Cases have been rapidly increasing over the past month, with Michigan now experiencing the "most severe surge of viral spread in the nation," according to the Michigan Health & Hospital Association.
Hospitalizations are also up, particularly among young adults. From March 1 to March 23, hospitalizations increased by 633% for adults ages 30 to 39 and by 800% for adults ages 40 to 49, according to the association.
"I'm very concerned about what we're seeing in the state of Michigan," Dr. Joneigh S. Khaldun, the state's chief medical executive, told "Good Morning America" this week. "We've seen over the past five to six weeks a significant increase in our cases. Our hospitalizations are going up as well. And we are seeing that younger people, ages 10 all the way up through 60, are getting sick, and many of them are also being hospitalized."
Khaldun pointed to COVID-19 fatigue, including a lack of mask compliance, and gatherings as contributing to the increase.
"I think everyone in Michigan really needs to double down right now," she said.
Gov. Gretchen Whitmer referred to the surge this week as a "compliance, mobility and variant problem."
According to the Centers for Disease Control and Prevention, the state currently ranks second in the nation for the most reported cases of the more transmissible B.1.1.7 variant first discovered in the U.K. As of Wednesday, Michigan has identified 1,468 cases of that variant, according to the state health department.
Both Whitmer and Khaldun stressed the importance of vaccinations at this time.
"We just have to even more so be laser-focused on our vaccination efforts," Khaldun told "GMA."
Starting Monday, COVID-19 vaccination eligibility in the state expands to all residents ages 16 and older.
In an interview with Detroit ABC affiliate WXYZ Thursday, Dr. Anthony Fauci, the nation's top infectious disease expert, posited the recent surge "very likely" may be due to Michigan opening up too soon.
"I hesitate to criticize anything the governor did because she's really quite a good governor," Fauci told the station. "I think the idea of pulling back prematurely, under pressure, it's understandable why you might want to do that, but the results, I think, are being manifested in what you're seeing in Michigan."
Among its recently loosened restrictions, the state reopened bars and restaurants for indoor dining on Feb. 1 at 25% indoor capacity, then increased it to 50%, with a maximum of 100 people, on March 5. That day, entertainment venues were also allowed to fill up to 50% capacity.
The state's mask order remains in effect, requiring face coverings in public.