CHICAGO (CBS) — Chicago Public Schools officials on Tuesday announced new quarantine procedures on Tuesday, after Mayor Lori Lightfoot earlier said the district has an issue with over-quarantining.

Under the new rules, effective Saturday, CPS will reduce the required quarantine timeline for close contacts of someone who test positive for COVID-19 from 14 days to 10 days. For CPS classrooms, a close contact is someone who was fewer than three feet away from someone with a reported COVID-19 case for more than 15 minutes with consistent mask use.

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CPS said a 10-day quarantine is safe – provided that no one is showing symptoms of COVID-19 – when layered mitigation measures such as masking and distancing are in place in schools. CPS also noted that the vast majority of COVID-19 cases now involve the Delta variant, which has a quicker symptom onset than earlier variants.

CPS also said there is only an estimated 1 percent risk of post-quarantine transmission of COVID-19 after 10 days of quarantine, and fewer than 2 percent of CPS students identified as close contacts have gone on to test positive for COVID-19. These positive cases are not necessarily even linked to in-school exposure, CPS said.

Meanwhile, the earlier comment from the mayor about “over-quarantining” is something the Chicago Teachers Union disagrees with. They say over-quarantining during a pandemic is a good thing, pointing to schools like Jensen Elementary, where 11 out of 17 classrooms were quarantined last month.

Two mothers of Jensen students have died from COVID after their children were required to quarantine because of exposure to classmates who tested positive.

District officials have said they are trying to get a handle of how schools determine who goes into quarantine. That’s where the need for new guidance comes in.

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“We have updated information from both the CDC and the city health department that we’re going to put in place immediately,” Chicago Public Schools CEO Pedro Martinez said.

Lightfoot has said some schools and principals are being too aggressive with how often students are asked to quarantine.

“Over-quarantining creates chaos, and that should not be a thing. So one of the reasons I said this, probably now two weeks ago, that I asked [Chicago Public Health Commissioner Dr. Allison] Arwady and her team to get directly involved, so that CPS has the benefit of the most up-to-date learning from the CDC and the [Chicago] Department of Public Heath,” she said.

Right now, according to the district’s website, 6,391 students are in quarantine, as are 306 adults.

As for positive COVID cases, more than 1,100 students have tested positive so far this school year, along with 307 adults.

So, during Arwady’s weekly COVID briefing Tuesday afternoon, we’ll learn more about the new rule for quarantining at CPS schools; a rule that will apply to every single school.

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“Making sure that the data is being updated real time, so that everybody in the system, and particularly the building principals, understand what’s going on across the system; but in individual schools, and the decision about who gets quarantined and who doesn’t, that should never be on the shoulders of the building principals in my view,” Lightfoot said.

CBS 2 Chicago Staff