School COVID-19 cases not always reflected in state data

With COVID-19 case numbers surging in Michigan, schools have been hit hard. Some school districts, including Waterford, have gone virtual during this holiday week due to the high number of cases.

Those numbers don’t always show up when the Michigan Department of Health and Human Services releases school outbreak data each Monday. That data involves outbreaks and clusters that are reported by local health departments.

When those numbers do not match the case numbers at certain schools it’s because those are individual cases not outbreaks or clusters. Parents often find it confusing.

If your school is on the outbreak list on Mondays, the local health department and school are investigating the cluster or outbreak and will contact you directly if you (or your minor/child) were possibly exposed to coronavirus on the school grounds.

Note that students or staff who were exposed to COVID-19 outside of school grounds and are not thought to have spread the disease on the school grounds (due to quarantine, self-isolation, etc.) are not included in the weekly report.

Many factors, including the lack of ability to conduct effective contact tracing in certain settings, may result in underreporting of clusters and outbreaks. The information on Mondays does not provide a complete picture of schoolrelated clusters and outbreaks in Michigan and the absence of identified clusters or outbreaks in an educational institution in no way provides evidence that, in fact, that school is not experiencing one.

Michigan schools are working hard to maintain a safe environment while also providing quality education. Parents with questions of concerns should contact their school or local health department.

The school case numbers reflect what is going on in the state. Michigan continues to lead the country with a 616.3 7-day COVID-19 case rate per 100,000 people.

In Oakland County the 7-day case rate is 489.89 per 100,000 as of Tuesday (Nov. 23) which is up 60.46% in the last 7 days.

In Macomb County the 7-day case rate is 593.7 per 100,000 as of Tuesday which is up 67.44% in the last week.

In order to promote consistent reporting amongst states, in September the MDHHS adopted the updated national Council of State and Territorial Epidemiologists’ Standardized COVID-19 K-12 school surveillance guidance for classification of clusters and outbreaks.

In accordance with these CSTE definitions:

• A K-12 school-associated COVID-19 case (confirmed or probable) is defined as a student, teacher, or staff member physically present in the school setting or participated in a school sanctioned extracurricular† activity within 14 days prior to illness onset (or a positive test result) OR within 10 days after illness onset (or a positive test result).

• A K-12 school-associated cluster is defined as an educational institution that has been found by their local health department to have multiple cases comprising at least 10% of students, teachers, or staff, within a specified core group OR at least three (3) cases within a specified core group meeting criteria for a probable or confirmed school-associated COVID-19 case with symptom onset or positive test result within 14 days of each other, AND no likely known epidemiologic link to a case outside of the school setting. COVID-19 cases who may have shared exposure on school grounds and are from different households are included. Case counts for school-related outbreaks include those associated with before and after school programs (e.g., school-sponsored sports, etc.).

• A K-12 school-associated outbreak is defined as an educational institution that has been found by their local health department to have multiple cases comprising at least 10% of students, teachers, or staff, within a specified core group OR at least three (3) cases within a specified core group meeting criteria for a probable or confirmed school-associated COVID-19 case with symptom onset or positive test result within 14 days of each other; who were not identified as close contacts of each other in another setting (i.e. household) outside of the school setting; AND epidemiologically linked in the school setting or a school-sanctioned extracurricular activity. COVID-19 cases who may have shared exposure on school grounds and are from different households are included. Case counts for school-related outbreaks include those associated with before and after school programs (e.g., school-sponsored sports, etc.).

A school-associated outbreak classification relies on confirming exposure linkages between cases, while a school-associated cluster classification accounts for cases where a definitive exposure linkage has not been established.

Michigan school outbreak information can be found at Michigan.gov/ coronavirus.