Staff photo by Troy Stolt / University of Tennessee at Chattanooga graduate student Mary Ferris volunteered to work with the Hamilton County Health Department to keep up with people undergoing 14 day quarantines after possibly being exposed to coronavirus. She is shown inside her home office on Friday, May 1, 2020 in Chattanooga, Tenn.

UPDATE: Hamilton County quarantine guidelines revised as of Dec. 4 

Quarantine is a longstanding public health tool thrust into the spotlight by the coronavirus pandemic, affecting everything from home life to work and travel schedules.

It's also become a source of confusion as people attempt to navigate the web of scenarios that could render them stuck at home waiting to see if they get sick.

The terms "isolation" and "quarantine" are distinct but have commonly been used interchangeably during COVID-19.

Isolation is separating sick people from healthy people to prevent spread of disease, whereas quarantine separates and restricts the movement of people who were possibly exposed to a contagious disease to see if they become infected, according to the U.S. Centers for Disease Control and Prevention.

People who have been within close contact — defined as 6 feet or less for 15 minutes or more — of someone who has COVID-19 should stay home for 14 days after their last contact with that person. However, that period could extend longer for those who are unable to distance themselves from infected people.

(READ MORE: Hamilton County teachers to follow strict COVID-19 quarantine rules as some Tennessee districts forgo CDC guidelines)

The Tennessee Department of Health issued an update last week aiming to clarify how long people who might have been exposed to the coronavirus should quarantine. Most startling for many was the realization that household contacts of people with COVID-19 might need to quarantine for 24 days or more.

Tennessee Commissioner of Health Dr. Lisa Piercey acknowledged the "sticker shock" that followed during a news conference on Thursday. She also emphasized that the 24-day quarantine only applies in specific cases and that the guidelines come from the federal CDC, not the state department of health.

"When you start your quarantine, you start that from the date of last exposure to a positive case. And if that positive case is in your household, then the last date of exposure is the last date of illness, which for most people is 10 days. So that's when the 14 days starts. That's how you get the 10 plus 14," Piercey said. "But hear me clearly, that doesn't apply to everyone if you're properly able to isolate yourself from that household contact."

She said only those who are unable to separate from sick people in their home for the duration of their illness need to worry about extended quarantine. For example, continuing to care for or share a bathroom with a COVID-19 positive household member.

"In instances where you can isolate from that household member, then your 14 days starts the day the last contact took place," Piercey said. "For some people, albeit not many, they are able to isolate that household member in a different residence. That's not possible a lot of the times. Sometimes it's possible to isolate that person in one part of the house where you don't share any common spaces.

"So if the contact is not going into the same room, not sharing common spaces like kitchens or bathrooms with the infected case, then they are no longer in ongoing contact," she said. "There are some instances where it's just impossible or impractical to separate oneself from that infected case. And in those instances, their period at home will be longer, because their quarantine doesn't start until the infection is resolved."

Because the coronavirus is new, guidelines can change as researchers learn more about how the virus spreads.

Contact Elizabeth Fite at or follow her on Twitter @ecfite.