Cyclospora: What You Need to Know About This Foodborne Parasite

As temperatures rise and fresh fruits, vegetables and herbs become staples of summer meals, so does the risk of a lesser-known foodborne illness: cyclosporiasis.

Unlike many foodborne infections that cause symptoms within hours, cyclosporiasis symptoms can take about a week to surface, according to Alexis Perera, M.D., medical director for Baptist Health Urgent Care.

“Symptoms usually begin about seven days after exposure but can appear from two to 14 days after,” he says. “And because symptoms may improve and then return, many people do not immediately realize they have been infected.”

While most healthy people recover with the right treatment, cyclosporiasis can last for weeks if left untreated, Dr. Perera says. It also may become more serious for older adults, young children and people with weakened immune systems.

What Is Cyclospora and How Does It Affect You?

Cyclospora cayetanensis is a microscopic parasite that infects the small intestine and causes the intestinal illness known as cyclosporiasis.

After a person consumes contaminated food or water, the parasite reaches the small intestine and enters the cells that line the intestinal wall. It then begins to multiply, causing inflammation and damage to the intestinal lining.

The small intestine is covered with millions of tiny, finger-like projections called villi. These structures increase the intestine’s surface area and help the body absorb water, 

electrolytes and nutrients from food. When cyclospora damages or flattens these villi, the intestine cannot absorb fluids and nutrients as efficiently.

This disruption can lead to frequent watery diarrhea, abdominal cramping, bloating, 

fatigue and weight loss. It can also cause dehydration and temporary difficulty absorbing nutrients, especially when the illness continues for several weeks.

“Cyclospora affects the part of the digestive system responsible for absorbing much of what the body needs from food,” says Dr. Perera. “When the intestinal lining becomes inflamed and damaged, the body loses water and electrolytes more easily, while absorbing nutrients less efficiently. This leads to weakness, dehydration and weight loss.”

How Can People Become Infected?

Unlike viruses such as norovirus, cyclospora does not typically spread directly from person to person.

Instead, the parasite is shed in the stool of an infected person. If it enters the environment and contaminates food or water, another person may become infected by consuming it. The parasite must spend time outside the body before it becomes infectious, which is why direct transmission between people is unlikely.

In the United States, outbreaks are most commonly linked to fresh produce, particularly items imported from tropical and subtropical regions.

Foods associated with previous outbreaks include:

·       Fresh berries, especially raspberries

·       Bagged salad mixes and leafy greens

·       Basil, cilantro and other fresh herbs

·       Other fresh fruits and vegetables

“Cyclospora is most often contracted through contaminated food or water rather than close contact with another person,” Dr. Perera says. “That makes it important to pay attention to food recalls and to consider recent meals and travel when symptoms develop.”

The parasite can survive for extended periods on food and in water. Although thoroughly rinsing produce under running water can reduce contamination, it does not reliably eliminate cyclospora, which is resistant to many common disinfectants.

Cases occur year-round but tend to increase during the spring and summer months.

What Symptoms Should You Watch For?

Symptoms typically begin about one week after exposure, although they can appear anywhere from a few days to two weeks later.

The most common symptom is frequent watery diarrhea. Other symptoms may include:

·       Abdominal cramping

·       Bloating and increased gas

·       Nausea

·       Occasional vomiting

·       Loss of appetite

·       Fatigue that may persist for several weeks after diarrhea improves

·       Low-grade fever

·       Weight loss

One feature that distinguishes cyclospora from many other causes of infectious diarrhea is that symptoms often improve temporarily before returning.

“Patients may think they are recovering, only to have the diarrhea and cramping come back,” Dr. Perera notes. “Without treatment, this pattern can continue for several weeks or even longer.”

Cyclosporiasis is generally not fatal in otherwise healthy people in the United States. However, untreated illness can become serious when diarrhea causes significant dehydration, electrolyte imbalances, malnutrition or worsening of an underlying medical condition.

When Should You Seek Medical Care?

Persistent or worsening diarrhea should not be ignored, particularly when it lasts more than a few days or is accompanied by weakness, dehydration or weight loss.

Contact a healthcare provider if you experience ongoing watery diarrhea, especially after eating fresh produce, traveling internationally or learning that a food you consumed may be linked to an outbreak.

