LITTLE ROCK, Ark. (KNWA/KFTA) — Thirty-three Arkansas public school districts have COVID-19 infection rates of 50 or more new known infections per 10,000 district residents over a 14-day period, up from 28 last week.

The Arkansas Center for Health Improvement released the numbers on Thursday, citing its analysis of Arkansas Department of Health data current as of Monday.

For the second week in a row, no district has an infection rate of 100 or more new known infections per 10,000 district residents over a 14-day period, according to this week’s data, the nonpartisan health policy center said.

ACHI’s map showing COVID-19 infection rates in school districts ― available at achi.net/covid19 ― uses the following color key: 0 to 9 new known infections per 10,000 residents over 14 days, dark green; 10 to 19 infections per 10K residents, light green; 20 to 29 infections per 10K residents, yellow; 30 to 49 infections per 10K residents, orange; 50 to 99 infections per 10K residents, red; and 100 or more infections per 10K residents, purple.

Most, but not all, of the red-zone districts on ACHI’s map are in northern parts of the state.

“Just five weeks ago, no Arkansas school districts were in the red or purple zones, but unfortunately we’ve seen a resurgence in community spread of COVID-19,” said ACHI President and CEO Dr. Joe Thompson. “Please get vaccinated if you haven’t, and get boosted if you’re eligible. If you plan to gather with members of other households over the holidays, agree on ground rules and vaccine expectations ahead of time, consider getting tested, and don’t attend if you’re sick.”

This week’s count of red-zone districts is the highest since the week of Oct. 4, when 40 districts were in the red zone and none were in the purple zone.