By Sukrut Dwivedi, DO, FACP, FIDSA
Table of Contents
A waterborne parasite that’s hard to detect and harder to treat is causing illness across multiple states — here’s what New Jersey residents need to know to protect themselves and their families.
The Centers for Disease Control and Prevention recently issued a Health Alert Network notice documenting a multi-state outbreak of cyclosporiasis, an intestinal infection caused by the Cyclospora cayetanensis parasite. While outbreaks typically occur during late spring and summer months, the 2026 case count has prompted heightened surveillance and public awareness efforts. For New Jersey residents, understanding transmission pathways and early warning signs can prevent weeks of debilitating illness.
Understanding the Current Cyclosporiasis Outbreak
What Is Cyclospora?
Cyclospora cayetanensis is a microscopic parasite that invades the small intestine after a person consumes food or water contaminated with infected fecal matter. Unlike many gastrointestinal pathogens, clinical overview of cyclosporiasis cannot spread directly from person to person. The parasite must mature outside the human body for days to weeks before it becomes infectious, which is why all documented cases trace back to contaminated produce or untreated water rather than household transmission.
The parasite is endemic to tropical and subtropical regions, particularly parts of Latin America, South Asia, and the Middle East. In the United States, most cases occur between May and August, coinciding with peak seasons for fresh berry and leafy green imports. The 2026 outbreak follows this seasonal pattern, but case counts have exceeded typical baseline levels across multiple states, triggering the CDC alert.
How Outbreaks Typically Occur
Historical outbreak investigations have repeatedly linked cyclosporiasis clusters to specific fresh produce items: raspberries, basil, cilantro, mesclun lettuce, and snap peas have all served as vehicles in past years. Contamination usually occurs in the country of origin — either through irrigation with untreated water or through field workers lacking access to sanitary facilities. Because the parasite’s oocysts (the infectious egg-like stage) are extremely small and adhere tightly to produce surfaces, standard rinsing often fails to remove them completely.
Restaurant and catered-event settings amplify outbreak spread. A single contaminated batch of herbs mixed into salsa or a garnish tray can expose dozens of diners simultaneously. The CDC Health Alert Network notice specifically urges clinicians and food-safety officials to coordinate case reporting, trace common food sources, and identify importers before additional shipments reach consumers.
Recognizing Cyclosporiasis Symptoms
One of cyclosporiasis’s most frustrating characteristics is its delayed onset. After consuming contaminated food or water, most people experience no symptoms for approximately seven days. This incubation period makes it difficult for patients to recall the specific meal or ingredient that caused their illness.
When symptoms finally begin, the hallmark is watery diarrhea — often explosive and occurring multiple times per day. Unlike viral gastroenteritis, which typically resolves within 48 to 72 hours, cyclosporiasis-related diarrhea persists for weeks or even months if left untreated. Patients commonly report:
- Loss of appetite and significant weight loss: The combination of nausea and malabsorption can lead to rapid, unintentional weight reduction.
- Abdominal cramping: Cramping often worsens after eating and may be severe enough to interfere with daily activities.
- Bloating and gas: The parasite disrupts normal digestion, causing uncomfortable distention.
- Fatigue and low-grade fever: Persistent dehydration and nutrient depletion leave patients exhausted; fever is usually below 101°F.
- Nausea with or without vomiting: Not everyone vomits, but nausea is nearly universal.
Because these symptoms overlap with bacterial gastroenteritis, viral infections, inflammatory bowel disease, and even food allergies, cyclosporiasis is frequently misdiagnosed during initial clinic visits. Standard stool cultures for common bacterial pathogens (Salmonella, Campylobacter, Shigella) return negative, leaving both patient and clinician puzzled.
Patients with weakened immune systems — including those living with HIV, undergoing chemotherapy, or taking immunosuppressive medications for organ transplants or autoimmune conditions — face heightened risk of severe, prolonged cyclosporiasis. In these individuals, the infection can spread beyond the intestines and cause life-threatening complications if not promptly treated.
Diagnosis and Treatment for Cyclospora Infection
Diagnosing cyclosporiasis requires a high index of suspicion and specialized laboratory testing. The parasite’s oocysts are too small to detect reliably on routine ova-and-parasite stool examinations. Laboratories must use modified acid-fast staining techniques or molecular PCR assays specifically designed to identify Cyclospora. Physicians who suspect the infection based on symptom duration, recent travel history, or known outbreak exposure must explicitly request Cyclospora testing when ordering stool studies.
Once confirmed, the first-line treatment is trimethoprim-sulfamethoxazole (TMP-SMX), commonly known by the brand name Bactrim or Septra. The standard regimen is one double-strength tablet twice daily for seven to ten days. Most patients notice symptom improvement within two to three days of starting therapy, but completing the full course is essential to eradicate the parasite and prevent relapse.
For patients allergic to sulfa drugs, treatment options are limited and less effective. Ciprofloxacin and nitazoxanide have been tried in small case series, but neither reliably clears the infection. Patients with documented sulfa allergies who contract cyclosporiasis require close infectious disease consultation to balance treatment efficacy against allergy risk.
