Estimation and evaluation of the risks of protozoa infections associated to the water from a treatment plant in southern Brazil using the Quantitative Microbiological Risk Assessment Methodology (QMRA).

In this study, the Quantitative Microbial Risk Assessment (QMRA) methodology was applied to estimate the annual risk of Giardia and Cryptosporidium infection associated with a water treatment plant in southern Brazil. The efficiency of the treatment plant in removing protozoa and the effectiveness of the Brazilian legislation on microbiological protection were evaluated, emphasizing the relevance of implementing the QMRA in this context. Two distinct approaches were employed to estimate the mechanical removal of protozoa: The definitions provided by the United States Environmental Protection Agency (USEPA), and the model proposed by Neminski and Ongerth. Although the raw water collected had a higher concentration of Giardia cysts than Cryptosporidium oocysts, the estimated values for the annual risk of infection were significantly higher for Cryptosporidium than for Giardia. From a general perspective, the risk values of protozoa infection were either below or very near the limit set by the World Health Organization (WHO). In contrast, all the risk values of Cryptosporidium infection exceeded the threshold established by the USEPA. Ultimately, it was concluded that the implementation of the QMRA methodology should be considered by the Brazilian authorities, as the requirements and guidelines provided by the Brazilian legislation proved to be insufficient to guarantee the microbiological safety of drinking water. In this context, the QMRA application can effectively contribute to the prevention and investigation of outbreaks of waterborne disease.

Prevalence of Cryptosporidium and microsporidial infection in HIV-infected individuals.

BACKGROUND: Microsporidia and Cryptosporidium are obligate intracellular protozoa. These medically important species are recognized as opportunistic organisms in intestinal complications in human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome patients. METHODS: The current cross-sectional study was designed and conducted from August 2016 to August 2017 to determine intestinal Cryptosporidium and microsporidia spp. in HIV-infected individuals from the Behavioral Diseases Counseling Center, Tabriz, Iran, by modified acid-fast and modified trichrome staining and nested polymerase chain reaction (PCR) and real-time PCR. RESULTS: Of 100 HIV-infected persons, 21.0% (95% confidence interval [CI] 13.0 to 30.0) and 18.0% (95% CI 11.0 to 26.0) were identified as Cryptosporidium and microsporidia, respectively, by the microscopic method. Of these 100 HIV-infected persons, 18.0% (95% CI 11.0 to 26.0) and 14.0% (95% CI 7.0 to 22.0) were positive for Cryptosporidium and microsporidia, respectively, by the molecular method. The predominant species of microsporidia in patients was Enterocytozoon bieneusi (85.7% [95% CI 57.0 to 98.0]) and Encephalitozoon cuniculi (14.3% [95% CI 1.7 to 42.0]), which were found by quantitative real-time PCR and its high-resolution melting tool. CONCLUSIONS: As far as we know, this study is the first to estimate the prevalence of infection with Cryptosporidium and microsporidia among HIV-infected persons in northwest of Iran. The prevalence of intestinal microsporidiosis and cryptosporidiosis in this area in HIV-infected people was higher than the global prevalence of infection among immunocompromised patients. In addition to the need for further studies to prove protozoan pathogenicity in the aforementioned group, preventive measures should be considered.

The risk of wild birds contaminating source water with zoonotic Cryptosporidium and Giardia is probably overestimated.

Cryptosporidium and Giardia are important waterborne protozoan parasites that are resistant to disinfectants commonly used for drinking water. Wild birds, especially wild migratory birds, are often implicated in the contamination of source and wastewater with zoonotic diseases, due to their abundance near water and in urban areas and their ability to spread enteric pathogens over long distances. This review summarises the diversity of Cryptosporidium and Giardia in birds, with a focus on zoonotic species, particularly in wild and migratory birds, which is critical for understanding zoonotic risks. The analysis revealed that both avian-adapted and zoonotic Cryptosporidium species have been identified in birds but that avian-adapted Cryptosporidium species dominate in wild migratory birds. Few studies have examined Giardia species and assemblages in birds, but the non-zoonotic Giardia psittaci and Giardia ardeae are the most commonly reported species. The identification of zoonotic Cryptosporidium and Giardia in birds, particularly C. parvum and G. duodenalis assemblages A and B in wild migratory birds, is likely due to mechanical carriage or spillback from birds co-grazing pastures contaminated with C. parvum from livestock. Therefore, the role of wild migratory birds in the transmission of zoonotic Cryptosporidium and Giardia to source water is likely overestimated. To address knowledge gaps, it is important to conduct more extensive studies on the prevalence of Cryptosporidium and Giardia in a broader range of migratory wild birds. There is also a need to investigate the extent to which zoonotic infections with C. hominis/C. parvum and G. duodenalis assemblages A and B are mechanical and/or transient, and to assess the load and viability of zoonotic oo/cysts shed in avian faeces. Understanding the contribution of birds to zoonoses is essential for effective disease surveillance, prevention, and control.

