Cyclospora cayetanensis in a pediatric hospital in Morelia, México

Multi-laboratory validation of a modified real-time PCR assay (Mit1C) for the detection of Cyclospora cayetanensis in fresh produce

Cyclospora cayetanensis is a foodborne protozoan parasite that causes the human diarrheal disease cyclosporiasis. Recently, the US FDA developed a modified real-time PCR method based on a specific mitochondrial target gene (Mit1C) to detect C. cayetanensis in fresh produce. The method was validated by single laboratory validation (SLV) studies in Romaine lettuce, cilantro, and raspberries. The present study aimed to evaluate the performance of the new real-time Mit1C (Mit1C qPCR) method by comparing it with the current BAM Chapter 19b qPCR (18S qPCR) as the reference method for the detection of the protozoan parasite C. cayetanensis in fresh produce in a multi-laboratory validation (MLV) setting with the participation of 13 collaborating laboratories. Each laboratory analyzed twenty-four blind-coded Romaine lettuce DNA test samples that included: two unseeded samples, three samples seeded with five oocysts, and one sample seeded with 200 oocysts in the first round and five unseeded samples, eight samples seeded with five oocysts, and five samples seeded with 200 oocysts in the second round. The overall detection rates across laboratories for Romaine lettuce samples inoculated with 200 and 5 oocysts and un-inoculated samples were 100% (78/78), 69.23% (99/143), and 1.1% (1/91), respectively, for Mit1C qPCR, and 100% (78/78), 61.54% (88/143) and 0% (0/91), respectively, for 18S qPCR. The relative level of detection (RLOD = LOD50, Mit1C/LOD50, 18S) was 0.81 with a 95% confidence interval (0.600, 1.095), which included 1. Thus, Mit1C qPCR and 18S qPCR had statistically similar levels of detection. Mit1C qPCR was highly reproducible as the between-laboratory variance in the test results was nearly zero (0) and showed a high specificity at 98.9%. In conclusion, this study demonstrated that the new, more specific Mit1C qPCR method is an effective alternative analytical tool for detection of C. cayetanensis in fresh produce.

Evaluating Foodborne Cyclosporiasis Using Foodborne Diseases Active Surveillance Network and Foodborne Disease Outbreak Surveillance System Data, 2015-2019

Cyclosporiasis has been a nationally notifiable disease in the United States since 1999, and cases have increased in recent years. We evaluated characteristics of U.S. cases and outbreaks to identify gaps and potential prevention measures for mitigating cyclosporiasis. We assessed Cyclospora data from the Foodborne Diseases Active Surveillance Network (FoodNet) and from the Foodborne Disease Outbreak Surveillance System (FDOSS) collected between 2015 and 2019. There were 1,376 cyclosporiasis cases in FoodNet between 2015 and 2019. Approximately one-fifth (n = 290, 21.1%) reported recent international travel. Most cases occurred in 2018 (n = 334, 24.3%) and 2019 (n = 758, 55.1%). There was strong seasonality, with 1,160 (90.9%) cases in the summer months. Most travelers reported visiting Mexico (n = 182, 62.8%) and Guatemala (n = 25, 8.6%). Approximately two-thirds of FoodNet cases were outbreak associated (n = 987, 71.7%). Of the 79 outbreaks reported to FDOSS, 31 (39.2%) occurred in 2018 and 40 (50.6%) occurred in 2019. Outbreaks tended to occur in spring and summer months (n = 78, 98.7%), The most common age groups among the 2,335 cases with data available included 20-49 years (n = 1,168, 50.0%), 50-74 years (n = 985, 42.2%), and ≥75 years (n = 120, 5.1%). Although direct comparisons between FoodNet and FDOSS are not possible, both datasets indicate that the majority of Cyclospora transmission is domestic and not travel associated, as previously thought. These findings show the need for continued investment in Cyclospora research, including identifying populations that are underrepresented, or at higher risk for cyclosporiasis, and improved understanding of national sources and pathways of infection.

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.

