Cyclospora Outbreak in the US Grows as Thousands Fall Ill After Contaminated Lettuce Exposure
A major foodborne illness outbreak in the United States is continuing to draw attention after thousands of people were diagnosed with cyclosporiasis, an intestinal infection caused by the parasite Cyclospora cayetanensis.
According to the latest US Centers for Disease Control and Prevention data available on August 25, 17,180 laboratory-confirmed cases of cyclosporiasis acquired in the United States had been reported since May 1, 2026. The cases were recorded across 48 states plus Washington, D.C., with 922 hospitalizations and two reported deaths.
Contaminated Lettuce Identified in a Major Outbreak
A substantial portion of the illnesses has been connected to a multistate outbreak involving iceberg lettuce sourced from central Mexico.
The CDC and US Food and Drug Administration traced the outbreak to iceberg lettuce supplied by Taylor Farms de Mexico. The company began voluntarily removing the affected lettuce from the US market on July 17 and initiated a recall.
The recalled products had best-by dates that have now passed, and federal authorities say the affected lettuce should no longer be available in stores or restaurants.
The specific lettuce outbreak had reached 10,930 illnesses in 17 states, along with 454 hospitalizations and two deaths, according to the CDC’s August 20 update.
A Wider Outbreak Than the Lettuce Investigation
An important distinction is that the 17,180 nationwide cases reported by CDC are not all attributed to the recalled lettuce.
The national figure includes laboratory-confirmed infections from multiple sources. CDC is separately investigating other clusters of cyclosporiasis whose sources have not yet been identified.
Health officials also believe the actual number of infections is higher than the confirmed total because some people recover without seeking medical attention and may never receive testing.
Recent cases can take weeks to appear in official statistics because identifying and reporting Cyclospora infections requires time. CDC notes that it can take approximately six weeks from the beginning of symptoms for a case to reach its surveillance system.
What Is Cyclospora?
Cyclospora is a microscopic parasite that infects the intestinal tract. People generally become infected by consuming food or water contaminated with the parasite.
The illness commonly causes persistent watery diarrhea, along with symptoms such as stomach cramps, bloating, nausea, fatigue, loss of appetite and weight loss. Some infected people may have few or no symptoms.
Symptoms can sometimes disappear and return, and untreated illness may continue for weeks or longer.
People experiencing persistent gastrointestinal symptoms should contact a healthcare professional, particularly if they may have been exposed to contaminated food.
Why Detecting the Infection Can Be Difficult
Cyclospora infections are not always identified through routine testing.
Healthcare providers may need to specifically request testing for the parasite when a patient’s symptoms and exposure history suggest possible cyclosporiasis. This is one reason official case numbers may underestimate the true number of infections.
Public-health investigators also interview patients about what they ate and where they travelled during the period before their illness began. These interviews help investigators identify common food exposures.
Federal Investigation Continues
The FDA says its investigation remains active and that federal officials are working with state and local authorities and Mexican counterparts.
The agency has conducted inspections and sampling at relevant lettuce production facilities in Mexico. Officials say they remain confident that the recalled lettuce associated with this particular outbreak has been removed from the US market.
Investigators are also using laboratory and epidemiological information to determine whether infections are connected to the same source.
Genotyping of parasite samples from patients in the lettuce outbreak has shown that the Cyclospora organisms involved are genetically related, providing additional evidence that affected people were exposed to a common source.
Consumers Urged to Remain Careful
Because the recalled lettuce’s best-by dates have passed, consumers should not normally encounter the affected products through legitimate retail or restaurant channels. Nevertheless, anyone who may still have recalled products should not eat them.
Federal agencies recommend following food-safety practices, including washing hands and fresh produce thoroughly under running water before eating, cutting or cooking it.
People who develop prolonged diarrhea or other symptoms consistent with cyclosporiasis should seek medical advice and mention any relevant food exposure.
A Significant Public-Health Challenge
The scale of this year’s outbreak has made cyclosporiasis a major US food-safety story. The CDC reported only 1,180 US-acquired laboratory-confirmed cases between May 1 and August 31, 2025, compared with more than 17,000 confirmed cases already reported during the comparable 2026 season.
Authorities caution that the 2026 figures are preliminary and can change as additional reports are received and cases are reviewed.
The continuing investigation illustrates how a contaminated ingredient can move through complex food-supply networks and cause illnesses across multiple states.
For consumers, the most important message is to remain aware of official recall information, practice safe food handling and seek medical attention for persistent symptoms.
