Disease

Four Cyclospora oocysts from fresh stool stained using a modified acid-fast stain. The oocysts are variably acid fast (that is, they range from unstained to light pink to deep red). Image: CDC (DPDx).

Symptoms of cyclosporiasis begin an average of 7 days (range, 2 days to ≥2 weeks) after ingestion of sporulated oocysts (the infective form of the parasite).

Symptoms of cyclosporiasis may include:

• Watery diarrhea (most common)
• Loss of appetite
• Weight loss
• Cramping
• Bloating
• Increased gas
• Nausea
• Fatigue

Other symptoms that may occur but are less common include:

• Vomiting
• Low-grade fever

If a person ill with cyclosporiasis is not treated, symptoms can persist for several weeks to a month or more. Some symptoms, such as diarrhea, can return; and some symptoms, such as muscle aches and fatigue, may continue after the gastrointestinal symptoms have gone away. The infection usually is not life threatening. Some infected persons do not have any symptoms, particularly persons from areas where cyclosporiasis is endemic.