Enteric parasites Cyclospora cayetanensis and Cryptosporidium hominis in domestic and wildlife animals in Ghana

BACKGROUND

Enteric parasitic infections remain a major public health problem globally. Cryptosporidium spp., Cyclospora spp. and Giardia spp. are parasites that cause diarrhea in the general populations of both developed and developing countries. Information from molecular genetic studies on the speciation of these parasites and on the role of animals as vectors in disease transmission is lacking in Ghana. This study therefore investigated these diarrhea-causing parasites in humans, domestic rats and wildlife animals in Ghana using molecular tools.

METHODS

Fecal samples were collected from asymptomatic school children aged 9-12 years living around the Shai Hills Resource Reserve (tourist site), from wildlife (zebras, kobs, baboons, ostriches, bush rats and bush bucks) at the same site, from warthogs at the Mole National Park (tourist site) and from rats at the Madina Market (a popular vegetable market in Accra, Ghana. The 18S rRNA gene (18S rRNA) and 60-kDa glycoprotein gene (gp60) for Cryptosporidium spp., the glutamate dehydrogenase gene (gdh) for Giardia spp. and the 18S rDNA for Cyclospora spp. were analyzed in all samples by PCR and Sanger sequencing as markers of speciation and genetic diversity.

RESULTS

The parasite species identified in the fecal samples collected from humans and animals included the Cryptosporidium species C. hominis, C. muris, C. parvum, C. tyzzeri, C. meleagridis and C. andersoni; the Cyclopora species C. cayetanensis; and the Gardia species, G. lamblia and G. muris. For Cryptosporidium, the presence of the gp60 gene confirmed the finding of C. parvum (41%, 35/85 samples) and C. hominis (29%, 27/85 samples) in animal samples. Cyclospora cayetanensis was found in animal samples for the first time in Ghana. Only one human sample (5%, 1/20) but the majority of animal samples (58%, 51/88) had all three parasite species in the samples tested.

CONCLUSIONS

Based on these results of fecal sample testing for parasites, we conclude that animals and human share species of the three genera (Cryptosporidium, Cyclospora, Giardia), with the parasitic species mostly found in animals also found in human samples, and vice-versa. The presence of enteric parasites as mixed infections in asymptomatic humans and animal species indicates that they are reservoirs of infections. This is the first study to report the presence of C. cayetanensis and C. hominis in animals from Ghana. Our findings highlight the need for a detailed description of these parasites using high-throughput genetic tools to further understand these parasites and the neglected tropical diseases they cause in Ghana where such information is scanty.

The global prevalence of Cyclospora cayetanensis infection: A systematic review, meta-analysis, and meta-regression

Cyclospora cayetanensis (C. cayetanensis) is a significant pathogen that causes diarrheal illness and causes large foodborne diarrhea outbreaks in the USA and Canada. However, there is currently a lack of published meta-analysis on the prevalence of C. cayetanensis infection in the global population. A real estimation of a disease prevalence should always be done on the basis of studies designed for that purpose. We conducted a comprehensive search of various databases for articles pertaining to the prevalence of C. cayetanensis infection in humans, spanning from the inception of these databases to March 10, 2023. Utilizing a random effects model, we estimated the prevalence of C. cayetanensis infection in humans. Our analysis included a total of 150 datasets sourced from 42 different countries, which were ultimately selected for the final quantitative assessment. The prevalence of C. cayetanensis infection in humans worldwide was estimated to be 3.4 % (5636/166,611). Notably, Africa exhibited the highest prevalence rate at 5.9 % (606/11,068). Further subgroup analysis revealed a significantly higher infection rate in humans residing in low-income countries (7.6 %, 83/921) compared to those in lower-middle-income countries (4.8 %, 3280/48,852), upper-middle-income countries (2.9 %, 2194/99,419), and high-income countries (0.4 %, 79/17,419). The results indicate that the global prevalence of C. cayetanensis infection in humans is relatively low, despite its extensive geographical distribution and children were found to be more susceptible to C. cayetanensis infection compared to those adults. Sensitivity analysis revealed that one study significantly affects the prevalence of C. cayetanensis, which was adjusted to 2.9 % (4017/160,049; 95 % CI: 2.7-3.1 %) by excluding this study. The findings highlight the relatively high prevalence of C. cayetanensis infection in low-income countries and among humans with diarrhea, particularly in Africa. Consequently, routine surveillance for intestinal protozoa is crucial in these regions.

Comparison of two novel one-tube nested real-time qPCR assays to detect human-infecting Cyclospora spp

IMPORTANCE

Human-infecting Cyclospora spp. cause gastrointestinal distress among healthy individuals contributing to morbidity and putting stress on the economics of countries and companies in the form of produce recalls. Accessible and easy-to-use diagnostic tools available to a wide variety of laboratories would aid in the early detection of possible outbreaks of cyclosporiasis. This, in turn, will assist in the timely traceback investigation to the suspected source of an outbreak by informing the smallest possible recall and protecting consumers from contaminated produce. This manuscript describes two novel detection methods with improved performance for the causative agents of cyclosporiasis when compared to the currently used 18S assay.

Retrospective evaluation of an integrated molecular-epidemiological approach to cyclosporiasis outbreak investigations - United States, 2021

Cyclosporiasis results from an infection of the small intestine by Cyclospora parasites after ingestion of contaminated food or water, often leading to gastrointestinal distress. Recent developments in temporally linking genetically related Cyclospora isolates demonstrated effectiveness in supporting epidemiological investigations. We used 'temporal-genetic clusters' (TGCs) to investigate reported cyclosporiasis cases in the United States during the 2021 peak-period (1 May - 31 August 2021). Our approach split 655 genotyped isolates into 55 genetic clusters and 31 TGCs. We linked two large multi-state epidemiological clusters (Epidemiologic Cluster 1 [n = 136 cases, 54 genotyped] and Epidemiologic Cluster 2 [n = 42 cases, 15 genotyped]) to consumption of lettuce varieties; however, product traceback did not identify a specific product for either cluster due to the lack of detailed product information. To evaluate the utility of TGCs, we performed a retrospective case study comparing investigation outcomes of outbreaks first detected using epidemiological methods with those of the same outbreaks had TGCs been used to first detect them. Our study results indicate that adjustments to routine epidemiological approaches could link additional cases to epidemiological clusters of cyclosporiasis. Overall, we show that CDC's integrated genotyping and epidemiological investigations provide valuable insights into cyclosporiasis outbreaks in the United States.

