Fecal Parasite Research Articles

Fecal and Molecular Survey of Neospora caninum in Farm and Household Dogs in Mashhad Area, Khorasan Province, Iran

Neospora caninum is an important cause of abortion in dairy cattle worldwide. Dog is the definitive host for N. caninum and can infect dairy cattle. The aim of this study is to determine the prevalence of Neospora oocysts in feces of dogs from dairy farms. A total of 174 fecal samples was collected from 89 farm dogs and 85 household dogs during 2006 and 2008. Fecal samples of dogs were microscopically examined for detecting Hammondia Neospora-like oocysts (HNLO) by Mini Parasep SF fecal parasite concentrator. HNLO were microscopically detected in 4 fecal samples (2.2%). The fecal samples with HNLO were examined by N. caninum-specific PCR. Two of the samples were positive for N. caninum. The 2 positive fecal samples were selected for inoculation to calves. Two inoculated calves were seronegative by ELISA for 4 months post-infection. This is the first report of finding N. caninum DNA in feces of farm dogs in Mashhad area, Iran.

MEASUREMENT OF TOTAL AND SPECIFIC IMUNOGLOBULIN E IN ADULT PATIENT WITH BRONCHIAL ASTHMA

Introduction: Asthma is a chronic inflammatory airway disease, with more present allergic component who cause disease. Pacient and Metods: In this study was included 35 patients who had been bronchial asthma whom was made total IgE determined by nefelometric metod and skin test by Prick metod. Subjects which had increased values of IgE, had been tested for fecal parasites . Subjects wich was positiv for scin allergens was tested for specific IgE on Hytec 288 instrument with ELISA metod. Results: Folowing resaults was obtained: 57.14% (20) of subjects had increased values of total IgE, while 42.86% (15) had normal total IgE. All patients with increased values of total IgE were tested negative for fecal parazites. Percent conform Prick tests and specific IgE was for house dust 54.55%, ragweed 53.85%, grass pollen 45.45%, Dermato-phagoides Pteronyssinus 43.75%, Pollen trees 25.00%. Conclusion and Discussion: Allergic bronchial asthma capture big percent in patients with bronchial asthma. The most frequent allergen was house dust.

Síndrome diarreico y carcinoma de células renales

A 36-year-old male with diarrhea and loss of weight underwent testing for blood chemistry, TSH, immunological parameters, celiac profile, and parasites in feces. All results were normal. C-reactive protein was elevated. Colonoscopy up to the cecum was normal, and a small-bowel follow-through with barium showed no alterations. Abdominal echography showed a left renal upper-pole mass about 4 cm in diameter, round, and isoechoic with hyperechoic areas inside consistent with necrotic areas (Fig. 1). CTA confirmed this lesion as 4.3 cm in size, hypodense, confined to the kidney and not affecting the perirenal fat or vascular pedicle. The patient was sent to the Urology Department and underwent a left laparoscopic nephrectomy -a mass could be macroscopically seen in a pole, with a complete Gerota’s capsule and no significant macroscopic changes. Cuts allowed identifying a rounded, well delimited lesion 4.8 x 4.5 cm in size in that pole, with a yellowish-brownish parenchyma with small millimetric cavities that was friable at the cut close to the renal capsule. The diagnosis was of papillary renal cell carcinoma, type 2 according to Delahunt and Eble (Fig. 2). The patient is now asymptomatic, and diarrhea is no longer present after surgery.

