Cyclospora (Cyclospora cayetanensis) is a parasite
that is composed of only one cell. It is too small to be
seen with the naked eye (only 8-10 microns in
diameter). It used to be called by such names as
Cyanobacterium-like, Coccidia-like, and Cyclosporalike
The first known cases of Cyclospora infection were
diagnosed in 1977 (reported in the medical literature
in 1979). Cases have been reported with increased
frequency since the mid-1980s, partly because of the
increased availability to detect the parasite in stool
samples. However, many questions remain about
this tiny organism.
How is Cyclospora transmitted?
Cyclospora is transmitted by a person putting
something in his or her mouth that was contaminated
with infected stool. The parasite can be transmitted
by swallowing contaminated water or food.
Who is at risk for infection?
People of all ages are at risk for infection.
to tropical countries may be at increased risk.
evidence suggests that outbreaks are most common
in spring and summer.
What are the symptoms of infection?
Cyclospora infects the small intestine and typically
causes an illness characterized by watery diarrhea,
with an average of six to seven stools per day.
symptoms can include:
Loss of appetite
Increased flatus (gas)
Other infectious organisms can cause illness that is
very similar to that caused by Cyclospora. Some
persons infected with Cyclospora do not develop any
How soon after infection do symptoms
Symptoms appear several days to a week after
exposure (average seven days).
What is the treatment for Cyclospora?
If not treated, the illness may last for a few days to a
month or longer and may come back one or more
Treatment with an antibiotic may shorten the
course of the illness.
Infected persons with diarrhea
should rest and drink plenty of fluids.
What should you do if you think you may be
If you think you may be infected with Cyclospora,
you should consult your doctor.
this parasite in stool requires special kinds of
laboratory techniques that are not routinely used.
Therefore, your doctor should specifically request
testing for this parasite.
More than one stool sample
may need to be checked to find the organism. Your
doctor may also want to check your stool for
other infectious organisms that cause similar
How do I avoid getting Cyclospora?
Avoiding water and food that may be contaminated
with stool probably is the best way to prevent
Infected persons should wash their hands
often to prevent the spread of infection.
have previously been infected with Cyclospora can
become infected again.
Where can I get more information?
Contact your doctor or the Southern Nevada Health District, Office of Epidemiology at (702) 759-1300.