The Significance of Opportunistic Parasitosis and Blastocystosis in Patients with Gastric Cancer: a Study with Control Group.

Objective: The aim of this study was to determine the prevalence of opportunistic parasites and Blastocystis spp. in patients with gastric cancer (CA) and to determine the significance of these parasite. Methods: The patient group and the control group were composed of 100 people each. The stool samples were examined under the microscope for intestinal parasites with the native-Lugol method. Then, samples were multiplied by formol-ethyl acetate method and stained with modified acid-fast method. Results: Intestinal parasite positivity was indicated in 14% of the gastric CA, and 2% of the healthy individuals (p=0.001). Blastocystis spp. (p=0.009) was identified in 11%, Cryptosporidium spp. was identified in 4%, G. intestinalis was identified in 2%, and C. cayetanensis was identified in 1% of the patient group. There were significant differences between the intestinal parasite positivity (p=0.012), abundant Blastocystis spp. positivity (p=0.041) and all Blastocystis spp. positivity (p=0.037) in patient and control groups. Most of the patients who were positive for parasites had diarrhea. Conclusion: Based findings, it was concluded that it would be beneficial to evaluate gastric CA patients, especially those with diarrhea, for intestinal parasites.

The detection and phylogenetic characterization of Cryptosporidium, Cystoisospora, and Giardia duodenalis of cats in South Korea.

Introduction: Cryptosporidium, Cystoisospora, and Giardia duodenalis are gastrointestinal protozoa parasites that cause diarrhea in various animals. However, information regarding the detection and phylogenetic characterization of gastrointestinal protozoa parasites in cats is limited throughout South Korea. Therefore, this study aimed to determine the detection and identify subspecies of gastrointestinal protozoa parasites in cats from South Korea. Methods: A total of 290 fecal samples were collected from stray, companion, and shelter cats in six provinces. Cryptosporidium, Cystoisospora, and G. duodenalis were identified by PCR. All positive samples were subtyped by PCR and sequencing of gp60, ITS-1, tpi, bg, and gdh. Results: The overall detection of gastrointestinal protozoan parasitic infection was 17.93%. G. duodenalis was the most prevalent, with 7.93%, followed by Cystoisospora spp. (7.24%) and Cryptosporidium spp. (4.48%). In addition, C. felis (n=10), C. parvum (n=2), C. ryanae (n=1), Cystoisospora felis (n=14), Cystoisospora suis (n=5), Cystoisospora ohioensis (n=1), Cystoisospora spp. were identified in subspecies analysis of positive samples. C. felis showed a significant association with diarrhea (7.81%) and living condition (6.04%), and Cystoisospora felis in diarreha (9.38%) according to detection. Through phylogenetic analysis of the tpi, bg, and gdh genes from 23 G. duodenalispositive samples, it was confirmed that the samples of present study belonged to assemblage A, B, C, and D. Discussion: South Korean cats have a high rate of gastrointestinal protozoan parasites infection with cat-specific Cryptosporidium and Cystoisospora, which are associated with living conditions and diarrhea symptoms. Moreover, zoonotic and other animal-specific subtype of protozoan parasites have been detected in cat feces.

Parasitic infections in hematopoietic stem cell transplant recipients.

INTRODUCTION: Hematopoietic stem cell transplantation (HSCT) is a vital treatment for various hematological disorders. However, HSCT recipients face increased risks of infectious complications due to immunosuppression. Parasitic infections are a significant concern in this vulnerable population and can lead to substantial morbidity and mortality. This review examines parasitic infections in HSCT recipients, focusing on major infections affecting different organ systems, including intestinal parasites (Giardia spp., Entamoeba histolytica, and Cryptosporidium spp.), hematologic parasites (Plasmodium spp. and Babesia spp.), and tissue/visceral parasites (Toxoplasma gondii, Leishmania spp., and Trypanosoma cruzi). METHODS: A systematic search of relevant literature was conducted and included studies up to August 2023. Databases included PubMed, Google Scholar, were queried using specific keywords related to parasitic infections in HSCT patients. The epidemiology, risk factors, clinical presentation, diagnostic methods, and treatment approaches for each infection were evaluated. RESULTS AND CONCLUSION: Knowing the epidemiology, risk factors, and clinical presentations are crucial for timely intervention and successful management. By emphasizing early detection, effective therapies, and the unique challenges posed by each of these infections, this review highlights the importance of tailored strategies for HSCT recipients. Future research can further refine management protocols to enhance care and outcomes for these patients.

