As students headed into winter break, some metro Atlanta school districts reported their highest number of coronavirus cases in weeks, according to data posted to their websites.

The uptick in cases is a troubling sign and happening at a time when the highly-contagious omicron variant is spreading rapidly across the country.

Atlanta Public Schools reported the biggest jump in infections ahead of the winter break. It’s 435 cases marked second highest weekly total since the school year began in August, according to data posted to the district’s website.

School systems in Clayton, Fayette, and Fulton counties recorded their highest case counts since mid- or late-September, though still below the surge reported in late August. The 256 cases reported by Gwinnett County Public Schools for the week ending Dec. 17 was its highest since early October.

The increased cases reported by school systems in metro Atlanta mirror a rise in infections among Georgians of all ages ahead of Christmas, state data show.

The seven-day rolling average of new confirmed and probable infections among all Georgians was up more than 900% from Nov. 28 through Monday, according to data from the Georgia Department of Public Health. Among Georgians under 18, the rolling average for confirmed infections is up more than 1,000% in that time.

Reporting over the holidays is likely to be uneven, but public health officials fear holiday gatherings could turbocharge the already rapid rise in infections.

The omicron surge so far is hitting metro Atlanta the hardest. Cobb, Clayton, DeKalb and Fulton counties reported single-day records for new confirmed and probable coronavirus infections within the past week.

Omicron spreads much faster than prior strains of the virus, but it is believed to produce less-severe disease than delta, which battered Georgia around the start of the school year. Still, public health experts warn omicron could still swamp hospitals because it infects people more efficiently.

The seven-day rolling average of patients hospitalized for COVID-19 is up nearly 75% since Thanksgiving. There were 1,889 people hospitalized statewide as of Monday at 3 p.m.

Before winter break, no metro Atlanta school system saw a rise as dramatic as APS, which had three schools pivot to virtual learning just before the two-week holiday break began on Dec. 20. Two Clayton County middle schools also switched to online learning before the break.

Since school began in August, 14 metro-Atlanta school districts have reported more than 40,000 coronavirus cases among students and staff. Because the data collected relies on self-reporting, health officials say the numbers are likely significantly higher.

Mask policies vary in those districts and only one — City Schools of Decatur — requires employees to be vaccinated.

“Every school should have a mask mandate for students and staff,” said Dr. Harry J. Heiman, , a clinical associate professor at the Georgia State University School of Public Health.

Though most children tend to suffer less severe disease than adults, the vast spread of omicron means Georgia will likely see growth in the number of children hospitalized for COVID-19, Heiman said.

“It should mean vaccine requirements for certainly teachers and staff and I would hope sooner rather than later all students who are eligible for the vaccines,” Heiman said. “It’s particularly worrisome going back to school given vaccination rates (among school-age children) are so low.”

The spread seen in the Atlanta area will certainly soon hit rural parts of the state where vaccination rates tend to be lower, he said.

As the pandemic continues, school districts have been challenged by staffing issues, disruptions stirred by national food supply shortages and addressing mental health issues among students.

Some districts didn’t see significant increases before the break. They include Buford City Schools and school systems in Douglas and Henry counties.

Below is a summary of the latest coronavirus data and news from metro school districts. Districts said the counts sometimes change after their reports have been posted so the figures aren’t exact.

Atlanta Public Schools

Masks: Required

Enrollment: Approximately 50,000 students

Cumulative COVID-19 cases (Aug. 2-Dec. 17): 3,442. Breakdown: 2,793 students; 622 staff

Latest report: For the week ending Dec. 17 the district reported 435 COVID-19 cases: 307 students, 129. That’s more than four times the cases reported the previous week. The district’s highest count — 520 — was recorded the week ending Aug. 27.

Schools with the highest case count in mid-December were: Jackson High School (45), King Middle Schools (47), Therrell High School (33) and Centennial Elementary School (19).

Just before the holiday break, King Middle School, Maynard Jackson High School and Herman J. Russell West End Academy switched to virtual learning after buildings were closed due to coronavirus cases.

Buford City Schools

Masks: Optional

Enrollment: About 5,800 students

Cumulative COVID-19 cases (Aug. 5-Dec. 17): 476. Breakdown: 417 students, 59 staff

Latest report: The district recorded six COVID-19 cases for the week ending Dec. 17. The district’s highest count — 102 — was recorded the week ending Sept. 3.

Cherokee County School District

Masks: Optional

School start: Aug. 2

Enrollment: Approximately 42,000 students

Cumulative COVID-19 cases (Aug. 2-Dec. 17): 3,790. Breakdown: 3,193 students, 597 staff

Latest report: The district recorded 50 cases for the week ending Dec. 17, which is the highest count since the first week of October. The district’s highest case count — 832 — was recorded the week ending Aug. 20.

City Schools of Decatur

Masks: Required

Vaccines: Required for staff, unless exempted; optional for students

Enrollment: Approximately 5,700 students.

Cumulative COVID-19 cases (Aug. 3-Dec. 19): 156. Breakdown: 129 students, 27 staff

Latest report: The district recorded 14 COVID-19 cases for the week ending Dec. 17. That’s the highest weekly count since mid-September. The district’s highest case count — 21 — was recorded the week ending Aug. 20.

