Cyclosporiasis Cases Rise in Five Outbreak States
The CDC has reported 4,173 confirmed cases of cyclosporiasis in the US between May 1 and July 20. Cases have now been reported in at least 41 states, with the highest number of lab-confirmed domestic cases in Michigan.
The Centers for Disease Control and Prevention (CDC) has reported 4,173 confirmed cases of cyclosporiasis in the US between May 1 and July 20. This number is already higher than the total number of US cases reported for all of 2025. The CDC has declared an outbreak in five states: Michigan, Ohio, Indiana, Kentucky, and West Virginia. Michigan has the highest number of lab-confirmed domestic cases, with an estimated infection rate of nearly 15 per 100,000 people.
The CDC continues to investigate contaminated iceberg lettuce as a potential source of the outbreak. The agency is also aware of at least 7,400 cases that have not yet been lab-confirmed, many of which are from Michigan and Ohio. Additionally, some people who get sick may never get tested for cyclosporiasis, so the actual number of cases may be higher than reported.
Health agencies are concerned about the growing number and concentration of cases this year. While cyclosporiasis cases occur every year, the increasing number of cases in 2026 has prompted the CDC to take action. The agency is working to mitigate the spread of the illness, but there is a lag between illness onset and reported case, so it may take some time to see the full impact of these efforts.
Go Deeper
What is cyclosporiasis?
Cyclosporiasis is a food-borne parasitic infection that causes diarrhea and other symptoms. It is typically spread through contaminated food or water.
How many cases of cyclosporiasis have been reported in the US?
The CDC has reported 4,173 confirmed cases of cyclosporiasis in the US between May 1 and July 20. There are also at least 7,400 cases that have not yet been lab-confirmed.
Which states have been affected by the outbreak?
The CDC has declared an outbreak in five states: Michigan, Ohio, Indiana, Kentucky, and West Virginia. Cases have also been reported in at least 36 other states.
What is the potential source of the outbreak?
The CDC is investigating contaminated iceberg lettuce as a potential source of the outbreak.
What can people do to protect themselves from cyclosporiasis?
People can protect themselves from cyclosporiasis by washing their hands frequently, especially after using the bathroom and before handling food. They should also wash fruits and vegetables thoroughly before eating them, and cook food to the recommended internal temperature to kill any bacteria or parasites that may be present.
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