Dynamics of protozoal excretion in the faeces of calves during the first 28 days after arrival at the fattening farm indicate infection before regrouping and show poor temporal correlation with diarrhoea.

BACKGROUND: Calves in dairy cattle production in Switzerland are transported to a fattening farm at the age of 3-5 weeks, and frequently suffer from diarrhoea within the first 14 days after arrival. To characterise the role of intestinal protozoa in this, we investigated the excretion dynamics of Eimeria, Cryptosporidium and Giardia during the first 28 days after the arrival and regrouping of calves at fattening farms. METHODS: A total of 610 faecal samples from 122 calves (mean age 37.3 days; mean body weight 79.8 kg) were collected on seven different fattening farms during the first 28 days after the arrival and regrouping of the animals. The farms were visited between January and April (cold season; n = 4) and between June and August (warm season; n = 3). The samples were collected rectally on days 1, 4, 7, 14 and 28, assessed for consistency, and analysed using the McMaster method for quantitative determination of the number of Eimeria oocysts per gram of faeces (OPG), flotation for morphological differentiation of the unsporulated Eimeria oocysts, a concentration method for the semi-quantitative determination of Giardia cysts, and modified Ziehl-Neelsen staining for semi-quantitative determination of Cryptosporidium oocysts. RESULTS: Overall, 50.8% (62/122) of the animals had diarrhoea during the study period. However, the faecal excretion of protozoal pathogens was neither associated with diarrhoea nor with body weight gain of the animals. Altogether, 90.2% (110/122) of the calves were Eimeria positive. Eimeria zuernii was excreted by 51 (41.8%) and Eimeria bovis by 68 (55.7%) animals. In the warm season more animals tested positive for Eimeria and OPGs were higher than in the cold season. There was no correlation between the age of the calves and the OPG values. Overall, 64.8% (79/122) of the calves excreted Eimeria oocysts within the first 7 days, indicating that they had been infected with the parasite on the dairy farm of origin. Eighty-nine calves (73.0%) excreted Giardia cysts, with more positive animals in the cold (80.3%) compared with the warm season (64.3%). Only Giardia duodenalis assemblage E was identified. Cryptosporidium oocysts were microscopically detected in 14 animals (11.5%) on five farms. Cryptosporidium spp. were present in a total of 12 animals, i.e. Cryptosporidium parvum in nine, Cryptosporidium ryanae in two, and Cryptosporidium bovis in one animal. CONCLUSIONS: A better understanding of the temporal dynamics of protozoal infections in calves is helpful for the implementation of appropriate measures to protect the health of these animals at a critical phase in their lives. Our results indicate that factors other than those examined in the present study contributed to the onset of diarrhoea in the calves.

Prevalence and public health relevance of enteric parasites in domestic dogs and cats in the region of Madrid (Spain) with an emphasis on Giardia duodenalis and Cryptosporidium sp.

BACKGROUND: Pet dogs and cats exert an unquestionable beneficial effect in the well-being of their owners, but can also act as a source of zoonotic infections if improperly cared. OBJECTIVES: We investigated the occurrence, risk factors, genetic variability and zoonotic potential of intestinal parasites in dogs and cats attended in a clinical veterinary setting in Spain. METHODS: Canine (n = 252) and feline (n = 35) faecal samples were collected during 2017-2019 and analysed by coproparasitological methods. A rapid lateral immunochromatographic test (ICT) was used for detecting Giardia duodenalis and Cryptosporidium sp. Samples positive at microscopy examination and/or ICT were reassessed by molecular methods. RESULTS: Overall, 48.8% (123/252) of dogs and 48.6% (17/35) of cats were infected by enteric parasites. In dogs, G. duodenalis was the most prevalent species (40.9%), followed by Cystoisospora sp. (7.1%), and Toxocara canis (5.2%). In cats, Joyeuxiella sp. and Toxocara cati were the dominant species (20.0% each), followed by G. duodenalis (14.3%), D. caninum (5.7%) and Cystoisospora felis and Toxascaris leonina (2.9% each). Pups and kittens were more likely to harbour intestinal parasites and develop clinical signs. Sequence analyses of dog isolates revealed the presence of assemblages A (n = 1), C (n = 4), D (n = 4) and C+D (n = 1) within G. duodenalis; C. parvum (n = 1) and C. canis (n = 4) within Cryptosporidium and PtEb IX (n = 1) in Enterocytozoon bieneusi. A novel C. canis subtype family, named XXi, is reported. CONCLUSIONS: Our results highlight that (i) well-cared dogs carry zoonotic enteric protozoan parasites of public health relevance, (ii) proper hygiene practices and routine veterinary treatment are essential to prevent zoonotic infections, (iii) vulnerable populations should avoid contact with pups/kittens with diarrhoea and (iv) infected dogs might be major contributors to the environmental contamination with soil-transmitted helminths (STHs) eggs.