Seek prompt medical attention if you develop signs of significant dehydration, including:

·       Dizziness or fainting

·       Very dark urine or reduced urination

·       Dry mouth

·       Rapid heartbeat

·       Confusion

·       Inability to keep fluids down

·       Severe weakness

Young children, older adults, pregnant women and people with weakened immune systems should be evaluated sooner because they may be more vulnerable to dehydration and other complications, Dr. Perera advises.

How Is Cyclosporiasis Diagnosed?

Cyclosporiasis is diagnosed through stool testing. However, routine stool tests may not automatically check for the parasite. Many modern gastrointestinal PCR panels include cyclospora, but not all laboratories routinely test for it.

“If cyclosporiasis is suspected, the provider may need to specifically request testing for it,” Dr. Perera says. “That is why it is helpful for patients to describe how long symptoms have lasted, whether they come and go and what foods they recently ate.”

In some cases, more than one stool sample may be needed because the parasite may not be present in every sample.

How Is Cyclosporiasis Treated?

The standard treatment for cyclosporiasis is the prescription antibiotic trimethoprim-sulfamethoxazole, commonly known by the brand names Bactrim or Septra.

The antibiotic is typically taken for seven days, although the exact duration may vary based on the patient’s health, symptoms and response to medication. Many patients begin to feel better within

48 to 72 hours of taking appropriate antibiotics. However, they should not stop their treatment, Dr. Perera cautions.

“When taking an antibiotic, it’s important to take it as prescribed by your physician and to take the full course. Discontinuing treatment just because you start feeling better is never a good idea—especially with cyclosporiasis,” he says.

Patients who are allergic to sulfa medications should tell their healthcare provider. Alternative treatment options may be considered, although there is no equally effective alternative antibiotic for cyclospora. In patients with sulfa allergy, physicians may consider desensitization or alternative approaches depending on the severity of illness.

Antidiarrheal medications should not be started without speaking with a healthcare professional, particularly if symptoms are severe or the cause of the diarrhea is not yet known, says Dr. Perera.

Caring for Yourself While You Recover

Replacing lost fluids is one of the most important parts of recovery from cyclosporiasis. Frequent diarrhea can cause the body to lose both water and essential electrolytes.

Patients should:

·       Drink water and oral rehydration solutions regularly.

·       Take small, frequent sips if nausea is present.

·       Avoid alcohol and excessive caffeine, which may worsen dehydration.

·       Eat mild, easy-to-digest foods as tolerated.

·       Avoid foods that worsen cramping or diarrhea.

·       Rest and monitor symptoms closely.

“Hydration is especially important,” Dr. Perera says. “If a patient cannot keep up with fluid losses at home, urgent care or emergency evaluation may be necessary.”

How Can You Protect Yourself?

Because cyclospora is resistant to many common sanitizing methods, rinsing produce or using commercial vegetable washes may not completely remove the parasite. No single step can eliminate all risk, but the following precautions may help reduce it:

·       Wash fresh fruits and vegetables thoroughly under running water before eating, cutting or cooking them.

·       Scrub firm produce with a clean produce brush.

·       Remove damaged or bruised areas.

·       Dry produce with a clean cloth or paper towel.

·       Wash hands with soap and water before preparing or eating food.

·       Keep raw produce separate from raw meat, poultry and seafood.

·       Refrigerate cut, peeled or cooked produce promptly.

·       Follow food recalls and outbreak alerts from public health agencies.

·       When traveling internationally, drink bottled or boiled water and avoid raw produce that you did not peel yourself.

·       Avoid untreated water, including ice made from unsafe water.

People who are immunocompromised may want to speak with their healthcare provider about additional precautions during an active cyclosporiasis outbreak.

What South Florida Residents Should Know

Fresh fruits and vegetables remain an important part of a healthy diet, and people should not avoid produce altogether. Instead, they should follow safe food-handling practices, stay aware of outbreak notices and recognize the symptoms of infection.

“If you develop persistent watery diarrhea, particularly during the summer or after eating fresh produce, do not assume it is simply a stomach bug,” Dr. Perera says. “Cyclospora is treatable, but the diagnosis is often missed unless it's specifically considered. The right testing can identify the cause, and early treatment can help patients recover and avoid complications from dehydration.”

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