% of people infected with COVID-19 are likely to have a fever while contagious. The Centers for Disease Control and Prevention (CDC) determined that people are usually most contagious within the first ten days of contracting COVID-19. Lambert's research shows that people are more likely to feel fatigued (14.44 percent), have a cough (10.65 percent) or headache (9.48 percent), experience shortness of breath (8.73 percent) or have a changed sense of taste (7.71 percent), rather than have a fever.

"Without access to rapid COVID-19 tests, the results of our survey indicate that health policies preventing people who exhibit any symptom of illness from entering buildings are the most effective method for preventing the spread of COVID-19," said Lambert. "However, such a strict and broad health policy would come at the cost of disruption of business and school activities."

While researchers have found that fever is a common symptom among patients who are hospitalized for COVID-19, with between 63 and 99 percent reporting high temperatures, most COVID-19 patients don't get sick enough to need to be hospitalized. Nearly 90 percent of the participants in Lambert's study were never hospitalized for COVID-19.

"People who are not ill enough to be hospitalized are also the group most likely to be entering public places while contagious," said Lambert. "Fever screening is commonly used to keep customers, students, and patients infected with COVID-19 from entering a public space where they could infect others. However, we have little data about how common early-onset fever is for people who have mild to moderate cases of COVID-19."

Another important factor to consider is asymptomatic spread of COVID-19, since the CDC has determined that about 40 percent of people diagnosed with the disease do not show any symptoms.

"A vaccine is an essential component to beating this pandemic, but we cannot ignore the need to implement better preventative policies to curb the spread of the disease, develop therapies that halt the damage COVID-19 does to the body early its progression, and help heal the hundreds of thousands of patients who are struggling to recover," said Lambert.

This study was conducted as a partnership between IU School of Medicine and Survivor Corps, a COVID-19 survivor advocacy group. Lambert's work is supported by the IU Precision Health Initiative data and informatics scientific pillar.