A Great Overview of a Nasty Bug
Cyclospora
- Cyclospora [SIGH-clo-SPOR-uh] infection is a newly emerging parasitic illness that can cause severe diarrhea.
- People most likely get cyclospora infection by eating food or drinking water that was contaminated with stool from an infected person.
- Cyclospora infection is treatable with antibiotics.
- Cyclospora infection can probably be prevented by avoiding food or water that might be contaminated with stool.
What is cyclospora infection?
Cyclospora infection is a rare infection of the intestines that can cause severe diarrhea.
What is the infectious agent that causes cyclospora infection?
Cyclospora infection is caused by Cyclospora cayetanensis, a microscopic one-celled parasite.
How do people get cyclospora infection?
Cyclospora is different from many other organisms because it is not infectious when it is passed in the stool of an infected person. Cyclospora needs days or weeks after being passed in a bowel movement to become infectious. Therefore, it is unlikely that the parasite is passed directly from one person to another. People most likely get Cyclospora infection by ingesting food or water that was contaminated with stool from an infected person. It is unknown if animals can be infected and pass infection to people.
In 1996, a large outbreak of cyclospora infection in the United States and Canada was caused by imported raspberries. It is not clear how the fruit became contaminated, but it might have happened when fruit touched the ground or when contaminated water was sprayed over fruit fields by sprinkling systems.
What are the signs and symptoms of cyclospora infection?
Cyclospora infects the small intestine and usually causes watery diarrhea, with frequent, sometimes explosive, bowel movements. Other symptoms can include loss of appetite, loss of weight, bloating, increased gas, stomach cramps, nausea, vomiting, muscle aches, low-grade fever, and tiredness. Some people who are infected with cyclospora have no symptoms.
How soon after exposure do symptoms appear?
The time between becoming infected and developing symptoms is unusually long for a disease spread by food -- about 1 week. If not treated, the illness can last for a few days to a month or longer. If untreated, it can also return one or more times.
How is cyclospora infection diagnosed?
Identification of this parasite in stool requires special laboratory tests that are not routinely done. A health-care provider must specifically request testing for Cyclospora. Because Cyclospora can be difficult to diagnose, more than one stool sample might be needed.
Who is at risk for infection?
Anyone can get Cyclospora infection.
What complications can result from cyclospora infection?
Without treatment, the infection can cause weeks of severe tiredness, loss of appetite, dehydration (loss of fluids), and weight loss.
What is the treatment for cyclospora infection?
Cyclospora infection is treated with an oral medicine that is a combination of two sulfa-based antibiotics: trimethoprim and sulfamethoxazole. For people with diarrhea Cyclospora can be difficult to diagnose. If Cyclospora infection is suspected, people should consult with their health-care provider before taking medicine for diarrhea.
How common is cyclospora infection?
Cyclospora infection is very rare in this country, and most states do not keep track of the number of cases. In the past, the infection was usually found in persons living or traveling in tropical countries. Increasingly, however, cases are being recognized in the United States and Canada. In the United States, infection is most common during spring and summer.
Is cyclospora an emerging infection?
Yes. The first human cases were reported in 1979, but cases began being reported more often in the mid-1980s. This may be partly because of the availability of better tests to detect the parasite in stool specimens. Several recent, very large outbreaks linked to raspberries, mesclun lettuce, and possibly basil have increased concerns about Cyclospora and stimulated health officials to learn more about how it is transmitted and what factors contribute to its spread.
How can cyclospora infection be prevented?
Based on what is known about Cyclospora, the best way to prevent infection is to avoid eating raw or undercooked foods or drinking untreated water that could be contaminated with stool. Cooking can kill Cyclospora, and freezing might, too. As a general food safety measure, always wash fresh produce, even if it is to be peeled before eating.