Review on Cyclosporiasis Outbreaks and Potential Molecular Markers for Tracing Back Investigations

Cyclosporiasis is an emerging disease caused by Cyclospora cayetanensis, which induces protracting and relapsing gastroenteritis and has been linked to huge and complicated travel- and food-related outbreaks worldwide. Cyclosporiasis has become more common in both developing and developed countries as a result of increased global travel and the globalization of the human food supply. It is not just a burden on individual human health but also a worldwide public health problem. As a pathogen of interest, the molecular biological characteristics of C. cayetanensis have advanced significantly over the last few decades. However, only one FDA-approved molecular platform has been commercially used in the investigation of cyclosporiasis outbreaks. More potential molecular markers and genotyping of C. cayetanensis in samples based on the polymorphic region of the whole genomes might differentiate between separate case clusters and would be useful in tracing back investigations, especially during cyclosporiasis outbreak investigations. Considering that there is no effective vaccine for cyclosporosis, epidemiological investigation using effective tools is crucial for controlling cyclosporiasis by source tracking. Therefore, more and more epidemiological investigative studies for human cyclosporiasis should be promoted around the world to get a deeper understanding of its characteristics as well as management. This review focuses on major cyclosporiasis outbreaks and potential molecular markers for tracing back investigations into cyclosporiasis outbreaks.

Intestinal apicomplexan parasitoses among a hospital-based population in Honduras, 2013-2019

Introduction:

Intestinal apicomplexa protozoa are a recognized cause of gastroenteritis. They are endemic in Honduras and their epidemiology varies in different population groups.

Objective:

To identify risk factors for cyclosporiasis, cryptosporidiosis, and cystoisosporiasis.

Materials and methods:

We conducted a case-control study in a hospital-based population. We performed the diagnosis using the modifed Ziehl-Neelsen staining technique and collected the information from laboratory records and clinical charts.

Results:

Cyclosporiasis was associated with diarrhea (OR=2.28; 95%CI: 1.10-4.89), weight loss (OR=12.7; 95%CI: 2.49-122.00), watery stools (OR=2.42; 95%CI: 1.26-4.65), and infection with another protozoan (OR=3.13; 95%CI: 1.66-5.95). Cryptosporidiosis was associated with HIV infection (OR=15.43; 95%CI: 3.34-71.22), diarrhea (OR=3.52; 95%CI: 1.40-9.40), lymphopenia (OR=6.16; 95%CI: 1.99-18.98), and green color stools (OR=3.00; 95%CI: 1.23-7.30). Cystoisosporiasis was associated with HIV infection (OR=11.20; 95%CI: 3.53-35.44), diarrhea (OR=7.30; 95%CI: 1.89-28.52), leukopenia (OR=4.28; 95%CI: 1.33-13.75), green color stools (OR=11.59; 95%CI: 1.16-558.60), and Charcot-Leyden crystals (OR=11.59; 95%CI: 1.16-558.60).

Conclusions:

In this hospital-based population from Honduras, HIV infection was a risk factor for cryptosporidiosis and cystoisosporiasis, but not for cyclosporiasis.

Understanding the Impact of Rainfall on Diarrhea: Testing the Concentration-Dilution Hypothesis Using a Systematic Review and Meta-Analysis

BACKGROUND

Projected increases in extreme weather may change relationships between rain-related climate exposures and diarrheal disease. Whether rainfall increases or decreases diarrhea rates is unclear based on prior literature. The concentration-dilution hypothesis suggests that these conflicting results are explained by the background level of rain: Rainfall following dry periods can flush pathogens into surface water, increasing diarrhea incidence, whereas rainfall following wet periods can dilute pathogen concentrations in surface water, thereby decreasing diarrhea incidence.

OBJECTIVES

In this analysis, we explored the extent to which the concentration-dilution hypothesis is supported by published literature.

METHODS

To this end, we conducted a systematic search for articles assessing the relationship between rain, extreme rain, flood, drought, and season (rainy vs. dry) and diarrheal illness.

RESULTS

A total of 111 articles met our inclusion criteria. Overall, the literature largely supports the concentration-dilution hypothesis. In particular, extreme rain was associated with increased diarrhea when it followed a dry period [incidence rate ratio ( IRR ) = 1.26 ; 95% confidence interval (CI): 1.05, 1.51], with a tendency toward an inverse association for extreme rain following wet periods, albeit nonsignificant, with one of four relevant studies showing a significant inverse association (IRR = 0.911 ; 95% CI: 0.771, 1.08). Incidences of bacterial and parasitic diarrhea were more common during rainy seasons, providing pathogen-specific support for a concentration mechanism, but rotavirus diarrhea showed the opposite association. Information on timing of cases within the rainy season (e.g., early vs. late) was lacking, limiting further analysis. We did not find a linear association between nonextreme rain exposures and diarrheal disease, but several studies found a nonlinear association with low and high rain both being associated with diarrhea.

