''Cyclospora cayetanensis'' is a

coccidia Coccidia (Coccidiasina) are a subclass of microscopic, spore-forming, single-celled obligate intracellular parasites belonging to the apicomplexan class Conoidasida. As obligate intracellular parasites, they must live and reproduce within an a ...

n parasite that causes a

diarrhea Diarrhea, also spelled diarrhoea, is the condition of having at least three loose, liquid, or watery bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin wi ...

l disease called

cyclosporiasis Cyclosporiasis is a disease caused by infection with '' Cyclospora cayetanensis'', a pathogenic protozoan transmitted by feces or feces-contaminated food and water. Outbreaks have been reported due to contaminated fruits and vegetables. It is not ...

in humans and possibly in other primates. Originally reported as a novel pathogen of probable coccidian nature in the 1980s and described in the early 1990s, it was virtually unknown in developed countries until awareness increased due to several outbreaks linked with fecally contaminated imported produce. ''C. cayetanensis'' has since emerged as an endemic cause of diarrheal disease in tropical countries and a cause of

traveler's diarrhea Travelers' diarrhea (TD) is a stomach and intestinal infection. TD is defined as the passage of unformed stool (one or more by some definitions, three or more by others) while traveling. It may be accompanied by abdominal cramps, nausea, fever, ...

and food-borne infections in developed nations. This species was placed in the genus ''

Cyclospora ''Cyclospora'' is a genus of apicomplexan parasites. It includes the species ''Cyclospora cayetanensis'', the causative agent of cyclosporiasis. Members of ''Cyclospora'' are characterized as having oocysts with two Apicomplexan life cycle, spor ...

'' because of the spherical shape of its sporocysts. The specific name refers to the

Cayetano Heredia University Cayetano Heredia University ( es, link=no, Universidad Peruana Cayetano Heredia, UPCH; or simply ''Cayetano Heredia'') is a private nonprofit university located in Lima, Peru. It was named in honor of Cayetano Heredia, one of the eminent Peruv ...

in Lima, Peru, where early epidemiological and taxonomic work was done.

History

The first published report of ''Cyclospora cayetanensis'' in humans appears to be by Ashford (1979), who found unidentified '' Isospora''-like

in the feces of three individuals in Papua, New Guinea. The photomicrographs in the paper reveal an organism morphologically identical to that seen now. Later, Narango et al. (1989) reported what may be the same organism from several Peruvians with chronic diarrhea and termed the organism ''

Cryptosporidium muris ''Cryptosporidium muris'' is a species of coccidium, first isolated from the gastric glands of the common mouse. ''Cryptosporidium'' does originate in common mice, specifically laboratory mice. However, it also has infected cows, dogs, cats, rats ...

''–like. Other investigators thought the unsporulated

oocysts Apicomplexans, a group of intracellular parasites, have Biological life cycle, life cycle stages that allow them to survive the wide variety of environments they are exposed to during their complex life cycle. Each stage in the life cycle of an a ...

appeared more similar to

cyanobacteria Cyanobacteria (), also known as Cyanophyta, are a phylum of gram-negative bacteria that obtain energy via photosynthesis. The name ''cyanobacteria'' refers to their color (), which similarly forms the basis of cyanobacteria's common name, blu ...

, and the name "cyanobacterium-like body" or CLB became prevalent in the literature (occasionally, authors also used the term "coccidian-like body", or CLB). Eventually, Ortega et al. (1992) published an abstract reporting that they had sporulated and excysted the oocysts, resulting in placement of the parasite in the genus ''Cyclospora''. They also created the name ''Cyclospora cayetanensis'' at this time. However, since no morphologic information was presented in the abstract, ''C. cayetanensis'' technically became a ''

nomen nudum In taxonomy, a ''nomen nudum'' ('naked name'; plural ''nomina nuda'') is a designation which looks exactly like a scientific name of an organism, and may have originally been intended to be one, but it has not been published with an adequate descr ...

