Search

The study was conducted to compare the specificity of immunological diagnostic methods used for the diagnosis of Cryptosporidium species capable of causing life-threatening infection in both immunosuppressed and immunocompetent patients. For the detection of Cryptosporidium species in 79 animals with diarrhoea, we used three Copro-antigen tests: RIDASCREEN ® Cryptosporidium test, Cryptosporidium 2nd Generation (ELISA) and RIDA ® QUICK Cryptosporidium . For immunoassays we used positive and negative samples detected by means of polymerase chain reaction and validated by sequencing and nested polymerase chain reaction to confirm the presence six different species of Cryptosporidium species. Prevalence of cryptosporidiosis in the entire group determined by enzyme immunoassay, enzyme linked immunosorbent assay, immuno-chromatographic test and polymerase chain reaction was 34.17%, 27.84%, 6.33% and 27.84%, respectively. Sensitivity of animal samples with enzyme immunoassay, enzyme linked immunosorbent assay, and immuno-chromatographic test was 63.6%, 40.9% and 22.7%, resp., when questionable samples were considered positive, whereas specificity of enzyme immunoassay, enzyme linked immunosorbent assay and immuno-chromatographic test was 75.9%, 78.9% and 100%, respectively. Positive predictive values and negative predictive values were different for all the tests. These differences results are controversial and therefore reliability and reproducibility of immunoassays as the only diagnostic method is questionable. The use of various Cryptosporidium species in diagnosis based on immunological testing and different results obtained by individual tests indicate potential differences in Copro-antigens produced by individual Cryptosporidium species.

The use of molecular tools in epidemiological investigations has provided new insights into the transmission of cryptosporidiosis in humans and animals. This study aimed to characterize the transmission of cryptosporidiosis in human immunodeficiency virus (HIV)-infected patients. Stool specimens were collected from 500 HIV-infected patients as part of the routine patient care. Cryptosporidium species in stool specimens were detected and differentiated using a small subunit rRNA-based polymerase chain reaction-restriction fragment length polymorphism technique. C. hominis and C. parvum were found and subtyped by DNA sequence analysis of the 60 kDa glycoprotein (gp60) gene. Cryptosporidium species were detected in 36 HIV patients and none were found among non-HIV patients. A CD4+ count < 200 cells/μL was a significant risk factor for acquiring cryptosporidiosis (odds ratio = 21.214; 95% confidence interval = 9.917, 45.381; p < 0.0001). Cryptosporidium infection was also associated with weight loss and diarrhea. Other risk factors included animal contact, and using stream/river or well water as drinking water. Genotyping of the Cryptosporidium species identified the presence of C. hominis (47.2%), C. parvum (44.4%), C. felis (5.6%) and C. canis (2.8%). The C. hominis specimens subtyped belonged to the Ia, Ib and Ie subtype families, whereas those of C. parvum belonged to the IIc and two new subtype families. Anthroponotic transmission appears to be important in cryptosporidiosis epidemiology in HIV-infected persons in Nigeria despite the high frequency of C. parvum infection and the identification of animal contact as a risk factor.

This review focuses on studies concerning cryptosporidiosis in three Asian countries. Cryptosporidium spp. infection was investigated in children < 12 years old afflicted with diarrhoea and admitted to the paediatric hospitals in Iraq, Jordan and Malaysia. Most of the patients complained of abdominal pain, watery diarrhoea and mild-to-severe dehydration. Stool samples were collected from children and five methods were used to detect oocysts of Cryptosporidium spp. including: direct wet mount, Sheather's sugar flotation, formalin-ether sedimentation, modified Ziehl–Neelsen and direct fluorescent antibody (DFA). The infection rate was 8.56, 37.3 and 4.6 in Iraq, Jordan and Malaysia, respectively. A combination of formalin ether sedimentation and acid fast stain was used to detect Cryptosporidium oocysts in Iraq. The DFA test showed the highest sensitivity for samples of children in Jordan. In Malaysia, direct wet mount, formalin-ether sedimentation, modified Ziehl–Neelsen and DFA gave the same results (4.62%) while Sheather's sugar flotation was 3.85%. Source of drinking water appeared to be an important risk factor in transmission of infection. In Jordan, the high rate of infection was recorded in rainy season (January–May).