Without treatment, the natural course of cyclosporiasis is unpredictable. Some patients experience spontaneous resolution after several weeks, but many endure a relapsing pattern — diarrhea improves for a few days, then returns with equal severity. This cycle can continue for two months or longer, leading to severe malnutrition and dehydration.
Preventing Cyclosporiasis at Home and While Traveling
Because no vaccine exists for cyclosporiasis, prevention relies entirely on rigorous washing and handling guidance for fresh produce. Even diligent home cooks can reduce but not eliminate risk when contaminated produce enters the supply chain.
Washing produce thoroughly is the first defense, but standard rinsing under cold tap water is insufficient. Scrub firm-skinned fruits and vegetables with a clean brush under running water. For leafy greens and herbs, separate leaves and rinse each individually. Even items labeled ‘pre-washed’ or ‘triple-washed’ should be rinsed again at home — processing facilities cannot guarantee complete parasite removal.
Understanding Cyclospora‘s resistance to common disinfectants is critical. The parasite’s oocysts survive standard chlorine and iodine water-treatment concentrations used in municipal systems and portable purification tablets. Boiling water for at least one minute (three minutes at high altitude) is the only reliable method to kill oocysts in drinking water. Travelers to endemic regions should avoid ice cubes, beverages mixed with tap water, and raw fruits or vegetables unless they can be peeled.
During known outbreak periods, additional precautions include:
- Choosing cooked vegetables over raw salads when dining out
- Avoiding buffet-style service where produce may sit at room temperature for extended periods
- Asking restaurants about the origin of fresh herbs and greens, particularly cilantro and basil
- Checking FDA and CDC websites for active outbreak alerts before purchasing implicated produce items
Travelers planning trips to Latin America, Southeast Asia, or the Middle East should schedule a pre-travel consultation with ID Care’s Travel Care team before departure. These visits provide destination-specific food and water safety guidance, review symptoms that warrant immediate medical attention abroad, and ensure travelers carry appropriate antimicrobial prescriptions for self-treatment if needed.
ID Care’s Role in Diagnosing and Managing Parasitic Infections
ID Care’s team of more than 50 board-certified infectious disease physicians brings deep expertise in travel medicine and emerging tropical infections to communities across New Jersey. With locations throughout New Jersey, the practice offers convenient access to specialized care for parasitic and other complex infectious diseases — call to find the office closest to you.
Our physicians maintain active relationships with reference laboratories capable of performing the modified acid-fast staining and molecular testing required to diagnose cyclosporiasis accurately.
Beyond acute infection management, ID Care’s travel medicine services provide pre-departure consultations for patients planning international trips. These visits include destination-specific risk assessments, preventive medication prescribing, and detailed counseling on food, water, and insect-borne illness avoidance strategies — all designed to keep travelers healthy abroad and prevent imported infections upon return.
Patient Questions
Can I get cyclosporiasis from someone who is infected?
No. Cyclospora cayetanensis requires an environmental maturation period outside the human body before it becomes infectious. The parasite is shed in stool but cannot immediately infect another person. All documented cases trace back to contaminated food or water, not person-to-person contact. Standard hygiene practices — handwashing after using the bathroom and before preparing food — remain important, but household members of an infected person face no direct transmission risk from casual contact.
How long does cyclosporiasis last without treatment?
Untreated cyclosporiasis typically causes symptoms for several weeks, but the course is highly variable. Some patients experience spontaneous improvement after three to four weeks, while others endure a relapsing pattern of diarrhea that continues for two months or longer. Weight loss, malnutrition, and dehydration become significant concerns in prolonged cases. Treatment with trimethoprim-sulfamethoxazole usually resolves symptoms within days and prevents relapse, making early diagnosis and therapy strongly preferable to waiting for spontaneous resolution.
Will washing produce with tap water remove Cyclospora?
Washing reduces but does not eliminate Cyclospora oocysts. The parasite’s oocysts are extremely small and adhere tightly to produce surfaces, especially the crevices in leafy greens and the dimpled skin of berries. Thorough scrubbing under running water is essential, but even aggressive washing cannot guarantee complete removal. Cooking produce to an internal temperature of at least 160°F kills oocysts reliably, which is why cooked vegetables carry no cyclosporiasis risk. During active outbreaks, choosing cooked over raw produce significantly reduces exposure.
Should I be tested for cyclosporiasis if I have diarrhea but no recent travel history?
Yes, if your diarrhea persists beyond three days and standard stool cultures return negative. While international travel to endemic regions increases cyclosporiasis risk, the majority of U.S. cases now occur in people with no recent travel history — they consumed contaminated produce purchased domestically. Multi-state outbreaks linked to imported berries, herbs, and salad greens have been documented nearly every year for the past two decades. If you have prolonged watery diarrhea, weight loss, and cramping, ask your physician to order Cyclospora-specific stool testing even if you have not traveled recently.