Fate of Cryptosporidium and Giardia through conventional and compact drinking water treatment plants.

Over the past three decades, a notable rise in the occurrence of enteric protozoan pathogens, especially Giardia and Cryptosporidium spp., in drinking water sources has been observed. This rise could be attributed not only to an actual increase in water contamination but also to improvements in detection methods. These waterborne pathogens have played a pivotal role in disease outbreaks and the overall escalation of disease rates in both developed and developing nations worldwide. Consequently, the control of waterborne diseases has become a vital component of public health policies and a primary objective of drinking water treatment plants (DWTPs). Limited studies applied real-time PCR (qPCR) and/or immunofluorescence assay (IFA) for monitoring Giardia and Cryptosporidium spp., particularly in developing countries like Egypt. Water samples from two conventional drinking water treatment plants and two compact units (CUs) were analyzed using both IFA and qPCR methods to detect Giardia and Cryptosporidium. Using qPCR and IFA, the conventional DWTPs showed complete removal of Giardia and Cryptosporidium, whereas Mansheyat Alqanater and Niklah CUs achieved only partial removal. Specifically, Cryptosporidium gene copies removal rates were 33.33% and 60% for Mansheyat Alqanater and Niklah CUs, respectively. Niklah CU also removed 50% of Giardia gene copies, but no Giardia gene copies were removed by Mansheyat Alqanater CU. Using IFA, both Mansheyat Alqanater and Niklah CUs showed a similar removal rate of 50% for Giardia cysts. Additionally, Niklah CU achieved a 50% removal of Cryptosporidium oocysts, whereas Mansheyat Alqanater CU did not show any removal of Cryptosporidium oocysts. Conventional DWTPs were more effective than CUs in removing enteric protozoa. The contamination of drinking water by enteric pathogenic protozoa remains a significant issue globally, leading to increased disease rates. Infectious disease surveillance in drinking water is an important epidemiological tool to monitor the health of a population.

Epidemiology of gastrointestinal infections: lessons learned from syndromic testing, Region Zealand, Denmark.

The aim of this study was to investigate the value of syndromic diagnostic testing for a better understanding of the epidemiology of gastrointestinal infections in Denmark. Here we evaluated the QIAstat-Dx® Gastrointestinal (GI) Panel 1 assay on 18,610 fecal samples requested for analysis for enteric pathogens in Region Zealand, Denmark, in 1 year (October 1, 2021, to September 30, 2022). In total, 6905 (37%) samples were detected positive for one or more diarrhoeal bacteria, viruses, and protozoa. The most common bacterial, viral, and parasitic pathogens detected with the QIAstat-Dx® Gastrointestinal Panel 1 were EPEC (in patients ≥ 2 years of age) (n = 1420 (20.6%)), rotavirus (n = 948 (13.7%)), and Cryptosporidium spp. (n = 196 (2.84%)). We identified a large diversity in infections likely reflecting substantial differences in the epidemiology including origin of infections, mode of transmission, seasonality, age-dependent susceptibility to disease, severity, and travel history. All pathogens were detected as both single and coinfections. Viral infections peaked in March with a positive rate of 31.6%, and bacterial infections peaked in August with a positive rate of 35.3%. ETEC, Shigella/EIEC, EAEC, and P. shigelloides were most related to travel activity, and coinfections were frequent. The distribution of Ct values varied significantly between the pathogens, with the lowest Ct values (median 17-18) observed in astrovirus, adenovirus, and rotavirus. Our results highlight the value of providing extensive diagnostic testing on fecal samples for sufficient detection of relevant diarrhoeal pathogens for optimal clinical care.

Occurrence and limited zoonotic potential of Cryptosporidium spp., Giardia duodenalis, and Balantioides coli infections in free-ranging and farmed wild ungulates in Spain.

