Cyclospora Outbreak in the US

[NorCal Dave]

Well, this is turning into a real s&#t-show state side. I've started to see some quasi-conspiracy postings on Facebook and it's likely to get worse if this outbreak does as well. Some problems include the nature of the parasite that makes it difficult to trace and has the CDC making and then retracting statements. Combined with industrial level farming, transport over international borders and the popularity of fast-food, it seemed a subject to get out ahead of.

Cyclospora is a parasite that causes sometimes severe and long lasting gastrointestinal issues. In simple terms, once infected, one could spend up to several explosive weeks on the toilet:

Cyclospora cayetanensis is a coccidian protozoan that causes cyclosporiasis, a severe gastroenteric disease, especially for immunocompromised patients, children, and the elderly. The parasite is considered as an emerging organism and a major contributor of gastroenteritis worldwide.

Currently, nineteen Cyclospora species have been reported to be causative agents of disease in various animal species [5] and only one species, C. cayetanensis, is known to be associated with syndromes of acute and chronic diarrhea in humans.

https://pmc.ncbi.nlm.nih.gov/articles/PMC7699734/

While a number of cases per year are normal, the current outbreak is much larger:

As of Tuesday, the Centers for Disease Control and Prevention said it had received reports of 1,645 confirmed cases of cyclosporiasis, the gastrointestinal affliction caused by the parasite Cyclospora.

But the true number of infections is likely much higher, because that figure only represents cases reported by states directly to the CDC. There is also a lag between symptom onset and reporting, and many people recover from the illness without medical treatment. Michigan alone reported 3,309 cyclosporiasis cases as of Tuesday.

Only 249 cases had been reported nationally at this time last year.

https://www.npr.org/2026/07/12/nx-s1-5890935/cyclosporiasis-cyclospora-outbreak-diarrhea-states-us

No fatalities as of now.

Cyclospora is transmitted through contaminated food, not person to person. The particular strain uses the human, not other animals, gastrointestinal system for its life cycle:

People can become infected when they drink water or eat raw food, usually raw produce, that is carrying the parasite. Food picks up the parasite most often through water supplies that are infected with human feces.

Cyclosporiasis is not transmitted via person-to-person contact.

https://www.hopkinsmedicine.org/health/expert-qa/cyclosporiasis-outbreak

C. cayetanensis is a parasite that must live inside a human host for part of its life cycle, as well as living outside the host during an environmental phase. Although there are many species of Cyclospora, only C. cayetanensis has been known to cause illness in humans, an infection called cyclosporiasis. A person can become infected after ingesting food or water contaminated with the parasite. Infected people (including those who are asymptomatic or show no symptoms of illness) can shed the parasite in their feces. Without good hygiene practices, among other protections, this can result in the contamination of food, water and the environment and lead to the infection of other people.

https://www.fda.gov/food/foodborne-pathogens/cyclosporiasis-and-fresh-produce

So, it likely gets into a water supply that then gets on fresh fruits and vegetables that are not cooked before serving, like lettuce on a taco. Further complicating matters, as the vector is an oocyst, it is highly resistant to the usual anti-microbial treatments, like good old bleach:

Although chlorine and other antimicrobial chemical treatments are effective at reducing harmful populations of bacteria and viruses, they are not considered effective on C. cayetanensis. In countries/regions where cyclosporiasis is endemic, microfiltration, ozone, or UV treatments may be necessary to effectively decrease populations of C. cayetanensis in irrigation waters.

https://www.fda.gov/food/foodborne-pathogens/cyclosporiasis-and-fresh-produce

While there are test for it, it's still difficult to identify on food:

Although clinical testing for the parasite in human feces has been available since the 1970s, FDA recently improved the method for the detection of this parasite on some fresh fruits and vegetables. Traditional microbial testing (such as for fecal indicators like generic E. coli or fecal coliforms) will not identify the presence of C. cayetanensis but may help identify poor water quality, which may also be an indicator of human fecal contamination.

https://www.fda.gov/food/foodborne-pathogens/cyclosporiasis-and-fresh-produce

Note, that while detection of things like E. coli may point to poor water quality, traditional anti-micropbial treatments, like chlorine, can kill E. coli while possibly leaving the cyclospora oocysts as active, though undetectable, vectors.

