What are the other Names for this Condition? (Also known as/Synonyms)

• Cyclospora Enteritis
• Cyclospora Infection

What is Cyclosporiasis? (Definition/Background Information)

• Cyclosporiasis is an infection of the small intestine caused by a protozoan parasite that is transmitted fecal-orally through contaminated food and water. The infection is most common in resource-limited tropical and subtropical countries with poor sanitation conditions
• Cyclosporiasis is caused by a tiny parasite called Cyclospora cayetanensis, which can be seen only with a microscope. Infection occurs on ingesting food or water contaminated with the infective form of the parasite i.e., the sporulated oocysts, which are formed by the maturation of oocysts shed in the feces of infected humans
• The infected individuals pass oocysts in their feces. These freshly passed oocysts are not infective and take 1-2 weeks to mature to become infective. Therefore, direct person-to-person transmission and transmission via freshly contaminated food or water do not occur
• Cyclosporiasis is characterized by watery diarrhea. Abdominal pain, nausea, weakness, and weight loss are some other symptoms associated with the condition. The illness is usually self-limited in individuals with healthy immune systems
• However, individuals with weak immunity, such as those who are HIV positive and those who have had organ transplants and are on immunosuppressants or steroids, are at increased risk for developing prolonged severe diarrhea and complications from Cyclosporiasis
• Stool samples over several days are analyzed to detect the presence of the parasite to arrive at an accurate diagnosis. The various diagnostic tests for Cyclosporiasis include microscopic observation of oocysts using special staining methods, antigen detection, and polymerase chain reaction test
• Cyclosporiasis is usually treated with antibiotics and plenty of fluids to maintain hydration. Severe cases of infection may require hospitalization. In most individuals with healthy immunity, the prognosis of the condition is excellent
• The best method of preventing Cyclosporiasis is to avoid consuming contaminated food and water. Thorough hand washing, thoroughly washing raw vegetables and fruits, using clean water for drinking and cooking, cooking to proper temperatures, etc. can reduce the chances of contracting the infection

Who gets Cyclosporiasis? (Age and Sex Distribution)

• Cyclosporiasis is most common in economically poor tropical and subtropical countries of the world, where sanitation conditions are also poor
• The infection affects individuals of all age groups and both male and female genders

In the United States, it occurs as foodborne outbreaks, which have been linked to various types of imported fresh produce, such as raspberries, basil, snow peas, mesclun lettuce, and cilantro, and infection in people traveling to endemic countries.

What are the Risk Factors for Cyclosporiasis? (Predisposing Factors)

The following are some of the risk factors for Cyclosporiasis:

• Individuals living in or traveling to the endemic areas
• Drinking from contaminated water supplies, e.g., streams, lakes, and ponds
• Consumption of imported fresh produce, including fresh cilantro, pre-packaged salad mix, raspberries, basil, snow peas, and mesclun lettuce
• Eating raw fruits and vegetables without washing them properly
• Individuals with weak immune systems are at risk of severe and prolonged disease. These include:
  • Individuals on medicines to suppress their immune systems
  • HIV infection or AIDS-affected individuals
  • Those who have undergone organ transplants
  • Young children and elderly adults

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one's chance of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Cyclosporiasis? (Etiology)

Cyclosporiasis is an infection of the small intestine caused by a parasite called Cyclospora cayetanensis, which is a single-celled protozoan parasite that is visible only under a microscope.

• People become infected by ingesting food or water contaminated with feces. The contaminated food and water contain sporulated cysts (infective form) of Cyclospora cayetanensis, which are the infective form of the parasite
• The ingested sporulated oocysts release sporozoites which invade the lining of the small intestine. They develop, multiply, and produce oocysts which are shed in the feces of infected individuals
• These oocysts contaminate the soil, its produce, and water. The oocysts then mature under favorable conditions and become infective and cause infection when ingested

The freshly passed oocysts are not infective and take 1-2 weeks to mature and sporulate (develop sporozoites inside) to become infective. Therefore, direct human-to-human transmission and transmission via freshly contaminated food or water does not take place.

