Cyclosporiasis Cases Rise Across the US: Symptoms, Causes, Prevention, and What You Need to Know

A sharp increase in cyclosporiasis cases across several US states has raised concerns among public health officials. Michigan is experiencing its largest recorded outbreak, while Ohio and other states have also reported significantly higher numbers of infections than usual. Although the illness is rarely life threatening, it can cause prolonged gastrointestinal symptoms that disrupt daily life and may require medical treatment.

The outbreak has prompted health authorities to investigate the source of the infections while encouraging consumers to take extra precautions when handling fresh produce. Here is everything you need to know about cyclosporiasis, including its symptoms, causes, treatment options, and practical ways to reduce your risk.

What Is Cyclosporiasis?

Cyclosporiasis is an intestinal illness caused by the microscopic parasite Cyclospora cayetanensis. People become infected after consuming food or water contaminated with the parasite. Unlike many foodborne illnesses caused by bacteria or viruses, Cyclospora infections are generally linked to fresh fruits, vegetables, and herbs that have been exposed to contaminated irrigation water or poor sanitation during production.

The parasite cannot usually spread directly from one person to another because it requires time outside the human body before it becomes infectious. This makes contaminated food and water the primary sources of infection.

Why Are Cases Increasing?

Health officials have reported a substantial increase in infections during the current summer season. Michigan has recorded nearly 1,000 suspected and confirmed cases, making it the state's largest outbreak on record. Ohio has also reported a significant rise, while additional cases have been identified across multiple US states.

Public health agencies continue to investigate the source of the outbreak. At this stage, no single food product has been officially confirmed as the cause. Previous outbreaks have often been traced to contaminated imported produce, highlighting the importance of food safety throughout the supply chain.

Common Symptoms of Cyclosporiasis

Symptoms typically begin about one week after consuming contaminated food or water, although they may appear as early as two days or as late as two weeks after exposure.

The most common symptom is watery diarrhea, which can be severe and frequent. Many patients experience episodes that improve before returning several days later.

Other common symptoms include:

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

Without treatment, symptoms may last from several days to more than a month. Some people may carry the parasite without developing noticeable symptoms.

Is Cyclosporiasis Dangerous?

For most healthy individuals, cyclosporiasis is unpleasant but not life threatening. However, prolonged diarrhea can lead to dehydration and nutritional deficiencies, especially in young children, older adults, and people with weakened immune systems.

Individuals with compromised immune systems may experience more severe illness and longer recovery times. Anyone experiencing persistent diarrhea, dehydration, or worsening symptoms should seek medical attention promptly.

How Is It Diagnosed?

Diagnosing cyclosporiasis can be challenging because its symptoms resemble many other gastrointestinal illnesses. Healthcare providers typically request stool samples for specialized laboratory testing to identify the parasite.

Since routine stool tests may not always detect Cyclospora, doctors may order specific diagnostic tests if they suspect the infection based on symptoms and recent food exposure.

Treatment Options

Although some people recover without medication, the standard treatment for cyclosporiasis is prescription antibiotics. Healthcare providers commonly prescribe trimethoprim and sulfamethoxazole, which are effective in eliminating the parasite.

Patients are also encouraged to:

• Stay well hydrated.
• Replace lost electrolytes.
• Eat easily digestible foods during recovery.
• Rest until symptoms improve.

People who cannot take the recommended antibiotic due to allergies or other medical conditions should consult their healthcare provider for alternative treatment options.

Previous Outbreaks

Cyclospora outbreaks are not new in the United States. Several notable outbreaks have occurred over the past three decades.

One of the largest occurred in 1996, when contaminated raspberries imported from Guatemala caused nearly 1,500 illnesses.

Another major outbreak occurred in 2019 and was linked to contaminated basil imported from Mexico, affecting more than 2,400 people across the United States and Canada.

In 2022, contaminated lettuce included in packaged salad kits led to hundreds of infections in Florida.

These recurring outbreaks demonstrate how fresh produce can become contaminated before reaching grocery stores.

How to Protect Yourself

While it is impossible to eliminate every food safety risk, several precautions can reduce your chances of infection.

Wash fresh fruits and vegetables thoroughly under clean running water before eating them.

Choose whole heads of lettuce instead of pre packaged salad mixes whenever possible.

Remove the outer leaves of lettuce before washing the remaining leaves.

Cook vegetables when appropriate because heat helps destroy many foodborne pathogens.

Avoid drinking untreated water from unknown sources.

Practice good hand hygiene before preparing meals and after handling fresh produce.

Keep kitchen surfaces and utensils clean to reduce cross contamination.

Although washing produce is important, experts note that Cyclospora can sometimes cling tightly to certain fruits and vegetables, making complete removal difficult.

Which Foods Have Been Linked to Cyclospora?

Past outbreaks have been associated with several fresh produce items, including:

• Basil
• Cilantro
• Spinach
• Lettuce
• Green onions
• Raspberries
• Blackberries
• Mixed salad greens

This does not mean these foods are unsafe in general. Millions of servings are consumed safely every year. However, these products have appeared more frequently in previous outbreak investigations because they are often eaten raw.

When Should You See a Doctor?

Seek medical care if you experience:

• Diarrhea lasting more than several days.
• Severe dehydration.
• Bloody stool.
• High fever.
• Persistent vomiting.
• Significant weight loss.
• Symptoms after recent travel or consumption of recalled food products.

Prompt diagnosis and treatment can shorten illness and reduce the risk of complications.

Final Thoughts

The recent increase in cyclosporiasis cases serves as an important reminder that foodborne illnesses can occur even when people eat healthy diets rich in fresh fruits and vegetables. While the current outbreak is still under investigation, maintaining good food hygiene and staying informed about public health recommendations remain the best ways to reduce your risk.

Most people recover completely, particularly when diagnosed early and treated appropriately. If you develop prolonged watery diarrhea or other concerning digestive symptoms, consult a healthcare professional for evaluation and testing.

Source

Publicly available information from the US Centers for Disease Control and Prevention (CDC).

Disclaimer

The information provided in this article is for educational and informational purposes only and should not be considered medical advice. It is not intended to diagnose, treat, cure, or prevent any disease. Always consult a qualified healthcare professional regarding any medical concerns or symptoms. Public health guidance may change as investigations continue.