Michigan is facing an unusually large outbreak of cyclosporiasis, a parasitic disease characterized by explosive diarrhea, with new cases still being reported in a nine-state outbreak. The state has been hit hardest, accounting for over 8,100 cases.
State and local health officials attribute the strain in managing the caseload partly to federal funding cuts and what some described as lagging or limited communication from federal agencies. This situation illustrates the challenges states face in responding to fast-spreading foodborne outbreaks without the federal resources available in past health emergencies.
In 2025, the Trump administration canceled approximately $12 billion in COVID-era grants to states, resulting in Michigan losing 23 infectious disease workers and 123 county health staff. "We have had to pull in dozens of staff from other areas, from hepatitis C and interns who are working on gun violence prevention," said Dr. Natasha Bagdasarian, Michigan's chief medical executive.
Ingham County, which includes part of the state capital, Lansing, has reported about 700 cases. However, its health department's staff of five nurses has only investigated about half of those. Anne Barna, deputy health officer for Ingham County, stated they have decided to drop older cases and focus on new ones to help the state and federal government identify the ongoing cause of the outbreak.
Investigation Challenges
The U.S. Food and Drug Administration (FDA) linked the outbreak to iceberg lettuce served at Taco Bell restaurants, sourced from Taylor Farms' operations in central Mexico. Taco Bell has since stopped using lettuce from this supplier nationwide, and Taylor Farms has removed lettuce from central Mexico from its shelves. The U.S. Centers for Disease Control and Prevention (CDC) has reported 4,173 laboratory-confirmed domestic cases and over 7,400 unconfirmed cases nationwide.
However, Michigan's investigation has not identified a single fast-food chain as the sole source, according to Bagdasarian. She noted that about 12% of patients have no clear link to consuming lettuce or eating at a fast-food chain.
In past outbreaks, the CDC typically takes a lead role in coordinating information among states. But some state and local officials reported learning new information from news reports, and communication with federal partners has not involved regular, formal meetings, according to a source familiar with the state's response. A spokesperson for the U.S. Department of Health and Human Services (HHS) rejected this characterization, stating the CDC was meeting daily with FDA and state officials nationwide. Spokespeople for Ohio and West Virginia, also part of the outbreak, confirmed regular calls with federal agencies.
Labor-Intensive Tracing
Tracing the parasite, Cyclospora cayetanensis, is labor-intensive as advanced testing methods are not effective. States largely rely on detailed interviews that can take up to 45 minutes each.
Oakland County, with nearly 1.3 million residents, is handling 710 cases with a team of four communicable disease nurses and three epidemiologists. During the COVID-19 pandemic, the county health department had 12 additional staff members for outreach, including four nurses who were later let go. The county has redeployed nurses from its hepatitis C and HIV programs to assist with the current outbreak.
Washtenaw County Health Department is investigating more than 770 cases, which has reduced time for addressing other illnesses or clinic appointments. Officials describe the outbreak as mysterious due to its size and the lack of definitive answers regarding its cause.
In rural Shiawassee County, the health department is enlisting qualified volunteers to help investigate about 450 cases. Health officials noted the outbreak's rapid onset, stating, "This really just hit us so fast. It was like, ‘Boom, here it is.’"