Ann Arbor Public Schools reinstated a two-week mask mandate just as students were returning to school Jan. 9. According to the district’s COVID-19 dashboard, the mask mandate did not stop the spread.

The week students resumed classes from winter break, 46 cases of COVID-19 were reported. The students most likely would have contracted the virus during winter break.

There were 30 cases reported the week of Jan. 19, and the case numbers increased to 30, 40, and 42 during the three subsequent weeks.

Students would still have been required to wear masks the week of Jan. 19. The average time when people start showing symptoms after exposure is between 5.6 and 12 days, according to WebMd.

In other words, COVID spread and case numbers increased in the weeks after students were forced to mask.

• Related reading: Stabenow maskless as she speaks at Ann Arbor high school

The district said masks were being required again to avoid absences due to the illness, disruption to families caused by school shutdowns, and general health risks. Yet when the 2022-23 school year began, the number of cases was significantly higher, and there was no mask requirement.

The week of Sept. 1, there were 89 cases in the district. The number jumped to 205 the week of Sept. 8. The weeks that followed saw 222, 194, and 133 cases, respectively.

Jeanice Kerr Swift, superintendent of Ann Arbor Public Schools, did not respond to a CapCon request for comment.

Swift stated in January that the Centers for Disease Control and Prevention said in December that masking is “a critical public health tool” and that it is effective in preventing the spread of respiratory illnesses.