Berry Berry Quite Contrary...Cyclospora Outbreaks
ATLANTA--Outbreaks of illness in the United States
causing infectious watery diarrhea, nausea, and vomiting have been
found to be related to a parasite called Cyclospora.
The Cyclospora parasite is transmitted to persons who contact
objects contaminated with infected stool. In 1997, reports of
outbreaks of Cyclospora infection were preliminarily associated
with the consumption of fresh fruits, such as strawberries and
The Center for Disease Control and Prevention (CDC) worked with the
federal, state, and local health departments to determine the extent
and causes of the recent outbreaks of Cyclospora. They pointed out
that although it is prudent to thoroughly wash produce that will be
eaten raw, this practice may not eliminate the risk of transmission
of Cyclospora. Further, they recommend that health care providers
consider Cyclospora infection in persons with prolonged diarrheal
illness and specifically request laboratory testing for this parasite.
The CDC has provided the following information:
What is Cyclospora?
Cyclospora is a parasite that is composed of one cell. It is too
small to be seen without a microscope. Its full name is
The first known human cases of Cyclospora infection were diagnosed in
1977. Cases began being reported more often in the
mid-1980s. This may be in part because better techniques are now
being used to detect the parasite in specimens of stool
(bowel movements). Because Cyclospora is a newly recognized
infectious organism, many questions remain about the ways
it is transmitted and the illness it causes.
How is Cyclospora transmitted?
Cyclospora is transmitted by a person putting something in his or her
mouth that was contaminated with infected stool. For
example, the parasite can be transmitted by swallowing contaminated
water or food. Cyclospora needs time (days or weeks)
after being passed in a bowel movement to develop into an infectious
organism. Therefore, transmission of Cyclospora
directly from an infected person to an uninfected person is unlikely.
Who is at risk for infection?
Persons of all ages are at risk for infection. In the past,
Cyclospora infection was usually found in persons living or traveling
tropical countries. More and more, cases are being recognized in
countries such as the United States and Canada. The risk
may vary with season. Infection may be most common in spring and
summer. However, we do not yet know how common
Cyclospora infection is.
What are the symptoms of infection?
Cyclospora infects the small intestine (bowel) and usually causes
watery diarrhea, with frequent bowel movements. Other
symptoms include loss of appetite, weight loss, bloating, increased
gas, stomach cramps, nausea, vomiting, tiredness, muscle
aches, and low-grade fever. Other infectious organisms can cause
similar illness. Some persons infected with Cyclospora do
not develop any symptoms.
The time between becoming infected and developing symptoms is usually
several days to a week. If not treated, the illness
may last for a few days to a month or longer. It may also return one
or more times.
What should you do if you think you may be infected?
If you think you may be infected with Cyclospora, you should consult
your physician. Identification of this parasite in stool
requires special laboratory tests that are not routinely used.
Therefore, your physician should specifically request testing for
Cyclospora. More than one stool sample may be needed. Your physician
may also want to have your stool checked for
other infectious organisms that can cause similar symptoms.
How is infection treated?
Infection with Cyclospora is treated with antibiotics. Trimethoprim-
sulfamethoxazole, also known as Bactrim*, Septra*, or
Cotrim* (a combination of two antibiotics), is recommended. Infected
persons with diarrhea should rest and drink plenty of
fluids. They should seek their physician's advice before taking
medicine to slow their diarrhea.
How is infection prevented?
Cyclospora infection can be prevented by avoiding water or food that
may be contaminated with stool. Persons who have
previously been infected with Cyclospora can become infected again.
For more information about Cyclospora infection, refer to the
Last Editorial Review: 2/13/2003
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- Hoge CW, et al. Placebo-controlled trial of co-
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- Hoge CW, et al. Epidemiology of diarrhoeal illness
associated with coccidian-like organisms among travellers and
foreign residents in Nepal. Lancet 1993;341:1175-9.
- Huang P, et al. The first reported outbreak of
diarrheal illness associated with Cyclospora in the United States. Ann
Intern Med 1995;123:409-14.
- Ortega YR, et al. Cyclospora species - a new protozoan
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- Pape JW, et al. Cyclospora infection in adults infected
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