Global Burden of Cyclospora cayetanensis Infection and Associated Risk Factors in People Living with HIV and/or AIDS

Cyclospora cayetanensis infections remain one of the most common protozoan opportunistic causes of gastrointestinal diseases and diarrhea among people living with HIV and/or AIDS (PLWHA). This study was conducted to provide a summary of the evidence on the global burden of C. cayetanensis infection and associated risk factors among PLWHA. Scopus, PubMed, Science Direct, and EMBASE were searched up to February 2022. All original peer-reviewed original research articles were considered, including descriptive and cross-sectional studies describing C. cayetanensis in PLWHA. Incoherence and heterogeneity between studies were quantified by I index and Cochran’s Q test. Publication and population bias were assessed with funnel plots and Egger’s asymmetry regression test. All statistical analyses were performed using StatsDirect. The pooled prevalence of C. cayetanensis infection among PLWHA was 3.89% (95% CI, 2.62–5.40). The highest prevalence found in South America was 7.87% and the lowest in Asia 2.77%. In addition, the prevalence of C. cayetanensis was higher in PLWHA compared to healthy individuals. There was a relationship between a higher C. cayetanensis prevalence in PLWHA with a CD4 cell count below 200 cells/mL and people with diarrhea. The results show that PLWHA are more vulnerable to C. cayetanensis infection and emphasizes the need to implement the screening and prophylaxis tailored to the local context. Owing to the serious and significant clinical manifestations of the parasite, an early identification of seropositivity is recommended to initiate prophylaxis between PLWHA with a CD4 count ≤200 cells/mL and PLWHA who do not receive antiviral therapy.

A review of Cyclospora cayetanensis in animals

Cyclosporiasis is a global, emerging disease in humans caused by Cyclospora cayetanensis. The role of animals in the epidemiology of cyclosporiasis is not fully understood. We conducted a narrative review of the published literature on C. cayetanensis in animals. MEDLINE® (Web of Science™ ), Agricola (ProQuest), CABI Global Health (1979 to December 2020) and Food Science and Technology Abstracts (EBSCOhost) (1979 to February 2020) were searched. Studies of C. cayetanensis in or on any species of animal were eligible. Thirteen relevant studies were found. C. cayetanensis was found in wild and farmed Mediterranean mussels (Mytilus galloprovincialis), wild grooved carpet shell clams (Ruditapes decussatus) and in the faeces of dogs (domestic and street), wild chickens, wild rhesus macaques (Macaca mulatta), chimpanzees (Pan troglodytes) from a wildlife research centre, and Cynomolgus monkeys (Macaca fascicularis) from an experimental primate research centre. As the small intestines of the naturally exposed animals were not biopsied, existence of a natural animal reservoir of C. cayetanensis could not be confirmed. Animals shedding oocysts in their faeces may be paratenic hosts. Investigators were able to successfully infect the following animals with C. cayetanensis: oysters, Asian freshwater clams (Corbicula fluminea), Swiss albino mice and guinea pigs. Future non-laboratory studies of animals should use PCR coupled with DNA sequencing to confirm that the species found is C. cayetanensis. The potential role of animals in the transport of oocysts and contamination of food, water, and soil could be explored through future primary research.

Gastrointestinal Parasitic Infections and Immunological Status of HIV/AIDS Coinfected Individuals in Nigeria

BACKGROUND

Parasitic infections of the gastrointestinal tract is one of the highest causes of morbidity and mortality among HIV infected individuals. This is due to the colonization of the intestinal tract by parasites influenced by induced enteropathy caused by HIV infection. CD+4 t-lymphocytes count is a marker of the immune status of HIV infected individuals.

OBJECTIVE

This study investigated the prevalence of gastrointestinal parasitic infections among HIV coinfected individuals in relation to their immunological status.

METHODS

CD+4 t-lymphocytes count was determined using fluorescence-activated cell sorting (FACS) count system. Parasitological examination of faecal samples was conducted using direct wet mount, modified Z-N and Giemsa stain techniques. All prepared slides were examined under x10 and x40 objectives.

FINDINGS

Out of the 891 HIV seropositive participants on antiretroviral therapy that were studied, 641 (71.9%) had CD+4 counts equals to or greater than 500 cells/mm3. All other seropositive participants had CD+4 counts below 500 cells/mm3. Gastrointestinal parasitic infections were recorded in 187 (20.9%) seropositive participants, with females (n = 108, 12.1%) having more infections than males. Multiple gastrointestinal parasitic infections were recorded in 28 (3.1%) seropositive participants. Out of the 150 seronegative participants, 79 (52.7%) of them had at least one gastrointestinal parasitic infection. Female seronegative participants also accounted for higher infection rate (n = 42, 28.0%) than males (n = 37, 24.7%). Multiple infections were also recorded in 18 (12.0%) seronegative individuals. The overall prevalence rate of infection between both positive and negative individuals was 25.5%. There was statistical significant difference in the infections of Cryptosporidium parvum (p < 0.003), Cyclospora cayetanensis (p < 0.011) and Cystoisospora belli (p < 0.011) between HIV seropositive and HIV seronegative individuals. Also, there was statistical significant difference in the infections of hook worm (p < 0.002) and Trichuris trichiura (p < 0.020) between seronegative and seropositive individuals. Gastrointestinal parasitic infection rate was significantly higher among seropositive participants with CD+4 counts between 200 and 350 cells/mm3 (n = 109, 58.3%).

CONCLUSION

The study shows that HIV infected individuals continue to experience gastrointestinal infections even with antiretroviral treatment, especially those with CD+4 counts below 350 cells/mm3. Health care providers should prioritise routine screening of HIV patients for gastrointestinal parasites and provide prompt treatment. Antiparasitic drugs should also be provided as prophylaxis.

Outbreak of cyclosporiasis in a U.S. Air Force training population, Joint Base San Antonio-Lackland, TX, 2018

Diarrheal illnesses have an enormous impact on military operations in the deployed and training environments. While bacteria and viruses are the usual causes of gastrointestinal disease outbreaks, 2 Joint Base San Antonio-Lackland, TX, training populations experienced an outbreak of diarrheal illness caused by the parasite Cyclospora cayetanensis in June and July 2018. Cases were identified from outpatient medical records and responses to patient questionnaires. A confirmed case was defined by diarrhea and laboratory confirmation, and patients without a positive lab were classified as suspected cases. In cluster 1, 46 suspected and 7 confirmed cases occurred among technical training students who reported symptom onset from 12 June to 21 June. In cluster 2, 18 suspected and 14 confirmed cases in basic military training trainees reported symptom onset from 29 June to 8 July. Numerous lessons from cluster 1 were applied to cluster 2. Crucial lessons learned during this cyclosporiasis outbreak included the importance of maintaining clinical suspicion for cyclosporiasis in persistent gastrointestinal illness and obtaining confirmatory laboratory testing for expedited diagnosis and treatment.

2015 Outbreak of Cyclosporiasis Linked to the Consumption of Imported Sugar Snap Peas in Ontario, Canada

An outbreak of cyclosporiasis in Ontario, Canada, was investigated in the fall of 2015. Thirty-five confirmed and 10 probable cases were linked to the investigation. Epidemiological and food safety evidence implicated fresh sugar snap peas imported from Guatemala as the source of the outbreak. We describe here the first documented cyclosporiasis outbreak in Canada involving the consumption of sugar snap peas.

