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PubMed1994

Cyclospora infection in adults infected with HIV. Clinical manifestations, treatment, and prophylaxis.

OBJECTIVE: To determine the prevalence and clinical manifestations of Cyclospora in Haitians infected with human immunodeficiency virus (HIV) who have diarrhea and to evaluate therapy and prophylaxis. DESIGN: Cohort study. From 1990 to 1993, stool samples were collected from adults seropositive for HIV who had had diarrhea for at least 3 weeks. SETTING: A clinic in Haiti. INTERVENTIONS: Stool samples were examined for enteric protozoa after acid-fast staining. Patients with Cyclospora infection were treated with trimethoprimsulfamethoxazole (160 mg and 800 mg, respectively) given orally four times a day for 10 days. After completion of therapy, patients were evaluated weekly and re-treated if clinical and parasitologic recurrences occurred, followed by trimethoprim-sulfamethoxazole prophylaxis three times a week. RESULTS: 804 of 2400 patients (33%) seropositive for HIV had a history of chronic or intermittent diarrhea; 502 of these 804 patients (62%) currently had diarrhea, and 450 patients each provided two stool specimens for examination. Enteric protozoa identified included Cryptosporidium (30%), Isospora belli (12%), Cyclospora species (11%), Giardia lamblia (3%), and Entamoeba histolytica (1%). Forty-three patients with diarrhea and Cyclospora infection were studied; their symptoms were indistinguishable from those seen in patients with isosporiasis or cryptosporidiosis. In all patients, diarrhea ceased and results from stool examinations were negative within 2.5 days after beginning oral trimethoprim-sulfamethoxazole therapy. Recurrent symptomatic cyclosporiasis developed in 12 of 28 patients (43%) followed for 1 month or more, but it also responded promptly to trimethoprim-sulfamethoxazole therapy. These 12 patients received trimethoprim-sulfamethoxazole three times a week as secondary prophylaxis, with only a single recurrence after 7 months. CONCLUSION: Cyclospora infection is common in Haitian patients with HIV infection, responds to trimethoprim-sulfamethoxazole therapy, and has a high recurrence rate that can be largely prevented with long-term trimethoprim-sulfamethoxazole prophylaxis.

AIDS-Related Opportunistic Infections↗
PubMed1999

Studies on a newly emerging protozoal pathogen: Cyclospora cayetanensis.

Cyclospora is frequently misdiagnosed with Cryptosporidia. Stool samples were collected from 150 immunocompromised patients and concentrated by the parasep faecal parasite concentration and the discontinuous percoll gradients methods. Wet mount examination was done and the parasite was successfully stained with modified Ziehl Neelsen (ZN) and safranin methylene blue stain. Cyclospora was detected in 4% of cases examined. Cyclospora was easily differentiated from Cryptosporidia by using the modified detergent ZN stain whereby Cyclospora resist staining and Cryptosporidia pick up the pink colouration. Scanning and transmission electron microscopic examination were done to the unsporulated Cyclospora oocysts. They appeared as spherical objects with an outer fibrillar coat, an indentation and sutures. These spherical objects also contained light and dark granules. In studying the possible sources of transmission of this parasite, sporulated and unsporulated oocysts were detected in tap water and lettuce heads which support the theory that water and food could be the sources of transmission of this parasite.

Animals↗
PubMed1997

Cyclospora infection: a review.