The main cause of the current outbreak, or at least a big contribution factor, may be linked to bulk lettuce from central Mexico. This was packaged and sold by Taylor Farms of Salinas CA:

A popular California company has been linked to the growing cyclosporiasis outbreak, according to a new report.

The Washington Post, citing two individuals familiar with the investigation, first reported Thursday that federal investigators have identified iceberg lettuce supplied by Taylor Farms to Taco Bell restaurants as a possible source of contamination.

CNN and others are also reporting the ongoing investigation into Taylor Farms as a source of the cyclosporiasis outbreak.

Taylor Farms, founded and headquartered in Salinas, California, describes itself as the "leading global producer of salads and healthy fresh foods." In addition to the Golden State, the company has production facilities across the U.S., along with Mexico, Canada and Europe.

https://fox40.com/news/national-and...sible-cyclosporiasis-outbreak-source-reports/

The problem seems to be, cyclospora is hard to trace the way other food-born pathogens are:

Some better-known foodborne pathogens, such as Salmonella or E. coli, cause symptoms within a few days of consumption. But cyclosporiasis symptoms can take up to two weeks to appear — too long for people to easily recall exactly what they ate, and where. ‌By that time, ⁠fresh produce items such as tainted lettuce may already be out of stores or restaurants.

The tiny parasite that causes cyclosporiasis cannot be traced using the most advanced testing methods in which scientists grow pathogens in their labs and sequence the full genome of the organism. This produces a genetic fingerprint that can be matched with contaminated food sources.

Because this is a parasite and not a bacterium, cyclospora cannot be grown or cultivated in labs — a process that increases the amount of genetic material used to confirm its presence.

https://www.reuters.com/legal/litig...-us-outbreak-so-challenging-trace-2026-07-20/

This has resulted in a bit of a "yes, well no" situation with some false positive tests of Taylor Farms produce at the border:

The US Food and Drug ⁠Administration (FDA) said on Sunday that laboratory experts re-checked lettuce sample results from Taylor Farms in an ⁠investigation into an ⁠outbreak of the cyclospora parasite and concluded the finding should be considered a false positive.

As of Sunday, there were ⁠no confirmed positive sample results for cyclospora, the FDA added. The FDA on Saturday had said that a ⁠sample of shredded iceberg lettuce supplied by Taylor Farms tested positive for the parasitic illness that has ‌sickened thousands of ‌people in the US.

https://www.theguardian.com/us-news/2026/jul/20/fda-taylor-farms-lettuce-cyclospora-false-positive

While Taylor Farms did recall produce from Mexico, the recently reported "positive test" was reported as being on non-recalled product:

"To be clear, at this moment, FDA has not identified a single positive product test result for cyclospora," the company said. Taylor Fresh Foods added that it had completed a voluntary recall of iceberg lettuce ‌from central Mexico out of an abundance of caution based on the initial information given.

Taylor Farms has also said that the FDA apologized. The company had earlier confirmed that ⁠the product was not part of its current recall, according to the FDA.

https://www.theguardian.com/us-news/2026/jul/20/fda-taylor-farms-lettuce-cyclospora-false-positive

For those at home, it was all a bit confusing. The outbreak was at least partially traced to lettuce from Mexico imported by Taylor Farms. Maybe. Then there was a report of product that was NOT recalled also testing positive. Then that test was revised to a negative. Prompting the apology according to Taylor Farms. But maybe not:

Health officials said they did not offer Taylor Farms an official apology.