Prevalence and Clinical Significance of Eosinophilia in Patients With Rheumatoid Arthritis in Argentina

The presence of eosinophilia in peripheral blood has been considered by some authors as an indicator of bad prognosis in patients with rheumatoid arthritis (RA); however, the methodology and the number of patients included in those studies were not appropriate. To determine the prevalence and possible causes of eosinophilia in patients with RA, and its relationship with a more severe disease. Patients with RA (American College of Rheumatology '87) were included, demographic, clinical, and laboratory data were collected. The presence of eosinophilia was defined as an eosinophil absolute count above 350/mm. Disease activity, health assessment questionnaire, and hand x-rays were performed in all patients. A coproparasitologic test and serology for Toxocara by enzyme-linked immunosorbent assay (ELISA) were determined in patients with eosinophilia. One hundred nine patients were included, 95 women (87.2%), mean age 50.6 +/- 13 years, mean disease duration 10.8 +/- 7.6 years. Eight patients (7.33%) showed eosinophilia. When demographic and clinical characteristics of patients with or without eosinophilia were compared, the former showed a higher erythrocyte sedimentation rate levels and significantly more frequency of dry mouth, anal pruritus, and paresthesia. The remaining clinical variables, as well as radiologic structural damage were comparable. Parasites in feces (Ascaris lumbricoides and Enterobius vermicularis) were found in 2 patients with eosinophilia. Seven patients with eosinophilia (87.5%) versus 4 (19%) without eosinophilia showed positive serology for Toxocara (P = 0.001). The frequency of eosinophilia in our population of patients with RA was 7.33%. It was not an indicator of severity of the disease and in all cases evidence for secondary causes (parasitosis) was found.

Health Assessment of TheEx SituPopulation of St Vincent Parrots (Amazona Guildingii) in St Vincent and The Grenadines

The St Vincent Amazon parrot (Amazona guildingii), listed as a CITES appendix I animal, is endemic only to the mainland of St Vincent and the Grenadines (SVG), Lesser Antilles. A health assessment that included physical examination, hematology, blood parasite evaluation, plasma biochemical analysis, plasma protein electrophoresis, level of exposure to selected infectious agents, and fecal parasites was performed in July 2002 on 37 (51%) of the parrots in the captive population in SVG. Clinical abnormalities noted in the 37 parrots included poor feathers, lipomas, abnormal choanal papillae, obesity, leg ulcers, respiratory abnormalities, cardiac abnormalities, seizure activity, old fractures, missing digits, skin disease associated with mites (Knemidokoptes species), oral granuloma, and a thin, friable beak. Only 7 of the birds were clinically normal on physical examination. Results of hematologic testing, plasma biochemical analysis, and plasma electrophoresis were not statistically different between female and male parrots. No blood parasites were found in any of the 32 samples examined. None of the 36 parrots evaluated had antibodies to the 12 infectious agents tested. Of the 21 fecal samples available, Capillaria species was detected in 1 bird. Findings from this study, in addition to nutritional, genetic, and husbandry evaluations, have been used to make recommendations to the Forestry Department of SVG for improvements in husbandry and veterinary care of this ex situ population.

Wet mounting using iodine–glycerol provides a semi-permanent preparation for microscopic observation of faecal parasites

Wet mounting using iodine–glycerol provides a semi-permanent preparation for microscopic observation of faecal parasites

Randomized trial of guava as source of ascorbic acid to reduce iron deficiency among indigenous schoolchildren in northern Mexico

This trial aimed at examining the effect of drinking 300 ml of guava juice containing 200 mg of ascorbic acid (AA) with the main meal for 10 weeks (5 d/wk) on the iron status of iron‐deficient children. A total of 295 children aged 6–9 years from 4 boarding schools were screened for anemia using altitude‐adjusted capillary hemoglobin (Hb) cut‐offs. The 95 anemic children were randomly allocated to a guava or placebo group, each with 16 and 14 iron‐deficient children (serum ferritin‐SF <12 ng/ml with negative C‐reactive protein), respectively. The placebo group was given guava‐flavored juice free of AA. Children with fecal parasites were treated. Dietary intake was collected for weeks 3, 5 and 7 at school and household level. Differences in mean Hb and SF between the groups at the end of the trial were the main outcomes. Dietary iron intake did not differ significantly between the guava and placebo groups at school (25 vs. 24 mg/d; p 0.3) and household level (19 vs. 20 mg/d; p 0.3). Baseline mean‐s.d. venous Hb (g/l) and SF (ng/ml) were 120‐6 and 8.2‐3.5 for the guava, and 115‐13 and 7.4‐4.6 for the placebo group, respectively (Hb: p 0.2; SF: p 0.6); at the end of the study these were 130‐7 and 17.9‐10.3, and 126‐15, and 15.4‐5.8 (Hb: p 0.4; SF: p 0.4). No differences on the iron status were found between the children who received guava and placebo juice after 10 weeks. Study supported by grant IMSS‐FOFOI/2005/1/I/029 and CDI‐Chihuahua

