A parasitic outbreak linked to shredded iceberg lettuce from central Mexico has now reached nine states and thousands of confirmed cases, far exceeding the few hundred infections the U.S. typically sees in an entire year.

The U.S. Department of Health and Human Services confirmed Friday that four more states, Illinois, Kansas, Oklahoma, and Pennsylvania, have been added to the outbreak map, CBS News reported. The outbreak had previously been confined to Indiana, Kentucky, Michigan, Ohio, and West Virginia. The expansion brings the total to nine states and raises fresh questions about how contaminated produce from Mexico moved so deeply into the American food supply before regulators caught up.

The CDC has received reports of 4,173 lab-confirmed domestic cases of cyclosporiasis since May 1. The agency says it is aware of more than 7,400 additional cases still requiring further analysis. In a normal year, the entire country reports between 200 and 1,000 cases total.

That means the confirmed count alone already exceeds the high end of a typical year by more than four times, and the unconfirmed backlog could push the real number far higher.

Michigan alone reported more cases than the U.S. usually sees in a year

Michigan has been the hardest-hit state by a wide margin. State health officials said Thursday that Michigan has confirmed 7,664 cases on its own. That single-state figure dwarfs the CDC's nationwide confirmed total, raising questions about how the federal and state counts overlap and whether the national picture is even more severe than the CDC's published numbers suggest.

Newsmax reported that Michigan had logged 102 hospitalizations and no deaths. The CDC's broader national count showed 308 hospitalizations across 41 states, with at least 7,400 additional unconfirmed cases still under review.

The FDA has confirmed 1,947 illnesses tied specifically to the iceberg lettuce outbreak between June 22 and July 20. The FDA is also investigating a separate cyclospora outbreak linked to an unspecified product, a detail that underscores just how widespread the parasite problem has become this summer.

Taylor Farms recalled its Mexican lettuce after the FDA traced the contamination

Federal investigators traced the contaminated lettuce to Taylor Farms, a major California-based produce supplier that sources iceberg lettuce from central Mexico. The company voluntarily recalled all of its iceberg lettuce from that region and suspended distribution.

Taylor Farms supplies some of the biggest names in American retail and fast food, including Walmart, Target, Whole Foods, and Taco Bell. That supply chain footprint helps explain how a single contamination source could ripple across so many states so quickly.

In a statement, Taylor Fresh Foods said it was "deeply concerned for those who became ill, their families, and the many Americans whose trust in the safety of their fresh produce has been shaken." The AP reported that the company voluntarily removed all iceberg lettuce sourced from central Mexico from the U.S. market.

The Washington Examiner reported that the recall covered bagged shredded iceberg lettuce distributed across 27 states. The CDC has reported at least 1,645 cyclosporiasis cases this year, roughly six times the number during the same period last year. Taylor Farms urged consumers who purchased the recalled lettuce to discard it immediately.

Taco Bell pulled the lettuce nationwide after 90 percent of interviewed patients reported eating it

The Taco Bell connection has been central to the outbreak investigation from the start. Across the original five affected states, 1,644 people infected with cyclospora reported exposure to Taco Bell locations. Of the 190 patients interviewed by investigators, 90 percent said they had eaten iceberg lettuce at the chain, Breitbart reported. Ninety-four hospitalizations were logged, with no deaths.

Taco Bell said it took "immediate action to voluntarily remove potentially impacted lettuce from a supplier in select states" and committed to replacing the ingredient within 24 hours. The chain said the affected ingredient was being "indefinitely removed" from its supply chain nationwide.

The CDC confirmed that Taco Bell committed to stop using any lettuce from the supplier identified by the FDA's traceback investigation.

A false positive muddied the investigation, but the FDA stood by its findings

The investigation hit an unusual complication. An initial laboratory result indicated that a Taylor Farms lettuce sample tested positive for cyclospora at the border. That result was later deemed a false positive. The FDA retracted the specific finding and apologized to Taylor Farms.

But the retraction did not change the broader conclusion. The FDA maintained its epidemiological link between Taylor Farms' central Mexico-grown lettuce and the outbreak, and it continued advising consumers to avoid the recalled product while the investigation remained open.

HHS Secretary Robert F. Kennedy Jr. declared the outbreak "under control" after investigators identified the source and recalls were implemented.

Fox News reported Kennedy's statement:

"We do have the outbreak under control. We have done extensive forensics, epidemiological forensics and we have identified the source of the outbreak."

Fresh produce from Mexico poses a recurring inspection challenge

Cyclospora is a microscopic parasite that infects people through contaminated food or water, causing cyclosporiasis, a gastrointestinal illness that can require hospitalization. The parasite is most commonly associated with imported fresh produce, and outbreaks tied to Mexican-grown herbs and greens have recurred for years.

Thomas Lew, an assistant clinical professor of medicine at Stanford University School of Medicine, pointed to a structural problem in outbreak response. The short shelf life of fresh produce means that by the time investigators trace an outbreak back to a supplier, the contaminated product may already have been consumed, making laboratory confirmation far more difficult.

The Associated Press noted that a record number of cyclospora cases have been reported in more than 30 states, and experts have cautioned that not every recent illness may stem from a single source. The separate FDA investigation into an unspecified product reinforces that warning.

Michigan's previous record for cyclospora cases was roughly 4,700, set in 2019. This year's count has already blown past that mark by thousands.

Several open questions remain. Investigators have not publicly identified the precise point of contamination in central Mexico. It is unclear whether the 7,400-plus unconfirmed cases awaiting CDC analysis will substantially change the scope of the outbreak once processed. And the separate FDA investigation into a different product has not yet yielded a public conclusion.

When contaminated food crosses the border and sickens thousands of Americans across nine states before regulators can even finish counting the cases, the system that is supposed to protect consumers has already failed the people it serves.