Cyclospora is a type of parasite. Its full name is Cyclospora cayetanensis. A parasite is a type of organism that needs to live off another organism or host in order to survive.

Cyclospora are tiny one-cell parasites. They can only be seen with a microscope. Cyclospora can be carried by humans and animals.

This parasite causes a stomach or digestive illness called cyclosporiasis. You may have had a cyclospora infection before without knowing it by name — this parasite is a cause of traveler’s diarrhea.

Cyclospora infections are more common in warm and tropical climates. However, you can get this infection anywhere in the world.

Cyclospora give off spores inside your body. The spores may infect and irritate the lining of the intestine. This can cause digestive symptoms. However, some people with cyclosporiasis have mild or even no symptoms.

You can get symptoms anytime from two days to two weeks after being infected. The main warning sign is severe diarrhea. You may also have:

  • loose or watery bowel movements
  • stomach cramping or pain
  • bloating and gassiness
  • nausea
  • vomiting
  • fatigue
  • fever
  • loss of appetite
  • weight loss

Without treatment, cyclosporiasis symptoms can last for weeks to months or even longer. You may recover and then have diarrhea and other symptoms again. Some symptoms like fatigue can last for months.

Tell your doctor if you think you or anyone close to you may have a cyclospora infection. Get urgent medical attention if you have diarrhea for longer than two days, or if you:

  • are dehydrated (excessive thirst, dry mouth, little or no urine)
  • have severe weakness or dizziness
  • have severe stomach pain
  • have a fever higher than 102ºF (38.9ºC)
  • have bloody or black bowel movements

Cyclosporiasis can be difficult to diagnose. In general, doctors use a bowel movement or stool sample. Then a special lab test with a high-powered microscope is used to find this infection.

However, even if you have symptoms, there may not be enough cyclospora in your bowel movements to be noticed. Your doctor might first give you a diagnosis based on your symptoms and your medical history.

Tell your doctor if you have traveled anywhere in the last few weeks or months. You may need to give more than one stool sample on different days. This may help confirm that you have a cyclospora infection.

Antibiotics are used to treat cyclosporiasis. Your doctor may prescribe a combination of antibiotics called trimethoprim-sulfamethoxazole (TMP-SMX). This drug is also known as co-trimoxazole; a brand name is Bactrim. You may need to take it three times a week for up to one month.

Medication is needed for a serious cyclospora infection. Sometimes, cyclosporiasis can lead to long-term symptoms. This parasite can also damage the lining of the intestines if it’s not treated.

Talk to your doctor before using any home remedies. Don’t use over-the-counter anti-diarrhea medications. These can make cyclospora and other parasite infections worse.

Your doctor may also recommend electrolyte drinks to help replace water and salts lost though diarrhea. You can also soothe an upset stomach and pain with:

People and animals with a cyclospora infection give off immature cyclospora in their bowel movements. At this stage, cyclospora isn’t infectious. It takes up to 15 days for this parasite to sporulate or become mature. This means it grows enough to be infectious.

Person-to-person infections of cyclospora are very rare. Cyclospora need the right conditions to become infectious. This includes a warm temperature of about 72º to 80ºF (22.2º to 26.7ºC) However, it may seem to be contagious if both you and someone close to you get sick. Generally, though, this happens because you were both exposed to the same source.

Cyclospora from sewage and animal waste can contaminate drinking water. It may also get into water that is used for growing food. Farm animals like cows can catch this parasite. Other animals that cyclospora has been found in include:

  • chickens
  • ducks
  • shellfish
  • dogs
  • mice
  • guinea pigs
  • monkeys

Cyclospora are typically carried by infected food or water. For example, in 2013 several cases of cyclosporiasis in Texas came from contaminated fresh cilantro. Other cases include infections from fresh raspberries and basil.

Risk factors

The effects of cyclosporiasis can be worse in young children and older adults. This is because their immune systems may be too weak to fight the illness.

This infection can also cause complications in people with serious health conditions. This includes people with HIV infections, cancers, and heart disease.

Be careful what you eat and drink, especially when you’re traveling to warmer climates. Check your local news and the Centers for Disease Control and Prevention (CDC) website for food safety alerts. Avoid foods that may be contaminated.

Washing food carefully isn’t enough to stop cyclosporiasis. This parasite can stick to foods very well. Food disinfectants are also not useful to prevent an infection. Food needs to be cooked thoroughly.

Additionally, avoid drinking water that may not be sanitary or comes from an area close to farm animals. For example, water from irrigation canals and, in some areas, well water may not be safe to drink.

You may not be able to avoid getting cyclosporiasis. You can get this infection anywhere in the world. It’s not only found in tropical areas or developing nations.

For example, in the past, cyclospora infections have been linked to a water storage container in Chicago and in food grown in the United States and Canada.

If you have a cyclospora infection, let your doctor know of any symptoms. Complete all medications exactly as prescribed, even if you feel better. See your doctor for any follow-up appointments and tests.

After treatment, your doctor may recommend another stool sample to make sure you no longer have cyclosporiasis. Talk to your doctor or nutritionist about the best diet plan for your digestive health.

It’s difficult to catch a cyclospora infection from a family member or someone else with this illness. However, it’s still important to practice good hygiene. Wash your hands carefully with soap after using the toilet and keep fingernails trimmed and clean.