Little information is currently available on the occurrence and molecular diversity of the enteric protozoan parasites Cryptosporidium spp., Giardia duodenalis, and Balantioides coli in wild ungulates and the role of these host species as potential sources of environmental contamination and consequent human infections. The presence of these three pathogens was investigated in eight wild ungulate species present in Spain (genera Ammotragus, Capra, Capreolus, Cervus, Dama, Ovis, Rupicapra, and Sus) by molecular methods. Faecal samples were retrospectively collected from free-ranging (n = 1058) and farmed (n = 324) wild ungulates from the five Spanish bioregions. Overall infection rates were 3.0% (42/1382; 95% CI: 2.1-3.9%) for Cryptosporidium spp., 5.4% (74/1382; 95% CI: 4.2-6.5%) for G. duodenalis, and 0.7% (9/1382; 95% CI: 0.3-1.2%) for B. coli. Cryptosporidium infection was detected in roe deer (7.5%), wild boar (7.0%) and red deer (1.5%), and G. duodenalis in southern chamois (12.9%), mouflon (10.0%), Iberian wild goat (9.0%), roe deer (7.5%), wild boar (5.6%), fallow deer (5.2%) and red deer (3.8%). Balantioides coli was only detected in wild boar (2.5%, 9/359). Sequence analyses revealed the presence of six distinct Cryptosporidium species: C. ryanae in red deer, roe deer, and wild boar; C. parvum in red deer and wild boar; C. ubiquitum in roe deer; C. scrofarum in wild boar; C. canis in roe deer; and C. suis in red deer. Zoonotic assemblages A and B were detected in wild boar and red deer, respectively. Ungulate-adapted assemblage E was identified in mouflon, red deer, and southern chamois. Attempts to genotype samples positive for B. coli failed. Sporadic infections by canine- or swine-adapted species may be indicative of potential cross-species transmission, although spurious infections cannot be ruled out. Molecular evidence gathered is consistent with parasite mild infections and limited environmental contamination with (oo)cysts. Free-ranging wild ungulate species would not presumably play a significant role as source of human infections by these pathogens. Wild ruminants do not seem to be susceptible hosts for B. coli.

Investigation of Giardia spp., Cryptosporidium spp. and Cyclospora cayetanensis in Samples Collected from Different Spring Waters Igdir, Türkiye

OBJECTIVE: In this study, it was aimed to investigate the physical and chemical properties of different spring waters and parasitic factors with different methods. METHODS: This study was carried out on 69 water samples collected from different spring waters in and around Igdir Province in April and June 2021. The samples were analyzed by native-Lugol, modified acid-fast staining, and nested polymerase chain reaction (nPCR). In addition, altitude (meter) and pressure (mmHg) measurements were made at the point where the water samples were taken. RESULTS: One or more parasites were detected in 27.5% of the 69 water samples examined. Only C. cayetanensis was found in 13% of the samples, only Cryptosporidium spp. in 10.1%, only Giardia spp. in 1.4%, only C. cayetanensis and Giardia spp. in 1.4%, only C. cayetanensis, Cryptosporidium spp., and Giardia spp. in 1.4%. Only Giardia spp. cyst (4.3%) was detected by the direct examination method. While C. cayetanensis and Cryptosporidium spp. oocysts were detected in 8.7% and 7.2% of the samples by the modified acid-fast staining method, C. cayetanensis was detected in 15.9% and Cryptosporidium spp. was detected in 11.6% of the samples by nPCR. When the C. cayetanensis and Cryptosporidium spp. positivity rates were compared according to the characteristics of the water, there was no statistical difference between the altitude, salinity, pH, mmHg, and temperature (kelvin) values, but a significant correlation was found between the amount of dissolved oxygen and Cryptosporidium spp. positivity (p=0.047). CONCLUSION: Cryptosporidium spp., C. cayetanensis, and G. intestinalis are important waterborne pathogens that can cause epidemics. It is our belief that in order to reduce the risk of contamination of these parasitic factors with spring waters, public awareness should be raised, infrastructures should be improved, and new water treatment techniques, such as ultraviolet, ozonation and monitoring systems, should be used.

Molecular characterization of Cryptosporidium and Giardia in environmental samples and faecal samples from biogas users in Bac Giang, Vietnam.

Little is known about Cryptosporidium and Giardia in biogas waste and humans in Vietnam. There is a potential risk of infections during or after using the biogas system. The detected protozoan genotypes are zoonotic pathogens, and contamination of vegetables may relay through runoff to the surface waters and soil. The objective of this study was to understand the role of the environment in the epidemiology of human infections in Bac Giang province, Vietnam, with a focus on investigating the presence of Cryptosporidium spp. genotypes and Giardia assemblages among 239 environmental samples and 94 faecal samples of biogas users. PCR and sequencing analysis were used to identify the occurrence and genotypes of Cryptosporidium and Giardia in these samples. Results showed that 13/333 (3.9 %) and 9/333 (2.7 %) samples were positive for Cryptosporidium oocyst and Giardia cysts, respectively. Characterization revealed the presence of Cryptosporidium scrofarum, C. suis, C. meleagridis, C. bailey and Giardia intestinalis assemblage A and E. C. scrofarum and Giardia assemblage E were identified for the first time in humans in Bac Giang. The current information from the above investigations will be valuable for protozoan source tracking and control interventions against Cryptosporidium and Giardia infection associated with biogas wastes in Vietnam.

