Cyclospora cayetanensis is a microscopic parasite that causes an intestinal illness known as cyclosporiasis. It is not new and has been well-studied for decades. Cases tend to rise in the warmer months, typically May through August. Cyclosporiasis has a favorable outcome and there are no reported long-term health consequences.

What are the symptoms of Cyclospora infection?

Symptoms include watery diarrhea, loss of appetite, weight loss, cramping, bloating, nausea, and fatigue. The illness can last from a few days to a month or more if left untreated. Some people infected with Cyclospora may not have any symptoms.

What should I do if I think I am sick with Cyclospora?

Contact your healthcare provider, who can order a stool test to look for the parasite. Cyclosporiasis is treatable with prescription antibiotics. If you are experiencing symptoms consistent with Cyclospora infection, seek medical attention promptly.

How does Cyclospora spread?

Cyclospora is spread by ingesting food or water contaminated with the parasite. It is not spread directly from person to person because the parasite needs time to become infectious after being passed in a bowel movement. The parasite must mature in the environment before it can cause infection in another person.

How can I reduce my risk of Cyclospora infection?

Follow standard food safety practices: wash your hands thoroughly, rinse fresh produce under running water, and clean food preparation surfaces. Follow public health guidance regarding recreational water quality. These everyday practices help reduce the risk of many foodborne illnesses, including cyclosporiasis.

Has a source of the 2026 Cyclospora outbreak been identified?

No. As of July 2026, no specific food, farm, grower, or supplier has been identified as the source of the outbreak in Michigan and Ohio. IFPA notes potential environmental factors such as municipal sewage overflows impacting Lake Erie and local water quality may be contributing factors.

Why is it difficult to identify the source of a Cyclospora outbreak?

Unlike bacteria, the Cyclospora parasite replicates only in humans, which makes DNA fingerprinting and molecular typing techniques less reliable for tracing the source of an outbreak. This limitation makes it more challenging for investigators to link cases to a specific food or environmental source.

Should consumers stop eating fresh produce because of Cyclospora?

No. Health officials do not recommend that consumers stop eating fresh produce. Standard food safety practices, including washing produce under running water, are advised. Fresh fruits and vegetables remain an essential part of a healthy diet.

Are the 2026 Cyclospora case numbers unusual?

In Michigan and Ohio, yes — the regional cluster is higher than expected and is under active investigation. Across the rest of the United States, national case counts remain within the historical average for this time of year.

Cyclospora Outbreak 2026: FAQs for Consumers

July 8, 2026

Cyclospora Outbreak July 2026

Last updated: July 8, 2026/3:30 PM — This page will be updated as new information becomes available.

Public health officials in Michigan and Ohio are currently investigating an increase in cyclosporiasis cases, and there has been a lot of conversation online and in the news. IFPA has been in contact with state and federal health officials since early July, and we've put together answers to the questions we're hearing most based on what is known right now.

We may update this page as new information is released about this current outbreak.

Frequently Asked Questions:

What is Cyclospora and what does it do?

What is Cyclospora? Cyclospora cayetanensis is a microscopic parasite that can cause an intestinal illness called cyclosporiasis. It's been a known, if uncommon, cause of foodborne illness in the U.S. for decades, with cases typically rising in the warmer months (May – August). Of note, infections with Cyclospora generally have a favorable outcome, even in immunocompromised patients, and no significant long-term health consequences have been reported.

What are the symptoms? The most common symptom is watery diarrhea, often along with loss of appetite, weight loss, cramping, bloating, nausea, and fatigue. Symptoms can start, on average, about a week after exposure and, without treatment, can last from a few days to a few months. It's treatable with prescription antibiotics, but can also self-resolve.

What should I do if I think I'm sick? Contact your healthcare provider, especially if you have prolonged watery diarrhea. Cyclosporiasis is treatable with prescription antibiotics, and a healthcare provider can confirm diagnosis with a stool test.

Current Outbreak

Has a specific food been identified as the source of this outbreak? No. As of this writing, neither the CDC, FDA, nor state health departments in the Lake Erie-bordering counties (larger Detroit/Toledo region) Michigan or Ohio have identified a specific food, farm, grower, or supplier associated with these cases. Investigators are still conducting patient interviews and have not yet collected product samples tied to a suspected source. Any claim naming a specific food or company right now is getting ahead of the data. While investigators are focusing on foods, IFPA continues to raise concerns about recent municipal sewage overflows in the Detroit/Toledo region and the likelihood of these inundations impacting the quality of drinking water (especially water wells), recreational water in Lake Erie and surrounding bodies of water.