Biomedical Evaluation of Free-Ranging Red Ruffed Lemurs (Varecia rubra) Within the Masoala National Park, Madagascar

Complete health assessments were performed on 22 adult red ruffed lemurs (Varecia rubra), comprising nine males and 13 females, found within the Masoala National Park in northeast Madagascar. Each animal was anesthetized using tiletamine and zolazepam and underwent a thorough physical examination, including measurement of its weight and vital signs; blood collection for hematology, plasma total protein concentration, serum chemistries, fat-soluble vitamins, trace minerals, assessment of iron metabolism, toxoplasmosis serology, viral serologies, and examination for hemoparasites; fecal collection for bacterial culture and parasite examination; and collection of a representative number of any ectoparasites. Comparison of blood values with those of captive lemurs demonstrated a number of significant differences thought to be associated with physiologic state (e.g., reproductive stage and stress), hydration, and diet. There was no evidence of serious infectious diseases, and hemoparasites were not detected. The enteric flora appeared unremarkable; however, results may have been skewed toward more cold-tolerant bacteria. The fecal parasite burden was low. Lemurostrongylus spp. was identified in two of the lemurs, and there were moderate numbers of Laelapidae mites present on approximately one third of the lemurs. This study demonstrated the substantial amount of data that can be collected from free-ranging populations, considered invaluable in the management of captive populations, in reducing the incidence of captivity-related diseases, and in the risk assessment associated with reintroduction programs.

Immune-Related Gene Expression in Two B-Complex Disparate Genetically Inbred Fayoumi Chicken Lines Following Eimeria maxima Infection

To investigate the influence of genetic differences in the MHC on susceptibility to avian coccidiosis, M5.1 and M15.2 B-haplotype-disparate Fayoumi chickens were orally infected with live Eimeria maxima oocysts, and BW gain, fecal oocyst production, and expression of 14 immune-related genes were determined as parameters of protective immunity. Weight loss was reduced and fecal parasite numbers were lower in birds of the M5.1 line compared with M15.2 line birds. Intestinal intraepithelial lymphocytes from M5.1 chickens expressed greater levels of transcripts encoding interferon-γ (IFN-γ), interleukin-1β (IL-1β), IL-6, IL-8, IL-12, IL-15, IL-17A, inducible nitric oxide synthase, and lipopolysaccharide-induced tumor necrosis factor-α factor and lower levels of mRNA for IFN-α, IL-10, IL-17D, NK-lysin, and tumor necrosis factor superfamily 15 compared with the M15.2 line. In the spleen, E. maxima infection was associated with greater expression levels of IFN-γ, IL-15, and IL-8 and lower levels of IL-6, IL-17D, and IL-12 in M5.1 vs. M15.2 birds. These results suggest that genetic determinants within the chicken MHC influence resistance to E. maxima infection by controlling the local and systemic expression of immune-related cytokine and chemokine genes.

Estudo da prevalência e fatores associados à fasciolose no Município de Canutama, Estado do Amazonas, Brasil

Summary This study of fecal parasites, conducted in Canutama, State of Amazon, Brazil, aimed at identifying the prevalence of fascioliasis and related exposure factors to this illness in the Municipality. The prevalence of Fasciola hepatica was 2.0% (CI 95% ; 1.0-3.6), and the general prevalence of enteroparasites found was 66.8% (CI 95% ; 62.7-70.7). The only statistically significant association with the illness was being a child ≤5 years old (p-value=0.008; OR=6.63). Other variables related to demographics, sanitary conditions and food consumption were not significantly associated to illness. This survey was conducted as part of fascioliasis outbreak inquiry and constitutes one of the first reports of this parasitose in the Brazilian Northern Region.

