In just eight weeks, the number of COVID-19 cases in Ohio experienced an increase of more than 21 times.

The count doesn’t include the 7,897 cases reported Thursday, which is the most for a single day since Jan. 9 with 8,374 cases.

The state was at 582.4 COVID-19 cases per 100,000 residents for the period between Aug. 26 and Wednesday, according to statistics provided Thursday by the Ohio Department of Health.

In comparison, the state was at 27 cases per 100,000 people July 15 — eight weeks ago.

The U.S. Centers for Disease Control and Prevention considers 100 cases per 100,000 to be high transmission areas for COVID-19 and recommends face masks while indoors at public places.

Ohio has 15 counties that have more than 1,000 cases per 100,000 residents, with the lowest among the state’s 88 counties being Ashtabula with 91 cases per 100,000.

Only one county in the state was higher than 100 cases per 100,000 on July 15.

The state was at 472.4 COVID-19 cases per 100,000 residents last week and at 338.1 COVID-19 cases per 100,000 two weeks ago.

It was at 259.2 COVID-19 cases per 100,000 residents three weeks ago. Four weeks ago, it was 194.2 cases per 100,000 and at 125.1 cases five weeks ago.

The delta variant among the unvaccinated, which spreads quickly, is almost entirely to blame for the increase Ohio has seen in cases in recent weeks, said Dr. Bruce Vanderhoff, ODH’s director.

“While we are not at an all-time high of cases recorded, these numbers are certainly troubling,” he said Thursday.

The latest ODH ranking by county has Trumbull with the fourth-fewest cases, with Mahoning and Columbiana in the lower third of the state’s 88 counties.

But all three counties, like the rest of the state, continue to experience increases in the number of cases over the past few weeks.

Mahoning is 71st in the state with 467 COVID-19 cases per 100,000 residents.

It was 66th last week with 377.8 COVID-19 cases per 100,000 and 56th two weeks with 306.5 COVID-19 cases per 100,000. Three weeks ago it was 62nd with 220.4 COVID-19 cases per 100,000. It was 66th four weeks ago with 158.3 COVID-19 cases per 100,000 residents and 52nd five weeks ago with 110.6 cases.

Trumbull is 85th this week with 322.8 cases per 100,000 residents.

It was 86th last week with 266.2 cases per 100,000 and 87th two weeks with 203.6 cases per 100,000 residents. It was 75th three weeks ago with 198 cases per 100,000. It was 64th four weeks ago with 162.1 COVID-19 cases per 100,000 residents and 55th five weeks ago with 105.1 cases.

Columbiana is 58th this week with 552.6 cases per 100,000 residents.

It was 61st last week with 413.2 cases per 100,000 residents and 34th two weeks ago with 398.5 cases per 100,000.

Three weeks ago it was 25th with 333.7 COVID-19 cases per 100,000. Four weeks ago it was 52nd in the state with 172.7 COVID-19 cases per 100,000 residents and 46th five week ago with 116.3 cases.

The ODH measures cases per 100,000 residents among counties to get a fair comparison because total cases would result in more-populous counties ranking higher.

The 7,897 new COVID-19 cases reported Thursday is up from the daily average of 5,009 for the past 21 days, according to the ODH. Two months ago, the state was averaging about 260 cases a day.

VACCINATIONS

There were 6,148,395 people, 52.6 percent of the state’s population, who at least had started getting inoculated as of 6 a.m. Thursday, including 9,336 in the previous 24 hours, according to the ODH.

In Mahoning County, 50.83 percent of the population (116,247 people) had received at least one dose, while 48.58 percent of the population in Trumbull County (96,185 people) and 41.22 percent in Columbiana County (41,996 people) had as of 6 a.m. Thursday, according to the ODH.

There were 5,685,455 people, 48.64 percent of the state’s population, who finished the vaccinations as of 6 a.m. Thursday, including 10,655 in the prior 24 hours.

In Mahoning County, 47 percent of the population (107,483 people) had completed the process, while 44.66 percent of the population in Trumbull (88,425 people) and 38.18 percent of the population in Columbiana (38,903 people) had as of 6 a.m. Thursday.