By: Robert W. Frenck, Jr. MD, FAAP
If your child has been dealing with watery diarrhea that won't seem to go away, especially during the summer months or after travel, they may have a parasitic infection called cyclosporiasis.
Cyclosporiasis most often spreads through contaminated water or food, especially fresh produce. Even without treatment, the infection usually goes away on its own in people who are otherwise healthy. But it can take weeks.
Here are answers to common questions parents have about cyclosporiasis, including what to watch for and when to seek care for your child.
States report cyclosporiasis outbreaks
Public health officials are investigating a rise in cyclosporiasis cases across multiple U.S. states, with reported outbreaks in
Michigan,
Ohio and others. If your child develops prolonged watery diarrhea, contact your pediatrician.
What is cyclosporiasis?
Cyclosporiasis is an infection of the intestines caused by the parasite Cyclospora cayetanensis. Infection occurs when a person consumes food or water contaminated with feces containing Cyclospora. Fresh produce, including herbs, berries, lettuce and other vegetables, has been linked to outbreaks of infection.
Cyclospora eggs need to mature in the environment for days to weeks before they can infect someone. This is why the infection is not likely to spread directly from one person to another. When we ingest mature Cyclospora eggs, they go to the small intestine. There, the parasites come out of the egg and infect cells in the small intestine and cause disease.
Some of these parasites form new eggs (called oocysts) that are released in the stool (poop), and this cycle is repeated.
What are the symptoms of cyclosporiasis in children?
The most common symptom is watery diarrhea. The diarrhea can be severe and may come and go over time. Other symptoms may include:
Some children develop symptoms that improve and then return days or weeks later. Without treatment, symptoms may last for several weeks or even months.
Not everyone infected with Cyclospora develops symptoms. But they can still pass the parasite's eggs in their stool, which can contribute to a continued outbreak.
How do children get cyclosporiasis?
Children become infected by eating or drinking something contaminated with the parasite.
Common sources of Cyclospora include:
Fresh fruits and vegetables
Herbs such as basil or cilantro
Contaminated drinking water
Food prepared with contaminated water
Most outbreaks in North America have been linked to fresh imported produce. Children may also become infected while traveling to countries where cyclosporiasis is more common.
Can cyclosporiasis spread from person to person?
No. The parasite is passed in stool, but must remain in the environment for about 1 to 2 weeks before it can cause infection in another person.
While someone with Cyclospora is not directly contagious to others, eggs that are shed in the stool can later infect other people through contaminated food or water.
When do symptoms of cyclosporiasis start?
Symptoms typically begin about 1 week after exposure, although they can start as soon as 2 days or as long as 2 weeks or more after infection.
Because symptoms may not appear right away, it can be difficult to identify the food or water source that caused the illness.
How are symptoms different from other stomach bugs?
Most intestinal infections make children feel miserable for a few days and then gradually get better. Cyclosporiasis is different because children often have watery diarrhea, bloating and fatigue that can linger for weeks. Some seem to recover, only to have symptoms come back again.
That unusually long or relapsing course of symptoms is one of the biggest clues that cyclosporiasis may be the cause.
How is cyclosporiasis diagnosed?
Your child's doctor may suspect cyclosporiasis based on symptoms, recent travel and possible exposure to contaminated food or water.
Diagnosis usually requires testing a stool sample for the parasite. Special laboratory tests may be needed because
Cyclospora can be difficult to detect. In some cases, more than one stool sample is needed to confirm the diagnosis. Many laboratories now use molecular testing panels that can identify Cyclospora along with other causes of infectious diarrhea.
How is cyclosporiasis treated?
The recommended treatment for cyclosporiasis is an antibiotic medication called trimethoprim-sulfamethoxazole (TMP-SMX).
Treatment usually lasts 7 to 10 days, although some children with weakened immune systems may need longer treatment.
Children who cannot take sulfa medications should discuss alternative treatment options with their doctor. There are fewer effective alternatives, but other medications may sometimes be considered.
Your child should also drink plenty of fluids to help prevent dehydration from diarrhea.
When should I call the pediatrician?
Contact your child's doctor if they have:
Diarrhea lasting more than a few days
Severe or persistent watery diarrhea
Signs of dehydration
Unexplained weight loss
Blood in the stool
Persistent vomiting
Fever with diarrhea
Symptoms that improve and then return
Seek urgent medical care if your child has severe
dehydration, is difficult to wake or cannot keep fluids down.
Are some children at higher risk for complications?
Most healthy children recover fully. However, cyclosporiasis can be more serious in children with underlying medical conditions or weakened immune systems, including those who:
Have cancer
Received an organ transplant
Take medicines that suppress the immune system
Have certain immune disorders
These children may have more severe or prolonged illness and may need closer medical supervision.
How can families prevent cyclosporiasis?
There is no vaccine to prevent cyclosporiasis, but there are steps you can take to help prevent infection.
To lower your family's risk:
Wash hands with soap and water before preparing or eating food.
Rinse fresh fruits and vegetables before eating them.
Use safe drinking water, especially when traveling.
Avoid food or water that may be contaminated.
- Follow food safety recommendations when preparing produce.
Even careful washing of produce may not completely remove Cyclospora, but it can help reduce risk.
Remember
Cyclosporiasis can cause prolonged watery diarrhea, stomach cramps, fatigue and weight loss in children. Most infections are linked to contaminated food or water, especially fresh produce.
Because symptoms can last for weeks or come and go over time, it is important to contact your pediatrician if diarrhea does not improve. Prompt diagnosis and treatment can help your child recover more quickly.
More information
Image: Cyclospora cayetanensis parasite oocysts (eggs) in a stool sample. Photomicrograph provided by CDC/ DPDx.
About Dr. Frenck
Robert W. Frenck Jr., MD, FAAP, is board-certified in pediatrics and pediatric infectious diseases and chair of the American Academy of Pediatrics Section on Infectious Diseases. He practices at Cincinnati Children's Hospital Medical Center and is a Professor of Pediatrics at the University of Cincinnati.