Staff photo by C.B. Schmelter / A worker fills out a patient's form before they are tested at the Alstom COVID-19 testing site on Tuesday, Sept. 22, 2020 in Chattanooga, Tenn.

As new cases of COVID-19 rise in Hamilton County, the county health department is testing more people than at any point in the past month and a half.

The health department conducted 9,525 COVID-19 tests in the past week, an average of 1,361 new tests a day. It is the highest weekly total for the county since the beginning of September, a period when the county was reporting fewer new cases a day than it is now.

On Wednesday, the department reported 94 new cases, bringing the county total to 10,907. The county is averaging 82 new cases a day in the past week, higher than its average of 61 new cases a day at the beginning of the month.

The health department also reported 67 hospitalizations from the virus, the highest total since the first weeks of September. Local leaders have said the increase in hospitalization is being driven by surrounding counties, most of which do not have countywide mask mandates.

However, over the short time period of just the last few weeks, it is difficult to determine whether the increase in cases is due to the virus spreading in the community or because of more testing.

The percent positive rate is one metric used to understand the prevalence of COVID-19 and whether testing is keeping up with disease transmission, according to experts, including the Johns Hopkins School of Public Health.

Calculating the positivity rate for the virus on a given day requires dividing the number of positive tests reported on a given day by the total number of tests administered on that day. But these figures are not always available because of lags in reporting. When a positive test is reported, it does not necessarily mean that is the day the test was taken.

At the same time, the total number of tests reported on a given day may not reflect the actual number of tests administered and may include tests given on previous days by other local groups that had not been logged in the county's total. To help correct for these variances, the Times Free Press took the average number of tests a day over a seven-day period. Most calculations of Hamilton County's positivity rate are around 6% in the past week.

On Tuesday, Rae Bond, chairwoman of the COVID-19 Joint Task Force, said cases continue to rise in the 11-30 age group. Since Oct. 1, nearly 40% of all new cases in the county have been in that age range, according to data from the health department.

Bond noted that while younger people may not experience the most serious effects of the virus, they can put others at risk.

"While they may not be as heavily impacted by COVID, they can share the virus with older relatives who are much more at risk, so that's something we want people to continue to be mindful of," Bond said Tuesday.

Case rates across the state, particularly in more rural counties, are increasing. On Wednesday, Hamilton County Sheriff Jim Hammond tested positive for the virus, though the sheriff's office said he was asymptomatic. Gov. Bill Lee is also quarantining after potentially being exposed to the virus through a member of his security team, who tested positive.

Becky Barnes, Hamilton County Health Department administrator, said the county has seen several rises and falls in new cases during the ongoing pandemic.

"It is important for us as a community to take all the precautions that we know are effective in working to address this increase in daily case counts — such as wearing a mask even around friends and small groups, socially distancing during all your activities, avoiding large crowds and gatherings, washing hands and not leaving home if ill," Barnes said in a statement.

Barnes urged people to remain cautious as temperatures drop and outdoor activities become less common.

"It is important to remember that as we spend more time indoors, the virus could spread more," she said. "We are going to have to all work together as a community, with everyone doing their part to keep the transmission rates down."

Contact Wyatt Massey at or 423-757-6249. Follow him on Twitter @news4mass.