Cyclospora FAQ
1. Why are people talking about Cyclospora right now?
Cyclospora infections are increasing across the United States, with thousands of cases reported in more than 30 states. While Michigan and Ohio have experienced large outbreaks, New Jersey has seen a more modest increase in cases. This FAQ addresses common questions about Cyclospora and how to reduce the risk of infection.
2. What is Cyclospora?
Cyclospora is a microscopic parasite that infects the small intestine and causes an illness called cyclosporiasis. Most people become infected after eating fresh produce, berries, or drinking water contaminated with the parasite.
3. What are the symptoms of Cyclospora infection?
The most common symptom is prolonged, watery diarrhea. People may also experience loss of appetite, stomach cramps, bloating, nausea, fatigue, and weight loss. Symptoms can last for days to weeks and may come and go if left untreated.
4. What is the incubation period for Cyclospora infection?
Typically, it is 1 to 14 days, with an average incubation period of about 1 week after ingesting contaminated food or water.
5. How long does Cyclospora illness last?
Without treatment: Symptoms can persist for several weeks and often follow a relapsing pattern in which diarrhea improves and then returns.
With treatment: With appropriate antibiotic therapy, symptoms usually begin improving within 2–3 days, although complete recovery may take longer.
6. Are there potential complications?
Although most people recover completely, prolonged illness can lead to dehydration and electrolyte imbalance, weight loss and temporary difficulty absorbing nutrients, and post-infectious complications including reactive arthritis and, rarely, prolonged gastrointestinal symptoms such as irritable bowel syndrome..
7. How is Cyclospora diagnosed?
Cyclospora is diagnosed by testing a stool sample. Laboratories may use specialized microscopic techniques, molecular tests such as Polymerase Chain Reaction (PCR), or both to identify the infection accurately. Two common PCR platforms the Biofire and QDX can both detect cyclospora
8. Why can Cyclospora be difficult to diagnose?
Its symptoms overlap with many other causes of diarrhea, and the parasite may not be present in every stool sample. In some cases, multiple specimens collected over several days may improve detection, although PCR testing is highly sensitive.
9. Can Cyclospora be detected on a routine stool test?
Not always. Some routine stool examinations may not detect Cyclospora unless specific testing is requested or the laboratory includes Cyclospora in its testing panel.
10. When should someone be tested for Cyclospora?
People with new-onset persistent watery diarrhea, especially if symptoms have lasted more than a few days or occurred after eating fresh produce, should discuss testing with their healthcare provider. During recognized outbreaks, clinicians should maintain a high index of suspicion for Cyclospora infection. For persons living in endemic areas, testing should be considered early during the course of illness. In areas with a hot outbreak testing may not be needed in patients with compatible diarrhea illness
11. How does Cyclospora spread?
People become infected by swallowing food or water contaminated with the parasite. Unlike many common gastrointestinal viruses, Cyclospora typically does not spread directly from one person to another because the parasite must mature in the environment before becoming infectious.
12. Is Cyclospora contagious?
Direct person-to-person transmission is uncommon and is not considered the primary mode of spread. Most infections are linked to contaminated food or water rather than close contact with an infected person.
13. What foods are commonly associated with Cyclospora outbreaks?
Outbreaks have most commonly been linked to fresh produce, including leafy greens, herbs, berries, and other foods that are frequently eaten raw.
14. How is Cyclospora treated?
Cyclospora is typically treated with prescription antibiotics, most often a sulfa-containing medication. Most people improve with appropriate treatment, although recovery may take longer if diagnosis is delayed.
15. Who is most at risk for Cyclospora infection?
Anyone can become infected. However, people with weakened immune systems may be at risk for more severe, prolonged, or recurrent illness.
16. Should people with Cyclospora stay home from work or school?
People with active diarrhea should remain home from work, school, or food-handling activities until symptoms have resolved. Good hand hygiene remains important, although direct person-to-person transmission of Cyclospora is uncommon.
17. Can washing produce prevent Cyclospora infection?
Washing fruits and vegetables is always recommended and may reduce contamination from dirt and other organisms. However, washing alone cannot reliably remove Cyclospora. Because the parasite can strongly adhere to produce surfaces, preventing contamination during growing, harvesting, and processing is the most effective way to reduce risk. The consensus of the CDC, FDA, and food-safety experts is that washing should not be relied upon to eliminate Cyclospora contamination. Cooking remains the most reliable way to destroy the parasite.
18. Is bagged salad riskier than whole lettuce?
Bagged or pre-cut salad products may carry a higher risk than whole heads of lettuce because cutting damages plant tissue, making contamination more difficult to remove. In addition, produce from multiple farms is often mixed during commercial processing, allowing contamination from one source to affect a larger number of products. While outbreaks have been linked to both whole and processed produce, many large multi-state Cyclospora outbreaks have involved pre-cut salad mixes. Consumers should always follow public health advisories and consider cooking vegetables when appropriate during recognized outbreaks.
ID Care has more than 50 highly skilled infectious disease physicians, a broad medical support staff of nurse practitioners and physician assistants, and a commitment to patient-centric empathetic care. Our mission is to lead in the prevention, diagnosis and treatment of infectious diseases. Make us your source for excellent infectious disease care:
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