Students are back in school in most parts of South Korea -- just as winter approaches and cases climb again. Sunday’s data showed 86 students had been diagnosed with COVID-19 as of Friday, since schools opened again in mid-October.

The latest school outbreak was at an arts high school in Jongno, central Seoul, where 16 cases have been identified among students and teachers so far. Public health authorities believe the transmission took place at a band practice.

Earlier the same week, 36 cases were traced to a private ballet school in Bucheon, Gyeonggi Province. All of the diagnosed students were second to fifth graders. School authorities said students as well as instructors had been wearing face masks during and between classes.

Outbreaks at schools put 702 students in quarantine as of Thursday, of whom 294 were high school students. This is roughly triple the figure of high schoolers on the first day in-person classes opened again on Oct. 19, which was 105. On a daily average, 9.2 students tested positive for the coronavirus between Oct. 22 and 29. At least 75 schools nationwide have closed down over the period following positive cases among students, faculty or staff.

The Ministry of Education’s tally last week showed over 690 students and 135 faculty members have come down with the virus since May, when in-person learning resumed after the initial wave of cases.

Worries are mounting over growing cases linked to schools.

Shin Hae-yeong, 37, a college counselor at a high school in northern Seoul’s Nowon said, “Whenever there is a suspected sick student, the whole school goes into sort of an emergency mode.”

She said the school runs temperature checks at least twice a day. “The rule for our school is students showing even very mild degrees of fever are sent back home,” she said. While there is still confusion, kids are well adjusted after months of new classroom rules dictated by the coronavirus. “Most kids have gotten used to having face masks on by now.”

But high school seniors -- who are set to sit for the college entrance exam in about a month -- have it harder, she said.

“Some early-action candidates can’t stay put. They need to move around for interviews and other assignments. So we worry there might be potential risks these students might be exposed over the course of the application process,” she said.

Meanwhile, public health authorities on Sunday reported a third official case of the multisystem inflammatory syndrome in children, or MIS-C, which is speculated to be a rare complication of COVID-19. The 14-year-old girl was diagnosed with the condition last month, after she was hospitalized on Oct. 13 with suspected symptoms such as fever and diarrhea.

Pediatric infectious disease specialist Dr. Eun Byung-wook of Nowon Eulji University Hospital in northern Seoul said the instances of spread at schools have become more common after the weather started to cool.

“The colder temperatures force people to congregate indoors, making social distancing harder,” he said.

“Wearing face masks, washing hands and disinfecting surfaces routinely and keeping rooms well ventilated are the best preventive measures that children, their family and teachers can follow.”

By Kim Arin (arin@heraldcorp.com)