Faecal and protozoan parasite contamination of water spinach (Ipomoea aquatica) cultivated in urban wastewater in Phnom Penh, Cambodia

To identify the level of contamination with thermotolerant coliforms (ThC), intestinal helminth eggs and protozoan parasites in water spinach (Ipomoea aquatica) cultivated in a wastewater-fed lake in Phnom Penh, Cambodia. The investigation was carried out from July 2004 to May 2005 in Boeng Cheung Ek lake, a main recipient of wastewater from the city of Phnom Penh. Water spinach samples were collected near two wastewater entry points in the northern part of the lake and near a wastewater exit point in the southern part of the lake, where water is discharged from the lake into a stream. Water spinach samples were harvested at each of the three locations with and without wastewater contact according to the normal practices of farmers, and analysed for ThC, protozoan parasites (Giardia, Cryptosporidium and Cyclospora), and helminth eggs (Ascaris lumbricoides, Trichuris trichura and hookworm) using standard methods. Wastewater samples were also collected at each of the three locations and analysed for ThC and helminth eggs. High concentrations of ThC (approximately 10(5)-10(7)/g) were found in water spinach samples. ThC mean counts did not differ significantly, neither between sample types at each location, nor between locations. ThC mean concentration of water spinach samples collected in the rainy season of 2005 was higher than that in the dry season of 2004. Protozoan parasites were detected in the samples from all three locations and in water spinach harvested with and without wastewater contact. Giardia spp. were present in 56% (20) of samples with an average cyst concentration of 6.6/g. Mean counts of Giardia were not significantly associated with wastewater contact status of water spinach. Cryptosporidium oocysts were found in 17% (six) of samples with an average concentration of 0.5 oocyst per gram of water spinach. Cyclospora oocysts were detected in 8% (three) of samples. Four (11%) water spinach samples contained helminth eggs (average concentration: 0.1 egg per gram). Water samples contained approximately 10(4)-10(7) ThC per 100 ml and a mean of 27.4 helminth eggs per litre. There was a 2-3 log reduction of ThC between the water samples collected at the wastewater entry and exit point(s) of the lake. Water spinach cultivated in the lake was highly contaminated with feces, as indicated by high ThC concentrations and the presence of protozoan parasites. A reduction in ThC numbers almost to WHO guideline levels for irrigation water occurred through natural biological and physical processes in the lake, as shown by differences in ThC counts at wastewater entry and exit points.

Persisting symptoms and duodenal inflammation related to Giardia duodenalis infection

After a large waterborne outbreak of Giardia infection in Bergen, some patients experienced persisting abdominal symptoms despite metronidazole treatment. This study aimed at investigating possible causes for their symptoms. Over a 15 month period, 124 referred patients were evaluated in a prospective cohort analysis with a standardised investigation including duodenal biopsies and aspirate, blood tests and faecal parasite and calprotectin tests. Recovered subjects were recruited for symptom analysis. Persisting Giardia duodenalis infection was found in 40 patients (32.3%). Duodenal biopsies showed signs of inflammation in 57 patients (47.1%). Microscopic duodenal inflammation was present in 34 (87.2%) of the Giardia positive and 23 (28.0%) of the Giardia negative patients. There were significant associations between persistent Giardia positivity, microscopic duodenal inflammation and a positive calprotectin test. Duodenal aspirate and duodenal biopsies performed poorly in diagnosis of persistent giardiasis. In patients with persisting symptoms after metronidazole treated Giardia infection we commonly found chronic Giardia infection and microscopic duodenal inflammation, especially in illness duration less than 7 months. Both these findings subsided over time. Increasingly, investigations could not determine a definite cause for the persistent symptoms. The very long-term post-giardiasis diarrhoea, bloating, nausea and abdominal pain documented here need further study.

