Two people have died in the cyclospora outbreak in Michigan in the first confirmed deaths in the U.S. related to the microscopic parasite, state health officials announced Monday. The Michigan Department of Health and Human Services said both people had underlying health conditions that may have been impacted by the intestinal illness and dehydration. When ingested, it causes intestinal illness marked by “frequent and sometimes explosive bowel movements,” according to the Centers for Disease Control and Prevention. Federal health officials have identified lettuce from Mexico served at Taco Bell locations across five U.S. states as a source of the widespread outbreak. Federal health officials have said other “brands, restaurants, retailers, or distribution channels” could be tied to the outbreak as the investigation continues.