Map shows 17 states hit by largest cyclospora outbreak linked to lettuce

Seventeen states are now affected by the largest cyclospora outbreak in the United States, which health officials have linked to to iceberg lettuce.

The U.S. Food and Drug Administration (FDA) said on Thursday that two new states—Maine and Massachusetts—have been added to the list of states tied to the outbreak.

Last week, health officials said the number of states affected had gone from nine to 15. Six states—Arkansas, Iowa, Missouri, Nebraska, New Hampshire and North Carolina—were added to a list that had previously included Illinois, Indiana, Kansas, Kentucky, Michigan, Ohio, Oklahoma, Pennsylvania and West Virginia.

The FDA has linked shredded iceberg lettuce served at Taco Bell to the outbreak, and said it is focused on produce giant Taylor Farms as the source of the lettuce. The company in July recalled iceberg lettuce grown in central Mexico.

The number of cases of cyclospora infections linked to the lettuce was 9,481 as of Thursday, including at least 398 people who had to be hospitalized, according to the latest update from the CDC, . Michigan reported the first two deaths tied to the outbreak earlier in August.

Cases of cyclosporiasis—the gastrointestinal illness caused by cyclospora, a diarrhea-causing parasite—have been reported in at least 47 states this year, and federal health officials are continuing to determine how many could be linked to a common contaminated source.

The FDA said it is working with the U.S. Centers for Disease Control and Prevention (CDC) and state and local partners to investigate the outbreak.

“Since the last update on August 5, 2026, state and local health officials have continued to interview additional cases of cyclosporiasis and CDC has added them to this multistate outbreak,” the FDA said on Thursday.

“The outbreak includes people who reported exposure to processed iceberg lettuce from Taylor Farms de Mexico served or purchased at various locations, including people who previously reported eating at Taco Bell.”

Taylor Farms said in a statement posted on its website: “When questions were raised about the source of the recent Cyclospora outbreak, we immediately removed all potentially implicated product from the marketplace, and out of an abundance of caution we issued an even broader recall of all iceberg lettuce sourced from the region.

“We have also voluntarily suspended all iceberg lettuce sourcing and production from central Mexico.”

The company’s statement said that there are “no confirmed positive sample results for product testing for Cyclospora as of August 13, 2026.”

Taco Bell said on in a statement on July 17 that it had “completed removal of affected Taylor Farms lettuce from our restaurants.

“Based on ongoing conversations with public health officials, and out of an abundance of caution, Taco Bell worked swiftly to voluntarily remove the product from restaurants and the affected ingredient has been removed from our supply chain nationwide. We took this action to ensure our guests can enjoy their Taco Bell favorites safely,” it said

In all, the CDC said that as of August 10, some 13,895 laboratory-confirmed cases of cyclosporiasis have been reported in 47 states plus the District of Columbia and Puerto Rico since May 1. The CDC said it is aware of at least 10,455 additional cases that had not been laboratory-confirmed or required further investigation to determine if they were acquired domestically, most of them in Michigan.

The previous year, between May 1 and August 31, 2025, 1,180 cases were reported in the United States.

What Is Cyclospora?

Cyclospora is a microscopic parasite that infects food that has come into contact with human feces, most commonly when produce is irrigated or washed with contaminated water. When ingested, the parasite causes intestinal illness marked by “frequent and sometimes explosive bowel movements,” according to the CDC.

How Many Cases Aren’t Reported?

The CDC said the official count represented only laboratory-confirmed cases, adding that state data may include probable and confirmed cases, which could lead to higher case counts than what the CDC reports.

The agency said it was aware of more than 12,000 additional cases that either had not been laboratory-confirmed or required further analysis, including to rule out whether the patients had traveled overseas before becoming ill.

The agency also said the true number of illnesses is likely even higher because some people recover without seeking medical care and are never tested, leaving many infections outside official tallies.

Cyclosporiasis Diagnosis and Treatment

Symptoms generally develop about a week after exposure. They can appear between two days and two weeks or longer afterward.

Without treatment, the illness may persist for more than a month, and symptoms can disappear before returning, according to the CDC.

Cyclosporiasis is diagnosed through stool testing, but detecting the parasite may require several samples and specialized tests that are not routinely performed.

The standard treatment is trimethoprim-sulfamethoxazole, an antibiotic combination commonly sold as Bactrim or Septra. Rest and fluids are also important, particularly for patients experiencing diarrhea. People with weakened immune systems or poor health may be more likely to develop severe or prolonged illness.