On Monday, the state's definition for a K-12 COVID-19 outbreak changed. Now, there need to be three school-associated cases instead of two.
New outbreak data can be found on the state Department of Health and Human Services’ website at the beginning of each week. But cases you might see on your own school’s COVID-19 dashboard will be different than what you see on MDHHS’s list.
Susan Ringler-Cerniglia, the Washtenaw County Health Department public information officer, acknowledged that it can be confusing for the public — and parents — to navigate.
“Those outbreaks really are a measure that can help us look at, ‘Is there some documentation that some spread might be happening in the school setting?’ versus ‘There are cases happening and being reported and that's expected,’” Ringler-Cerniglia said.
What is the definition of an outbreak?
Michigan's new definition of an outbreak is when:
- There are at least three COVID-19 cases within a core group (a core group includes extracurricular activities, a cohort, a classroom, or after school care)
- OR at least 10% of students, teachers or staff in a core group are COVID-positive within the last 14 days.
The cases in an outbreak cannot be close contacts outside of school, like a household. They must also be epidemiologically linked in the school-related setting.
This is a change from the previous definition MDHHS relied on — which needed local health departments to identify two or more cases linked to the school. COVID-19 cases among staff or students linked to other places, like social gatherings outside of school, were never and still are not counted in school outbreaks.
To make things even more confusing, the “two or more” definition still holds for outbreaks in other settings — including colleges and universities. And K-12 outbreak data from before this change in definitions will also not be adjusted. So apples-to-apples comparisons will be hard to make because the standards are different now.
(Dawn Mirsa, an epidemiologist with Michigan State University, told the Detroit Free Press having two standards was "kind of silly.")
Why did the definition change?
MDHHS follows guidance published by the Council of State and Territorial Epidemiologists. And CSTE updated its definition in an effort to provide a standardized way of collecting data across states.
CSTE’s “basic definition” of a K-12 outbreak was originally published in July 2020, and defined an outbreak as two or more cases linked in place and time.
The updated guidance and suggested best practices were published August 6, at the start of the 2021 school year. The updated recommendations are a result of a workgroup of epidemiologists from Michigan, Los Angeles County, Tri-County Colorado, Alabama, Iowa, Connecticut, New York City and CDC COVID-19 response team members.
“The recommendations are an effort to provide uniformity amongst states when gathering this data,” Arieh explained. “With the national push to return to in-person learning in mind, the updated guidance was modeled after other respiratory illness surveillance and was also based on the data available in August.”
This August guidance allows more confidence in determining whether a particular school has an outbreaks versus a more sporadic transmission, CSTE spokesperson Jeremy Arieh explained in an email.
Why didn't MDHHS change its definition before school started?
MDHHS began the process of adopting the new definition shortly after Aug. 6. MDHHS spokesperson Lynn Sutfin said local health departments were notified in mid-September that the new definition would be used.
"The state took a bit over a month to coordinate this inclusion because it involves the thorough review of the new guidance and the modification of several core surveillance processes among the state’s 45 local public health jurisdictions," Sutfin wrote in an email to Michigan Radio. "There were several changes that needed to be incorporated, surveillance protocols needed to be updated, reporting tools needed to be modified and changes needed to be communicated."
Does this change much for my local county health department?
Probably not. Both Midland County Health Department’s director Fred Yanoski and Washtenaw County's Susan Ringler-Cerniglia said it doesn't change how they gather their information — just how they report it.
“By increasing it though, from two to three, it may mean that it's going to take more significant outbreaks for schools to make that list,” Ringler-Cerniglia said.
Midland is also reporting its "clusters" to the state. Clusters account for school cases where a definitive exposure link has not been established.
Yanoski said the state is including those clusters in Midland's outbreak data, making it appear that the county has more outbreaks than it does. Midland County currently has the highest number of new outbreaks in the recent update.
MDHHS spokesperson Lynn Sutfin later clarified to Michigan Radio that the health department "now reports both outbreaks and clusters in aggregate." The clusters definition is a new feature from the CSTE's updated guidance.
In an email, she writes, "MDHHS feels that both for consistency and transparency in public reporting that both clusters and outbreaks be reported as there are numerous barriers to identifying epidemiological or exposure linkages between cases, including:
- Limited resources to perform in-depth case investigations at the local level.
- The depth in which schools are able to participate in the case investigation process.
- Public engagement with investigators in the case investigation process."
Why do I need to know this?
The outbreak data help tell us whether and how much COVID-19 infection and transmission is happening in schools. (MDHHS also flags in its website that outbreaks can be underreported, since contact tracing can be hard in some environments.)
“We have active disease in the community, and largely how well your community does, can be equated to how well your schools are doing.” Midland County Health Director Fred Yanoski said.
For example, the CDC currently identifies Washtenaw County as a county with“high-level” transmission. Ringler-Cerniglia said when that happens, you can expect to see cases reported among students and staff when school is in session — but just because cases appear on your school’s dashboard doesn’t always mean the transmission and spread is happening in the school.
“Because outside of the school environment, there's a lot of gathering activity, extracurricular things happening all over the place, right?” she said. “So there's spread happening, then what those outbreaks help us figure out is if we're seeing evidence of that spread within the school setting. So in other words, those are a little bit more concerning than the fact that we have cases in school.”
Ringler-Cerniglia said the outbreak data is helpful to see the bigger picture, especially with the more contagious delta variant and going back to school in-person. But she said a school’s dashboard might actually be more useful for parents.
“When you're investigating disease, it's not a perfect science," said Yanoski. "So often, we don't know the origin of the case. But in this particular response, we're more worried about mitigating disease than we are solving the crime, so to speak."
Yanoski said with the delta variant and kids under 12 still not yet eligible for the vaccine, families need be diligent outside of school, too.
“When there are safeguards in place at school, and then you go home or elsewhere in the community, and there's none in place, it continually puts that student or school staff at risk,” he said.
The CDC recommends using layered protection in schools to lower spread of disease: vaccines, masking, distancing, cohorting, screen testing, isolation, and quarantine.
As of Sept. 16, 43% of Michigan school districts require masks. The Michigan Parents Alliance for Safe Schools is petitioning the state to issue a statewide mask mandate for schools.
You can view what the biggest school districts in Michigan are doing by viewing this tool.
*Clarification: A previous version of this article stated, "MDHHS spokesperson Lynn Sutfin wrote in an email the state is not asking local health departments to report clusters, but will look into Midland's numbers." After looking into Midland's case, Sutfin then followed up with Michigan Radio to say that clusters are being counted.
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