Rising Cyclospora Infections Across the U.S.: What Experts Know About the Growing Foodborne Illness Outbreak

A foodborne parasite linked to severe digestive illness is spreading across parts of the United States, with health officials reporting a sharp rise in infections. The parasite, known as Cyclospora, has caused thousands of illnesses in previous outbreaks, and recent case numbers are increasing as investigators continue searching for the source.

Michigan has become the most affected state, reporting more than 1,200 cases along with dozens of hospitalizations. Other states, including New York, Ohio, and North Carolina, have also recorded significant increases. Health experts warn that the actual number of infections may be higher because not every person seeks medical care and some states may not have reported updated figures.

The growing number of cases has raised concerns among public health officials, although investigators have not yet identified a single food product or exposure source responsible for the current spread.

What Is Cyclospora and Why Is It Causing Concern?

Cyclospora is a microscopic parasite that can infect the human digestive system. Most infections are caused by a species called Cyclospora cayetanensis, which spreads when people consume food or water contaminated with the parasite.

Unlike some common stomach illnesses that pass quickly, cyclosporiasis can cause prolonged and uncomfortable symptoms. The infection often affects the intestines and may lead to diarrhea that can become severe.

Common symptoms include:

• Frequent watery diarrhea
• Stomach cramps
• Bloating and gas
• Nausea
• Loss of appetite
• Fatigue
• Flu-like symptoms

Symptoms usually appear about one week after exposure, although they may develop within a few days or take up to two weeks. Some infected individuals may not experience noticeable symptoms, which makes tracking and controlling outbreaks more difficult.

Cases Continue to Increase in Several States

Michigan has reported the highest number of infections during the current increase, with case numbers rising rapidly in a short period. Health officials have also recorded hundreds of cases in New York, while Ohio and North Carolina have reported substantial numbers as well.

Federal reporting from the U.S. Centers for Disease Control and Prevention has been slower than some state updates. National figures may increase as more states submit information and additional cases are confirmed.

Experts believe the real number of infections could be much higher because people with mild symptoms may recover without visiting a doctor. In addition, many cases require laboratory testing for confirmation, meaning infections can go undetected.

Previous Cyclospora Outbreaks Have Been Linked to Food Products

The United States has experienced several major Cyclospora outbreaks in the past. One of the largest recent outbreaks occurred in 2019, when thousands of people became sick after exposure linked to contaminated fresh basil.

Earlier outbreaks have also been connected to imported produce. In 1996, more than 1,400 illnesses across multiple states were associated with contaminated raspberries.

Past investigations have frequently identified fresh fruits and vegetables as possible sources. Foods such as leafy greens, herbs, and other raw produce can become contaminated during growing, harvesting, processing, or handling.

However, health officials investigating the current increase have not confirmed a specific food source. Until more information is available, experts recommend following general food safety practices.

How Cyclospora Spreads

Cyclospora spreads when microscopic parasite particles called oocysts enter the digestive system. These particles can contaminate food, drinking water, or surfaces.

People usually become infected by:

• Eating contaminated raw fruits or vegetables
• Drinking contaminated water
• Consuming food that was not properly washed or handled

The parasite is not typically spread directly from person to person because Cyclospora requires time outside the body before it becomes infectious.

Fresh produce requires special attention because contaminated items may look completely normal. Washing fruits and vegetables carefully can reduce risk, although cleaning alone may not remove every parasite particle.

Treatment and Recovery

Cyclosporiasis is generally treatable and is not considered life-threatening for most healthy people. Doctors commonly prescribe antibiotics to clear the infection.

People who experience persistent diarrhea, dehydration, or worsening symptoms should contact a healthcare professional. Severe cases may require medical support, especially for older adults, young children, or people with weakened immune systems.

Staying hydrated is important because prolonged diarrhea can lead to fluid loss and dehydration.

Steps to Reduce the Risk of Infection

Health experts recommend several steps to lower the chance of Cyclospora infection:

Wash Produce Thoroughly

Fresh fruits and vegetables should be washed under running water before eating or preparing. Even produce purchased from grocery stores should be cleaned carefully.

Cook Food When Possible

Heating food can help destroy parasites. Experts note that temperatures around 158 degrees Fahrenheit can kill Cyclospora organisms.

Practice Safe Food Handling

Avoid cross-contamination by keeping raw foods separate from ready-to-eat foods. Wash hands, utensils, and preparation surfaces regularly.

Be Careful With Unknown Water Sources

Untreated water may carry parasites and other microorganisms. Travelers and outdoor visitors should use safe drinking water sources.

Experts Continue Searching for Answers

Although case numbers are rising, health investigators have not found one confirmed cause behind the current increase. Identifying the source of a foodborne outbreak can take time because officials must examine food supply chains, patient histories, and laboratory evidence.

Public health agencies continue monitoring infections and collecting information from affected states. Additional guidance may be released as investigators learn more about how and where exposures occurred.

For now, experts emphasize awareness rather than panic. Most infections can be treated successfully, and simple food safety measures can reduce the risk of illness.

Sources

• U.S. Centers for Disease Control and Prevention (CDC) information on Cyclospora and cyclosporiasis
• State health department outbreak updates, including Michigan and New York public health reports
• Health reporting from The New York Times and other public health news sources
• Infectious disease specialists quoted in regional health coverage

Disclaimer

This article is for informational and educational purposes only. It is not medical advice and should not replace guidance from a qualified healthcare professional. Anyone experiencing persistent diarrhea, dehydration, severe symptoms, or concerns about possible infection should seek advice from a healthcare provider.