The number of cases of cyclosporiasis — a parasitic infection linked to contaminated water or food that causes severe intestinal issues — has more than doubled to over 4,173 cases across 41 states this week, up from the 1,645 confirmed cases in 34 states reported last week by the federal Centers for Disease Control and Prevention.

Cyclosporiasis causes symptoms that include watery or “explosive” diarrhea, nausea and stomach cramps. The surge in cases had made 2026 the worst year for the infection on record.

The CDC estimates that there are likely more than 7,400 additional cases that have not yet been confirmed. No deaths have been reported, but 308 people have been hospitalized, more than double the 141 hospitalizations reported last week.

State and federal officials suspect there are multiple sources of the outbreak, but they had reported that the cases in Indiana, Kentucky, Michigan, Ohio and West Virginia were connected to shredded iceberg lettuce grown in central Mexico and sold by Taylor Farms. On Monday, however, federal officials said tests making the connection were a false positive.

Michigan, the first state to report an outbreak, reported 7,171 cases and 102 hospitalizations as of July 16. Indiana, New York, North Carolina, Ohio, and Indiana also have seen high case counts, alongside New York City.

The Association of State and Territorial Health Officials, which represents public health agencies across the country, said labs have a hard time tracking case connections because cyclospora is a parasitic genome that is more complex than the bacterial pathogens that cause other foodborne illnesses. As a result, state and local heath investigators must resort to reviewing restaurant and grocery receipts, menus and supply chain records, according to the organization.

“Case interviews and traceback investigations are often time intensive, creating a burden on state and local public health infrastructure,” senior analyst Heather Tomlinson and environmental health director Courtney Anderson wrote.

North Carolina had confirmed more than 560 cyclosporiasis cases as of July 20. Dr. Carl Williams, state public health veterinarian for the North Carolina Department of Health and Human Services, told reporters on Tuesday that the state has relied heavily on its 86 local health departments to track cases.

Williams said twice weekly calls with the CDC also have been helpful.

“The CDC has been very responsive to us and the other states,” Williams said during the briefing. “But as you can imagine, I mean, it’s a lot to go through.”

Stateline reporter Shalina Chatlani can be reached at schatlani@stateline.org.

WASHINGTON — The Centers for Disease Control and Prevention announced Friday that public health officials have linked the ongoing outbreak of cyclosporiasis in five states to shredded iceberg lettuce from Taco Bell restaurants.

The fast food chain wrote in a statement that it plans to remove the “potentially impacted lettuce” from its “supply chain nationwide and will be replaced within 24 hours in select states.”

“While no official advisory has been issued, we believe public health is a shared responsibility among restaurants, their suppliers, and authorities, and we are proud to have consistently acted quickly and proactively to protect our guests,” the statement said. “Taco Bell has taken precautionary action, and we encourage all relevant restaurants, retailers, and foodservice operators to do the same.”

The CDC statement said it had linked the ongoing outbreak to Taco Bell restaurants in Indiana, Kentucky, Michigan, Ohio and West Virginia. The statement didn’t say whether the lettuce was the cause of the severe gastrointestinal illness caused by a parasite in other states. 

Taylor Farms wrote in a statement that based on information from the U.S. Food and Drug Administration “Taylor Farms de Mexico is voluntarily removing all iceberg lettuce sourced from central Mexico.”

“While the FDA traceback is indicating a specific independent farm that represents less than 1% of the U.S.’s iceberg lettuce supply as the potential source of the outbreak, we have removed all iceberg lettuce from the region indefinitely,” the statement said. 

Taylor Farms added that none of their “salads or kits are associated with this outbreak.”

The CDC has confirmed more than 1,600 cases in 34 states since the outbreak began. Nearly 150 of those people were hospitalized, though no deaths have been reported so far. 

The CDC writes on a webpage about the outbreak that it expects the number of confirmed cases will continue to increase given the six-week “reporting lag between illness onset and case reporting to CDC.”

WASHINGTON — President Donald Trump’s pick to lead the Centers for Disease Control and Prevention didn’t appear to secure the support needed to take over the public health agency during a lengthy and often tense confirmation hearing Wednesday. 

