Several states, particularly in the Midwest and East Coast, have reported thousands of cases of cyclosporiasis, a parasitic disease that can cause debilitating diarrhea.
There have been cases of cyclosporiasis infection in California this year, but none linked to the current outbreak. Public health officials, however, have advice for residents to avoid getting sick.
Cyclosporiasis is an intestinal disease caused by several types of microscopic parasites Cyclospora cayetanensis and is spread through the feces of an infected person who has contaminated food or water, according to the Centers for Disease Control and Prevention.
People become infected by eating food or water infected with the parasite – the virus is not transmitted from person to person.
The origin of the current outbreak is in Michigan, which has reported more than 1,000 cases since June, including 44 people hospitalized. The state usually reports about 50 cases of cyclosporiasis per year. Hundreds more may now be infected with the virus as 17 states have reported multiple cases.
Officials say the actual number of infected people may be higher because some people recover without medical help and are not tested for the parasite..
In the United States, foodborne outbreaks of cyclosporiasis have been linked to various types of fresh produce from Latin America, including raspberries, cilantro, basil, snow peas and mixed salad, according to the California Department of Public Health.
Officials say those who have been sick became ill after eating food in the United States and did not report travel within 14 days before becoming ill.
Those infected with cyclosporiasis range in age from 5 to 86.
There is currently no evidence of a single, multi-regional state cyclospora outbreaks, meaning there is no common source linking all cases, according to the CDC and the US Food and Drug Administration, which is working with public health authorities to investigate cases in each state.
Currently, there are no local outbreaks in California, and the current cases of cyclosporiasis infection are not linked to the multistate outbreak, according to the California Department of Public Health.
“From January to June 2026, California reported 41 temporary cases of cyclosporiasis, compared to 80 cases during the same period in 2025,” said Beth Deines, chief information officer at the state agency.
Most of these cases are linked to recent international travel, he said.
“With the large increase in cases in the Eastern and Midwestern states, we will look at cases that may be linked to travel to areas of the country that have this increase,” said Deines.
Similarly, public health department officials will look for a cluster of cases that may indicate an infection occurring in California.
There have been four domestic cases reported since May 1, 2026.
Two of those infected reported traveling to the Midwest. The investigation of these cases is still ongoing. To protect patient privacy, the public health department does not disclose where patients live in the state.
Symptoms of cyclosporiasis
Cyclosporiasis cases are reported throughout the year; however, diseases are more common when temperatures are warm, in the summer and early fall.
Infected people develop symptoms from two days to two weeks after eating food or drinking water containing the parasite.
Some infected people, especially those from areas where cyclosporiasis is endemic, may not have symptoms.
Those who develop symptoms may experience:
- Watery diarrhea
- Loss of food
- Weight loss
- Constipation
- Constipation
- Gas expansion
- Nausea
- Fatigue
Unusual symptoms may include:
- Vomiting
- Body pain
- A headache
- A low-grade fever
- Other flu-like symptoms
Cyclospriasis can be treated with a combination of antibiotics. Without treatment, symptoms can last from a few days to a month or more.
Some symptoms, such as diarrhea, may go away and come back.
A way to protect yourself
When traveling to areas where cyclospriasis is found – including tropical or subtropical areas – avoid drinking tap water. And make sure hot food is served piping hot, health officials say, and cold food should be kept cool. Bacteria that cause food poisoning can grow quickly in warm food.
A complete list of food and drink considerations provided by the CDC can be found here.
Most foodborne cyclosporiasis outbreaks in the US have been linked to various types of imported fresh produce, so public health officials in California and states reporting cases of infection recommend:
- Wash your hands with soap and water before and after handling or preparing raw fruits and vegetables. Note that hand sanitizer does not kill the parasite that causes cyclosporiasis.
- Wash all fruits and vegetables thoroughly under running water before eating, cutting or cooking.
- Scrub hard fruits and vegetables, such as melons and cucumbers, with a clean produce brush.
- Cut off any bruised or damaged areas on fruits and vegetables before preparing and eating.
- Refrigerate cut, peeled or cooked fruits and vegetables as soon as possible.