What are the Signs and Symptoms of Cyclosporiasis?

Cyclosporiasis most commonly presents with watery, non-bloody diarrhea 2-14 days after ingestion of the oocysts of Cyclospora cayetanensis.

The following are the other signs and symptoms that may be noted:

• Loss of appetite
• Weight loss
• Stomach cramps/pain
• Bloating and gas
• Nausea, vomiting
• Fatigue (extreme tiredness)
• Dehydration
• Slight fever

If Cyclosporiasis is not treated adequately, the symptoms may persist for more than a month. Symptoms, such as diarrhea, may get better and reappear after a few days.

How is Cyclosporiasis Diagnosed?

To make a diagnosis, it is important to have a high index of suspicion and collect information about the signs and symptoms, conduct a physical examination, and evaluate history of travel to the endemic regions.

The healthcare provider may need to make a specific request to test for Cyclospora. Several stool samples over several days may need to be tested to confirm Cyclosporiasis.

Stool specimens are tested using different techniques such as:

• Microscopy using modified acid-fast staining
• Direct fluorescent antibody (DFA) test
• Enzyme immunoassays to detect the parasite-specific antigens
• Molecular methods, such as polymerase chain reaction (PCR), to detect the genetic material of the parasite

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Cyclosporiasis?

The complications that may arise from Cyclosporiasis could include:

• Severe dehydration needing hospitalization to receive fluids through the veins
• Severe malnutrition
• Biliary tract disease

Individuals who are at higher risk of developing complications include:

• Those with other chronic illnesses
• HIV infected and AIDS positive individuals
• Individuals taking steroids and immunosuppressive medications (e.g., transplant recipients)
• Infants and young children
• Older adults

How is Cyclosporiasis Treated?

Cyclosporiasis is typically treated with antibiotics. The affected individuals are advised to take plenty of fluids to prevent dehydration.

Additionally, the following treatment methods may be considered:

• Fluid and electrolyte replacement therapy - either oral or intravenous replacement may be done to treat dehydration
• Anti-motility drugs may be used to slow the movement of the intestine and increase fluid and nutrient absorption, This can help reduce the risk of dehydration. However, these medications should be taken only after consulting a healthcare provider

How can Cyclosporiasis be Prevented?

There is no vaccine currently available for Cyclosporiasis. Avoiding consumption of contaminated food and water is the best method to prevent infection. The following measures may be helpful in reducing the risk of contracting Cyclosporiasis:

• Washing hands with soap and water after handling fruits and vegetables and before eating or cooking
• Thoroughly washing and peeling raw vegetables and fruits before consuming them. Fruits and vegetables labelled ‘prewashed’ do not need to be washed again at home
• Avoid eating raw fruits and vegetables, especially imported ones; cooking the fruits and vegetables prior to consuming them
• Washing utensils and food preparation surfaces with soap and hot water after preparing food
• Refrigerating cut, peeled, and cooked fruits and vegetables as soon as possible (generally within 2 hours)
• Avoiding the use of untreated water for drinking purposes. Using bottled water for drinking and cooking (if purified water is not available) or purifying drinking water via boiling and filtration

Note: A routine chemical disinfection of water is unlikely to kill Cyclospora cayetanensis since it is highly resistant to killing by chlorine.

What is the Prognosis of Cyclosporiasis? (Outcomes/Resolutions)

• In healthy individuals, Cyclosporiasis resolves by itself after a few bouts of diarrhea. If left untreated, the symptoms can even persist for more than a month
• Individuals with weak immunity (due to various reasons), or those who have HIV infection, are at an increased risk of developing severe prolonged diarrhea or biliary disease that could potentially lead to severe complications

Additional and Relevant Useful Information for Cyclosporiasis:

The following DoveMed website link is a useful resource for additional information:

https://www.dovemed.com/diseases-conditions/infection-center/