The Prevalence of Cyclospora cayetanensis and Cryptosporidium spp. in Turkish patients infected with HIV-1

Opportunistic infections such as cryptosporidiosis and cyclosporiasis are commonly encountered in patients with acquired immunodeficiency syndrome (AIDS). We investigated the existence of opportunistic protozoans that significantly affect the quality of life in HIV-1 infected patients using conventional and molecular methods. The study group comprised 115 HIV-1 positive patients. In the identification of Cyclospora cayetanensis and Cryptosporidium, the formol-ether precipitation method was used and smears were evaluated in optical microscope by staining modified Ziehl-Neelsen (ZN). The primers and probes used for PCR were Heat shock protein 70 for C. cayetanensis and the oocysts wall protein for Cryptosporidium spp.. Cyclospora and Cryptosporidium spp. oocysts were detected in one and two patients, respectively, by staining, whereas we detected C. cayetanensis in three patients out of 115 (2.6%) by PCR, and Cryptosporidium spp. in a further three patients (2.6%). C. cayetensis was detected in patients with CD4 counts of 64 cells/μm, 182 cells/μm and 287 cells/μm, respectively. Cryptosporidium spp. was detected in patients with CD4 counts of 176 cells/μm, 241 cells/μm and 669 cells/μm. As conclusion, PCR method is faster and more sensitive than microscopic methods and to screen intestinal pathogens routinely in patients infected with HIV should not be neglected in developing countries like Turkey.

Intestinal coccidian parasites as an underestimated cause of travellers' diarrhoea in Polish immunocompetent patients

Intestinal coccidian parasites are intracellular protozoa most frequently transmitted during food-borne and water-borne infections. This group of parasites is responsible for acute diarrhoeal illnesses especially among immunocompromised patients. However, they are more frequently detected in immunocompetent individuals including travellers, and they should also be considered as important etiologic factors of travellers' diarrhoea. We examined 221 immunocompetent patients hospitalized due to acute or chronic diarrhoea and other gastrointestinal symptoms after returning from international journeys to hot climates. A basic microscopical examination and acid - fast staining of stool samples was performed. Each patient was also a part of the epidemiological investigation to define potential risk factors of tropical gastrointestinal infections. Intestinal coccidiosis was confirmed in 12 out of 221 successively hospitalized patients (5.4%). The most common coccidian parasite was Cryptosporidium spp., detected in nine Polish travellers (4.1%). Cyclospora spp. was diagnosed in three cases (1.4%), including two mixed infections with Cryptosporidium spp., and Cystoisospora spp. in two other cases (0.9%). The study has revealed that intestinal coccidian parasites are a significant threat to immunocompetent travellers and should be always considered in the differential diagnosis of gastrointestinal disorders. Therefore, it is necessary to perform specialized diagnostic methods for the detection of Cryptosporidium spp., Cystoisospora spp., and Cyclospora spp. oocysts in reference parasitology laboratories. Clinical observations demonstrated simultaneously an insufficient level of knowledge in Polish tourists concerning the main risk factors of intestinal parasitic diseases during international travels, particularly to developing countries with lower economic and sanitary conditions.

Multistate product traceforward investigation to link imported romaine lettuce to a US cyclosporiasis outbreak - Nebraska, Texas, and Florida, June-August 2013

During June-August 2013, 25 US states reported 631 cyclosporiasis cases including Nebraska and Iowa where a regional investigation implicated common-source imported salad mix served in two chain restaurants. At least two common-origin growing fields were likely sources of contaminated romaine lettuce. Using producer- and distributor-provided data, we conducted a grower-specific traceforward investigation to reveal exposures of ill US residents elsewhere who reported symptom onset during 11 June-1 July 2013, the time period established in the Nebraska and Iowa investigation. Romaine lettuce shipped on 2-6 June from one of these Mexico-origin growing fields likely caused cyclosporiasis in 78 persons reporting illness onsets from 11 June to 1 July in Nebraska, Texas, and Florida. Nationwide, 97% (314/324) of persons confirmed with cyclosporiasis with symptom onset from 11 June to 1 July 2013 resided in 11 central and eastern US states receiving approximately two-thirds of romaine lettuce from this field. This grower's production practices should be investigated to determine potential sources of contamination and to develop recommendations to prevent future illnesses.

Regional investigation of a cyclosporiasis outbreak linked to imported romaine lettuce - Nebraska and Iowa, June-August 2013

A regional, multistate investigation into a June-August 2013 cyclosporiasis outbreak was conducted in Nebraska, Iowa, and neighbouring states. Cases were confirmed on the basis of laboratory and clinical findings. Of 227 cases in Iowa (n = 140) and Nebraska (n = 87) residents, 162 (71%) reported dining at chain A/B restaurants - 96% reported house salad consumption. A case-control study identified chain A/B house salad as the most likely vehicle. Traceback was conducted to ascertain production lot codes of bagged salad mix (iceberg and romaine lettuce, red cabbage, and carrots) served as house salad in implicated restaurants. A single production lot code of salad mix supplied by both a common producer and distributor was linked to the majority of confirmed cases in persons reporting regional chain A/B exposure. The salad mix linked to illnesses contained imported romaine lettuce from two separate single-grower fields-of-origin and ⩾1 additional field from another grower.

Centers for Disease Control and Prevention (CDC). Incidence and trends of infection with pathogens transmitted commonly through food - foodborne diseases active surveillance network, 10 U.S. sites, 1996-2012

Foodborne diseases are an important public health problem in the United States. The Foodborne Diseases Active Surveillance Network* (FoodNet) conducts surveillance in 10 U.S. sites for all laboratory-confirmed infections caused by selected pathogens transmitted commonly through food to quantify them and monitor their incidence. This report summarizes 2012 preliminary surveillance data and describes trends since 1996. A total of 19,531 infections, 4,563 hospitalizations, and 68 deaths associated with foodborne diseases were reported in 2012. For most infections, incidence was highest among children aged <5 years; the percentage of persons hospitalized and the percentage who died were highest among persons aged ≥65 years. In 2012, compared with the 2006-2008 period, the overall incidence of infection† was unchanged, and the estimated incidence of infections caused by Campylobacter and Vibrio increased. These findings highlight the need for targeted action to address food safety gaps.

[Research progress on the biology and epidemiology of Cyclospora cayetanensis]

Cyclosporiasis is one of the emerging parasitic diseases. Cyclospora cayetanensis is so far the only species infecting humans in the Cyclospora genus. This paper reviews mainly the biological characteristics of C. cayetanensis and the current epidemiology status of human infection.

[Microsporidia in pediatric patients with leukemia or limphoma]

INTRODUCTION

Microsporidia are intracellular micro-organisms, characterized by mature spores with chitin walls and by one extrusive polar tube through which they pour their sporoplasm to the host cells. In immunocompromised patients, Enterocytozoon bieneusi and Encephalitozoon intestinalis produce diarrhea and systemic dissemination. In Mexico there is not information about microsporidia in children with cancer.

OBJECTIVE

The aim of this pilot study was to investigate the presence of microsporidia species in pediatric patients with leukemia or lymphoma.

MATERIAL AND METHODS

We obtained fecal samples from thirteen patients. The samples were processed to detect microsporidia by both modified Ziehl-Neelsen and clacofluor white stains, DNA was isolated to amplify rRNA specific sequences, to identify E. bieneusi, E. intestinalis, E. cuniculi and E. hellem by DNA polymerase chain reaction (PCR). Other parasites and pathogenic bacteria were also tested.

