🚨 Cyclospora Outbreak Alert: What Cancer Patients Need to Know
As someone who has undergone cancer treatment, I clearly remember the dietary restrictions I faced. I also remember how difficult it was to enjoy food when treatment changed my sense of taste. Even finding one good meal sometimes felt impossible. I know many of you can relate.
Now comes a major public health headline about a sharp increase in illnesses caused by Cyclospora, a parasite known for causing frequent—and sometimes explosive—diarrhea. Cases acquired within the United States have been reported across many states, and health officials are also investigating a specific multistate outbreak.
While the headlines may sound alarming or even a little uncomfortable to discuss, we need to have a serious conversation about this. For our community—especially people currently undergoing chemotherapy, receiving certain immunotherapies, or living with a weakened immune system—this may not be just a stomach bug you can “wait out.”
The culprit is a microscopic parasite called Cyclospora cayetanensis. Because some cancer treatments weaken the immune system and increase the potential consequences of infection and dehydration, patients may need to take additional precautions.
What Is Cyclospora and How Does It Spread?
Cyclospora cayetanensis is a single-celled parasite that infects the small intestine, causing an illness called cyclosporiasis.
Unlike a typical viral stomach illness, Cyclospora can be difficult to eliminate from contaminated produce. People generally become infected by consuming food or water contaminated with the parasite. In the United States, previous outbreaks have been linked to different types of fresh produce.
The Symptoms
Cyclospora can cause frequent, watery and sometimes explosive diarrhea. Other symptoms may include:
Severe stomach cramps
Bloating and increased gas
Loss of appetite
Nausea
Fatigue
Weight loss
Low-grade fever
Symptoms can temporarily improve and then return if the infection is not treated.
The Concern for Cancer Patients
The main concern is that patients undergoing cancer treatment are often left vulnerable to opportunistic infections. So while while many otherwise healthy people eventually recover, people with weakened immune systems may experience more severe or prolonged illness.
Persistent diarrhea can lead to dehydration, electrolyte imbalances, weakness and weight loss. It may also complicate or interrupt cancer treatment.
Person-to-Person Spread Is Unlikely
Cyclospora is not usually transmitted directly from one person to another. After leaving the body, the parasite generally needs one to two weeks in the environment to mature and become infectious. Most infections are therefore associated with contaminated food or water.
Three Important Steps for Cancer Patients and Caregivers
1. Ask About the Right Test
If you develop sudden or persistent watery diarrhea, do not automatically assume it is a side effect of your cancer treatment. Contact your oncology team promptly.
Ask About Specific Cyclospora Testing
Testing for Cyclospora may not be included in every routine stool examination. Your healthcare provider may need to request a gastrointestinal PCR panel that includes Cyclospora or order a specific Cyclospora test.
Because the parasite may be shed intermittently and in small amounts, one negative sample may not completely rule it out. Some patients may need to provide several stool samples collected on different days.
Make Sure You Receive the Appropriate Treatment
The preferred treatment for cyclosporiasis is the prescription antibiotic trimethoprim-sulfamethoxazole, commonly known as TMP-SMX, Bactrim or Septra. A seven- to 10-day course is commonly used, although the treatment plan may differ depending on the patient’s condition and medical history.
There is no universally effective alternative for people who cannot take TMP-SMX. If you have a sulfa allergy, kidney problems, medication interactions or another medical concern, make sure your oncology team and the prescribing clinician know before treatment begins.
Do not start, stop or substitute an antibiotic on your own.
2. Change How You Buy and Prepare Produce
Cyclospora can be resistant to chlorine and other commonly used chemical treatments. Washing fresh produce is still important, but it may not completely eliminate the parasite from contaminated food.
As for me? I am sticking with more foods I can peel for the time being. It is a small personal choice that makes me feel a little more comfortable while health officials continue investigating the source of these illnesses.
Food-safety precautions include:
Wash your hands with soap and water before and after handling produce.
Rinse fruits and vegetables thoroughly under running water before cutting, cooking or eating them.
Scrub firm produce, such as cucumbers and melons, with a clean produce brush.
Remove damaged or bruised areas before eating.
Keep washed produce separate from raw meat, poultry and seafood.
Refrigerate cut, peeled or cooked produce promptly.
Cook produce when practical.
If your immune system is severely compromised, ask your oncologist or oncology dietitian whether you should temporarily avoid certain raw or ready-to-eat foods. The right precautions may depend on your treatment, blood counts and overall health.
3. Pay Close Attention to Hydration
Frequent diarrhea can lead to dehydration quickly, particularly when your body is already managing cancer and treatment.
Replace Fluids and Electrolytes
Drink water and other fluids as tolerated. Oral rehydration solutions may be helpful because they replace both fluid and electrolytes. Clear broths may also be useful.
Ask your medical team how much fluid you should drink, especially if you have heart disease, kidney disease, swelling or another condition that requires fluid restrictions.
Ask Before Taking Over-the-Counter Medication
Check with your oncology team before taking an anti-diarrheal medicine such as loperamide, commonly known as Imodium. Your clinicians may want to test for an infection before recommending medication that slows the movement of your intestines.
Knowledge Is Your Best Defense
đźš© When Should You Call Your Oncology Team?
Contact your oncology team the same day if you experience:
Persistent or frequent watery diarrhea
Dizziness, weakness, dry mouth or dark urine
Fever
Blood in your stool
Severe abdominal pain
Difficulty keeping fluids down
Several episodes of diarrhea while receiving active cancer treatment
Symptoms that improve and then return
Seek urgent medical attention if you become confused, faint, experience extreme weakness, cannot keep fluids down or develop other signs of severe dehydration.
Being a self-advocate does not mean diagnosing yourself. It means recognizing when something may not be “just another treatment side effect” and knowing when to contact your oncology team. Prompt testing and treatment may help prevent dehydration, hospitalization and avoidable complications.
I know it can already be challenging to shop, prepare food and create a meal—especially when you are not feeling your best. But awareness, careful food handling and early communication with your healthcare team can help you and your family reduce your risk.
Knowledge is one of the most powerful tools we have as patients. Stay informed, stay hydrated and never hesitate to call your oncology team when something does not feel right.
That is what self-advocacy looks like.
Hugs,
Karen
*This article is intended for educational purposes and is not a substitute for individualized medical advice. Contact your oncology team for recommendations based on your diagnosis, treatment and immune status.
References
Centers for Disease Control and Prevention. “Domestically Acquired Cyclosporiasis Cases in Multiple U.S. States.”
Patient Power “Are Cancer Survivors Immunocompromised”
Centers for Disease Control and Prevention. “About Cyclosporiasis.”
Centers for Disease Control and Prevention. “Clinical Overview of Cyclosporiasis.”
Centers for Disease Control and Prevention. “Clinical Care of Cyclosporiasis.”
U.S. Food and Drug Administration. “Cyclospora.”
American Cancer Society Food Safety During Cancer Treatment