Transplanted and hemodialysis patients are frequently affected by parasitic diseases such as cryptosporidiosis. Cryptosporidium is a parasite causing self-limited diarrhea and enteritis in healthy individuals. The presence of Cryptosporidium infection was studied in three groups including 87 renal transplant patients, 103 hemodialysis patients, and 60 healthy individuals as the control group. Two stool specimens were obtained from each case. The specimens were concentrated by the formalin-ether method and two smears were prepared from each. The smears were stained by modified acid-fast method and were observed under a light microscope. Ten (11.5%) renal transplant and 4 (3.88%) hemodialysis patients were positive for Cryptosporidium infection. No positive results were obtained in the control group. The results showed a statistically significant difference between renal transplant and control groups (P= 0.02), but the difference between hemodialysis and control groups was not significant (P= 0.2). The results also showed that the rate of Cryptosporidium infection in renal transplant patients was much higher than hemodialysis patients. The susceptibility of renal transplant patients to Cryptosporidium infection is much more than other studied groups and this could be due to immunosuppressive therapy in these patients.

Dissertação de Mestrado Integrado em Medicina Veterinária A criptosporidiose é uma zoonose difundida por todo o mundo e é provocada por protozoários pertencentes ao género Cryptosporidium que têm a capacidade de infetar mamíferos, aves, répteis, anfíbios e peixes. A via de transmissão do parasita é fecal-oral podendo ocorrer de forma direta através do contacto com fezes provenientes de animais portadores ou de forma indireta através do contacto com superfícies, águas ou alimentos contaminados com oocistos esporulados. Os vitelos infetam-se nos primeiros dias de vida, sendo estes os principais responsáveis pela perpetuação da doença nas explorações. Este estudo teve como principal objetivo a avaliação da percentagem de infeção de Cryptosporidium spp. em vitelos pertencentes a explorações de carne do Alentejo Central e Litoral. As amostras foram obtidas por conveniência a partir de 105 vitelos com idades compreendidas entre os 10 e os 30 dias de vida e pertencentes a 22 explorações sediadas nas referidas sub-regiões. Os resultados foram obtidos através de observação ao microscópio das amostras após realizados os esfregaços fecais e respetivas colorações com a técnica de Ziehl-Neelsen modificada. A percentagem global de infeção por Cryptosporidium spp. ficou definida em 25,7% dos animais examinados e 63,6% das explorações alvo de estudo apresentaram pelo menos um animal positivo à observação microscópica das amostras. Os dados obtidos demonstraram uma forte relação entre a consistência das fezes e a presença de Cryptosporidium spp., sendo que 48,5% dos animais com fezes diarreicas na altura na colheita das amostras apresentaram-se infetados pelo parasita. Embora o lactato de halofuginona esteja descrito como tratamento efetivo para o Cryptosporidium spp., a execução do seu protocolo em explorações em regime extensivo não é fácil e as melhores alternativas passam pela adoção de boas práticas de maneio, tratamento das águas de bebida dos animais e vacinação do efetivo contra outros agentes patogénicos causadores de diarreias neonatais. ABSTRACT - CONTRIBUTION TO THE DETERMINATION OF Cryptosporidium spp. INFECTION IN CALVES OF BEEF FARMS FROM CENTRAL AND COASTAL ALENTEJO SUBREGIONS - Cryptosporidiosis is a widespread zoonosis caused by protozoa of the genus Cryptosporidium. They are parasites that have the ability to infect mammals, birds, reptiles, amphibians and fish. The parasite transmission pathway is fecal-oral and may occur directly through contact with feces from animal carriers or indirectly through contact with surfaces, waters or food contaminated with sporulated oocysts. Calves become infected in their first days of life, and these are the main responsible for the perpetuation of the disease on the farms. The main objective of this study was to evaluate the percentage of Cryptosporidium spp. infection in calves belonging to beef cattle farms in the Central and Coastal Alentejo. Convenience sampling was obtained from 105 calves aged between 10 and 30 days old and belonging to 22 farms based in these sub-regions. The results were obtained by microscopic observation of the samples after being colored with modified Ziehl-Neelsen technique. The overall percentage of Cryptosporidium spp. infection was defined in 25.7% and 63.6% of the study target farms presented at least one positive animal to the microscopic observation of the samples. The obtained data showed a strong relationship between feces consistency and the presence of Cryptosporidium spp. A percentage of 48.5% of the animals with diarrheal feces at the time of sampling were infected by the parasite. Although halofuginone lactate is described as an effective treatment for Cryptosporidium spp. the protocol in beef farms is not easy to apply and the best alternatives are the adoption of good animal husbandry practices, treatment of animal drinking water and vaccination of herds against pathogens which cause neonatal diarrhea. N/A

