CDC Investigates Rising Cyclospora Infections Across 18 States as Hundreds Report Severe Diarrhea

The United States is experiencing a noticeable rise in infections caused by Cyclospora, a microscopic parasite that leads to an intestinal illness known as cyclosporiasis. Health officials at the Centers for Disease Control and Prevention (CDC) are actively investigating the source of the outbreak after more than 400 people across 18 states reported becoming ill.

Although the illness is usually not life threatening, the sudden increase in cases has raised concerns among public health experts. The CDC, along with the U.S. Food and Drug Administration (FDA) and state health departments, is working to identify contaminated food sources and prevent additional infections.

What Is Cyclospora?

Cyclospora is a microscopic parasite that infects the intestines and causes a disease called cyclosporiasis. People become infected after consuming food or water contaminated with human feces containing the parasite.

Unlike many foodborne illnesses, Cyclospora is not commonly spread directly from one person to another. Instead, infections are usually linked to contaminated fresh produce or untreated water.

The parasite has been associated with several fresh fruits and vegetables in previous outbreaks, including:

• Basil
• Cilantro
• Spinach
• Mixed salad greens
• Raspberries and other berries

Since many of these foods are consumed raw, proper washing and food handling practices are important, although washing alone may not completely remove the parasite.

More Than 400 Cases Reported

According to the CDC, 145 confirmed cases of cyclosporiasis were reported across 17 states between May 1 and June 16, with 20 people requiring hospitalization.

Outside that reporting period, state officials identified a much larger increase in infections. Michigan alone has reported more than 300 cases since late June, making it one of the state's largest Cyclospora outbreaks in recent years.

States reporting cases include:

• New York
• Texas
• Illinois
• Michigan
• Alaska
• Colorado
• Connecticut
• Florida
• Georgia
• Louisiana
• Massachusetts
• New Jersey
• North Carolina
• Ohio
• Pennsylvania
• Tennessee
• Virginia
• Wisconsin

Health officials say there is currently no evidence linking every infection to a single nationwide outbreak. Instead, investigators believe multiple clusters may be connected to different contaminated food sources.

Symptoms of Cyclosporiasis

Symptoms typically appear between two days and two weeks after a person consumes contaminated food or water.

The most common symptom is severe watery diarrhea, which can occur frequently and may become explosive.

Other symptoms include:

• Stomach cramps
• Nausea
• Vomiting
• Fatigue
• Loss of appetite
• Low grade fever
• Weight loss
• Bloating
• Increased gas

Some infected individuals experience only mild symptoms or none at all, making it more difficult to identify and trace outbreaks.

Without treatment, symptoms may last for several days or even weeks. In some cases, people experience cycles of improvement followed by recurring illness.

Why Cases Increase During Summer

Cyclospora infections in the United States are seasonal. Cases usually rise between May and August when fresh fruits and vegetables become more widely available.

Because many fresh produce items are imported or distributed across multiple states, contaminated products can expose large numbers of consumers before investigators identify the source.

Previous outbreaks have been connected to imported produce as well as domestically distributed vegetables. Public health officials continue monitoring food supply chains to identify potential contamination points.

Investigation Continues

The CDC and FDA are working closely with state health departments to interview patients, review food purchase histories, and analyze laboratory samples.

Investigators are focusing on people who became sick after eating food within the United States and who had not traveled internationally before developing symptoms.

At this stage, officials have not identified one single food product responsible for every reported infection. Instead, they believe multiple contamination events may be contributing to the increase in cases.

Because identifying contaminated produce can take time, officials continue encouraging consumers to practice safe food handling while the investigation remains ongoing.

Treatment and Recovery

Most healthy adults recover from cyclosporiasis without serious complications.

However, symptoms can be prolonged and uncomfortable. Doctors may prescribe antibiotics in more severe cases or for patients whose symptoms persist.

People experiencing diarrhea should drink plenty of fluids to prevent dehydration, especially young children, older adults, and those with weakened immune systems.

Anyone experiencing persistent diarrhea, severe stomach pain, or signs of dehydration should seek medical attention promptly.

Healthcare providers may order laboratory testing to confirm Cyclospora infection before recommending treatment.

How to Reduce Your Risk

Although it is impossible to eliminate every risk associated with fresh produce, several precautions can lower the chance of infection.

Health experts recommend:

• Wash fresh fruits and vegetables thoroughly under running water.
• Clean cutting boards, utensils, and countertops before preparing food.
• Wash hands with soap and water before handling food.
• Separate fresh produce from raw meat and poultry.
• Drink safe, treated water when traveling or visiting areas with uncertain sanitation.
• Seek medical care if diarrhea lasts several days or becomes severe.

Consumers should also stay informed about food recalls or outbreak notices issued by public health authorities.

Is Cyclospora Dangerous?

For most healthy individuals, cyclosporiasis is unpleasant but not life threatening.

The recent outbreak has not resulted in any reported deaths, according to health officials.

However, prolonged diarrhea can lead to dehydration and nutritional deficiencies if left untreated. Individuals with weakened immune systems may experience more severe illness and should contact a healthcare provider promptly if symptoms develop.

Early diagnosis helps reduce complications and assists public health investigators in tracking outbreaks.

Public Health Officials Continue Monitoring

Health officials expect additional cases may be identified as laboratory testing continues and more patients seek medical care.

Because symptoms can take up to two weeks to appear after exposure, reported case numbers may continue changing over the coming weeks.

The CDC advises anyone diagnosed with cyclosporiasis to cooperate with local health departments, as information about recent meals and food purchases can help investigators identify contaminated products and prevent additional illnesses.

Consumers are encouraged to remain aware but not alarmed. Practicing proper food hygiene and seeking medical advice when symptoms appear remain the most effective ways to protect individual health while investigators work to determine the source of the outbreak.

Disclaimer

This article is intended for informational and educational purposes only and should not be considered medical advice. If you experience persistent diarrhea, dehydration, or other concerning symptoms, consult a qualified healthcare professional. Public health guidance may change as the investigation continues.

Sources

• Centers for Disease Control and Prevention (CDC)
• U.S. Food and Drug Administration (FDA)
• Michigan Department of Health and Human Services
• New York State Department of Health
• Reporting by The Guardian (rephrased and independently summarized)