Michigan health officials reported 12,218 cases linked to an outbreak of cyclosporiasis on Wednesday, an increase of 710 cases since ​its last update a day earlier.

Michigan has reported the first ‌two deaths associated with the outbreak, saying both individuals had significant underlying health conditions.

The state reported that the two Michigan cases became ill prior to the voluntary recall of iceberg lettuce announced by the U.S. Food and Drug Administration on July 17. The outbreak in Michigan has resulted in 193 hospitalizations as of July 30, according to the state health department’s latest update.

Cases of the intestinal infection caused by the cyclospora parasite, which can cause diarrhea, nausea, and other gastrointestinal symptoms, have risen steadily across the United States in recent months, according to the U.S. Centers for Disease Control and Prevention. Nationwide, the CDC has received reports of 10,468 laboratory-confirmed domestic cases of cyclosporiasis and is aware of more than 12,255 additional cases that are not laboratory-confirmed.

The agency’s surveillance lags state reporting by several weeks.

An FDA investigation has linked the multistate outbreak that has expanded to nine states to iceberg lettuce served at Taco Bell restaurants and sourced from privately held Taylor Farms operations in central Mexico, though authorities are still looking for other potential sources. Consumers in the U.S. have been steering clear of some restaurant chains and buying less lettuce in grocery stores, as the multistate outbreak of this parasitic disease has fueled confusion over what is safe to eat.

Cyclosporiasis can be contracted by consuming food—typically raw fruits and vegetables—or water contaminated with feces.