The Michigan Department of Health and Human Services says there are now a dozen confirmed or probable cases of severe lung disease associated with vaping. The department is investigating another 14 possible cases.
Nationwide, 530 people have been diagnosed with vaping-related breathing illnesses. Eight deaths have been reported.
The U.S. Centers for Disease Control and Prevention says cases have been reported in 38 states and one U.S. territory. The total number of illnesses is up from 380 a week ago.
All patients had used an electronic cigarette or other vaping device.
Two-thirds of the cases involved 18- to 34-year-olds. Most are men.
All patients had used an electronic cigarette or other vaping device. Doctors say the illnesses resemble an inhalation injury, with the lungs apparently reacting to a caustic substance.
The cause remains unknown.