RESULTS

Based on morphologic traits 7/13 samples were found positives to microsporidia and 6/10 by PCR. Was identified E. bieneusi in three patients with leukemia and one with lymphoma, another two children with leukemia were infected with E. intestinalis. Almost all children were high-risk patients and in phase of re-induction, consolidation or with many chemotherapy treatments. All the patients with microspiridia did not present diarrhea at the moment of the sampling; however, in two children with diarrhea it was found Cyclospora cayetanensis. Also we obtained feces from five patients' mothers and microsporidia spores were identified by stain in all of them and by PCR it was diagnosed the species in three of them.

CONCLUSION

It was demonstrated that the feces of patients with leukemia or lymphoma had microsporidia, therefore is necessary to know the prevalence of these microorganisms and to analyze their impact in evolution of cancer patients.

Surveillance for laboratory-confirmed sporadic cases of cyclosporiasis--United States, 1997-2008

PROBLEM/CONDITION

Cyclosporiasis is an enteric disease caused by the parasite Cyclospora cayetanensis. Cyclosporiasis is reported most commonly in tropical and subtropical regions. In the United States, outbreaks of cyclosporiasis associated with various types of imported fresh produce have been documented and described since the mid-1990s. No molecular tools are available for linking C. cayetanensis cases. National data regarding laboratory-confirmed sporadic cases (i.e., cases not linked to documented outbreaks) have not been summarized previously.

REPORTING PERIOD

This summary includes laboratory-confirmed sporadic cases that occurred during 1997-2008 and were reported to CDC by 2009.

DESCRIPTION OF SYSTEM

In January 1999, cyclosporiasis became a nationally notifiable disease, and, as of 2008, it was a reportable condition in 37 states, New York City (NYC), and the District of Columbia. For 1997-2008, CDC was notified of laboratory-confirmed cases via two active surveillance systems (the Cyclospora Sentinel Surveillance Network and the Foodborne Diseases Active Surveillance Network), two passive systems (the National Notifiable Diseases Surveillance System and the Public Health Laboratory Information System), and informal mechanisms (e.g., electronic mail).

RESULTS

CDC was notified of 1,110 laboratory-confirmed sporadic cases of cyclosporiasis that occurred during 1997-2008. The overall population-adjusted incidence rates ranged from a low of 0.01 cases per 100,000 persons in 1997 to a high of 0.07 in 2002. Of the 1,110 cases, 849 (76.5%) were reported by seven states: 498 (44.9%) occurred in residents of Florida (228 cases), NYC (200 cases), and elsewhere in New York state (70 cases); and >50 cases were reported by each of five other states (Connecticut, Georgia, Massachusetts, New Jersey, and Pennsylvania). Overall, the case-patients' median age was 44 years (range: 3 months-96 years); 50.5% were female, 47.2% were male, and the sex was unknown for 2.3%. A total of 372 case-patients (33.5%) had a documented history of international travel during the 2-week period before symptom onset or diagnosis, 398 (35.9%) reported no international travel, and 340 (30.6%) had an unknown travel history. Some details about the travel were available for 317 (85.2%) of the case-patients with a known history of international travel; 142 (44.8%) had traveled to Mexico (60 persons), Guatemala (44 persons), or Peru (38 persons). Among the 398 case-patients classified as having domestically acquired cases, 124 persons (31.2%) lived in Florida, and 64 persons (16.1%) lived either in NYC (49 persons) or elsewhere in New York state (15 persons). The majority (278 [69.8%]) of onset or diagnosis dates for domestically acquired cases occurred during April-August.

INTERPRETATION

Approximately one third of cases occurred in persons with a known history of international travel who might have become infected while traveling outside the continental United States. Domestically acquired cases were concentrated in time (spring and summer) and place (eastern and southeastern states): some of these cases probably were outbreak associated but were not linked to other cases, in part because of a lack of molecular tools.

PUBLIC HEALTH ACTION

Surveillance for cases of cyclosporiasis and research to develop molecular methods for linking seemingly sporadic cases should remain U.S. public health priorities, in part to facilitate identification and investigation of outbreaks and to increase understanding of the biology of Cyclospora and the epidemiology of cyclosporiasis. Unidentified, uninvestigated cases and outbreaks represent missed opportunities to identify vehicles of infection, modes of contamination, and preventive measures. Travelers to known areas of endemicity should be advised that food and water precautions for Cyclospora are similar to those for other enteric pathogens, except that this parasite is unlikely to be killed by routine chemical disinfection or sanitizing methods. The diagnosis of cyclosporiasis should be considered for persons with persistent or remitting-relapsing diarrheal illness, and testing for Cyclospora should be requested explicitly.

[Cyclospora cayetanensis: biology, environmental distribution and transfer]

Cyclospora cayetanensis is an apicomplexan protozoan that has emerged as an important pathogen causing endemic or epidemic diarrheal disease worldwide. In industrialized countries, the parasite has been recognized as the causative agent of several outbreaks of diarrheal illness mostly associated with produce imported from endemic areas. In developing countries, human cyclosporosis is widely distributed. Infection rates from 0% to 41.6% have been described in the general population. However, the epidemiology, biology, and ecology of C. cayetanensis are not fully understood. The life cycle is not completely characterized, although it appears to require a single human host to be accomplished. The role of animals as natural reservoirs of the parasite remains to be determined. Little information is available concerning the environmental distribution and vehicles of transmission of C. cayetanensis. Contaminated water, foods or soil can be vehicles of spread of the parasite. The significant uncertainties that remain in the knowledge of C. cayetanensis highlight the need for continuing research in several areas, including its basic biology and environmental distribution.

A foodborne outbreak of Cyclospora infection in Stockholm, Sweden

During May and June 2009 an outbreak of Cyclospora cayetanensis infection involving 12 laboratory-confirmed and 6 probable cases was detected in Stockholm County, Sweden. Imported sugar snap peas from Guatemala were the suspected vehicle, based on information obtained from patient questionnaires. This is the first reported outbreak of cyclosporiasis in Sweden and the second in Europe.

[Importance of contact with soil in the transmission of cyclosporosis]

Cyclospora cayetanensis is an emergent pathogen that causes endemic and epidemic diarrhea worldwide. The epidemiology of the infection is not well known. Transmission of the parasite occurs through an environmental vehicle. In industrialized countries, cyclosporosis has been most often associated with either food-borne outbreaks or traveller's diarrhea. In developing countries, infection has been linked with contaminated water or food, contact with animals or soils, and variables related with socioeconomic status. In a Venezuelan community, a strong correlation between environments conducive to fecal contamination and infection was observed, suggesting that direct contact with contaminated soil may be an important route of transmission in areas with substandard housing developments, and poverty a predisposing factor for cyclosporosis.