Enterocytozoon bieneusi and Encephalitozoon intestinalis (microsporidia) in HIV-positive patients in central Spain.

Microsporidia are fungi-related eukaryotic intracellular parasites that opportunistically infect immunocompromised individuals such as those infected by the human immunodeficiency virus (HIV). Among them, Enterocytozoon bieneusi and Encephalitozoon spp. are the most clinically relevant species. We investigated the occurrence and genetic diversity of microsporidial and protist infections in mostly immunocompetent HIV-positive patients in Madrid, Spain. A structured questionnaire was used to retrieve data on factors potentially associated with an increased risk of infection, including sexual attitudes and sex-risk behaviour. Faecal samples (n = 96) from 81 HIV-positive patients were collected and analysed by molecular (PCR and Sanger sequencing) methods. Two microsporidial pathogens were detected: Ent. bieneusi (2.5%, 95% CI: 0.3-8.6) and Enc.intestinalis (4.9%, 95% CI: 1.4-12.2). The two Ent. bieneusi isolates were identified as zoonotic genotype A. Among protists, Entamoeba dispar was the species most prevalently found (33.3%, 95% CI: 23.2-44.7), followed by Blastocystis spp. (19.8%, 95% CI: 11.7-30.1), Giardia duodenalis (13.6%, 95% CI: 7.0-23.0), and Cryptosporidium spp. and Entamoeba histolytica (2.5%, 95% CI: 0.3-8.6 each). Cyclospora cayetanensis and Cystoisospora belli were not detected. Subtypes ST1 (70.6%, 12/17) and ST3 (29.4%, 5/17) were identified within Blastocystis sp., sub-assemblages AII and BIII (50%, 1/2 each) within G. duodenalis, and Cry. parvum and canine-adapted Cry. canis (50%, 1/2 each) within Cryptosporidium spp. Microsporidial and protist parasites were frequent in well-controlled, mostly immunocompetent HIV-positive patients and should be included in diagnostic algorithms when diarrhoea is present.

Opportunistic microsporidial and protist intestinal infections were relatively common in well-controlled HIV-positive patients in Madrid, Spain. These agents should be suspected and appropriately diagnosed in HIV-positive patients presenting with diarrhoea regardless of their immunological status.

Role of Cryptosporidium spp in Development of Colorectal Cancer.

BACKGROUND: Colorectal cancer is one of the most common malignancies in humans. About 20% of the cancer incidence was attributed to infectious agents highlighting the association between infectious agents and the development of cancers. It has been suspected that Cryptosporidium spp. infection may be correlated with colon adenocarcinoma.  Aim: investigate the percentage of cryptosporidiosis among colorectal cancer patients. SUBJECTS: 100 patients were recruited from Medical Research Institute, Alexandria University. METHODS: Fresh stool specimens were collected, homogenized and examined using direct wet mount and by permanent staining of faecal smears using Modified ZN staining. Molecular detection by PCR amplification of Cryptosporidium COWP gene. RESULTS: Significantly higher proportion of colorectal cancer patients (32.5%, 42.5%) tested positive by MZN and ELISA respectively compared to only 3.3% and 5% of positive MZN and ELISA among control group. Also, positive PCR was detected among higher proportion of colorectal cancer patients (47.5%) and only 5% of control group. Odds of colorectal cancer is 19 times among positive cases of Cryptosporidium by PCR than those without proven infection by PCR (OR 19.12; 95% CI 4.82-75.99). Comparison of the assessment of Cryptosporidium infection made by two techniques produces a kappa value of 0.770, and .759 respectively between NZN, ELISA and PCR as a gold standard, suggesting a good agreement between the two techniques and PCR. This value of kappa is significantly different from zero, K.770, p<0.001 for MZN and K.759, p<.001 for ELISA. Specificity of MZN (100%) is higher than that of ELISA (96.2%) and both reported higher specificity than sensitivity denoting that both tests are good positive to rule in the presence of infection at 40% prevalence. CONCLUSION: Cryptosporidium infection is significantly higher among cancer colon patients reinforcing that it might be considered as a likely risk factor for the development cancer colon.

Molecular identification and genetic characteristics of Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi in human immunodeficiency virus/acquired immunodeficiency syndrome patients in Shanghai, China.

