Lettuce from a Taco Bell supplier has been identified as the possible source of the cyclosporiasis outbreak centered in the Great Lakes region, according to multiple reports, as federal and state health officials have yet to publicly announce the cause of the parasitic illness’ spread.

Investigators have identified shredded iceberg lettuce supplied by Taylor Farms to Taco Bell restaurants as the potential contamination source in a cyclosporiasis outbreak, according to two unnamed individuals familiar with the investigation who spoke to The Washington Post , with CNN also citing an unnamed source in reporting a potential link.

Taco Bell said Tuesday it was removing ingredients such as lettuce, cilantro, onion, pico de gallo and guacamole from its menus in the Detroit area.

Taylor Farms produces fruits, vegetables and pre-packaged salads, doing business with restaurants and grocery stores.

The Centers for Disease Control and Prevention has confirmed 1,645 cases across 34 states as of Tuesday, according to its latest data, which notes the agency is investigating roughly 5,100 additional possible cases.

Forbes has reached out to Taco Bell, Taylor Farms and the CDC for comment.

Michigan, the epicenter of the outbreak, recorded an additional 600 cases Thursday, logging a total of 4,312 cases in the state.

White House press secretary Karoline Leavitt said Thursday the Trump administration “has a handle on the situation,” though she acknowledged an “unusually high number of cases” and reiterated CDC guidance to wash and cook raw produce to prevent infection.

The cyclosporiasis outbreak began in May and has since resulted in 141 hospitalizations and no deaths, according to CDC data. The illness can cause watery diarrhea, loss of appetite, weight loss and low grade fever. As Michigan has reported more cases than the CDC has, the federal agency has noted it expects case counts to rise as more data is received, citing a six-week reporting lag between illness onset and case reporting. The agency has faced backlash for scaling down a federal program that previously required the 10 states participating in it to monitor cyclospora, the parasite that causes cyclosporiasis. The Trump administration said this week federal tracking of the illness did not cease because of the changes, though health care experts have warned the reduced requirements could make it more difficult for investigators to identify and track foodborne illnesses.

White House Says It Has ‘Handle’ On Cyclosporiasis Outbreak—While Urging Precautions (Forbes)

Taco Bell Investigated In Multistate Cyclosporiasis Outbreak, Report Says (Forbes)

Michigan’s Cyclosporiasis Case Count Triples In One Week—Over 4,300 Confirmed (Forbes)