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IFST Issues Statement on Cyclospora

The independent Institute of Food Science & Technology has issued a new Information Statement on Cyclospora dated May 2008, replacing that of March 2003.

The updated version makes the following new conclusions:

  • Care must be exercised in implicating any source of food or water as the source of any pathogen before the pathogen has both been identified and shown to occur in the incriminated vehicle.
  • Both national and international reporting and communicating cases/outbreaks of food or water borne disease need to be improved.
  • Every importer of fresh products (i.e. not pasteurised by heat/irradiation or other means), especially if these come from tropical countries, should be alert to the possibility that hazards, little known in the developed world, may be present and ensure that best practice is followed throughout the chain from farm to table.
  • Chlorination may be an inadequate safeguard against some such contaminants.
  • Routine laboratory analysis may be inadequate to identify all pathogens, some of which call for unusually sophisticated analytical techniques.

The Institute of Food Science & Technology (IFST) is the independent professional qualifying body for food scientists and technologists. It is totally independent of government, of industry, and of any lobbying groups or special interest groups.


TD Advice That Includes Cyclospora

Maybe its because we are thinking about a spring trip to some destination in South or Central America that an especially good write up on Travelers’ Diarrhea caught our attention.

It includes this about treatment of TD caused by protozoa like cyclospora:

The most common parasitic cause of TD is Giardia intestinalis, and treatment options include metronidazole, tinidazole, and nitazoxanide (10). Although cryptosporidiosis is usually a self-limited illness in immunocompetent persons, nitazox-anide can be considered as a treatment option. Cyclosporiasis is treated with TMP-SMX. Treatment of amebiasis is with metronidazole or tinidazole, followed by treatment with a luminal agent such as iodoquinol or paromomycin.”

Its the sort of helpful advice that you might want to slip into your permanent travel file.

At Least For Now, Cyclospora Is No Longer No. 1

We thought it worth noting here that record no longer stands as its been bested by Mexican hot peppers that have now made almost 1,300 ill with Salmonella Saintpaul in 43 U.S. states, the District of Columbia and Canada.

The 1997-98 Cyclospora outbreak have been subject to much academic research and medical reviews.   Just as tomatoes were first fingered in the Salmonella Saintpaul outbreak, strawberries were initially thought responsible for the Cyclospora outbreak.

WebMD has a paper on its website that details what happened.   There were actually several years where Guatemalan raspberries were a problem, and it took some doing to eradicate it. WebMD says:

The year 2000 was the fifth year since 1995 (i.e., 1995, 1996, 1997, 1998, and 2000) that outbreaks of cyclosporiasis occurred in the spring in the United States or Canada that definitely or probably were associated with Guatemalan raspberries.[7] However, the recent outbreaks have been much smaller than the multistate outbreaks in 1996 and 1997.[7] After the outbreaks in 1996 and 1997,[2,3]

FDA began working with the Guatemalan government and berry industry to improve farming and exporting practices for raspberries. Only farms that meet certain standards–including water, sanitation, and worker hygiene issues–have been allowed to export fresh raspberries to the United States during the “spring season” (March through August). The standards are reviewed and updated yearly. During the spring of 2000, five Guatemalan farms were allowed to export to the United States. After the outbreaks in Pennsylvania and Georgia, FDA did not allow the farm that was in common to the events to export raspberries to the United States during the spring of 2001. No U.S. outbreaks of cyclosporiasis associated with Guatemalan raspberries were identified that spring. During the spring of 2002, only three farms, which have never been implicated in outbreaks of cyclosporiasis, were allowed to export raspberries to the United States.

You can find the rest with the footnotes and such here.

Cyclospora “Season” Is Not Over Until November

We missed “Digging for Mummies” when the blog published an item about the “season” for Cyclospora.  From Nepal writer  

“Cyclospora season starts each year in May and peaks in June and July. The risk of infection decreases from August until the organism disappears altogether in November. Formerly known as “blue-green algae,” it is a protozoan parasite that infects the upper intestine causing profound fatigue, loss of appetite, and diarrhea….Untreated, the infection can last from two to twelve weeks….

“…7-11 percent of all expatriates living in Kathmandu during this season are affected each year. The risk is highest among new foreign residents...” (The CIWIC Clinic Health News, June 2006)

Thanks to CIWIC and a little something called Bactrim, the little parasite in my intestine will be gone for good in a matter of days.”