Background Controversies exist on the potential role of companion animals in the transmission of enteric pathogens in humans. This study was conducted to examine the genotype distribution of Cryptosporidium spp., Enterocytozoon bieneusi, and Giardia duodenalis in companion animals in Shanghai, China, and to assess their zoonotic potential. Methods Fecal specimens from 485 dogs and 160 cats were examined for the occurrence and genotype distribution of the three pathogens by PCR. PCR products were sequenced to determine the species and genotypes. The χ2 test was used to compare differences in infection rates between living conditions or age groups. Results Cryptosporidium spp., E. bieneusi and G. duodenalis were found in 39 (8.0 %), 29 (6.0 %) and 127 (26.2 %) of dogs, and 6 (3.8 %), 9 (5.6 %) and 21 (13.1 %) of cats, respectively. Infection rates of the pathogens in dogs from pet shops and a clinic were higher than those in household dogs, and higher in cats from one animal shelter than from pet shops. No significant differences in infection rates were detected among age groups. Cryptosporidium canis and C. felis were the only Cryptosporidium species found in dogs and cats, respectively. Enterocytozoon bieneusi genotype PtEb IX was the dominant genotype in dogs, whereas Type IV and D were the most common ones in cats. Multi-locus sequence typing at the glutamate dehydrogenase, β-giardin, and triosephosphate isomerase loci revealed the presence of G. duodenalis assemblages A (n = 23), B (n = 1), C (n = 26), and D (n = 58) in dogs (only A in household dogs) and assemblages A (n = 2), B (n = 6), C (n = 2), D (n = 1), and F (n = 7) in cats. Co-infection was detected in 24 dogs and 5 cats, especially those living in crowded conditions. Conclusions Living condition is a major risk factor affecting the occurrence of enteric protists in companion animals in China, and although dogs and cats can be potential sources of human infections, the different distribution of pathogen species and genotypes between dogs and cats suggests that inter-species transmission of these pathogens is probably rare in the study area.

Cryptosporidium spp., a common enteric pathogen of animals and humans, has been involved as a cause of diarrhea in foals both immunocompetent and immunocompromised (Sgorbini et al, 2003, Ippologia, 4: 5-9; Grinberg et al, 2009, New Zeal Vet J, 57: 284-289; Perrucci et al, 2011, Vet Paras 182: 333-336). Several aspect of this infection in horse, such as prevalence, clinical onset, risk factors, economic relevance and the species status are not completely defined (Veronesi et al, 2009 Zoon Pub Health, 57: 510-517). So far, the literature on equine cryptosporidiosis, describe the presence of Cryptosporidium parvum “cattle” genotype and Cryptosporidium “horse” genotype (Grinberg et al, 2003 Vet Rec, 153: 628-631; Grinberg et al, 2008 J Clin Microbiol, 46: 2396-2398; Chalmers et al, 2005, Vet Rec, 156: 49-50; Chalmers et al, 2009, Eurosurveillance, 14: 1-9; Xiao et al, 2009 J Clin Microbiol, 47: 3017-3020). AIM: During the last horse breeding seasons at the Neonatal Intensive Care Unit of Department of Veterinary Medical Science Alma Mater Studiorum-University of Bologna during past several cases of cryptosporidiosis have been observed in foals and mare. With the aim of undertake a study of epidemiology of these outbreak and in order to set up adequate control measures, a molecular study on Cryptosporidium spp. isolates from foals hosted in this structure in 2007 and from diarrheic goat housed in 2006 in a separate experimental stable have been carried out. Furthermore a human isolate from a technician with gastro-intestinal symptoms working on goat during the outbreak was also analyzed. MATERIALS AND METHODS. The following fecal samples, tested positive by Ziehl-Neelsen stain and stored frozen, were examined: 4 from foals with diarrheic syndrome, 1 from goat and 1 from man. All the samples were subjected to DNA extraction with QIAamp DNA Stool Mini Kit (Qiagen) and to nested PCR, amplifying the 18S rRNA (Miller et al, 2006, J Microbiol Meth, 65: 367-379) and the gene encoding the Cryptosporidium oocyst wall protein (COWP) (Traversa et al, 2008, Mol Cell Probes, 22: 122-128). The PCR products were sequenced in both direction by ABI 3730 DNA Analyzer at StarSEQ GmbH (Mainz, Germany). RESULTS. Sequence analysis of both genes revealed that all the isolates (foal, goat and human) were identical to each other and showed 100% identity with the Cryptosporidium parvum “cattle” genotype. CONCLUSIONS. The presence of C. parvum “cattle” genotype has already been recorded all around the world in a wide host range comprising human (Chalmers et al, 2005, Vet Rec, 156: 49-50; Grinberg et al, 2003, Vet Rec, 153: 628-630; Grinberg et al, 2008, J Clin Microbiol, 46: 2396-2398; Imhasly et al, 2009, Arch Tierheilkd, 151: 21-26; Veronesi et al, 2009, Zoon Pubbl Health, 57: 510-517; Traversa et al., 2010, Parassitologia, 52: 214; Perrucci et al, 2011, Vet Parasitol, 182: 333-336; Grinberg et al., 2012, Vet Rec, 153: 628-631) while only few researches reported the presence of Cryptosporidium “horse genotype” in foals (Ryan et al, 2003, Appl Environ Microbiol, 69: 4302-4307; Xiao and Fayer, 2008, Int J Parasitol, 38: 1239-1255; Xiao and Feng, 2008, FEMS Immunol Med Microbiol, 53: 309-323) with a single case of human infection (Xiao et al, 2009, J Clin Microbiol, 47: 3017-3020). Our results confirm the data obtained by Grinberg et al (2012) on the evidence that C. parvum “cattle” genotype could be a co-factor of foals diarrhea. The isolation of the same genotype also from goat and humans, suggest the possible cross-transmission between animals and man, pointing out the zoonotic professional risk linked to the presence of C. parvum “cattle” genotype as already described in previous studies reporting outbreak of cryptosporidiosis in vet students (Pohjola et al, 1986, Scand J Infect Dis, 18: 173-178; Levine et al, 1988, J Am Vet Med Ass, 193: 1413-1414; Reif et al, 1989, Am J Public Health, 79: 1528-1530; Preiser et al, 2003, J Am Coll Health, 51: 213-215; Gait et al, 2008, Vet Rec, 162: 843-845). Further investigations are necessary in order to verify the presence of sub-genotypes by studying other more suitable genes such as the GP60 and the Hsp70 in order to link the epidemiologically related isolates.

