School-Related Outbreak Reporting

The tables below provide information about COVID-19 clusters and outbreaks associated with K-12 educational institutions, as reported by local health departments each week to the Michigan Department of Health and Human Services (MDHHS).

In order to promote consistent reporting amongst states, MDHHS has adopted the updated national Council of State and Territorial Epidemiologists' (CSTE) 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.

General School Cluster/Outbreak Information

The updated surveillance definitions will be applied going forward (as of 9/27/2021) and will not be applied retrospectively to historical data. K-12 school-associated clusters and outbreaks will be reported as a single aggregate number.

New clusters and outbreaks are those that were first identified during the current reporting week. Ongoing clusters and outbreaks are those that had already been identified in previous weeks but have had at least one new associated case reported to the local health department in the last 28 days. New and ongoing clusters or outbreaks are counted only once (i.e., a new cluster/outbreak is not also counted in the ongoing category). Clusters and outbreaks will be removed from the list when there are no new confirmed or probable COVID-19 cases identified after 28 days have passed since the last known school exposure from a case.

The previous CSTE definition had a lower outbreak threshold; requiring 2 or more COVID-19 cases associated with a school. The new cluster and outbreak definition thresholds may exclude some circumstances, which previously met the outbreak definition. In addition, the data may shift based on current COVID-19 activity in the county. 

If your institution is listed, 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. Please 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 tables below.

Many factors, including the lack of ability to conduct effective contact tracing in certain settings, may result in underreporting of clusters and outbreaks. This information does not provide a complete picture of school-related 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. Should you have questions or concerns about this information, please contact your school or local health department.

This page will be updated on Mondays by 3 p.m.

Reporting as of 5/16/2022