While Dr. Erica Schwartz told lawmakers on the U.S. Senate Committee that oversees health policy she would “never betray the science,” she didn’t seem to win the trust of Democrats or key Republicans needed to advance. 

Chairman Bill Cassidy, R-La., repeatedly questioned Schwartz about whether she would follow the example set by former CDC Director Susan Monarez, who testified last year that she was fired after refusing to pre-approve vaccine recommendations or fire career officials for no reason.

“We need unbiased leaders who make decisions based upon science, not politics or ideology, and are committed to protecting children’s health,” Cassidy said in his opening statement. 

More than two hours later, at the end of the hearing, Cassidy told Schwartz he believed administration officials had overprepared her and that some of her answers missed the mark. 

“I felt like you were always trying not to answer my question, which was disappointing,” he said. 

Cassidy, or any Republican on the committee where the party holds a thin 12-11 majority, could effectively block Schwartz’s nomination if Democrats unanimously oppose it.

Restoring trust

Schwartz, who worked as a Navy occupational medicine physician, earning the rank of admiral, and deputy surgeon general, testified that, if confirmed, she would work to rebuild the CDC’s reputation among all Americans. 

“My first priority will be restoring trust in public health institutions through radical transparency and unwavering scientific integrity,” Schwartz said. “As CDC director, my sacred responsibility is to provide the American people with public health guidance that is clear, honest and evidence-based.”

Schwartz said she would work to “modernize the CDC into a near real-time public health enterprise” while ensuring local, state and tribal governments become the “operational backbone of American public health.”

Schwartz testified in response to questions from both Democrats and Republicans on the Health, Education, Labor and Pensions Committee that she “accept(s) that evidence” that vaccines don’t lead to an autism diagnosis. She said mRNA vaccine “technology is safe and effective.”

Tracking abortions

Missouri Republican Sen. Josh Hawley asked Schwartz to look into the possible health implications for people who live close to a data center, saying his constituents regularly ask him about it and he doesn’t know what to tell them. 

Schwartz said she didn’t know whether the National Institute for Occupational Safety and Health, which is housed within the CDC, had done any research on potential data center health implications. If confirmed, she committed to working with Hawley and his staff to look into the issue. 

Hawley also asked Schwartz if she would ensure the CDC secures data from every state in the country on when and how abortions take place. 

“The CDC collects data on abortions that are committed in the United States of America through a system called the Abortion Reporting System,” Hawley said. “This system is voluntary, and so a number of states, not coincidentally large blue states, do not turn over any data, so that it’s difficult to get a picture of just how many abortions and under what circumstances are committed in this country.” 

Schwartz testified she would look into the issue if confirmed, adding that “abortion surveillance is absolutely a critical component of what the CDC is currently doing.”

“But I also want to also make sure that certain states are not conflating emergency services and hiding abortions in that emergency services case definition,” she said. “We need to make sure we’re pulling out true abortions and making sure that we’re really having clear case definitions regarding abortions, so the data is actually accurate.” 

Cyclosporiasis

Washington Democratic Sen. Patty Murray asked about the ongoing outbreak of cyclosporiasis and the CDC’s disease monitoring programs during her round of questions. 

Schwartz said she believed “that one of the core missions of the Centers for Disease Control and Prevention is tracking outbreaks domestically and also internationally.” 

Schwartz said she was unaware the Trump administration moved to make reporting of cyclosporiasis optional last year after Murray asked whether there would be “any scientific or medical justification for CDC having eliminated mandatory reporting of that parasite.”

“The CDC used to conduct surveillance on this very infection through a program called FoodNet, but in July of ’25, thanks to Trump, CDC made reporting on that illness optional,” Murray said. “Now we are here a year later, and we’re already seeing over 7,000 confirmed or under investigation cases and over 100 hospitalizations with no single cause having yet been identified.”

Schwartz didn’t commit to reinstating mandatory reporting of cyclosporiasis if confirmed to run the CDC, but said she would work with Murray and her staff to understand why that stopped and what the options would be moving forward.

As state and federal officials work to identify the source of the recent outbreak of the intestinal illness cyclosporiasis, Michigan health officials have identified lettuces or salad greens as one potential culprit.