BACKGROUND: Opportunistic infections are a ubiquitous complication in human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) patients. Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi are common opportunistic intestinal pathogens in humans. In China, despite the number of HIV/AIDS patients being extremely large, only a few studies have investigated opportunistic infections caused by intestinal pathogens in this patient population. The aims of this study were to elucidate the occurrence and genetic characteristics of Cryptosporidium spp., G. duodenalis, and E. bieneusi in HIV/AIDS patients. METHODS: We collected fecal specimens from 155 HIV/AIDS patients (one from each patient). All of the specimens were examined for the presence of the pathogens by genotyping using polymerase chain reaction and sequencing of the small subunit ribosomal RNA gene for Cryptosporidium spp.; the triosephosphate isomerase, ß-giardin and glutamate dehydrogenase genes for G. duodenalis; and the internal transcribed spacer region of the rRNA gene for E. bieneusi. The Cryptosporidium-positive specimens were further subtyped by polymerase chain reacion and sequencing of the 60-kDa glycoprotein gene. RESULTS: Six (3.9%), three (1.9%), and eight (5.2%) HIV/AIDS patients were positive for Cryptosporidium spp., G. duodenalis, and E. bieneusi, respectively. No statistical differences were observed in occurrence rate between the groups by gender, clinical symptom (diarrhea), and CD4+ cell count. Four Cryptosporidium species were identified: Cryptosporidium hominis (n = 2), Cryptosporidium parvum (n = 1), Cryptosporidium meleagridis (n = 1), and Cryptosporidium andersoni (n = 2). Furthermore, two C. hominis subtypes (IeA12G3T3 and IaA28R4) were detected. Three G. duodenalis-positive specimens were successfully amplified and sequenced at the triosephosphate isomerase and ß-giardin loci, which led to the identification of assemblages C and B, respectively. Seven genotypes (D, Type IV, EbpC, Peru11, EbpD, A, and I) were identified in E. bieneusi-positive specimens. CONCLUSIONS: Our findings should increase awareness of AIDS-related opportunistic intestinal pathogens, and indicate the need for routine examination in clinical practice for the detection of Cryptosporidium spp., G. duodenalis, and E. bieneusi. Homology analyses of the three intestinal pathogens at the nucleotide and/or amino acid levels indicated their zoonotic potential.

Health risks of Cryptosporidium and Giardia in the application of surface water and septic tank effluent in Chinese agriculture: Impact on cancer patients identified by quantitative microbial risk assessment.

The protozoa Cryptosporidium and Giardia are major causes of diarrhea and are commonly found on vegetables in China. They pose a health risk, particularly to immunocompromised individuals, including cancer patients. A quantitative microbial risk assessment of Chinese data evaluated the risks of Cryptosporidium and Giardia exposure arising from the application of surface water and septic tank effluent to agricultural land. Exposure via agricultural produce consumption (consumers) and agricultural practices (farmers) was considered for subpopulations of cancer patients and immunocompetent people in urban and rural areas, and risk mitigation scenarios were modelled. The cumulative disease burdens attributable to cryptosporidiosis and giardiasis were, respectively, 9.68×10-6 and 5.57×10-5 disability-adjusted life years per person per year (DALYs pppy) for immunocompetent people, and 3.14×10-5 and 1.51×10-4 DALYs pppy for cancer patients. Cancer patients were approximately three times more likely to have an individual disease burden than immunocompetent people. The disease burden was higher for consumers than farmers, and higher in rural areas than urban areas (all exceeding the maximum recommended by the World Health Organization). The highest burdens were in provinces of high population, such as Henan, Guangdong, and Sichuan, while the burden associated with human and livestock fecal effluent application was higher than with surface water irrigation. Of the three vegetables studied, lettuce posed the greatest risk, followed by bok choy, while cucumber posed the least risk. Risk mitigation scenario analysis showed that pre-treatment of surface water and feces, and appropriate post-harvest handling of vegetables, including disinfection, cooking, and adequate surface heat treatment (75 °C for 60 s), should be considered when attempting to reduce disease burdens. The methodology and findings of this study are useful for evaluating and reducing the burden of Cryptosporidium and Giardia infections associated with agricultural irrigation and fertilization practices, particularly on cancer patients.

Detection of unusual Cryptosporidium parvum subtype in patients with gastrointestinal cancer in Egypt.