Cyclospora is a coccidian parasite responsible for a syndrome of acute and chronic diarrhoea. The organism first come to worldwide attention in 1990 following the publication of three reports. The largest series of cases and the first clinical description of the illness associated with this organism came from Kathmandu where travellers and expatriates were noted to have prolonged diarrhoea with a previously undescribed organism. The organism has been identified as a coccidian both by observation of sporulation and subsequent molecular phylogenetic analysis. Cyclospora organisms appear as non-refractile double-walled spheres, 8-10 microns in diameter. The organism floats in Sheather's sucrose solution and appears variably red on the modified acid-fast stain. It can also be identified on plain wet mounts. Since its first description, Cyclospora has been noted in an increasing number of countries throughout the world. Water-borne transmission has been implicated in several studies. There is a distinct seasonality in Cyclospora outbreaks and cases. In Nepal, the organism has occurred in virtually identical seasonal outbreaks since 1989. The clinical illness associated with Cyclospora is characterized by diarrhoea, nausea, anorexia and weight loss, which may persist for weeks to months if untreated. Evidence of malabsorption of D-xylose has been noted and small bowel biopsies revealed moderately severe villous atrophy and crypt hyperplasia. Successful treatment with trimethoprim-sulfamethoxazole has been identified, but to date no alternative treatment exists for the sulfa allergic patient.

Animals↗
PubMedDate not supplied

[Morphological, clinical and therapeutic characteristics of Cyclospora cayetanensis].

In the last years Cyclospora sp. has been increasingly associated to human intestinal diseases. The first studies have been reported to this parasite as a Cyanobacterium-like body, large Cryptosporidium or coccidian-like body. The ultrastructural characteristic and the "in vitro" sporulation have revealed the existence of oocyst constituted for two sporocysts with two sporozoites per sporocyst. This evidence has allowed its classification as a coccidian within the genus Cyclospora and its designation as a new pathogen species in humans, Cyclospora cayetanensis. Recently phylogenetic analysis based on rDNA sequences suggested that Cyclospora sp. was closely related to the Eimeria genus. The identification, morphological characteristics, clinical evaluation and chemotherapy of the human intestinal disease associated to Cyclospora sp. are commented in the present paper.

Animals↗
PubMed2002

Cryptosporidium parvum and Cyclospora cayetanensis: a review of laboratory methods for detection of these waterborne parasites.

Cryptosporidium and Cyclospora are obligate, intracellular, coccidian protozoan parasites that infest the gastrointestinal tract of humans and animals causing severe diarrhea illness. In this paper, we present an overview of the conventional and more novel techniques that are currently available to detect Cryptosporidium and Cyclospora in water. Conventional techniques and new immunological and genetic/molecular methods make it possible to assess the occurrence, prevalence, virulence (to a lesser extent), viability, levels, and sources of waterborne protozoa. Concentration, purification, and detection are the three key steps in all methods that have been approved for routine monitoring of waterborne oocysts. These steps have been optimized to such an extent that low levels of naturally occurring Cryptosporidium oocysts can be efficiently recovered from water. The filtration systems developed in the US and Europe trap oocysts more effectively and are part of the standard methodologies for environmental monitoring of Cryptosporidium oocysts in source and treated water. Purification techniques such as immunomagnetic separation and flow cytometry with fluorescent activated cell sorting impart high capture efficiency and selective separation of oocysts from sample debris. Monoclonal antibodies with higher avidity and specificity to oocysts in water concentrates have significantly improved the detection and enumeration steps. To date, PCR-based detection methods allow us to differentiate the human pathogenic Cryptosporidium parasites from those that do not infect humans, and to track the source of oocyst contamination in the environment. Cell culture techniques are now used to examine oocyst viability. While fewer studies have focused on Cyclospora cayetanensis, the parasite has been successfully detected in drinking water and wastewater using current methods to recover Cryptosporidium oocysts. More research is needed for monitoring of Cyclospora in the environment. Meanwhile, molecular methods (e.g. molecular markers such as intervening transcribed spacer regions), which can identify different genotypes of C. cayetanensis, show good promise for detection of this emerging coccidian parasite in water.

Animals↗
PubMed2000

Cyclospora cayetanensis: a review, focusing on the outbreaks of cyclosporiasis in the 1990s.