Cyclospora cayetanensis: a review, focusing on some of the remaining questions about cyclosporiasis

Cyclosporiasis is a protracted, relapsing gastroenteritis and has a short recorded history. Cyclospora cayetanensis is an enigmatic parasite since its discovery highlights the need for isolation of cases of infection that could be part of widespread outbreaks. It is associated with diarrhoea among children in developing countries in the Americas, where C. cayetanensis is endemic; traveller's diarrhoea and/or food and waterborne outbreaks sometimes occur in the developed countries. In SubSaharan Africa and Egypt, cyclosporiasis has been reported to occur in both immunocompromised and immunocompetent patients. Zoonotic species of Cyclospora have also been identified worldwide in primates, indicating likely endemicity of this underreported disease. This can be attributed to the lack of awareness in the public and medical profession concerning the disease, which is, therefore, not routinely tested at the health centres. The correlation between the density of water contamination and the prevalence of cyclosporiasis among the individuals of each area is significant. No doubt, water is the main vehicle of transmission in the present community. Soil contact and poultry are significant risk factors. All literature on C. cayetanensis, cyclosporiasis worldwide, and endemic cyclosporiasis was searched from libraries, colleagues and internet. Although cyclosporiasis is considered an enigma worth unravelling, with many aspects of this disease and its transmission having been uncovered only recently, the situation has been rapidly changing since the disease first came to medical attention in the 1970s.

Cyclosporiasis: an emerging public health concern around the world and in Africa

BACKGROUND

Cyclosporiasis is an emerging gastro-enteric disease caused by the coccidia protozoan Cyclospora cayetanensis. It is associated with diarrhoea among children in developing countries, in the Americas where C. cayetanensis is endemic, traveller's diarrhoea and/or food and waterborne outbreaks in the developed countries.

OBJECTIVES

The aim of this review is to highlight cyclosporiasis and its relevance to public health in East Africa and Africa at large.

METHODS

All literature on Cyclospora, C. cayetanensis, cyclosporiasis in Africa, and endemic cyclosporiasis was searched from libraries, colleagues and internet but only literature on its history, clinical presentation, epidemiology in endemic settings, and occurrence in Africa were scrutinised.

RESULTS

In Sub Saharan Africa, cyclosporiasis has been reported in at least 3 countries, including Tanzania, in East Africa, occurring in both immunocompromised and immunocompetent patients. Zoonotic species of Cyclospora have also been identified in East African primates, indicating likely endemicity of this little reported disease in the region. This can be attributed to lack of awareness in the public and medical profession concerning the disease, and therefore not routinely checked at the health centres. Cyclosporiasis is characterized by intermittent diarrhoea, and secondary conditions or sequelae such as reactive arthritis syndrome (Reiter's syndrome), have been associated with progression of the disease. Its management is based on antibiotics, an unusual scenario for a protozoa.

CONCLUSIONS

Although many aspects of this disease and its transmission remain an enigma, the situation has been rapidly changing since the disease first came to medical attention in the 1970s.

Correlation between CD4 counts of HIV patients and enteric protozoan in different seasons - an experience of a tertiary care hospital in Varanasi (India)

BACKGROUND

Protozoan infections are the most serious among all the superimposed infections in HIV patients and claim a number of lives every year. The line of treatment being different for diverse parasites necessitates a definitive diagnosis of the etiological agents to avoid empirical treatment. Thus, the present study has been aimed to elucidate the associations between diarrhoea and CD4 counts and to study the effect of HAART along with management of diarrhoea in HIV positive patients. This study is the first of its kind in this area where an attempt was made to correlate seasonal variation and intestinal protozoan infestations.

METHODS

The study period was from January 2006 to October 2007 wherein stool samples were collected from 366 HIV positive patients with diarrhea attending the ART centre, inpatient department and ICTC of S.S. hospital, I.M.S., B.H.U., Varanasi. Simultaneously, CD4 counts were recorded to assess the status of HIV infection vis-à-vis parasitic infection. The identification of pathogens was done on the basis of direct microscopy and different staining techniques.

RESULTS

Of the 366 patients, 112 had acute and 254 had chronic diarrhea. The percentages of intestinal protozoa detected were 78.5% in acute and 50.7% in chronic cases respectively. Immune restoration was observed in 36.6% patients after treatment on the basis of clinical observation and CD4 counts. In 39.8% of HIV positive cases Cryptosporidium spp. was detected followed by Microsporidia spp. (26.7%). The highest incidence of intestinal infection was in the rainy season. However, infection with Cyclospora spp. was at its peak in the summer. Patients with chronic diarrhea had lower CD4 cell counts. The maximum parasitic isolation was in the patients whose CD4 cell counts were below 200 cells/microl.

CONCLUSION

There was an inverse relation between the CD4 counts and duration of diarrhea. Cryptosporidium spp. was isolated maximum among all the parasites in the HIV patients. The highest incidence of infection was seen in the rainy season.

Six human cyclosporiasis: with general review

Cyclospora cayetanensis is an emerging coccidian pathogen known in animal since a long time, but recognized in human in last two decade. The present study of cyclosporiasis specified its characteristic features. An epidemiological, clinical and biological retrospective study was carried out on 6 patients, 24 to 67 years old, who complained of diarrhea and weight loss, after a travel abroad. The only pathogenic agent found in every patient was Cyclospora cayetanensis. The patients returned back from Asian countries and from Madagascar. They were cured by Trimethoprim-sulfamethoxazole (TMZ). Diarrhoea was the main symptom of infection by C. cayetanensis. Undoubtedly, transmission occurred by the oro-fecal route, and/or by consumption of infected water or foods. Diagnosis was asserted, recovery of this protozoan parasite in the stools samples. TMZ proved to be the most effective and possibly replaced Ciprofloxacine. The prophylaxis recommended control measure of water supply and foods. Cyclospora should be considered in the assessments of patients with unexplained prolonged diarrhoea, if the investigation for bacterial and parasitological diarrhoea or the traveler's diarrhoea were negative.

Epidemiology of Cyclospora cayetanensis infection in San Carlos Island, Venezuela: strong association between socio-economic status and infection

The epidemiology of Cyclospora cayetanensis is not well understood. Few community-based studies have addressed this issue. A study was conducted to determine the prevalence and risk factors for cyclosporiasis in San Carlos Island, Venezuela. A sample of 515 subjects (mean+/-SD: 21.4+/-17.8 years) was surveyed. For identification of the parasite, stools were examined with modified Ziehl-Neelsen carbolfuchsin staining of formalin-ether concentrates. Infections with Cyclospora (43 of 515, 8.3%) were common. There were differences in prevalence of the parasite among sectors of the community: 30 out of 43 (69.8%) cases of cyclosporiasis clustered in two sectors with extreme poverty. Living in these sectors versus the remainder, living in a hut or small residence versus a concrete or larger house, using an area of backyard rather than a toilet or latrine for defecation, and having contact with soil contaminated with human feces were factors strongly associated with the infection (P<0.01). Contact with soil contaminated with human feces might be an important mode of transmission, and poverty a predisposing factor, for the infection.