'' (a named species without a description). Although Ortega et al. (1993) later published additional details about this coccidian, a complete morphologic description was not published to validate the name until 1994. Thus, the correct name for this parasite is ''Cyclospora cayetanensis'' Ortega, Gilman, & Sterling, 1994, and the etymology of the ''nomen triviale'' is derived from Cayetano Heredia University in Lima, Peru. During this two-year period when ''C. cayetanensis'' was a ''nomen nudum'', anyone wishing to publish a complete morphologic description and change the name would have been free to do so.

Characterization

''Cyclospora cayetanensis'' is an apicomplexan, cyst-forming coccidian

protozoa Protozoa (singular: protozoan or protozoon; alternative plural: protozoans) are a group of single-celled eukaryotes, either free-living or parasitic, that feed on organic matter such as other microorganisms or organic tissues and debris. Histo ...

n that causes a self-limiting diarrhea. In terms of morphology, It has spherical

oocyst Apicomplexans, a group of intracellular parasites, have life cycle stages that allow them to survive the wide variety of environments they are exposed to during their complex life cycle. Each stage in the life cycle of an apicomplexan organism i ...

s that are between 7.5 and 10

μm The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Unit ...

in diameter that also have a 50- nm-thick wall with an outer thread-like coat that has been called a wrinkle by some researchers. The oocyst formula is O.2.2 because one oocyst contains two sporocysts and each sporocyst contains two sporozoites. The only confirmed hosts for ''C. cayetanensis'' are humans. The protozoan lives out its lifecycle intracellularly within the host's

epithelial cell Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercellula ...

s and

gastrointestinal tract The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organ (biology), organs of the digestive syste ...

. Infection is transmitted through the fecal-oral route, and begins when a person ingests oocysts in feces-contaminated food or water. Various chemicals in the host's gastrointestinal tract cause the oocysts to excyst and release sporozoites; generally, two are observed per oocyst. After these sporozoites invade the epithelial cells, they undergo merogony, a form of

asexual reproduction Asexual reproduction is a type of reproduction that does not involve the fusion of gametes or change in the number of chromosomes. The offspring that arise by asexual reproduction from either unicellular or multicellular organisms inherit the fu ...

that results in many daughter merozoites. These daughter cells may either infect new host cells and initiate yet another round of merogony or take on a sexual track via

gametogony Apicomplexans, a group of intracellular parasites, have life cycle stages that allow them to survive the wide variety of environments they are exposed to during their complex life cycle. Each stage in the life cycle of an apicomplexan organism i ...

: Daughter merozoites become male macrogamonts—which form many

microgamete {{Short pages monitor Foodborne outbreaks of cyclosporiasis have been reported in the United States since the mid-1990s and have been linked to various types of imported fresh produce, including raspberries, basil, snow peas, mesclun lettuce, and cilantro; no commercially frozen produce has been implicated to date. U.S. foodborne outbreaks of cyclosporiasis that occurred before 2000 wer
summarized
previously, as were the major documented outbreaks i

an

Foodborne outbreaks during the 15-year period of 2000–2014 are summarized in table. The table provides information about 31 reported foodborne outbreaks of cyclosporiasis that occurred in the United States during 2000–2014; the total case count was 1,562. No outbreaks were reported in 2003, 2007, or 2010. Overall, a median of two outbreaks were reported per year, with a median of 20 cases per outbreak (range, 3 to 582 cases). Although the outbreaks occurred during 8 different months (December through July), the peak months were May, June, and July. As indicated in the table, a food vehicle of infection was identified for 15 of the 31 outbreaks. Summary of U.S. foodborne outbreaks of cyclosporiasis, 2000–2014 * The entries in the first three columns refer to the known or likely year(s), month(s), and jurisdiction(s) in which the exposure(s) to ''Cyclospora'' occurred.
** For additional details, see summary information about th