The objective of the study was to determine the prevalence of Cryptosporidium spp. and its associated risk factors in female calves in central Veracruz, Mexico. A cross-sectional study with a convenience sampling was conducted. One fecal sample was obtained from each of 120 female calves. The lateral flow immunochromatographic (LFIC) and the Ziehl- Neelsen (ZN) tests were performed. A questionnaire was applied in each farm to obtain individual and herd information. Overall prevalence was 3.33% (CI95% 1-8) through LFIC and 12.50% (CI95% 8-20) through ZN. Prevalence by municipality was 0 to 9.1% (CI95% 0.03-0.24) through LFIC and 0 to 30.43% (CI95% 16-51) through ZN. Prevalence by age was 0% at 31-45 days and 9.10% at 1-15 days through LFIC, and 0% at 31-45 days and 18.8% at 1-15 days through ZN. The calves with diarrhea had the highest prevalence, which was 14.3% (CI95% 3-51) through LFIC and 57.1% (CI95% 25-84) through ZN. The protective factors were calves housed in individual stalls, compared with those in common stalls but separated one from the other (OR=0.27; 0.09-0.85, P0.04), as well as calves that ingested colostrum 30 to 60 min after birth, compared with those that ingested colostrum 2 to 3 h after birth (OR=0.22; 0.05-0.87, P0.04). In conclusion, Cryptosporidium spp. was present in the suckling female calves from the farms surveyed, and the protective factors should be considered when establishing a program for controlling diarrhea in calves.