Cyclospora cayetanensis, a coccidian parasite that causes protracted, relapsing gastroenteritis, has a short recorded history. In retrospect, the first 3 documented human cases of Cyclospora infection were diagnosed in 1977 and 1978. However, not much was published about the organism until the 1990s. One of the surprises has been the fact that a parasite that likely requires days to weeks outside the host to become infectious has repeatedly caused foodborne outbreaks, including large multistate outbreaks in the United States and Canada. In this review, I discuss what has been learned about this enigmatic parasite since its discovery and what some of the remaining questions are. My focus is the foodborne and waterborne outbreaks of cyclosporiasis that were documented from 1990 through 1999. The occurrence of the outbreaks highlights the need for health care personnel to consider that seemingly isolated cases of infection could be part of widespread outbreaks and should be reported to public health officials. Health care personnel should also be aware that stool specimens examined for ova and parasites usually are not examined for Cyclospora unless such testing is specifically requested and that Cyclospora infection is treatable with trimethoprim-sulfamethoxazole.

Animals↗
PubMed2005

Detection of Cyclospora cayetanensis oocysts in human fecal specimens by flow cytometry.

A diagnosis of cyclosporiasis typically involves stool examinations for the presence of Cyclospora oocysts by means of microscopy. In recent years, flow cytometry has been gaining in popularity as a novel method of detecting pathogens in environmental and clinical samples. The present study is an evaluation of a flow cytometric method for the detection and enumeration of Cyclospora oocysts in human fecal specimens associated with food-borne outbreaks of cyclosporiasis in Ontario, Canada. Flow cytometry results were generally very comparable to the original microscopy results for these specimens, in terms of both presence or absence of oocysts and relative oocyst concentrations. Of the 34 fecal specimens confirmed positive for Cyclospora by microscopy, 32 were also found positive by flow cytometry, and 2 others were considered equivocal. Of the eight fecal specimens reported to be negative by microscopy, two were found positive by flow cytometry and five others were considered equivocal. These two flow cytometry-positive samples and one of the equivocal samples were confirmed by microscopic reexamination, suggesting that flow cytometry may be more sensitive than microscopy. While the sample preparation time for flow cytometry is similar to or slightly longer than that for microscopy, the actual analysis time is much shorter. Further, because flow cytometry is largely automated, an analyst's levels of fatigue and expertise will not influence results. Flow cytometry appears to be a useful alternative to microscopy for the screening of large numbers of stool specimens for Cyclospora oocysts, such as in an outbreak situation.

Animals↗
PubMedDate not supplied

[Acute diarrhea associated with Cyclospora cayetanensis].

Acute diarrhea is a major problem with high morbidity and mortality rates in developing countries, especially in children. Complex laboratory investigations are required to define the etiology because of the broad spectrum of etiological agents and the non-specific clinical signs. In the last decade, Cyclospora cayetanensis--a new acid-fast coccidian species--was pointed to be the cause of watery self-limited or prolonged diarrhea in immunocompetent and immunocompromised patients, with very good evolution after treatment with co-trimoxazole. Unlike Cryptosporidium parvum, nonsporulated Cyclospora oocysts are eliminated in feces, with no risk of human to human transmission. Cyclospora cayetanensis is widely spread, producing endemic infections, in Asia and South America and was reported to produce infections in foreign travellers in these areas and epidemic outbreaks of foodborne diarrhea. We describe the first case of acute diarrhea associated with Cyclospora cayetanensis in an immunocompetent child admitted to Iaşi "Sf. Maria" Hospital.

Anti-Infective Agents↗
PubMed2004

[Prevalence of Cyclospora sp., Cryptosporidium sp, microsporidia and fecal coliform determination in fresh fruit and vegetables consumed in Costa Rica].