For the purposes of this table, the exposure month(s) and case counts are limited to those explicitly linked in the investigations to the food item specified in the last column.
† The case counts include laboratory-confirmed and probable cases of cyclosporiasis. By definition, each outbreak included at least two linked cases, at least one of which was laboratory confirmed.
‡ A food vehicle is specified only if a single ingredient or commodity was identified in an outbreak investigation.
¶ Cases that occurred in Canadian travelers to the United States were not included.
†† For additional perspective, see summary information abou

For the purposes of this table, the exposure months and the case count for the outbreak in Texas are limited to those explicitly linked in the investigations to the food item specified in the last column.

2013 United States outbreak

At least 285 people in 11 states had been affected as of July 26, 2013. The exact cause of the outbreak had not yet been identified according to the

U.S. Centers for Disease Control and Prevention The Centers for Disease Control and Prevention (CDC) is the national public health agency of the United States. It is a United States federal agency, under the Department of Health and Human Services, and is headquartered in Atlanta, Georgi ...

(CDC). The majority of cases were located in the

Midwest The Midwestern United States, also referred to as the Midwest or the American Midwest, is one of four Census Bureau Region, census regions of the United States Census Bureau (also known as "Region 2"). It occupies the northern central part of ...

, with 138 reported cases in

Iowa Iowa () is a state in the Midwestern region of the United States, bordered by the Mississippi River to the east and the Missouri River and Big Sioux River to the west. It is bordered by six states: Wisconsin to the northeast, Illinois to the ...

and 70 in

Nebraska Nebraska () is a state in the Midwestern region of the United States. It is bordered by South Dakota to the north; Iowa to the east and Missouri to the southeast, both across the Missouri River; Kansas to the south; Colorado to the southwe ...

. The other states affected are:

Texas Texas (, ; Spanish language, Spanish: ''Texas'', ''Tejas'') is a state in the South Central United States, South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2 ...

Florida Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...

, Georgia,

Wisconsin Wisconsin () is a state in the upper Midwestern United States. Wisconsin is the 25th-largest state by total area and the 20th-most populous. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake M ...

Connecticut Connecticut () is the southernmost state in the New England region of the Northeastern United States. It is bordered by Rhode Island to the east, Massachusetts to the north, New York to the west, and Long Island Sound to the south. Its cap ...

Illinois Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. Its largest metropolitan areas include the Chicago metropolitan area, and the Metro East section, of Greater St. Louis. Other smaller metropolita ...

Kansas Kansas () is a state in the Midwestern United States. Its capital is Topeka, and its largest city is Wichita. Kansas is a landlocked state bordered by Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to the ...

Minnesota Minnesota () is a state in the upper midwestern region of the United States. It is the 12th largest U.S. state in area and the 22nd most populous, with over 5.75 million residents. Minnesota is home to western prairies, now given over to ...

New Jersey New Jersey is a state in the Mid-Atlantic and Northeastern regions of the United States. It is bordered on the north and east by the state of New York; on the east, southeast, and south by the Atlantic Ocean; on the west by the Delaware ...

, and

Ohio Ohio () is a state in the Midwestern region of the United States. Of the fifty U.S. states, it is the 34th-largest by area, and with a population of nearly 11.8 million, is the seventh-most populous and tenth-most densely populated. The sta ...

. As of July 29, 2013, the CDC reported 373 people in 15 states had been affected by the outbreak, and 21 patients from three states had been hospitalized, with no deaths reported. No food source had been identified, but health officials in Iowa—the state reporting the most cases—said they suspected imported vegetables. On July 30, 2013, the

Nebraska Department of Health & Human Services The Nebraska Department of Health & Human Services (DHHS) is a state agency of Nebraska, headquartered in Lincoln.Contact Us
" ...

and the Iowa Department of Health announced that a restaurant chain's packaged salad was the disease vector for the parasite. However, the CDC and the U.S.

Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respon ...