While foods are traditionally listed as sources of Cyclospora infections for when sources of outbreaks were established, the majority of infections have no known cause. Complicating our understanding of persistence of Cyclospora in the environment is the fact that detection methods used in the past for this purpose have been reported to have 90% false positive rates, and while FDA now recommends a different protocol for the isolation and detection of Cyclospora from the environmental and food samples, this new method is not currently widely used.

Are these case numbers unusual? Michigan and Ohio are seeing case counts well above their typical numbers for this time of year, which is why they've drawn attention and investigation. Reports of cyclosporiasis across multiple other states are within the range typically expected during the May through August season, and do not indicate unusual activity beyond normal seasonal patterns. However, looking at the U.S. as a whole, total national case counts so far this year are within the normal historical range for this point in the season. In other words, this currently appears to be a regional cluster under active investigation, not a signal of a nationwide outbreak.

Why does Cyclospora tend to show up in certain places or times of year? Cyclospora is closely tied to environmental conditions. The parasite needs warmth and moisture to become infectious, so cases tend to rise in the summer, and clusters can follow periods of heavy rainfall or water system disruptions, which can affect water used in irrigation or food handling as well as recreational water areas (however, this correlation does not hold in locations outside of continental North America). Investigators in this case are looking at reports of heavy rain and sewer overflows in the affected areas in mid-June as one line of inquiry, alongside many others.

How it spreads

How does someone get cyclospora? People get infected by ingesting contaminated food and water. Importantly, a person who is sick with cyclosporiasis cannot pass it directly to someone else the way a cold or flu spreads; the parasite needs to spend time (typically days to weeks) in the environment, usually in soil or water, before it becomes capable of infecting someone else. That's part of why finding the exact source of an outbreak takes time.

How does Cyclospora end up in a production environment? Because Cyclospora cayetanensis only infects humans, it can only enter a farm environment through human sanitation failures. Oocysts shed by an infected person are not immediately infective though. They need 7-15 days in a warm, moist environment to mature before they can cause illness, which means the contamination pathway almost always runs through the environment rather than directly from person to produce.

What does water have to do with Cyclospora on a farm? While infected individuals are the only source of Cyclospora, water is believed to be a way that Cyclospora travels into and through a production environment. Surface water sources including rivers, canals, ponds, and reservoirs can carry oocysts if exposed to sewage or inadequate sanitation upstream. If irrigation or processing water comes into contact with a compromised sewage line, a poorly maintained septic system, or runoff from a nearby facility with inadequate sanitation controls, it can carry the parasite to crops before or after harvest. Soil can also harbor oocysts for weeks to months, and flooding or runoff can move them into production areas.

Can farms, municipal water systems, or recreational water facilities like pools add chlorine to water to eliminate Cyclospora? No, and this is an important distinction from most other waterborne pathogens. Chlorine and other standard antimicrobial chemical treatments are not considered effective against Cyclospora, regardless of whether they are applied at the farm level in an irrigation system, at a municipal water treatment facility, or in a recreational water setting such as a swimming pool or splash pad. This includes the chlorination levels typically used in all of those settings.

Alternative treatment approaches such as UV light, ozone, or microfiltration can reduce the parasite in water and may be appropriate depending on the source and the level of risk identified.

This is one of the reasons prevention at the source matters so much for Cyclospora specifically. For farms, that means the annual water assessment and source protection are the primary line of defense rather than chemical treatment after the fact. For municipalities, standard disinfection protocols that reliably handle bacteria and viruses do not provide the same assurance for this parasite. For pools and other recreational water facilities, the chlorine levels maintained for routine sanitation are not sufficient to kill Cyclospora, which is why people who swallow water in a pool or other recreational water body are not protected the way they might be from other waterborne illnesses. People traveling to regions where Cyclospora is more common should also be aware that locally treated tap water and recreational water may not eliminate the risk, even when it meets local treatment standards.

What consumers can do

What can I do to reduce my risk? Standard food-safety practices apply: wash your hands before and after preparing food, rinse fresh produce under running water, and keep preparation surfaces clean. These are good practices at any time, not just during an active investigation. During recreational activities (swimming, water sports, visiting aquatic parks), it is imperative to follow advice of public health officials based on water quality.

Should I stop eating fruits and vegetables? No. Public health officials are not recommending that people stop eating any specific category of produce, let alone all fruits and vegetables. Fruits and vegetables remain an essential part of a healthy diet.