The presence of Cyclospora sp., Cryptosporidium sp. and microsporidia and the levels of fecal coliforms were determined in lettuce, parsley, cilantro, strawberries and blackberries acquired in local agricultural markets of the Central Valley of Costa Rica, in order to establish the possible transmission risk of these microorganisms and other pathogens from the consumption of these raw products. During the second semester of 2001 and the first of 2002, 50 different samples of each product, 25 taken in the dry season and 25 in the rainy season and coming from five different local agricultural markets were evaluated. The fecal coliforms count was done according to the technique recommended by Vanderzant & Splittstoesser. The parasite determination was done using Zielh Nielsen and Weber staining techniques from a sediment obtained through the rinse of the mentioned products, using sterile peptonated water 0.1% and centrifuging at 900 G for 15 min. One hundred per cent of vegetable samples had fecal coliforms and the greatest prevalence was obtained during the rainy season. Although all vegetables presented fecal coliforms in high concentrations, lettuce and cilantro presented statistical difference between rainy and dry season, being greater during the rainy season. Fecal coliforms were not detected in strawberries and blackberries probablydue to its low pH. All products evaluated presented, at least once, Cryptosporidium sp., Cyclospora sp. and microsporidia, showing the risk they represent to Public Health. Cryptosporidium was present in all products but strawberries. Microsporidia was present in all products except blackberries and Cyclospora was only isolated from lettuce during the dry season. These results show the importance of introducing in the country Good Agricultural Practices, especially due to the resistance of Cryptosporidium and Cyclospora to disinfecting agents.

Animals↗
PubMedDate not supplied

Cyclospora cayetanensis: first imported infections in Germany.

Over the last decade increasing numbers of enteritis cases have been attributed to infection with a new coccidian species that was named Cyclospora cayetanensis in 1993. Diarrhea caused by this agent is clinically indistinguishable from cryptosporidiosis, isosporiasis and microsporidiosis, but Cyclospora infections are often very prolonged (up to 15 weeks) and may cause severe weight loss. Diagnosis of infection is important because, in contrast to diarrhea caused by Cryptosporidium and microsporidia, treatment with co-trimoxazole is effective. Here we report the cases of two female patients, aged 70 and 58 years old, respectively, who suffered from severe, prolonged diarrhea after a vacation in Singapore, Java and Bali. Routine microbiological laboratory diagnostics were unable to demonstrate the presence of known enteropathogenic bacteria. Modified Ziehl-Neelsen staining of fecal smears revealed oocysts of Cyclospora cayetanensis, and treatment of the patients with co-trimoxazole was promptly effective. We would like to increase awareness of the possibility of Cyclospora infections in patients with prolonged diarrhea who have travelled to endemic areas.

Aged↗
PubMed1996

Light and electron microscopic identification of Cyclospora species in the small intestine. Evidence of the presence of asexual life cycle in human host.

This is the first case of cyclosporiasis in which the parasite was clearly demonstrated in a duodenal biopsy by light microscopy. Electron microscopy identified the stages of sporozoite, trophozoite, schizont, and merozoite. Although only asexual forms were identified in our case, the sexual cycle must have taken place in the human host, because oocysts were detected in stools of the patients. Therefore, it appears that Cyclospora species require only a single host to complete its entire life cycle. Despite the heavy infection, only enterocytes were invaded. The lamina propria and submucosa were not involved. The morphology of Cyclospora in the intestine is similar to that of Isospora, but differs from that of Cryptosporidium. The morphology of the oocyst of Cyclospora resembles that of Cryptosporidium, but differs from that of Isospora. Thus, a combined study of both stool and intestinal biopsy should readily distinguish Cyclospora from Cryptosporidium and Isospora.

AIDS-Related Opportunistic Infections↗
PubMed1997

An Open Trial of Trimethoprim Alone against Cyclospora Infections.

Cyclospora is a coccidian parasite that infects the upper intestine and causes a prolonged illness consisting of fatigue, anorexia, and diarrhea. Untreated infections can last for several weeks.1 Trimethoprim-sulfamethoxazole (co-trimoxazole) was found to be an effective treatment for Cyclospora infections in a 1994 study performed in Nepal.2 However, people with known allergies to sulfa drugs cannot take co-trimoxazole. A number of antibiotics have been tried against Cyclospora infections without success, including norfloxacin, tinidazole, diloxanide furoate, and quinacrine hydrochloride. Azithromycin was not successful in a small open trial in 1993.3 Trimethoprim is not chemically related to sulfa, and allergy to co-trimoxazole is usually attributed to the sulfamethoxazole component. In order to find a treatment for people infected with Cyclospora who are allergic to sulfa drugs, we undertook an open trial of trimethoprim alone, in a dose of 200 mg twice a day for 7 days.