DISCUSSION

Our meta-analysis suggests that the effect of rainfall depends on the antecedent conditions. Future studies should use standard, clearly defined exposure variables to strengthen understanding of the relationship between rainfall and diarrheal illness. https://doi.org/10.1289/EHP6181.

Acute kidney injury associated with intestinal infection by Cyclospora cayetanensis in a kidney transplant patient. A case report

This study shows a clinical case report of a kidney transplant patient who traveled from Mexico to The Netherlands and ate green vegetables in an international food restaurant. After 5 days, he started having diarrhea, nausea, colic, and a physical feeling of malaise. The patient only received symptomatic treatment after showing the characteristic symptoms of traveler's diarrhea. When he returned to Mexico, the clinical picture worsened, and he was hospitalized. Clinical analyses indicated dehydration and acute kidney injury stage II. Coproparasitoscopic study showed the presence of Cyclospora cayetanensis. Parenteral solutions, gastric mucosal protector, ciprofloxacin, and a soft diet were administrated as treatment. The patient was discharged 72 h later with an improvement of the kidney function.

Sporadic cyclosporiasis in symptomatic Cuban patients: Confirmation of positive results from conventional diagnostic methods by molecular assay

In Cuba, there are few studies on cyclosporiasis. Here, we report results from 1247 stool samples from symptomatic patients that were examined by microscopy methods and positive cases confirmed by nested PCR targeting the 18S rRNA gene, followed by sequencing. Seven positive samples, all diagnosed during May-June, were confirmed by the molecular method, indicating an occurrence in this patient cohort of 0.56%.

Cyclospora cayetanensis infection in humans: biological characteristics, clinical features, epidemiology, detection method and treatment

Cyclospora cayetanensis, a coccidian parasite that causes protracted and relapsing gastroenteritis, has a short recorded history. At least 54 countries have documented C. cayetanensis infections and 13 of them have recorded cyclosporiasis outbreaks. Cyclospora cayetanensis infections are commonly reported in developing countries with low-socioeconomic levels or in endemic areas, although large outbreaks have also been documented in developed countries. The overall C. cayetanensis prevalence in humans worldwide is 3.55%. Among susceptible populations, the highest prevalence has been documented in immunocompetent individuals with diarrhea. Infections are markedly seasonal, occurring in the rainy season or summer. Cyclospora cayetanensis or Cyclospora-like organisms have also been detected in food, water, soil and some other animals. Detection methods based on oocyst morphology, staining and molecular testing have been developed. Treatment with trimethoprim-sulfamethoxazole (TMP-SMX) effectively cures C. cayetanensis infection, whereas ciprofloxacin is less effective than TMP-SMX, but is suitable for patients who cannot tolerate co-trimoxazole. Here, we review the biological characteristics, clinical features, epidemiology, detection methods and treatment of C. cayetanensis in humans, and assess some risk factors for infection with this pathogen.

Cyclospora cayetanensis and Cyclosporiasis: An Update

Cyclospora cayetanensis is a coccidian parasite of humans, with a direct fecal-oral transmission cycle. It is globally distributed and an important cause of foodborne outbreaks of enteric disease in many developed countries, mostly associated with the consumption of contaminated fresh produce. Because oocysts are excreted unsporulated and need to sporulate in the environment, direct person-to-person transmission is unlikely. Infection by C. cayetanensis is remarkably seasonal worldwide, although it varies by geographical regions. Most susceptible populations are children, foreigners, and immunocompromised patients in endemic countries, while in industrialized countries, C. cayetanensis affects people of any age. The risk of infection in developed countries is associated with travel to endemic areas and the domestic consumption of contaminated food, mainly fresh produce imported from endemic regions. Water and soil contaminated with fecal matter may act as a vehicle of transmission for C. cayetanensis infection. The disease is self-limiting in most immunocompetent patients, but it may present as a severe, protracted or chronic diarrhea in some cases, and may colonize extra-intestinal organs in immunocompromised patients. Trimetoprim-sulfamethoxazole is the antibiotic of choice for the treatment of cyclosporiasis, but relapses may occur. Further research is needed to understand many unknown epidemiological aspects of this parasitic disease. Here, we summarize the biology, epidemiology, outbreaks, clinical symptoms, diagnosis, treatment, control and prevention of C. cayetanensis; additionally, we outline future research needs for this parasite.

