Two people have died from cyclosporiasis in Michigan, the state’s health department said on Monday, marking the first fatalities in the largest US outbreak ⁠of the intestinal illness.

Both ⁠individuals had significant ​underlying health conditions that may have been affected by cyclosporiasis and dehydration, according to medical records.

There are no updates on the investigation, the state ⁠health department told Reuters in an email.

An FDA investigation linked the outbreak that has expanded to nine states to iceberg lettuce sourced from privately held Taylor Farms ⁠operations in central Mexico, but authorities are still looking for other potential sources.

Cyclosporiasis is generally not a ​life-threatening illness.

Michigan health officials reported 11,234 outbreak-linked cases ‌on Monday, up 461 ‌from Friday’s update. The outbreak has resulted in 193 hospitalizations, according to the health department’s latest data.

Wayne ‌county has reported the highest number of cases, with 1,379 infections. Adults aged 30 to 39 years have been the hardest hit, accounting for 2,216 reported cases, state data showed.

Cases of the intestinal illness caused by the Cyclospora parasite have been rising steadily across the United States in recent weeks, according to the US Centers for Disease Control and Prevention (CDC). Symptoms include severe diarrhea, nausea ‌and other gastrointestinal issues.

Nationwide, the CDC has recorded 6,707 laboratory-confirmed cases of cyclosporiasis as of 28 July, with more than 11,500 additional suspected cases still awaiting confirmation ​or further investigation.

The CDC surveillance updates include only laboratory-confirmed cases, while state health departments may also report probable infections, resulting in higher case counts. The agency has said it is working with states to update the national tally as additional cases are confirmed.

Former CDC officials and food safety experts have said cuts across federal ⁠health agencies have complicated the government’s ability to respond to foodborne disease outbreaks.

The ​US Department of Health and ​Human Services said it is aware of ​the deaths in Michigan.

“This development highlights the importance of identifying the source of ​the outbreak and ‌preventing additional illnesses,” said Wade ​Syers, food safety ​specialist at Michigan State University Extension.

Consumers in the US have been steering clear of some restaurant chains and buying less lettuce in grocery stores as the multi-state outbreak of the parasitic disease has fueled confusion over what is safe to eat.