Real-time PCR and flow cytometry in detection of Cyclospora oocysts in fecal samples of symptomatic and asymptomatic pediatrics patients

The magnitude of Cyclospora oocysts excretion in relation to infection intensity among cyclosporiasis patients was assessed using flow cytometry and quantitative real-time PCR (RT-PCR). Oocysts from stool samples of 25 (14.8%) gastro-intestinal symptomatic pediatrics patients (169) and of 10 (2.8%) asymptomatic gastrointestinal ones (350) were identified by modified Ziehl-Neelsen (MZN) and modified Acid Fast Trichrome (MAFT) staining methods and confirmed by its auto-fluorescent characterizations. Also, 10 infants with negative stool samples were selected as controls. The intensity of infection was calculated as number of oocysts/200 microscopic filed with immersion 400. Flow cytometry and RT-PCR assessed relation between symptoms and oocysts excretions compared to MZN & MAFT. The infection severity in symptomatic patients were identified by MZN & MAFT as mild (16%), moderate (24%) and severe (60%) All asymptomatic patients had mild infection. Flow cytometry was done for stool samples and 100% Cyclospora oocysts were in symptomatic and asymptomatic patients. None was detected in controls. RT-PCR was done for stools with both a species-specific primer set and dual fluorescent labeled Cyclospora cayetanensis hybridization probe by unique regions of 18S rRNA gene sequence. DNA of C. cayetanensis was in 100% of symptomatic and asymptomatic patients and in 20% of controls. In repetitive examination of stools Cyclospora oocysts were neither detected by staining nor flow cytometry. Based on oocysts counts, no differences were found between flow cytometry and RT-PCR in compared to staining methods.

First reported waterborne outbreak of cryptosporidiosis with Cyclospora co-infection in Turkey

In September 2005, an outbreak of cryptosporidiosis with co-infection of Cyclospora occurred in western Turkey, in a village about 25 kilometres from Izmir, the country’s third largest city.

Incidence of cyclosporiasis in patients with gastrointestinal symptoms in western Turkey

BACKGROUND

This study was designed to investigate the distribution of cyclosporiasis between October 2003 and October 2004 and the relationship between Cyclospora infection and seasonal as well as patient factors in western Turkey.

MATERIAL/METHODS

Stool samples from 4660 immunocompetent patients with gastrointestinal symptoms and 326 immunocompetent patients with allergic symptoms from western Turkey were examined between October 2003 and October 2004 using wet preparation, formalin-ethyl acetate concentration, Trichrome stain, and modified Kinyoun's acid-fast staining methods.

RESULTS

Twenty-three patients were found to be infected with Cyclospora oocysts. Parasites such as Cryptosporidium, Giardia intestinalis, Entamoeba histolytica/dispar, Blastocystis hominis and others were also observed. The incidence of cyclosporiasis was higher in summer and early autumn and most of the Cyclospora-infected patients were without diarrhea.

CONCLUSIONS

Clinicians with patients from Turkey and abroad who have intestinal symptoms after visiting the country should be aware that Cyclospora infections could be considered as a possible cause of gastrointestinal symptoms in the absence of diarrhea in immunocompetent patients during the summer period in Turkey.

Brote epidémico por Cyclospora cayetanensis en Medellín, Colombia

OBJECTIVE

Describing an outbreak of gastrointestinal disease in a group of 56 patients from Medellín, Colombia.

METHODS

An unusual number of cases of diarrhoea appeared in April 2002 and 56 samples of stool from the same number of individuals were collected because a patient proved Cyclospora cayetanensis positive. A clinical-epidemiological survey, direct coprology, formol-ether concentration and modified Zielhs Neelsen staining were then carried out. Some food samples were also studied for parasites by direct and modified Zielh Neelsen staining.

RESULTS

55.4% (31/56) of the patients being evaluated proved positive for C. cayetanensis. 77.4% (24/31) were women and 83.9% (26/31) belonged to the University of Antioquia, 88.6% of whom were not teachers. There was no statistically significant difference between positive and negative patients for Cyclospora regarding clinical manifestations, except for dehydration which was greater in patients having cyclosporiasis. However, there was a significant difference regarding consuming salads and juice, this being greater amongst positive patients than negative ones.

CONCLUSION

An outbreak of C. cayetanensis appeared in symptomatic patients being taken care of by the GIEPI group during April 2002.

[Laboratory diagnosis of opportunistic intestinal parasites with emphasis on human microsporidiosis, in Goiânia-Go]

Microsporidia are emergent and opportunistic protozoa that are responsible for diseases with high morbidity and mortality, especially among individuals with immune disorders. This study had the aim of determining the clinical-laboratory profile of these agents. In total, 723 patients were evaluated, divided into two groups: I) Immunosuppressed/immunodepressed individuals; II) Apparently immunocompetent individuals. After obtaining free informed consent, these patients were interviewed and gave fecal samples. These samples were all subjected to the HPJ, Rugai and Faust techniques and to specific staining for Coccidia and Microsporidia. The frequency of Microsporidia was 1.3% (5/393) in group I, whereas it was a quarter of this in group II. The occurrence of other opportunistic intestinal parasites was also greater in group I. It was concluded, firstly, that these agents are present in our environment and, secondly, that there is a need to improve the clinical and laboratory diagnosis, in order to define the geographic distribution of these agents in the State of Goiás and throughout Brazil.

Cyclosporiasis: a point source outbreak acquired in Guatemala

BACKGROUND

Cyclosporiasis is a disease due to Cyclospora cayetanensis, an emerging coccidian parasite first described in 1979. It is an orally transmitted disease that is more frequent in tropical and subtropical areas. Cyclospora cayetanensis has been mainly described as a cause of travelers' diarrhea. This pathogen has given rise to a number of epidemic outbreaks attributable to ingestion of imported foods, particularly from tropical areas.

METHODS

Descriptive study of clinical and epidemiological data of a small epidemic outbreak of C cayetanensis-induced gastroenteritis.

RESULTS

Seven confirmed cases of C cayetanensis among Spanish nationals who had traveled to Antigua Guatemala are described. The incubation period was 6 days. Diarrhea, asthenia, anorexia, borborygmi, flatulence, and abdominal distension were present in all cases. Fever and heart burn in 85.7%. Weight loss in 71.4%. Abdominal pain, rectal tenesmus, and nausea in 42.8%. Vomiting and eructation in 14.2%. Heart burn was a frequent symptom, a finding not often previously described. The infection was probably acquired from raspberry juice. All cases improved with trimethoprim/sulphametoxazol.

CONCLUSIONS

Cyclosporiasis is a cause of travelers' diarrhea. Parasitology laboratories must be advised of clinical suspicion of cyclosporiasis so that they can conduct a suitable targeted study; otherwise, false negative results may arise.

Outbreak of cyclosporiasis at a naval base in Lima, Peru

Cyclospora cayetanensis is emerging as an important cause of food-borne diarrheal outbreaks, especially in developed regions like the United States and Europe. We describe an outbreak of cyclosporiasis in Peruvian naval recruits that we believe to be the first among a local population in a developing region.

Cyclosporiasis outbreak, Indonesia

We describe an outbreak of Cyclospora cayetanensis infection among Dutch participants at a scientific meeting in September 2001 in Bogor, Indonesia. Fifty percent of the investigated participants were positive for C. cayetanensis. To our knowledge, this outbreak is the first caused by C. cayetanensis among susceptible persons in a disease-endemic area.

Cyclospora infection in five immunocompetent patients in a Turkish university hospital

Infection with Cyclospora has been increasingly reported worldwide in both immunocompetent and immunocompromised individuals. Here the cases of five patients infected with Cyclospora cayetanensis, who sought medical care at Hacettepe University in Turkey, are reported. Diarrhoea occurred from five to fifteen times a day in all of these patients, whose ages ranged from 27 to 67 years. All the patients were considered immunocompetent. Identification of C. cayetanensis was made by detection of the oocysts by using a modified acid-fast stain.