Enteroparasitism and Risk Factors Associated with Clinical Manifestations in Children and Adults of Jalisco State in Western Mexico

Objectives

To determine the prevalence and risk factors associated with intestinal parasites in the population of San Juan Cosala, Jalisco, Mexico.

Methods

A total of 277 samples from 104 participants were analysed using direct smear, flotation, formaldehyde/ethyl acetate, and modified Kinyoun's acid-fast stain methods. The Graham method was applied only for samples from children under 12 years of age for the diagnosis of Enterobius vermicularis.

Results

The prevalence of parasite infections in the study population was 77.9% including: Entamoeba histolytica/E. dispar/E. moshkovskii/E. bangladeshi (37.5%), Giardia intestinalis (11.5%); commensals: Endolimax nana (44.2%), Entamoeba coli (27.9%), Chilomastix mesnili (6.7%) and Iodamoeba bütschlii, (2.9%); emerging intestinal protozoans: Blastocystis spp. (49%), Cryptosporidium spp. (7.7%) and Cyclospora cayetanensis (2.9%); and helminths: Enterobius vermicularis (18.3%) and Ascaris lumbricoides (5.8%). The results also showed that 58.64% of the studied population presented polyparasitism. A significant association was found between protozoan infections and housewives, and houses that were not built with concrete ceilings, brick walls and cement floors (p < 0.05).

Conclusion

Polyparasitism was observed in over half the study population. The most prevalent parasite was Blastocystis spp, whilst the prevalence of helminths was less than that of protozoans. The risk factors for infection to intestinal parasites were being a housewife and not having solid brick, cement and concrete materials for house construction.

Detection of Cryptosporidium parvum and Cyclospora cayetanensis infections among people living in a slum area in Kathmandu valley, Nepal

Objective

The aim of this study is to determine the prevalence of Cyclospora cayetanensis and Cryptosporidium parvum infections among people living a slum in Kathmandu valley, Nepal.

Results

Ten different parasites were detected in the stool samples; the prevalence of any parasite was in 27.1% (71/262). The prevalence of C. cayetanensis and C. parvum were 14.1% (10/71) and 5.6% (4/71), respectively. This study showed high prevalence of intestinal parasitic infections along with the coccidian parasites in the slum area of Kathmandu Valley.

Electronic supplementary material

The online version of this article (doi:10.1186/s13104-017-2779-2) contains supplementary material, which is available to authorized users.

Multilocus sequence typing and clonal population genetic structure of Cyclospora cayetanensis in humans

To investigate the prevalence of Cyclospora cayetanensis in a longitudinal study and to conduct a population genetic analysis, fecal specimens from 6579 patients were collected during the cyclosporiasis - prevalent seasons in two urban areas of central China in 2011-2015. The overall incidence of C. cayetanensis infection was 1·2% (76/6579): 1·6% (50/3173) in Zhengzhou and 0·8% (26/3406) in Kaifeng (P 0·05). All the isolates clustered in the C. cayetanensis clade based on the small subunit ribosomal RNA gene sequence phylogenetic analysis. There were 45 specimens positive for all the five C. cayetanensis microsatellite loci, and formed 29 multilocus genotypes (MLGs). The phylogenetic relationships of 54 distinct MLGs (including 25 known reference MLGs), based on the concatenated multilocus sequences, formed three main clusters. A population structure analysis showed that the 79 isolates (including 34 known reference isolates) of C. cayetanensis produced three distinct subpopulations based on allelic profile data. In conclusion, we determined the frequency of C. cayetanensis infection in humans in Henan Province. The clonal population structure of the human C. cayetanensis isolates showed linkage disequilibrium and three distinct subpopulations.

Cyclospora infection linked to travel to Mexico, June to September 2015

Cyclospora cayetanensis was identified in 176 returned travellers from the Riviera Maya region of Mexico between 1 June and 22 September 2015; 79 in the United Kingdom (UK) and 97 in Canada. UK cases completed a food exposure questionnaire. This increase in reported Cyclospora cases highlights risks of gastrointestinal infections through travelling, limitations in Cyclospora surveillance and the need for improved hygiene in the production of food consumed in holiday resorts.