Background: Cryptosporidiosis is a common coccidian parasite infection in patients with diarrhea that has worldwide distribution especially in developed countries. Therefore,the aim of this study was to determine the occurrence of Cryptosporidium infection in patients with gastroenteritis admitted to hospitals of Mazandaran University of Medical Sciences by parasitological and molecular methods in Sari, Iran. Methods: Stool samples were collected from 348 patients with gastroenteritis admitted to the hospitals of Medical University in the Sari and Ghaemshahr cities in Mazandaran Province, Northern Iran in 2010-2011. Oocysts of Cryptosporidium identified using Formalin-Ether concentration method and stained by Aacid-fast staining (AFS)and Auramine phenol fluorescence (APF). Genomic DAN extracted from microscopically positive samples and nested PCR -RFLP by using SSU rRNA that identifies of the species of cryptosporidium. Results: In 348 patients with gastroenteritis, the most clinical symptoms were diarrhea, nausea, vomiting, dehydration, fever and weight loss. 2.3% (8 cases) of diarrheal samples tested by both microscopy and molecular methods were positive for the presence of cryptosporidium. Nested PCR products yielded unique bands of 846 bp, correspond to cryptosporidium. Species diagnosis carried out by digesting the secondary PCR product with SspI restriction enzyme, which noted 3 clearly bands of 449, 254, and 108 bp correspond to Cryptosporidium spp. Conclusion: The results of present study on Cryptosporidium spp. in this area can make a background data for control programs and further molecular analyses. Thus, further work needs to determine the origin of Cryptosporidium species in this area.

To determine the prevalence of cryptosporidiosis among HIV infected and HIV non-infected patients with diarrhea in Edo State, Nigeria, as well as the effect of CD4+ lymphocyte count on the prevalence of cryptosporidial infection among the HIV patients. Stool samples were collected from 300 patients consisting of 200 HIV-infected and 100 HIV non-infected patients with diarrhea. Blood samples were collected from the HIV-infected patients. The stool samples were processed to detect Cryptosporidium species using a modified Ziehl-Neelsen stain, as well as other intestinal parasites using saline and iodine preparations. The blood samples were used to determine CD4+ lymphocyte count. The prevalence of intestinal parasites was higher in HIV-infected patients compared with their HIV non-infected counterparts (39% vs 24% respectively, p=0.0097). Cryptosporidiosis was diagnosed only among HIV-infected patients and was the only parasite whose prevalence was significantly different between HIV-infected and HIV non-infected patients. CD4+ lymphocyte count of

International audience; Contamination of natural aquatic ecosystems by Cryptosporidium is a major environmental and human health issue. In Haiti, environmental Cryptosporidium oocysts pollution has been well documented by previous studies conducted in several cities of the country. In groundwater from Les Cayes of Haiti, significant concentrations from 1 to 989 oocysts in 100 liters of filtered water were calculated. Results of these studies revealed high level of Cryptosporidium oocysts pollution in surface water and groundwater. Therefore, regarding cryptosporidiosis, contaminated water resources constitute a real sanitary risk mainly for children and immunocompromised individuals. So, it is necessary to assess the biological risk for populations served by those polluted water resources. The aim of this study is to present: (i) the steps of a procedure intended to evaluate risks to human health linked to the consumption of water from groundwater; and (ii) the results of its application on groundwater from Les Cayes, city located in southwestern Haiti. The procedure is based on a scenario that describes the existence of an uncontrolled landfill leachate which are neither collected nor treated. The refuse has a close contact with the soil making easy the transfer of various pollutants from the surface to groundwater. Moreover, latrines and septic tanks are often discharged into the unsaturated zone of the geological matrix are also retained. Risk estimation was calculated for two groups in the exposed population: immunocompetent and immunocompromised individuals. As expected, the study revealed a high risk for individuals in the immunocompromised group.; La contaminación de los ecosistemas acuáticos naturales por Cryptospridium parvum constituye una verdadera preocu-pación de salud humana e ambiental principalmente en los países en desarrollo. En Haití, los oocitos de cryptosporidios se han encontrado en muchas ciudades del país en las aguas de superficie y las aguas destinadas al consumo humano. En las aguas subterráneas en Les Cayes de Haití, concentraciones significativas de 1 a 989 oocitos en 100 litros de agua filtrada han sido determinadas. Los resultados de estos estudios han revelado un nivel elevado de polución por oocitos de Cryptosporidium en las aguas de superficie y aguas subterráneas. Por ende, los recursos en agua contaminados por oocitos constituyen un verdadero riesgo sanitario para los niños y las personas inmunodeprimidas. Así, se hace necesario evaluar el riesgo biológico para las poblaciones que se abastecen de estos recursos en agua contaminados. El objetivo de este estudio es presentar: (i) las etapas de un procedimiento destinado a evaluar los riesgos para la salud humana ligados al consumo de agua proveniente de las aguas subterráneas; et (ii) los resultados de la aplicación de este proced-imiento en las aguas subterráneas en Les Cayes, ciudad situada en el suroeste de Haití. El procedimiento está basado en un escenario que describe la existencia de una descarga violenta en donde los lixiviados no son ni recolectados ni tratados. Las basuras están directamente en contacto con el suelo y siguen los mecanismos de transferencia hacia la capa de agua subterránea. Además, las letrinas y fosas sépticas, rechazando sus efluentes en la zona no saturada de la matriz geológica, están igualmente retenidas. La estimación del riesgo ha sido calculada para dos grupos en la población expuesta: inmunodeprimida y immunocompetente. Este aparece como un riesgo elevado para los inmunodeprimidos.; La contamination des écosystèmes aquatiques naturels par Cryptospridium parvum constitue une véritable préoccupa-tion de santé hu et environnementale principalement dans les pays en développement. En Haïti, des oocytes de cryptosporidies ont été retrouvés dans plusieurs villes du pays dans les eaux de surface et dans les eaux destinées à la consommation humaine. Dans les eaux souterraines Les Cayes d'Haïti, des concentrations significatives de 1 à 989 oo-cystes dans 100 litres d'eau filtrée ont été déterminées. Les résultats de ces études ont révélé un niveau élevé de pollution par des oocystes de Cryptosporidium dans les eaux de surface et des eaux souterraines. Par conséquent, les ressources en eau contaminés par des oocystes constituent un véritable risque sanitaire principalement pour les enfants et les per-sonnes immunodéprimées. Ainsi, il apparaît nécessaire d'évaluer le risque biologique pour les populations desservies par ces ressources en eau polluées. Le but de cette étude est de présenter: (i) les étapes d'une procédure destinée à évaluer les risques pour la santé humaine liés à la consommation d'eau provenant des eaux souterraines; et (ii) les résultats de l'application de cette procédure sur les eaux souterraines Les Cayes, ville située dans le sud-ouest Haïti. La procédure est basée sur un scénario qui décrit l'existence d'une décharge sauvage où les lixiviats ne sont ni collectés, ni traités. Les déchets sont directement en contact avec le sol et suivent les mécanismes de transfert vers la nappe. En outre, les latrines et fosses septiques, rejetant leurs effluents dans la zone non saturée de la matrice géologique, sont également retenues. L'estimation du risque a été calculée pour deux groupes dans la population exposée: immunodéprimé et immunocompétent. Il apparaît comme attendu un risque élevé pour les immunodéprimés.