Clayton County School District

Masks: Required

Enrollment: About 52,000

Cumulative COVID-19 cases (Aug. 5-Dec. 17): 1,865. Breakdown: 1,569 students, 296 staff

Latest report: The district recorded 113 cases for the week ending Dec. 17. That’s more than three times the count for the previous week and the highest weekly total since mid-September. The district’s highest case count — 287 — was recorded the week ending Aug. 20.

Two Clayton County middle schools also switched to online learning before the December break: Adamson and Pointe South. The district closed about 20 schools earlier this year due to the delta variant of COVID-19.

Prior to winter break, the district issued a statement recommending that all employees — vaccinated and unvaccinated — get tested for the coronavirus before returning to work after the break. The statement said that all unvaccinated employees will be required to participate in weekly tests.

“Let’s get tested and get vaccinated,” Superintendent Morcease Beasley said in a Twitter post. “We must all do our part. No more excuses and hesitancy.”

Cobb County School District

Masks: Optional

Enrollment: Approximately 107,000 students

Cumulative COVID-19 cases (Aug. 2-Dec. 17): 6,818. Breakdown: District data doesn’t provide that information.

Latest report: For the week ending Dec. 17, the district recorded 131 cases in schools another 52 cases, possibly involving non-school staff. The highest count — 1,033 — was recorded the week ending Aug. 27.

The case count reported just before winter break mirrors that of the first week of school in August. But it’s still well below the number seen in late August and September.

DeKalb County School District

Masks: Required

Enrollment: Approximately 93,500 students

Cumulative COVID-19 cases (Aug. 6-Dec. 16): 3,753. Breakdown: 3,046 students, 707 staff

Latest report: The district recorded 78 COVID-19 cases for the week ending Dec. 16. That’s the district’s highest count since late October. Still, the district’s numbers have remained until 100 since the first week of October. The highest count — 930 — was recorded the week ending Aug. 20.

Douglas County School System

Masks: Initially required, but now optional, except on buses

Enrollment: Approximately 25,890 students

Cumulative COVID-19 cases (Aug. 4-Dec. 16): 1,612. Breakdown: District data break down data on students and staff.

Latest report: The district reported 26 COVID-19 cases from Dec. 10-16. Counts have remained below 100 since mid-September. The district recorded its highest case count — 273 — from Aug. 28 to Sept. 2.

Fayette County Public Schools

Masks: Required from Aug. 27-Oct. 25; now required only on buses

Enrollment: Approximately 20,000 students

Cumulative COVID-19 cases (Aug. 2-Dec. 17): 1,089. Breakdown: 129 students, 966 staff

Latest report: The district recorded 46 COVID-19 cases for the week ending Dec. 17 — the highest weekly count since mid-September. The highest case count — 266 — was recorded the week ending Aug. 20.

Forsyth County Public Schools

Masks: Optional

Enrollment: Approximately 53,000 students

Cumulative COVID-19 cases (Aug. 4-Dec. 18): 4,432

Latest report: For the week ending Dec. 18, the district recorded 102 new cases. The district had not topped 100 cases since early October.

The districts also posts daily reports of active cases. The highest case count for mid-December — 98 — was reported on Dec. 18.

Fulton County Schools

Masks: Masks are optional where infection rates are low, as of Nov. 1

Enrollment: Approximately 90,000 students

Cumulative COVID-19 cases (Aug. 9-Dec. 16): 4,515. Breakdown: The district doesn’t breakdown cases for students and staff.

Latest report: The district recorded 194 COVID-19 cases from Dec. 10-16. That’s more than twice the number recorded the previous week and the highest count since late September. The district’s highest case count — 892 — was recorded the week ending Aug. 26.

Note: The district has said the data posted on its website contain inaccuracies. Corrected reports are not posted.

Gwinnett County Public Schools

Masks: Required on buses. Effective Jan. 4, masks will only be required when there is substantial or high community transmission in the county. If transmission has maintained at a moderate level for two consecutive weeks, masks will be optional.

Enrollment: Approximately 179,600 students

Cumulative COVID-19 cases (Aug. 4-Dec. 19): 7,974. Breakdown: 7,043 students, 931 staff

Latest report: The district reported 256 COVID-19 cases from Dec. 13 to Dec. 19. That’s the district’s highest total since mid-October. It’s also a marked increase since mid-November, when counts dropped to under a hundred. The highest count — 1,159 — was documented from Aug. 30 to Sept. 6.

Henry County School District

Masks: Optional

Enrollment: Approximately 43,000 students

Cumulative COVID-19 cases (Aug. 4-Dec. 17): 2,363. Breakdown: 2,025 students, 338 staff

Latest report: The district recorded 27 COVID cases for the week ending Dec. 17. Weekly counts have remained below 100 cases since the last full week of September. The district’s highest case count — 480 — was recorded the week ending Aug. 20.

Marietta City Schools

Masks: Optional

Enrollment: Approximately 8,700 students

Cumulative COVID-19 cases (Aug. 3-Dec. 17): 606. Breakdown: 521 students, 85 staff

Latest report: The district recorded 25 cases for the week ending Dec. 17. The district’s highest case count — 65 — was recorded the week ending Aug. 27.

AJC staff writer Cassidy Alexander contributed to this report.