Testing

How does a doctor test for Cyclospora if someone is sick?

Testing for Cyclospora requires a stool sample, but it will not show up on the standard parasite test that most labs run as a matter of routine. A doctor must specifically ask the lab to look for it, and the lab must use the right technique to find it. This is one of the reasons Cyclospora infections are frequently missed or diagnosed late.

There are two main ways labs look for it. The first is examining the sample under a microscope using special staining techniques that make the parasite visible. The most reliable approach uses ultraviolet light, under which Cyclospora naturally glows blue or green, but not all labs have that equipment. The second approach uses a DNA-based test called PCR, which looks for the parasite's genetic characteristics rather than trying to spot it visually. Some broader panels that test for many GI illnesses at once do include Cyclospora, but not all of them do, so a negative result on a general stomach illness panel does not automatically rule it out.

How do investigators test produce for Cyclospora, and is that the same as the clinical test? It is a similar concept but a different process, and the two are not interchangeable.

When investigators test produce, they wash the surface of the food and then test the wash liquid for signs of the parasite's DNA. They are not testing the food itself in the way you might imagine. The FDA has an official method for this which was updated relatively recently. The method can detect very small amounts of contamination, as few as five oocysts (the microscopic form of the parasite) on a sample.

Do all labs use the same method to test produce for Cyclospora? No. The FDA has an official validated method (BAM Chapter 19b) that its regulatory labs use, but there is currently no international standard requiring all labs to follow the same approach. The International Organization for Standardization is in the process of developing one, but until it exists, labs in different countries, and potentially different labs within the U.S., may be using approaches with different levels of sensitivity and precision. This makes it harder to compare results across investigations and complicates coordination during international outbreaks.

What does a negative test result on produce actually mean? Testing is one important tool in outbreak investigations, but it works best when samples are collected early and in sufficient quantity. The FDA's validated method for detecting Cyclospora on produce (BAM Chapter 19b) should be specific and scientifically rigorous. When samples are available and tested promptly, results are meaningful.

The challenge in many investigations is not the method itself but the combination of two compounding factors. First, investigators frequently do not yet know which product, if any, to test. Identifying the vehicle requires patient interviews, purchase records, and traceback work that takes time, and until that picture comes together, there is no clear target. Second, by the time a likely vehicle is identified, the implicated product (if food) has often already been consumed or has deteriorated past the point where reliable testing is possible.

When testing is part of a well-coordinated, timely response with a clearly identified vehicle, it is a valuable piece of that larger picture.

What makes identification of a source of a Cyclospora infection difficult? Unlike common bacterial pathogens like Salmonella or E. coli, Cyclospora is a parasite with a more complex biology. The way it reproduces (replicates only inside a human host) makes whole-genome DNA fingerprinting tools unavailable, which means investigators have fewer tools to quickly connect individual cases to a common source or trace them back to a specific food or farm. This is one reason outbreak investigations involving Cyclospora take longer than those involving bacteria. It is of note that CDC has a multi-locus typing approach for Cyclospora genotyping.

Regulatory and Industry

Are farms required to do anything about their water to prevent this? Yes. Under the FDA's Food Safety Modernization Act (FSMA) Produce Safety Rule, farms that grow fruits and vegetables covered by the rule must meet standards for agricultural water, which is any water used during growing, harvesting, packing, or holding that is likely to contact the produce or surfaces that touch the produce. The core requirement is that all agricultural water must be safe and of adequate sanitary quality for its intended use.

What specifically are farms required to do to check their water? As of a 2024 update to the rule, farms are required to take a careful, documented look at their water supply every year before and during the growing season. This goes beyond simply running a water test. It is a whole-picture review: where the water comes from, how it moves through the farm, how it is applied to crops through irrigation systems, and whether anything nearby could affect its quality. That includes evaluating surrounding land uses such as wastewater treatment facilities, septic systems, and portable or fixed restroom facilities, whether those are located on the farm itself or on neighboring properties. Importantly, if a neighboring property is upstream of a farm's water supply and the farm cannot get information about what that neighbor is doing, the rule expects the farm to account for that uncertainty by treating it as a potential risk rather than assuming everything is fine. Based on what they find, farms determine whether any changes or safeguards are needed, with the goal of catching potential issues before produce ever reaches a store shelf.

