On a day when Knox County reported its highest number of new COVID-19 cases yet, the Health Department announced it would no longer be able to engage in contact tracing for every case.

Some county residents who test positive for COVID-19 will need to notify their close contacts on their own.

Dr. Martha Buchanan, the Health Department’s director, said during a news briefing on Tuesday that high case volumes, lagging laboratory processing times, and slow reporting at the state level led to the decision. She said jurisdictions across Tennessee are taking the same steps, which are in line with federal Centers for Disease Control and Prevention guidelines and have the blessing of the Tennessee Department of Health.

Contact tracing is the process used by public health agencies to find and notify people who have been exposed to someone known to be infected. During the COVID-19 pandemic, that has meant interviewing people who have tested positive for the coronavirus and then notifying the people they had been in close contact with recently to recommend they get tested as well.

Until now, the Health Department has been launching a case investigation of every person who has tested positive. The new process sets priorities for the effort.

“Case investigations will be prioritized for COVID-19 cases reported to us within six days of their testing, except for cases 18 years and younger and 60 years old and older.” Buchanan said. “We will continue to investigate all of the cases in the latter two categories in an effort to reach two priority populations.”

Seniors are particularly vulnerable to COVID-19 complications — 158 of Knox County’s 194 fatalities from the illness have been 65 years old or older. Buchanan said many minors and seniors also spend time indoors with large groups of people in schools, nursing homes and other facilities. 

Many of the rest of the county residents who test positive will have to conduct contact tracing on their own, by notifying anyone they may have exposed. While the Health Department receives test results from the lab it uses within two days, tests on samples collected by other providers can take substantially longer. 

During the week ending Nov. 28, the last period for which statistics have been published, the overall average time between sample collection and test results was close to seven days. Given the incubation period of COVID-19, contact tracing loses its effectiveness at that point.

Buchanan said people who test positive for COVID-19 should not wait to hear from the Health Department before taking action.

“We recommend that all positive patients immediately isolate upon learning of their positive test result and notify their close contacts of the need to quarantine,” she said.

The Health Department has a page on its website with links to the recently revised isolation and quarantine guidelines, as well as other resources, including a quarantine and isolation calculator. Close contacts are defined as people who are within 6 feet of a person who has tested positive for at least 15 minutes; a caregiver; or someone who lives in the same household as a COVID-19 patient.

 “The local situation is the worst we have seen, and the entire system is fundamentally overwhelmed,” Buchanan said. “Cases are increasing at a rapid rate, hospitalizations are incredibly high, and, most tragically, the past couple of weeks have been the deadliest in our community regarding COVID-19.”

For months, the Health Department had been able to start investigations within 24 hours of receiving notification of a positive result. Case counts have exploded in the past two months, going from an average of 85 new cases per day for the seven days ending Oct. 8 to an average of 320 per day for the past seven days. Monday’s 450 new cases set a single-day record for the pandemic.

Medical and public health officials are warning of more illness and death in the coming weeks.

“We are in a predicament that we haven’t been in before,” said Dr. Keith Gray, chief medical officer for University of Tennessee Medical Center. “We expect to see daily new cases to continue to increase secondary to the Thanksgiving holiday, which we’re starting to see the impact of this week, and the rest of the holiday season which will extend through early January.”

He said following the five core actions — maintaining physical distancing, wearing cloth face coverings, washing hands, sanitizing surfaces and staying home when sick — remains the best way to combat the spread.

“We understand that many of you are experiencing COVID-19 messaging fatigue, but now more than ever it is imperative to consider how our actions affect others,” Gray said.

Buchanan said the surge in cases indicates that people are not consistently following the five core actions, and that COVID-19 doesn’t take a break during holiday parties and gatherings. 

“COVID-19 requires us to rethink how we socialize,” she said.

Gray said not all recent developments are grim.

“Help is on the way,” he said. “We are expecting our first doses of vaccine to arrive on or shortly after Dec. 18, which will give us an opportunity to vaccinate our frontline workers, our healthcare providers, and shortly thereafter, we hope that a phased vaccine distribution and administration plan will be available for our community members in early 2021.”

Until then, health officials urge continued vigilance. Buchanan said the Health Department’s decision to redeploy its contact tracing resources should not be interpreted as a surrender to COVID-19.

“We are not giving up,” she said. “We are still in this fight and we’re not going anywhere.”