“Early information has shown lettuce as a common product that regularly comes up during the investigation,” said Dr. Natasha Bagdasarian, chief medical executive at the Michigan Department of Health and Human Services, in a news release. “We will continue to provide updates as we learn more.”

Officials cautioned they haven’t ruled out other food items as the source. The U.S. Centers for Disease Control and Prevention (CDC) has confirmed 1,645 cases in 34 states, but that is a significant undercount based on the numbers being reported by state health officials.

Cyclosporiasis is caused by the parasite cyclospora. Symptoms include watery or “explosive” diarrhea, nausea and stomach cramps. It’s often contracted by eating or drinking something contaminated with the parasite, which lives in feces.

Michigan first reported an outbreak of cyclosporiasis on July 1 after nearly 200 cases were reported across seven counties. The state now leads the nation in cases, with the state health department reporting 2,640 cases Monday and 44 hospitalizations. The case numbers jumped 69% from Friday.

New York, Ohio, Illinois, Indiana and Kentucky also have reported a higher than usual number of cases. New York City alone has seen 403 cases this year, most of them since May 1. The New York City Health Department said in a statement to Stateline that it’s working with partners to determine a common source.

Ohio health officials reported 177 cases as of July 2, with 28 hospitalizations.

“Fortunately there have been no deaths in Ohio, as is consistent with our past experiences with this illness,” said Dr. Bruce Vanderhoff, director of the Ohio Department of Health, in a statement.

“Nevertheless, this is a serious illness that can cause dehydration and require people to seek emergency medical care, and it should be taken seriously.”

The CDC expects case numbers to continue rising, given a typical six-week lag between the onset of illnesses and when cases are typically reported to the CDC. The New York Times reported it has independently confirmed at least 4,800 cases this year.

States such as  Michigan are rushing to do their own sleuthing after cutbacks have reduced surveillance capabilities at the federal level. Last year, the CDC scaled back its surveillance program that monitors foodborne illnesses. It no longer requires monitoring for six pathogens, including cyclospora, only requiring reporting for two: salmonella and Shiga toxin-producing E.coli.

The CDC acknowledged that while it’s working to collect and analyze data at the national level, “State health departments may have more timely information about the situation in their jurisdictions.”

The Trump administration said on social media on Monday that the CDC is working with 3,000 health departments to gather data, and that the U.S. Food and Drug Administration is investigating the outbreak alongside the CDC and state and local partners.

Local health departments in Michigan have conducted more than 1,000 interviews of those who’ve tested positive for cyclosporiasis, to try to trace the source of the outbreak, state officials said.

But in many states, the risk to the public remains low.

It’s  not uncommon for states to see at least a few cases of cyclosporiasis each year. Michigan typically identifies 40-50 each year, while Rhode Island documented six cases last year and 12 in 2024. Because it can take up to two weeks for symptoms to develop after a person is exposed to the parasite, state officials say it takes time to investigate the source.

There’s currently no evidence that links recreational water exposure, such as swimming in lakes, as a risk factor for the illness. And in none of the cases confirmed by the CDC did the affected person report any travel during the two weeks prior to falling ill.

In previous cyclosporiasis outbreaks, bagged salad mixes and kits were identified as the culprit, along with fresh cilantro, basil, raspberries, snow peas and green onions. One of the largest outbreaks of cyclosporiasis was in 2020, which resulted in 701 people falling ill in 14 states, and which the CDC linked to Fresh Express bagged salads.

The CDC has identified cases in the current outbreak in the following states: Alaska, Arkansas, California, Colorado, Connecticut, Florida, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maryland, Massachusetts, Michigan, Minnesota, Nebraska, New Hampshire, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, Tennessee, Texas, Utah, Virginia, West Virginia and Wisconsin.

This story was updated to reflect new numbers from the Centers for Disease Control and Prevention. Janine Weisman of the Rhode Island Current, Kyle Davidson of the Ohio Capital Journal and Jon King of the Michigan Advance contributed to this report. Stateline reporter Anna Claire Vollers can be reached at avollers@stateline.org.