"To clarify, this false-positive lab sample DOES NOT change the basis for FDA's ongoing outbreak investigation or the overwhelming epidemiological data supporting the current voluntary recall by Taylor Farms," it said.

https://www.cnn.com/2026/07/20/health/taylor-farms-lettuce-cyclospora-investigation

I'm not suggesting anything nefarious here, though I can see where this could be used by those already prone to conspiratorial thinking about the CDC, the FDA and other government agencies trying to track this outbreak. Which does bring up the strange situation, that the current head of HHS, which oversees the CDC and FDA, RFK Jr. has a history of somewhat non-mainstream views on health and disease. Now, like some of his supporters have accused his predecessors of doing in a time of potential negative media coverage, he is claiming everything is just fine:

Health and Human Services Secretary Robert F. Kennedy Jr. told ABC News on Tuesday that the multi-state cyclosporiasis outbreak in the U.S. is "under control."

"We do have the outbreak under control," Kennedy said. "We have an extensive forensics, epidemiological forensics, and we've identified the source of the outbreak. We and the companies that are involved have implemented a recall."

This stems from criticism leveled at HHS after they paired back the FoodNet program, and reduced the mandatory reporting pathogens to just one E. coli variant and Salmonella:

In a letter sent to Kennedy last week, Ossoff said the CDC's Foodborne Diseases Active Surveillance Network, known as FoodNet, no longer requires reporting the parasite that causes cyclosporiasis.

The CDC ended mandatory reporting last year. Beginning July 1, 2025, reporting became optional for all pathogens except Salmonella and Shiga toxin-producing E. coli, according to the CDC.

RFK maintains that the Food net program was redundant and the proper investigations are ongoing:

Kennedy told ABC News criticisms of the federal response are "invalid" saying they're "still doing surveillance in this space."

"We had no cuts in our surveillance program. We did cuts in the FoodNet program, but they were for redundant surveillance," Kennedy said. "And all this space will tell you that we're still doing forensics. We're still doing surveillance in all this space."

https://abc7ny.com/story/rfk-jr-say...trol-amid-least-1600-cases-5-states/19552078/

In the end, limited cyclospora infections are not uncommon in the US, especially in summer and they are rarely fatal. For most reasonably healthy people, either it runs it's uncomfortable course or is treatable with Bactrim or Septra:

For those with cyclosporiasis, Talaat says there is an effective treatment: The antibiotic trimethoprim/sulfamethoxazole, brand name Bactrim or Septra, taken for seven to 10 days. While Cyclospora is a parasite, not bacteria, the antibiotic is effective against it.

Talaat says many won't even realize they had cyclosporiasis. "For most healthy adults, it's often a self-limited infection; it will go away by itself," she says.

https://www.npr.org/2026/07/12/nx-s1-5890935/cyclosporiasis-cyclospora-outbreak-diarrhea-states-us

Interesting if the ivermectin crowd will get in on this. Cyclospora IS a parasite and ivermectin CAN be an effective anti-parasitic. If they can claim it cures cancer, because cancer is a parasite, then one would think they would be touting it for cyclospora.

Personally, we fix probably 85-90% of our meals at home, BUT we do like some of the Taylor Farms pre-packaged salad kits sometimes after a long day. We'll fix the rest of dinner, but the throw together salad is great. Or at least it was. Pretty sure we had 1 or 2 in the last couple of weeks, so even the slightest rumble in the tummy sets off alarms. The salad kits were still in the store today as they supposedly are not related to potential problem lettuce from Mexico and California has so far escape any major outbreaks. Possibly, much of Taylor Farms domestic production in the Salinas Monterey area ends up in Californa. But I'm going to wait and see.

 

[Ann K]

I've always preferred my veggies cooked rather than raw, so this seems a very good time to continue that practice. However the statement "It's under control", coming as it does from the mouth of RFK jr, leaves me apprehensive. He is noted for swimming in polluted water, chain-sawing off a whale head to take it home, collecting penises from roadkill raccoons, and snorting cocaine off a toilet seat, all of which he freely admits. This is a REALLY bad time to accept medical advice from our federal government.

 

[John J.]

Interesting if the ivermectin crowd will get in on this.

Depressingly, a US Congresswoman has proposed using ivermectin in the context of the current cyclosporiasis outbreak,
as has a former Representative.