Cryptosporidium spp. is a pathogenic protozoan present in the gastrointestinal tract of several hosts. This protozoan was originally classified as within the Coccidia Class and has recently been reclassified to gregarine based on studies that observed the evolutionary phases from the process of excision and sequencing of the 18S rRNA gene. Molecular biology techniques have become diagnostic tools and have also been used to understand the epidemiology of Cryptosporidium spp., since several species of this genus are very similar morphologically and morphometrically. Molecular techniques have been used in the identification of parasites, at the species and subtypes levels and to study disease transmission. The laboratory diagnosis of human cryptosporidiosis can be made by parasite detection methods, such as optical microscopy, antigens or genetic material detection, as well as serum antibodies raised to Cryptosporidium spp. Molecular methods were developed and allowed, not only an extensive revision of the taxonomy, but also an improvement in the laboratory diagnosis. In Brazil, there are few reports of Cryptosporidium spp. outbreaks in humans and all of them took place in nurseries. A few epidemiological studies developed in Brazil have used molecular methods for the detection of Cryptosporidium spp., as well as genotyping studies of their species and subtypes. The use of real-time PCR, together with microscopy and immunochromatography techniques, would result in a more precise diagnosis of cryptosporidiosis. The analysis of genotypes, subtypes and clonality of Cryptosporidium could be useful to understand and define the prognosis and severity of infections.

El objetivo fue determinar la prevalencia y posibles factores de riesgo asociados a la excreción de ooquistes de Cryptosporidium spp en excremento de bovinos Holstein en fincas de producción lechera de Boyacá, Colombia. Se colectaron 100 muestras de materia fecal de bovinos hembras mediante estimulación rectal. Con la técnica de Ziehl Neelsen modificada se determinó la excreción de ooquistes de Cryptosporidium spp. Para conocer los posibles factores asociados se usó la prueba de Ji cuadrada teniendo como variable dependiente la presencia de ooquistes de Cryptosporidium spp y como independientes la presencia de diarrea (si, no), edad (12 meses), finca de procedencia (1, 2, 3, 4) y estado reproductivo (gestante, vacía). Las variables con P0.05). Las variables que durante el análisis con X2 tuvieron valores P