Cyclospora Outbreak May Be Slowing in Michigan After Lettuce Recall

A foodborne illness outbreak linked to contaminated lettuce may be starting to slow down in Michigan, the state hit hardest by the spread. Health officials say more than 18,000 people across the United States have been confirmed or suspected sick from a parasite called Cyclospora. The illness, called cyclosporiasis, is caused by a tiny parasite found in human feces that can contaminate food and water. Most cases in nine states have been linked to shredded iceberg lettuce from a company called Taylor Farms de Mexico.

In Michigan alone, more than 9,500 people have gotten sick and about 160 have been hospitalized over the past two months. The Michigan Department of Health and Human Services shared those numbers on Tuesday. That makes Michigan the center of this multistate outbreak.

A company called Taylor Farms voluntarily recalled, or pulled back, its iceberg lettuce from some Taco Bell restaurants, grocery stores, and food suppliers more than a week ago. The recall happened after investigators connected the lettuce to many of the illnesses. However, health officials warn that some contaminated food could still be out there.

Dr. Natasha Bagdasarian, Michigan's chief medical officer, said there are signs the outbreak may have peaked in her state. She noted that the number of emergency room visits for diarrhea — one of the main symptoms — appears to be slowing. Still, she cautioned that some people with milder symptoms may not be getting tested, so the true number of cases could be higher.

Testing has also been limited because hospital labs are backed up and short on supplies. Because of this, some health systems are only testing people who are very sick or who have weakened immune systems. This makes it harder for investigators to know exactly how many people are still getting ill.

Bagdasarian said she is not sure the lettuce recall alone caused the slowdown. She also pointed to public health advice that told people to peel produce, cook it, and remove the outer leaves. She added that some sick people never reported eating lettuce at all, which suggests other foods may also be involved.

Other foods like cilantro and parsley have been suspected as sources of the parasite this season. In New York, officials traced an earlier cluster of cases in April to cilantro at a Brooklyn restaurant, though they never fully confirmed it. In North Carolina, which has reported 561 cases, investigators believe cilantro and parsley could be behind those illnesses, and neither state's outbreak has been connected to Taylor Farms lettuce.

Experts say it is hard to track down the exact source of a food outbreak. Jennifer McEntire, founder of a food safety consulting firm, explained that food products often move or change hands many times before reaching consumers. Health officials also lack real-time tools to genetically match a contaminated product to a specific person's illness, which slows the investigation.

Some experts believe contaminated water used for irrigation or food processing at Taylor Farms' site in central Mexico may have spread the parasite to different batches of produce. Barbara Kowalcyk, a food safety expert at George Washington University, said two separate waves of illness in Michigan suggest the contaminated product was supplied in two different batches. She warned that if water sources in the region are contaminated, the problem could be wider than just one farm or one crop.

Experts say this outbreak reveals weaknesses in the U.S. food safety and public health system. Kowalcyk said the country needs better lab tools to detect Cyclospora in the environment and more funding for food safety research. Until those improvements are made, tracking down the sources of outbreaks like this one will remain a slow and difficult process.