Journal Article↗
PubMedDate not supplied

Morphologic and molecular characterization of new Cyclospora species from Ethiopian monkeys: C. cercopitheci sp.n., C. colobi sp.n., and C. papionis sp.n.

In recent years, human cyclosporiasis has emerged as an important infection, with large outbreaks in the United States and Canada. Understanding the biology and epidemiology of Cyclospora has been difficult and slow and has been complicated by not knowing the pathogen s origins, animal reservoirs (if any), and relationship to other coccidian parasites. This report provides morphologic and molecular characterization of three parasites isolated from primates and names each isolate: Cyclospora cercopitheci sp.n. for a species recovered from green monkeys, C. colobi sp.n. for a parasite from colobus monkeys, and C. papionis sp.n. for a species infecting baboons. These species, plus C. cayetanensis, which infects humans, increase to four the recognized species of Cyclospora infecting primates. These four species group homogeneously as a single branch intermediate between avian and mammalian Eimeria. Results of our analysis contribute toward clarification of the taxonomic position of Cyclospora and its relationship to other coccidian parasites.

Animals↗
PubMed1996

Short report: case report of Cyclospora infection acquired in Indonesia and treated with cotrimoxazole.

A detailed chronology of unsuccessful efforts to diagnose and treat a sudden-onset case of chronic diarrhea acquired in Jakarta Indonesia, and ultimately attributed to Cyclospora is presented. A modified Kato technique was used to quantify Cyclospora oocysts during successive days prior to, during, and after successful cotrimoxazole therapy (160 mg of trimethoprim, 800 mg sulfamethoxazole twice a day for seven days) for this infection. Cyclospora was associated with 6.4% of the gastrointestinal illness and/or diarrhea cases that presented during a seven-month period to a Jakarta clinic that serves a small population of expatriates. Cyclospora and Giardia lamblia were identified with equal frequency during this period and were the dominant pathogenic intestinal parasite species found in this community.

Animals↗
PubMed1998

Template preparation for PCR and RFLP of amplification products for the detection and identification of Cyclospora sp. and Eimeria spp. Oocysts directly from raspberries.

Raspberries were epidemiologically associated with cyclosporiasis outbreaks during 1996 and 1997. The 18S rRNA genes of Cyclospora cayetanensis and several species of a closely related genus, Eimeria, were sequenced and primers for a nested PCR developed in a previous study. The ability to distinguish amplified products of Cyclospora sp. from those of Eimeria spp. is important for testing food and environmental samples. Therefore, an RFLP analysis of amplified products was used to differentiate Cyclospora cayetanensis from Eimeria spp. PCR inhibitors and the low levels of Cyclospora oocysts present in raspberries make template preparation for PCR challenging. Several approaches for PCR template preparation from raspberry samples were evaluated. Template preparation methods using various washing and concentration steps, oocyst disruption protocols, resin matrix treatment, DNA precipitation, and/or the addition of nonfat dried milk solution to a PCR using modified primers were evaluated first with oocysts of Eimeria tenella then refined with oocysts of C. cayetanensis. Approximately 10 E. tenella oocysts per PCR or approximately 19 C. cayetanensis oocysts per PCR were detected with the optimized template preparation method. The addition of 20 microliters of raspberry wash sediment extract and nonfat dried milk solution did not inhibit the amplification of DNA from as few as 10 E. tenella and 25 C. cayetanensis oocysts in a 100-microliter PCR. The nucleotide sequences of C. cayetanensis and the Eimeria spp. are 94 to 96% similar in the amplified region, but the amplification products from the two genera were distinguished using an RFLP analysis with the restriction enzyme MnlI.