From Reuters, "Fact Check: No evidence that ivermectin can treat Cyclospora infections", 17 July 2026
https://www.reuters.com/fact-check/...n-can-treat-cyclospora-infections-2026-07-17/:

Cyclosporiasis is caused by a single-celled protozoan parasite that would not be susceptible to the anti-worm drug ivermectin, experts say, contrary to posts from current and former U.S. congresswomen promoting ivermectin in the context of a Cyclospora outbreak affecting 34 states.

Posts on X by U.S. Representative Nancy ‌Mace and former U.S. Representative Marjorie Taylor Greene referred to a current outbreak and a parasite that causes "explosive diarrhea".

Mace asserted that "Ivermectin solves this problem."

Greene's post said ivermectin kills parasites, and offered a discount code for an online provider that sells ivermectin.

As of July 14, the U.S. Centers for Disease Control and Prevention (CDC) was reporting locally acquired cases of cyclosporiasis in 34 states with many patients experiencing severe diarrhea and 141 people admitted to ⁠hospital. There have been 1,645 cases confirmed since May.

However, there is no evidence that ivermectin would benefit the people infected.

Experts told Reuters that ivermectin is effective at treating parasitic worms and arthropods such as scabies mites, but there's no reason to think its therapeutic mechanism would counteract Cyclospora. When it has been tested on related organisms, it had no effect.

"The posts are false and dangerous," Dr Cynthia Sears, a professor at Johns Hopkins University School of Medicine, said in an email. "Ivermectin works on roundworms/flatworms and ectoparasites (lice, mites) by binding to ion channels in the cells of these multicellular parasites, leading to their paralysis, expulsion and death."

Cyclospora is a single cell protozoan parasite that lacks ‌any cells ⁠able to bind, so it is not susceptible to ivermectin, Sears added. She said it was "readily treatable with a combination antibiotic trimethoprim-sulfamethoxazole (brand names Bactrim, Septra)."

Joel Barratt, an associate professor in the Department of Pathology and Laboratory Medicine at Emory University, also said "the known mechanism of action for ivermectin (muscle paralysis) does not apply to protozoans like Cyclospora."

Pointing to a recent study of ivermectin used ⁠against the parasite that causes malaria, which is in the same family as Cyclospora, Barratt said in an email that the authors concluded, "ivermectin does not have clinically relevant activity against the asexual blood stages of Plasmodium falciparum."

Based on that result, "it seems highly unlikely ⁠that ivermectin would have any significant activity against Cyclospora," he said.

The FDA said ivermectin was not approved for the treatment of cyclosporiasis and referred Reuters to the product label.
Nancy Mace, CDC and Marjorie Taylor Greene did not immediately ⁠respond to requests for comment.

Merck, the company that manufactures ivermectin in the U.S., did not respond to a Reuters request for comment.

VERDICT
No Evidence. There is no evidence that the antiparasitic drug ivermectin would have any effect in a cyclosporiasis infection.

Marjorie Taylor Greene has a record of saying, um, interesting things about current affairs, including her infamous and rightly-ridiculed claim that Californian wildfires in 2018 might have been caused by space-based lasers, perhaps somehow connected with the Rothschild banking family. Discussed on Snopes website, "Rep. Marjorie Taylor Greene Said 'Jewish Space Lasers' Caused California Wildfires?", 06 March 2024, Nur Ibrahim https://www.snopes.com/fact-check/mtg-space-lasers/
The search function here shows her name has cropped up in connection with other stuff discussed on Metabunk.

Nancy Mace's views have also been of interest on this forum. Her interest in UAP is reasonably well-known, e.g.

In an interview with OutKick, Mace cited the cases of Bob Lazar and David Grusch to conclude that explanations of UFO sightings that did not involve space aliens "didn't add up"

Wikipedia https://en.wikipedia.org/wiki/Nancy_Mace
During her unsuccessful campaign to become Governor of South Carolina, Mace declared she would ban chemtrails,
"Nancy Mace says she would ban 'chemtrails' as South Carolina governor", The Independent 07 August 2025 https://www.independent.co.uk/tv/news/nancy-mace-chemtrails-ban-south-carolina-b2803930.html

There are effective and relatively safe, cheap treatments for Cyclosporiasis, some mentioned by @NorCal Dave. Many afflicted people won't require them.
Why Nancy Mace and Marjorie Taylor Greene think ivermectin would be as effective is anyone's guess.

