Health officials explain when coronavirus patients are no longer infectious

COLUMBIA, Mo. (KMIZ)

People diagnosed with coronavirus must meet three criteria before being released from isolation or considered recovered, according to local health departments.

Both Cole and Columbia/Boone County Health department officials say they use the CDC recommended, symptom-based measure to monitor the number of recovered cases or people removed from isolation.

Under this measure, the health department can release someone from isolation only if it has been 10 days since their symptoms first started, they have been fever free for at least 24 hours without fever-reducing medication, and there has been an improvement of all symptoms.

Once all three criteria are met, the Cole County Health Department considers that person as recovered, said Communicable Disease Coordinator Chezney Schulte.

In Boone County that person would be considered “removed from isolation,” said Assistant Director Scott Clardy.

Clardy said the health department does not use the term “recovered case” as people could meet all three criteria but still not be fully recovered from COVID-19, as the long term effects of the virus are still unknown.

“Some people can come off isolation meaning they're no longer infectious with COVID,” Clardy said. “But they may not be fully recovered yet. We read a study that it's taking… in some cases, up to three weeks for even young people to go back to their original state of health, after having COVID."

If a person tests positive for the virus but shows no symptoms, that person would still need to isolate themselves for 10 days after that test was collected.

If the person remains symptom free throughout those 10 days, then they can be released from isolation.

Another method of measuring those removed from isolation is test-based. This measure would have the health department require the positive case to test negative one or two tests in a row during a certain time frame, before being counted as recovered.

“We've found, and CDC also reports, that individuals might continue testing positive by that PCR (Polymerase chain reaction) nasal swab for quite some time after no longer being symptomatic,” Schulte said. “And that test can detect if the virus is still present in the nasal cavity, but it doesn't tell us if it's alive or dead.”

Schulte said the CDC has done that research to say that viral load is considerably lower at that point, and that it's a dead virus where it can’t be spread to others.

Both Cole and Boone County had more positive COVID-19 cases in July, as a result there have been more people that have recovered or been removed from isolation.

“We saw more cases… in the end of June and July,” Clardy said. “So as we see more cases, if everybody is… getting better then that should be more people we have coming out of isolation also.”

According the Boone County, MO COVID-19 Information Hub, as of Thursday, Boone County has a total of 1,146 number of cases, with 956 people removed from isolation.

According to the Cole County website, as of Thursday, Cole County has a total of 273 total cases, with 219 recovered.

Schulte said many people are focusing on the total number of cases rather then the breakdown of those that are still in quarantine, those people that are still having the act of infection, versus those who have recovered.

"Which is a great difference to point out," Schulte said. "Obviously the total number is going to continue accumulating, but we also have a lot recovered versus active, which is a great ratio to look at.”