Role of water in the transmission of cyclosporiarsis in Sharkia Governorate, Egypt

Water samples were collected form five residential areas in El-Ekhewa Village where the human populations use this water for daily activity and for consumption. These water sources were Bahr El-Baker drain, low running irrigation canal, underground water at shallow depth (3-8 m), finished piped water and underground water >35 m deep. The samples were concentrated by flocculation method and the concentrated pellets were examined by ultraviolet (UV) epifluorescence microscopy for Cyclospora oocysts. The densities of water contamination by 8-10 microm oocysts/liter in the five sources were respectively: 2400, 1900, 700, 200 and zero. This indicated that finished water was sewage contaminated. Stool samples from 109 diarrheal patients and 231 non-diarrheal ones from these areas were examined by the acid fast-trichrome stain, Saline Haemo De single slide trichrome stain and by standard bacteriologic techniques. Those with Cyclospora as single pathogen were considered (5.6%) of diarrheal and (2.3%) of the non-diarrheal individuals. The correlation between the density of water contamination and the prevalence of cyclosporiasis among the individuals of each area was significant. No doubt, water was the main vehicle of transmission in the present community. Soil contact and poultry were significant risk factors.

Study on cyclospora cayetanensis associated with diarrheal disease in Nepal and Loa PDR

A study of diarrheal diseases associated with Cyclospora cayetanensis was conducted in Nepal and Lao PDR. A total of 2083 samples were included in this study. Samples in Nepal were collected from October 1999 to August 2002 whereas samples in Lao PDR were collected from February 2002 to June 2003. C. cayetanensis was detected by direct microscopy using ultraviolet and differential interference contrast microscopy. The overall positive rate in Nepal was 9.2% (128/ 1397). A higher positive rate was observed in children aged 10 years and under (11.1%) and was lowest in the age group of 51-60 years (3.1%). A significantly higher positive rate was observed in the summer (rainy season) (12.6%) with the lowest prevalence in the spring (dry season) (1.8%) (p < 0.05). The positive rate was closely associated with rainfall (ml/month). Interestingly, only one of the total 686 samples (0.1%) from Lao PDR was found to be positive for Cyclospora oocysts.

[Cyclosporosis: an emergent parasitosis. (I) Clinical and epidemiological aspects]

PURPOSE

Determine the prevalence of Cyclospora cayetanensis in asymptomatic patients consulting a physician, or dwellers of marginal urban settlements surrounding Lima, Peru.

MATERIALS AND METHODS

The population was composed of 3,259 individuals: 2,968 individuals between 1 month and 87 years of age, who consulted a private physician because of digestive disorders, particularly diarrhea, and 291 individuals between 5 months and 75 years of age from marginal areas, all apparently healthy. The presence of Cyclospora was investigated through "fresh" microscopic techniques using a saline solution and Lugols solution. A new staining technique described in other publication was used. A record was created containing all clinical and epidemiological data, which were assessed statistically.

RESULTS

Cycloscopora incidence was 7.3% in the first group, and 41.6% in the second group. A higher rate was observed in young and elder adults up to 60-year-old. No major seasonal incidence was found. Clinical signs/symptoms for individuals consulting a private physician were mainly diarrhea and abdominal pain while individuals from marginal urban areas mainly showed meteorism, abdominal plain, occasional diarrhea and general symptoms such as fatigue and weight loss.

CONCLUSIONS

Cyclospora showed a high incidence, particularly in marginal urban areas. Two types of clinical signs/symptoms were found: an acute and very severe condition that can cause dehydration, and a chronic condition with several digestive signs/symptoms, particularly meteorism and abdominal pain. Individuals consulting a private physician show acute and chronic episodes while individuals from marginal urban areas do show a chronic condition. Apparently individuals showing acute episodes are immunologically exposed to the parasite, but they do not acquire immunity later in spite of the treatment because they may become re-infected from time to time. However, individuals showing chronic episodes apparently keep a host-parasite balance due to a permanent contact with the parasite. The contamination source appears to be the water. Therefore all required epidemiological actions shall be taken to prevent this problem from reaching higher dimensions.

Retrospective study of the occurrence of Cyclospora cayetanensis at Clinical Hospital of the University of São Paulo Medical School, SP

Cyclospora cayetanensis causes watery diarrhea in tropical countries, among travelers and after ingestion of contaminated water and food. Very little is known about its epidemiology, pathogenic aspects and reservoirs. In Brazil, its prevalence is unknown and to date there have been reports of three outbreaks. We report here a retrospective study of 5,015 stool samples from 4,869 patients attended at Clinical Hospital of the University of São Paulo Medical School, SP, Brazil between April 1996 and January 2002, with 14 cases of Cyclospora cayetanensis being detected there was a prevalence of 0.3%. Of the 14 infected patients, the mean age was 38 years and 71.4% were female. Ten patients presented symptoms; six presented levels of immunological markers and five patients were immunodeficient.

Outbreak of cyclosporiasis in British Columbia associated with imported Thai basil

Sporadic outbreaks of cyclosporiasis, a common cause of protracted diarrhoea in underdeveloped countries, are often undetected and undiagnosed in industrial countries. In May 2001, an outbreak of Cyclospora cayetanensis gastroenteritis was identified in British Columbia, Canada, with 17 reported cases. We conducted a case-control study involving 12 out of the 17 reported and confirmed case patients. Eleven (92%) of the patients had consumed Thai basil, an essential ingredient in Vietnamese cuisine, compared to 3 out of 16 (19%) of the control patients (P = 0.003). Trace-back investigations implicated Thai basil imported via the United States as the vehicle for this outbreak. This is the first documented sporadic outbreak of cyclosporiasis linked to Thai basil in Canada, and the first outbreak of cyclosporiasis identified in an ethnic immigrant population. This outbreak provides the opportunity to increase our understanding of this emerging pathogen and improve on our prevention and control for future outbreaks.

Comparison of three microscopic techniques for diagnosis of Cyclospora cayetanensis

Cyclospora cayetanensis oocysts in the feces of humans from Kathmandu, Nepal were identified on the basis of their size and other morphological characteristics. We compared the detection of C. cayetanensis oocysts in the feces using three microscopic techniques such as formalin-ether sedimentation, sucrose centrifugal floatation, and direct smear. Standard procedures were used for the formalin-ether sedimentation and the sucrose centrifugal floatation techniques using 0.5 g of feces, however, the direct smear technique was performed using 10 microl of fecal suspension (0.005 g of feces) and observed under the fluorescent microscope. Of the 403 samples examined, 21 samples were positive for oocysts by all three techniques. Therefore, in these 21 samples, the number of oocysts recovered by the three techniques were compared. The highest number of oocyst was obtained by the sucrose centrifugal floatation technique. In contrast, the formalin-ether sedimentation technique was found to be the least reliable concentration technique for the detection of Cyclospora in human feces. Surprisingly, the direct smear technique was found to be an effective and rapid technique for diagnosis of C. cayetanensis making it a technique of choice for routine epidemiological investigation of the prevalence of this infection in human populations.