 

[JMartJr]

Why Nancy Mace and Marjorie Taylor Greene think ivermectin would be effective is anyone's guess.

I don't assume that they DO think that, though they may. But they are aware of where there political base is, and the position aid base takes on Ivermectin as the miracle drug that cures whatever you would like it to cure but is suppressed by Big Conspiracy.

 

[NorCal Dave]

Marjorie Taylor Greene has a record of saying, um, interesting things about current affairs, including her infamous and rightly-ridiculed claim that Californian wildfires in 2018 might have been caused by space-based lasers, perhaps somehow connected with the Rothschild banking family. Discussed on Snopes website, "Rep. Marjorie Taylor Greene Said 'Jewish Space Lasers' Caused California Wildfires?"

Guess I missed that one, even though I live in the middle of 2018's most destructive and deadliest of those fires. And I'll note, our good Jewish friend and our part Jewish daughter-in-law are still constantly complaining they have yet to receive their "Jew lasers".

On a more serious note, thanks for finding the pro-ivermectin take on this. I found that at least some people I know, think ivermectin is a wonder drug, despite the fact it was created, marketed and is still produced by Merck. The very definition of "big pharma".

I think they hear the word "parasite" and assume they're all the same and therefore can all be treated the same. So much so, that some believe cancer is a parasite, because the wonder drug, ivermectin, is an anti-parasitic.

We have a small hobby vineyard and participate in a bi-monthly on line vineyard growers class. One thing we learn about is fungicides, as grape vines can be susceptible to a variety of fungi, particularly east of the Rockies (not us). The various fungicides used have different MoAs identified by different FRAC numbers.

MoA is the Method of Action, that is, how does the fungicide kill the fungus. Different MoAs are grouped by FRAC number, the Fungicide Resistance Action Committee. All that to say, different fungi and different parasites are controlled by different means. Ivermectin works on multi-cellular worms and such by interrupting the signaling process between cells. Cyclospora is a single cell parasite, and thus, ivermectin is useless.

 

[NorCal Dave]

This is a REALLY bad time to accept medical advice from our federal government.

This becomes the problem, right? An over emphasis on those, often temporary political appointees, that head these agencies and the day in, day out, people doing the work. Does who we believe depend on the political appointee in front of the mike?

 

[jarlrmai]

day in, day out, people doing the work.

They got fired/reduced/replaced by cronies by DOGE or resigned because RFK is an insane nutcase with actively harmful ideas about health.

Trump is dangerous and his presence makes it all possible but mostly he seems to be about rinsing the US government and his position for as much money as he can, RFK is Nergal from the Mesopotamian pantheon made manifest.

 

[FatPhil]

Well, this is turning into a real s&#t-show state side. I've started to see some quasi-conspiracy postings on Facebook and it's likely to get worse if this outbreak does as well. Some problems include the nature of the parasite that makes it difficult to trace and has the CDC making and then retracting statements.

It's harder to trace because of its longer lifecycle, but one of the reasons we know how much higher the number of cases is compared to the yearly average is because FoodNet was tracing it since the 90s:

1997
FoodNet begins conducting surveillance for infections caused by the parasites Cyclospora and Cryptosporidium.

Until:

2025
Reporting for data collected on or after July 1, 2025, becomes optional for all pathogens except Salmonella and STEC. Reporting for pediatric HUS data also becomes optional.

https://www.cdc.gov/foodnet/about/timeline.html

This was a deliberate planned deregulation. I.e. Republican *policy*.

 

[Dan Burt]

I simply stopped eating lettuce that wasn't from the local farmer's market. A friend had posted on Facebook that after coming home from a Volkswagen gathering in Germany (we live in the U.S.) he got sick after eating a salad and some cherries. That was on July 6th. Then I read something about people getting sick on a cruise ship? Then we heard about the diarrhea lettuce thingy. I may never eat lettuce not sourced locally again.