(FDA) continued to assess information from other states to see if the findings applied to illnesses there. In an August 1, 2013, update, the CDC reported 397 cases, while Iowa and Texas added another 22 more. This pushed the unofficial count to over 400 cases. Additionally, Louisiana reported its first case, bringing the total number of states affected to 16. On August 3, 2013, CNN reported that the outbreak was traced to packaged salad served at Olive Garden and Red Lobster restaurants that was manufactured by Taylor Farms de Mexico. On August 15, 2013, the CDC reported nine more ''Cyclospora'' infections, raising its case count to 548. The number of affected states remained at 19, but the CDC said that not all cases were confirmed to be linked to an outbreak in Iowa and Nebraska traced to a contaminated salad mix from Mexico. On August 19, 2013, the CDC reported 10 more ''Cyclospora'' cases, raising the unofficial count to over 600. Tennessee also reported its first case, bringing the number of states affect to 20. The CDC still cautions that whether cases in all of the states are related to outbreaks in Iowa and Nebraska is not clear. As of August 27, 2013, the origin of the outbreak still remained a mystery. The FDA said it found no food safety violations at the Taylor Farms de Mexico salad plant that was linked to some of the illnesses.

2015 Texas outbreak

In an FDA statement, the CDC is quoted, "there is currently (in July 2015) another ongoing outbreak of cyclosporiasis in the United States in which both the Texas Department of State Health Services and the Wisconsin Department of Health Services and the Wisconsin Department of Agriculture, Trade and Consumer Protection have identified cilantro from the Mexican state of Puebla as a suspect vehicle with respect to separate illness clusters." Last year, Texas had 200 cases, some of which were associated with cilantro from the Puebla region.

2016 Texas outbreak

Health officials said more than a dozen cases of cyclosporiasis had been confirmed in North Texas' four major counties and that the source was likely contaminated food. The Texas Department of State Health Services said Wednesday the parasite was found in Dallas, Tarrant, Collin and Denton counties and that the origin may have been linked to a fresh produce item. County officials told NBC 5 there were four cases recorded in Dallas County, three in Collin County, four in Denton County and seven in Tarrant County. The Denton County cases and at least four of the Tarrant County cases had recently traveled out of the country—calling into question the point of origin. Across the state, there were currently 66 confirmed cases of cyclosporiasis—though the sources of infection were unconfirmed. For most people, the symptoms were not serious. "But for those who are very young and those who are older, or those who have a suppressed immune system, this illness can cause major problems," said Dr. Khang Tran, chief medical officer at The Medical Center of Plano. In recent years, 2012–2015, cyclospora outbreaks were associated with fresh cilantro imported from Puebla, Mexico. Since the summer of 2015, the Food and Drug Administration has instituted ban on imports from that region between from April through August.

2018 Midwestern Del Monte vegetable outbreak

Del Monte recalled packaged Del Monte Fresh Produce vegetable trays, which contained broccoli, carrots, cauliflower, celery sticks, and dill dip, from certain retailers, including Kwik Trip and Peapod, according to the CDC. Residents in four states — Iowa, Michigan, Minnesota, and Wisconsin got sick from ''Cyclospora''.

2018 Midwestern McDonald's salad outbreak

McDonald's stopped selling salads supplied by Fresh Express at some 3,000 locations across the country mostly in the

United States due to a multistate parasite outbreak that had sickened 551 people caused by ''Cyclospora''.

2020 Midwestern Fresh Express bagged garden salad outbreak

In June 2020, the CDC and other regulatory bodies began investigating an outbreak of Cyclosporiasis in the Midwestern United States linked to bagged salad mix. On June 27, 2020, Fresh Express announced a voluntary recall of over 91 Fresh Express and private label salad products. IR=incidence rate per 100,000
* incidence rates are based on projected census data obtained from the DSHS Center for Health Statistics.

References

* * * * {{Taxonbar, from=Q3008600 Conoidasida