What happens if the assessment finds a problem with the water? Finding a potential issue does not mean a farm is in trouble. It means the system is working as intended. When an assessment identifies a concern, farms are required to take steps to address it, and the rule gives them several practical options for doing so. They might repair or upgrade part of the water system, change how water is delivered to crops (for example, switching from overhead sprinklers that spray water onto leaves to drip irrigation that delivers water directly to the roots instead), or treat the water using a method verified to be effective. For concerns tied to sanitation issues on nearby land, the rule asks farms to act on a faster timeline than they would for other types of issues, reflecting how seriously that particular risk is taken.

Are water safety requirements under the rule limited to the growing season, or do they extend to harvest and packing as well? They extend well beyond harvest. Water used for washing, cooling, transporting, or packing produce after it leaves the field is also regulated under the rule, and it is actually held to a stricter standard than pre-harvest water. It must meet a specific measurable microbial quality criterion with no detectable generic E. coli per 100 milliliters of water, and it is subject to testing requirements rather than the assessment-based approach used for pre-harvest water. Water used to make ice that contacts produce and water used for handwashing during harvest activities are also included in these requirements.

Some third-party audit programs go further still on water quality, requiring that water used in post-harvest operations meet potable (drinking-quality) standards rather than simply the regulatory criterion of no detectable E. coli. For a parasite like Cyclospora, where E. coli testing does not directly indicate the parasite's presence or absence, that higher standard provides a meaningful additional layer of protection.

What can growers do to reduce the risk of Cyclospora contamination on their farm?

Growers have a clear set of tools and practices for reducing Cyclospora risk, and federal regulation and industry guidance together provide a well-developed roadmap for putting them in place. Because Cyclospora cannot be eliminated by standard sanitizers the way some bacterial pathogens can, the focus is on preventing the parasite from reaching crops and water sources in the first place. University of Florida researchers have published two practical guides specifically addressing what that looks like on the farm: Cyclospora prevention on the farm: Prevention of Cyclospora Contamination and Transmission on the Farm (UF/IFAS Extension) and Preventing Foodborne Illness: Cyclospora cayetanensis (USDA/NIFA).

Their key recommendations include the following, though growers with specific questions are encouraged to consult their local university extension service, regulatory contacts, or other qualified technical resources for guidance tailored to their specific situation.

Know your water sources. Map all water sources on and adjacent to your farm, including nearby sewage systems, septic tanks, and drain fields. After crops are established, avoid using surface water for any activity that contacts the harvestable portion of the crop. Where water quality is uncertain, use potable (drinking-quality) water for washing produce and for any post-harvest activities that contact food surfaces.
Have a plan for weather events. Flooding and heavy rainfall can move contamination from sanitation infrastructure into growing areas and water systems. UF researchers specifically recommend developing a written corrective action plan for significant weather events before they occur, not after.
Maintain sanitation infrastructure. Provide sufficient, accessible, and properly functioning toilet facilities for all workers. Use reputable companies for cleaning and maintaining portable toilets and site those facilities away from growing areas and all water sources. Have written corrective action procedures in place for any spills or leaks.
Train workers thoroughly and in their language. Training materials should be appropriate for workers' native language and background, and should cover proper handwashing, recognizing illness symptoms, not working while sick, and correct use of toilet facilities.
Avoid untreated manure. Do not use untreated manure as fertilizer on crops eaten raw. If composted amendments are used, follow applicable USDA guidelines on timing and application.

IFPA Actions to Date

What is IFPA doing? IFPA has been monitoring this situation since July 2 and is in ongoing contact with CDC, FDA, and state health officials in Michigan and Ohio. We're sharing verified updates with our members as they become available and are working to help make sure our members, our media partners and others have up to date information to understand the actual state of the evidence. We recognize that an active investigation with no confirmed source, combined with seasonal timing and elevated case counts in Michigan and Ohio has naturally raised questions and generated significant public attention, and that response is understandable. What we know, we will share. What remains under investigation, we will say so clearly rather than speculate.

Where can I get updates? This page will be updated as new information is confirmed. We encourage the public to rely on verified updates from public health agencies. For deeper technical background on the parasite and its relationship to the fresh produce industry, visit IFPA's Cyclospora resource page. For members with specific questions, IFPA's food safety experts are available.

Media Contact: Media@freshproduce.com

Food Safety Contact: Foodsafety@freshproduce.com

What Is Cyclospora? FAQs from IFPA

Frequently Asked Questions:

Current Outbreak

How it spreads

What consumers can do

IFPA Actions to Date

Additional Press