Animals↗
PubMed1999

Giardia, Cryptosporidium, and Cyclospora and their impact on foods: a review.

While the risk from pathogenic microorganisms in foods has been recognized for hundreds of years, bacterial agents are generally implicated as the contaminants. Although many outbreaks of gastroenteritis caused by protozoan pathogens have occurred, it is only in the last 3 years that attention has focused on protozoan association with foodborne transmission. Recognized as waterborne parasites, Giardia, Cryptosporidium, and Cyclospora have now been associated with several foodborne outbreaks. The oocysts and cysts of these organisms can persist and survive for long periods of time both in water and on foods. While Cyclospora oocysts require a maturation period, Cryptosporidium oocysts and Giardia cysts are immediately infectious upon excretion from the previous host. As a result, these parasites have emerged as public health risks and have become a concern to the food industry. More than 200 cases of foodborne giardiasis (seven outbreaks) were reported from 1979 to 1990. Four foodborne Cryptosporidium outbreaks (with a total of 252 cases) have been documented since 1993. Cyclospora caused a series of sporadic outbreaks of cyclosporasis throughout North America that have affected over 3,038 people since 1995. Control and prevention of protozoan foodborne disease depends upon our ability to prevent, remove, or kill protozoan contaminants. This review will address the biology, foodborne and waterborne transmission, survival, and methods for detection and control of Giardia, Cryptosporidium, and Cyclospora.

Animals↗
PubMed1995

The first reported outbreak of diarrheal illness associated with Cyclospora in the United States.

OBJECTIVE: To investigate and characterize the epidemiology of a diarrheal outbreak associated with a potentially new pathogen, Cyclospora species (previously referred to as Cyanobacteria [blue-green algae]-like bodies). DESIGN: Three retrospective cohort studies supported by laboratory studies, environmental investigation, and community surveillance. SETTING: A hospital in Chicago. PARTICIPANTS: Housestaff physicians and hospital administrative staff. MEASUREMENTS: Identification of clinical features associated with illness and potential risks for acquisition of infection. RESULTS: Illness was characterized by watery diarrhea, abdominal cramping, decreased appetite, and low-grade fever. Symptoms typically occurred in a distinctive cycle of remissions and exacerbations lasting up to several weeks. Stool cultures and examinations for known ova and parasites were negative. Microscopic examination of stool specimens from 11 ill persons showed many spherical bodies, 8 to 10 microns in diameter, that were identified as Cyclospora organisms. The organisms disappeared by 9 weeks after onset of illness in the 7 patients from whom follow-up specimens were obtained. Epidemiologic studies implicated tap water from a physicians' dormitory as the most likely source of the outbreak. Environmental investigation suggested that stagnant water in a storage tank may have contaminated the water supply after a pump failure. CONCLUSIONS: This is the first reported outbreak of diarrhea associated with Cyclospora in the United States. Cyclospora may be a human enteric pathogen able to produce bouts of acute and relapsing diarrhea, and it should be considered in assessments of patients with unexplained, prolonged diarrheal illness.

Adult↗
PubMed1997

Laboratory diagnosis of Cyclospora infections.

The laboratory diagnosis of newly recognized infectious agents, such as Cyclospora cayetanensis, is frequently problematic because appropriate diagnostic techniques and algorithms are not available. The methods currently available for diagnosis of Cyclospora are described and compared, including concentration procedures, examination of wet preparations, various staining techniques, and the use of molecular-based assays. Because of the autofluorescent properties of the oocysts, particular attention is drawn to the role of fluorescent microscopy in providing a rapid, inexpensive, and sensitive technique for diagnosis of Cyclospora infections in stool samples. In addition to text descriptions, photomicrographs are provided to illustrate Cyclospora oocysts in wet and stained preparations and compare them with Cryptosporidium and Isospora oocysts, the other two most common coccidian infections in man.

Animals↗