Cyclospora cayetanensis, a food- and waterborne coccidian parasite

Food- and waterborne coccidia including Cryptosporidium parvum, Cyclospora cayetanensis, Sarcocystis hominis and Sarcocystis suihominis, and Isospora belli are cyst-forming apicomplexan protozoa that cause intracellular infections, predominantly in the epithelial cells of the intestine. They are transmitted by oocysts from person-to-person by the fecal-oral route or via contaminated water or food. The most common symptom of infection is diarrhea, however, asymptomatic infections occur. Infections are associated with intestinal inflammation, with pathological lesions such as villus blunting, and abnormal function such as malabsorption. Mild-to-moderate, self-limiting diarrhea is common in healthy individuals ingesting infective stages of these organisms. However, patients with immune dysfunction can have severe intestinal injury and prolonged diarrhea. Diagnosis in many cases is made by a microscopic examination of the stool, and the use of appropriate staining techniques, but more recently molecular methods for detection are used increasingly. Effective antimicrobial treatment for prolonged infection in immunocompromised patients is available for most of these infections. These gastrointestinal coccidial pathogens have important similarities in epidemiology, disease pathogenesis, clinical manifestations, diagnosis, and treatment. Although there are many other cyst-forming coccidia of public health, veterinary and/or economic importance, discussion in this chapter will be limited to C. cayetanensis, as an important example of the group. Aspects of the biology, epidemiology, diagnosis, disease, treatment and control are considered. This parasite is considered to be an emerging pathogen. From 1990 to 2000, there were 11 foodborne outbreaks of cyclosporosis in North America that affected at least 3600 people. There are many outstanding questions regarding this parasite and under-reporting is common because general diagnostic methods for intestinal parasites are inadequate for detection of Cyclospora.

[Cyclosporidiosis: clinical and diagnostic characteristics of an epidemic outbreak]

BACKGROUND

Cyclospora cayetanensis, a coccidian parasite, has increasingly been recognized as a cause of gastrointestinal tract illness. We describe a group of patients with this infection.

OBJECTIVES

Our aim was to describe the observed clinical course and spectrum of the disease.

METHODS

We conducted a prospective study of 101 patients with diarrhea who attended the same wedding reception.

RESULTS

Mean incubation period was 8 days; commonly reported symptoms included diarrhea (91%), with 10 or more loose stools in a 24-h period. The illness had a characteristic waxing and waning course and in nearly 72% of patients there occurred symptom recurrence. Other reported symptoms in our patient group included vomiting and fever; 72% of patients had received antibiotics, mainly quinolones, without good response. Watercress was probable vehicle of transmission.

CONCLUSIONS

Cyclospora may cause severe diarrhea with a long incubation period and recurring symptoms, which should be considered in evaluation of prolonged gastrointestinal illness. To our knowledge, this is the first outbreak reported in Mexico.

Centers for Disease Control and Prevention (CDC). Outbreak of cyclosporiasis associated with snow peas--Pennsylvania, 2004

During June-July 2004, public health officials in Pennsylvania were notified of cases of the parasitic disease cyclosporiasis among persons associated with a residential facility (e.g., residents, staff, and volunteers). CDC confirmed the diagnosis of Cyclospora cayetanensis infection by examining stool specimens from multiple patients. By early July, local public health officials had been notified of approximately 50 potential cases of cyclosporiasis associated with the facility; onsets of illness were from early June through early July. This report describes the findings of the epidemiologic and traceback investigations, which determined the cases were linked to consumption of raw Guatemalan snow peas at five special events, for which food was prepared by the facility staff, from late May through late June. This is the first documented outbreak of cyclosporiasis linked to snow peas. The Food and Drug Administration (FDA) and CDC are working with Guatemalan officials to determine the sources of the snow peas and possible modes of contamination.

Point prevalence of Cryptosporidium, Cyclospora, and Isospora infections in patients being evaluated for diarrhea

From March to September 2001, 315 specimens from "nonrepeat" patients that were submitted for ova and parasite examination were stained using the Kinyoun modified acid-fast stain to detect the intestinal coccidians. Four patients (1.3%) were infected with coccidians, 2 with Cryptosporidium parvum and 2 with Cyclospora cayetanensis. No infections with Isospora belli were detected. In comparison, 15 patients (4.8%) had infections with one or more intestinal parasites detected by routine trichrome staining: 5 had Giardia lamblia; 2, Dientamoeba fragilis; 3, Strongyloides stercoralis; 1, Iodamoeba bütschlii; 3, Endolimax nana; 6, Blastocystis hominis; and 1, Entamoeba coli. Four patients were multiply infected. Coccidians made up 29% of the clinically significant parasitic infections. The coccidians were missed in all 4 cases because no special staining was ordered. Clinicians need to be reminded that additional tests should be ordered to fully evaluate patients with chronic diarrhea in which no diagnosis is found by routine testing.

Epidemiological survey of intestinal parasitic infections of diarrhoeal patients in Nepal and Lao PDR

Intestinal parasitological survey was conducted to clarify the distribution of intestinal parasites in Nepal and Lao Peoples' Democratic Republic (Lao PDR) from 2001 to 2003. A total of 401 diarrheal fecal specimens were collected from patients aged one to 75 years (250 from Nepal and 151 from Lao PDR). The specimens were examined using the formalin-ether sedimentation (FES) and sucrose centrifugal flotation (SCF) techniques. Nine species (3 Nematoda, 1 Cestoda, and 5 Protozoa) of parasites were recovered from Nepal, whereas seven species (3 Nematoda, 1 Trematoda, and 3 Protozoa) from Lao PDR. Of the parasites detected, (14.4%) was the most common in Nepal, and was Opisthorchis viverrini (29.8%) in Lao PDR. Infection rates were markedly different among age groups in both countries; higher rates were observed in age groups of 10-29 years than in 0-9 years group. Scanning electron microscopic observation revealed that trematoda eggs recovered from Lao PDR were identified as O. viverrini, which could not be done by a light microscope.

Cyclospora cayetanensis infection in Lagos, Nigeria

Although reports of Cyclospora infection continue to increase globally, few cases have been reported from the African continent. We present 11 cases of cyclosporiasis detected from stool samples submitted to seven major hospital laboratories in Lagos, Nigeria between March 1999 and April 2000.

Intestinal coccidia in Cuban pediatric patients with diarrhea

From May to August 1999, we evaluated 401 patients from a pediatric hospital of Havana City. One group was composed of 113 patients with diarrhea admitted to the Gastroenterology ward and a second consisted of 288 patients without diarrhea, admitted for other reasons, and hospitalized within the same time period. Three stool samples were collected from each child and were examined using three parasitological techniques. When we compared the frequency of parasite species between both groups, we found Cryptosporidium spp. and Cyclospora cayetanensis, only in the group of children with diarrhea (P < 0.01). However, no significant differences were found in the occurrence of the other intestinal parasites (P > 0.05). In addition, in those children infected with Cryptosporidium, the diarrhea had a more prolonged duration (P < 0.01), while those infected with Cyclospora, the abdominal cramps or pain, and acute diarrhea were more frequently detected (P < 0.01). Our results showed that emerging intestinal coccidia are pathogens strongly associated in this group of children with diarrhea.