You can find the blog entry here.

All About Cyclospora

Cyclospora is a parasite composed of one cell, too small to be seen without a microscope. The organism was previously thought to be a blue-green alga or a large form of Cryptosporidium. Cyclospora cayetanensis is the only species of this organism found in humans. The first known human cases of illness caused by Cyclospora infection (that is, cyclosporiasis) were first discovered in 1977. An increase in the number of cases being reported began in the mid-1980s, in part due to the availability of better diagnostic techniques. Over 15,000 cases are estimated to occur each year in the United States. The first outbreak in North America occurred in 1990 from contaminated water. Since then, several outbreaks of cyclosporiasis have been reported in the U.S. and Canada, many associated with eating fresh fruits or vegetables. In some developing countries, cyclosporiasis is common among the population and travelers to those areas have become infected as well. – William Marler



  • Where does Cyclospora come from?
  • Diagnosis
  • Treatment
  • Serious and long-term risks
  • Prevention

Where does Cyclospora come from?

Cyclospora is spread by people ingesting water or food contaminated with infected stool. For example, exposure to contaminated water among farm workers may have been the original source in raspberry-associated outbreaks in North America.  Cyclospora needs time (one to several weeks) after being passed in a bowel movement to become infectious. Therefore, it is unlikely that Cyclospora is passed directly from one person to another. It is not known whether or not animals can be infected and pass infection to people.


Cyclospora infects the small intestine (bowel) and usually causes watery diarrhea, bloating, increased gas, stomach cramps, loss of appetite, nausea, low-grade fever, and fatigue. In some cases, vomiting, explosive diarrhea, muscle aches, and substantial weight loss can occur. Some people who are infected with Cyclospora do not have any symptoms. The time between becoming infected and becoming ill is usually about one week. If not treated, the illness may last from only a few days up to six weeks. Symptoms also may recur one or more times (relapse). In addition, people who have previously been infected with Cyclospora can become infected again.

When diagnosing Cyclospora, health care providers should ask the patient to submit stool specimens to see if he or she is infected. Because testing for Cyclospora infection can be difficult, the patient may be asked to submit several stool specimens over several days. Identification of this parasite in stool requires special laboratory tests that are not routinely done. Therefore, health care providers should specifically request testing for Cyclospora if it is suspected. A patient’s health care provider might have his or her stool checked for other organisms that can cause similar symptoms.


The recommended treatment for infection with Cyclospora is a combination of two antibiotics, trimethoprim-sulfamethoxazole, also known as Bactrim, Septra, or Cotrim. People who have diarrhea should rest and drink plenty of fluids. No alternative drugs have been identified yet for people with Cyclospora infection who are unable to take sulfa drugs. Some experimental studies, however, have suggested that ciprofloxacin or nitazoxanide may be effective, although to a lesser degree than trimethoprim-sulfamethoxazole. See your health care provider to discuss alternative treatment options.

Serious and long-term risks

Cyclospora has been associated with a variety of chronic complications such as Guillain-Barré syndrome, reactive arthritis or Reiter’s syndrome, biliary disease, and acalculous cholecystitis. Since Cyclospora infections tend to respond to the appropriate treatment, complications are more likely to occur in individuals who are not treated or not treated promptly. Extraintestinal infection also appears to occur more commonly in individuals with a compromised immune system.


Avoiding water or food that may be contaminated is advisable when traveling. Drinking bottled or boiled water and avoiding fresh ready-to-eat produce should help to reduce the risk of infection in regions with high rates of infection. Improving sanitary conditions in developing regions with poor environmental and economic conditions is likely to help to reduce exposure.  Washing fresh fruits and vegetables at home may help to remove some of the organisms, but Cyclospora may remain on produce even after washing.


1. Division of Parasitic Diseases – Cyclospora Infection

Fact sheets and studies with cause, symptoms, prevention, and treatment.

2. Cyclospora Facts – People most likely get cyclospora infection by eating food or drinking water.

3. Cyclospora cayetanensis – History

4. US FDA/CFSAN – Bad Bug Book – Cyclospora cayetanensis

Provides basic facts about cyclospora cayetanensis.