While the importance of cryptosporidiosis in immunocompromised persons is well known, the prevalence of Cryptosporidium spp. in cancer patients is not clear. The current study was designed to assess the occurrence and genetic characteristics of Cryptosporidium spp. in patients with gastrointestinal (GI) cancer in Egypt. Stool samples were collected from 100 patients with GI malignancies and 20 healthy individuals without any GI manifestations (control group). They were screened by microscopy and the immunochromatographic RIDA®QUICK Cryptosporidium kit. Subtyping of Cryptosporidium spp. was conducted by sequence analysis of the glycoprotein 60 (gp60) locus. Sociodemographic, environmental data and information on GI symptoms, cancer types, and clinical treatment were obtained via a questionnaire. By microscopy and RIDA®QUICK, only 7% (7/100) of GI cancer patients were positive for Cryptosporidium, compared with 40% (40/100) by gp60 nPCR. No positives were obtained from the control group. Male sex (P = 0.02) and younger age (P = 0.004) were major Cryptosporidium risk factors for infection. The occurrence of Cryptosporidium was also significantly more frequent (P = 0.003) in watery stool samples. Sequence analysis of the gp60 amplicons (~ 400 bp) identified a novel C. parvum subtype with nine TCA repeats and eleven ACATCA repeats. A formal subtype designation could not be made due to the short sequence length. More studies should be conducted to verify the common occurrence of this unusual C. parvum subtype and establish its genetic identity.

Gastrointestinal parasites in young dogs and risk factors associated with infection.

Young dogs are particularly susceptible to infections with endoparasites. The occurrence of endoparasites was investigated in young dogs from Central Germany between July 2020 and July 2022. In total, 386 fecal samples originating from 171 dogs were examined for the prevalence of endoparasites using a combined flotation- and sedimentation technique and conventional PCR. Overall, in 41.2% (159/386) of the examined samples, endoparasites were detected. The most frequently occurring endoparasites were Giardia duodenalis (29%), Cryptosporidium spp. (9.1%), Cystoisospora spp. (7.3%), and Toxocara canis (6%). Sequencing of G. duodenalis positive samples showed that most infections belonged to the host-specific assemblages C (38.4% (43/112)) and D (35.7% (40/112)). The zoonotic assemblage A was identified in 8% (9/112) of the samples. Moreover, mixed infections were observed as follows: C/D in 5 (4.5%), D/A in 4 (3.6%), and C/A in 3 (2.7%) samples. All assemblage A infections were assigned to the potentially zoonotic subassemblage AI. Co-infections of G. duodenalis and Cryptosporidium spp. were observed in 3.1% (12/386) of the samples. Analyzing several host factors for their potential association with endoparasitic infection, the origin of dogs, as well as the living environment were identified as the main risk factors for infection with endoparasites. Overall, this study shows a high infection rate with endoparasites, especially G. duodenalis, in young dogs from Germany. The results of this study contribute to further insight into the distribution and potential risk factors associated with endoparasitic infections, as well as the zoonotic potential these parasites may present.

Spatially explicit model of the Cryptosporidium and Giardia disease burden from surface and ground waters in urban and rural areas of the Three Gorges Reservoir watershed in Chongqing, China.

Cryptosporidium and Giardia (major causes of diarrhea) are widely distributed in Chinese source waters and threaten human health. A new spatially explicit GloWPa-TGR-Crypt-Giar C1 model is presented to simultaneously estimate mean monthly (oo)cyst concentrations in surface and ground waters in the Three Gorges Reservoir (TGR) watershed. A quantitative risk assessment of protozoal infections considered different source waters, transmission pathways, regions, susceptible subpopulations, and drinking water treatments. Monthly mean Cryptosporidium oocyst and Giardia cyst concentrations ranged between 0.5-19.3 oocysts/10 L and 0.2-5.0 cysts/10 L in surface water, respectively, and 0.007-0.3 oocysts/10 L and 0.002-0. 2 cysts/10 L in groundwater. The cumulative disease burdens attributable to cryptosporidiosis and giardiasis were, respectively, 5.77×10-5 DALYs (disability-adjusted life years/person/year) and 4.63×10-6 DALYs in urban areas, and 6.35×10-4 DALYs and 8.84×10-5 DALYs in rural areas, which were much higher than the reference risk level recommended by the World Health Organization ([Formula: see text] DALYs). The annual burden associated with consuming surface water was calculated to be 3.84×10-4 DALYs for Cryptosporidium and [Formula: see text] DALYs for Giardia, whereas consuming groundwater entailed the lower burdens (1.26×10-5 and 3.50×10-6 DALYs, respectively). Most DALYs were a consequence of consumption of directly supplied surface water. Fifty percent of the health burden was carried by immunodeficiency with HIV. Children (0-4 years) were more likely to have an individual disease burden than adults (15-64 years). Males were more susceptible than females. Improving sanitation through adequate ozone and microfiltration treatment should be considered when attempting to reduce disease burden. Sensitivity analysis highlighted the importance of reducing (oo)cyst loads to protect the watershed. The methodology and results described will help in evaluating and reducing the burden of protozoal infection associated with surface and ground waters in the TGR and similar watersheds.