5. Cyclospora Parasite – Digestion and digestive-related information. Digestion information covering the digestion system and related diseases, procedures and tests, medications, and treatments.

6. Food Research Institute Briefings: Cryptosporidium and Cyclospora. Few people, even in the medical establishment, knew much about Cyclospora and Cryptosporidium until recently.

7. eMedicine – Cyclospora : Article by William H Shoff, MD, DTMandH. Cyclospora – Cyclospora cayetanensis (8-10 µm in diameter), a coccidian protozoan parasite, produces an intestinal infection.

8. Nebraska HHS System: Cyclospora Epidemiology Fact Sheet

Cyclospora is a parasite that is composed of one cell.

9. Cyclospora Lawyer & Attorney: Marler Clark: Cyclospora Blog

Cyclosporiasis is a disease due to Cyclospora cayetanensis, an emerging coccidian.

Cyclospora cayetanensis in Wikipedia

Cyclospora cayetanensis gets a new listing in Wikipedia, the free online reference source.  According to the new entry:

Cyclospora “is a protozoan that causes disease in humans, and perhaps other primates. It has been linked in the United States from fecally-contaminated imported raspberries and was virtually unknown before about 1990, but has been on the rise since. The health risk associated with the disease is usually confined to adult foreigners visiting endemic regions and acquiring the infection: this is why C. cayetanensis has been labeled as causing “traveler’s diarrhea.”

For more, go here.

Cyclospora Infection Fact Sheets Are Updated At CDC

Cyclospora infection or cyclosporiasis (sigh-clo-spore-EYE-us-sis) is caused by a one cell, microscopic parasite. It is spread by people ingesting something (for example food or water) that was contaminated with infected stool. People of all ages are at risk for infection and infection is found worldwide. Prescription medication is available.


From time to time, the Centers For Disease Control & Prevention (CDC) updates its fact sheets and other information on its website. We failed to note that it updated its discussion of Cyclospora infection.  We do so now.

For the rest of CDC’s write-up, go here.


Cyclospora Is Just An “Additional Common Culprit” That Can Ruin Your Trip

Cyclospora was mentioned as among the “additional common culprits”  in an excellent and timely update on “Traveler’s Diarrhea.” in the New York Times.

In addition to covering the infectious causes, food and water precautions, preventive drugs and treatments, the newspaper also provides a current risk by country analysis.  It says:

“High-risk destinations include most of the developing countries of Latin America, Africa, the Middle East, and Asia. The risk varies widely, however. In different studies, 73 percent of children who traveled to Africa, 61 percent who went to India, 55 percent of travelers to Asia, and 39.5 percent of travelers to South America experienced diarrhea.”

The Traveler’s Diarrhea guide says:

“A number of infectious organisms, including bacteria, parasites, and viruses, can cause diarrhea in travelers. These organisms are most often transmitted through contaminated food and water”  Included in the list:  “Additional common culprits are the bacteria Salmonella, parasites (Cryptosporidiosis, Cyclospora. microsporidia), and rotavirus (usually in Latin America).

Travelers should save this handy reference.

Only 17 Cases Of Cyclospora Last Year Reported In The Ten FoodNet States

The FoodNet surveillance system, which gathers foodborne disease data from ten states that account for about 15 percent of the US population, counted only 17 confirmed cases of cyclospora last year.

Operated by the Centers for Disease Control and Prevention (CDC) in Atlanta, FoodNet figures the cyclospora rate in the ten states at a mere 0.04 per 100,000. It means cyclospora comes dead last on the “top ten” list below.

(Number of cases and rate per 100,000 provided.)

  • Salmonella, 7,444, 16.2
  • Campylobacter, 5,825, 12.68
  • Shigella, 3,029, 6.59
  • Cryptosporidium, 1,036, 2.25
  • Escherichia coli O157, 513, 1.12
  • Shiga-toxin-producing E coli non-O157, 205, 0.45
  • Yersinia, 164, 0.36
  • Listeria, 135, 0.29
  • Vibrio, 131, 0.29
  • Cyclospora, 17, 0.04

According to newspaper archives, the last major cyclospora outbreak in the United States occurred five years ago in Florida when 300 people got the parasitic illness from contaminated fresh basil.

Isolated cases like the 17 that occurred in the ten FoodNet states last year are often associated with foreign travel to areas of the world where the parasite is more common.