Epidemiological Study of Non‐systemic Parasitism in Dogs in Southeast Mediterranean Spain Assessed by Coprological and Post‐mortem Examination

The prevalence and risk factors of non-systemic canine ecto- and endoparasitism and anthelminthic use in Murcia located at the centre of the Spanish Mediterranean coastal arch, was investigated by coprology and necropsy in up to 275 pet, city shelter and stray dogs in 2001-2004. Faecal parasite stages were detected in 25% of dogs. Species frequency was 6-10% for Toxocara canis, Ancylostomatidae spp., Toxascaris leonina and Isospora canis, and 0.4-1% for Trichuris vulpis, Giardia lamblia, and Dipylidium caninum. Logistic regression indicated that the risk of intestinal parasitism was highest for dogs <or=1 year old, in the middle to low weight range and kept at the city shelter. Although risk factors varied according to the species, T. canis was most common in <1 year old and Ancylostomatidae spp. was more prevalent in older dogs. This suggests that the dominant species was Uncinaria spp. and not the more zoonotically important Ancylostoma spp. This was further supported by necropsy findings; however, the degree of agreement between post-mortem and coprological examination for intestinal parasites was generally poor. Necropsy revealed 10%G. lamblia, 12%Taenia spp. 38%D. caninum infections. Fleas, ticks and lice were also found in 38%, 6% and 2% of necropsied stray dogs. These results demonstrate the need for an urgent parasite control programme at the city dog shelter and the need to improve the owner's education on zoonotic risks, the proper use of anthelminthics, and other parasite control practices.

Gastrointestinal Involvement in Pediatric Polyarteritis Nodosa

Gastrointestinal Involvement in Pediatric Polyarteritis Nodosa

Association between intestinal parasitic infections and type of sanitation system in rural El Salvador

To identify demographic, behavioural and environmental determinants of intestinal parasitic infection, evaluate the impact of a variety of dry sanitation systems on intestinal parasitic infection, and evaluate the safety of using stored biosolids in agriculture in order to guide future sanitation interventions in rural areas of El Salvador. Interviews were conducted with 109 households in eight communities where double-vaulted and solar urine-diverting desiccating latrines, pit latrines or no latrines were used. Faecal samples from 499 individuals were tested for enteric helminths and protozoa. Users of solar desiccating latrines had the lowest prevalence of enteric parasite infection. Double-vault, urine-diverting desiccating latrines effectively reduced the transmission of some pathogens, but may not achieve the conditions sufficient for the complete destruction of the more environmentally persistent pathogens, Ascaris lumbricoides and Trichuris trichiura. Contact with inadequately treated latrine biosolids was associated with an increased risk of Ascaris infection. Solar latrines were associated with the overall lowest prevalence of enteric parasitic infections. Members of households where latrine biosolids were used in agriculture had a higher prevalence of infection than those where biosolids were buried. We therefore recommend the promotion of solar latrines in rural areas of El Salvador over other dry sanitation systems, and recommend that stored biosolids not be used in agriculture.

Oral fecal parasites and personal hygiene of food handlers in Abeokuta, Nigeria.

Ingestion of infective eggs and cysts of faecal orally transmissible parasites has been linked with the level of environmental and personal hygiene. The possibility of contamination of food with eggs and cysts by infected food vendors has also been recorded. This study was aimed at assessing the prevalence of parasites with direct transmission and the level of hygiene among food vendors. Stools of randomly selected food vendors selling in schools and streets in Abeokuta were examined for ova and cysts of parasites using formo-ether concentration method. Questionnaires, interviews, and field observation were also used to assess the activities of food vendors. Ninety-seven (97%) percent of the food vendors were infected with one or more faecal-orally transmissible parasites while 3% were free from such parasites; Parasites observed were Entamoeba histolytica with a prevalence of 72% Ascaris lumbricoides (54%), Enterobius vermicularis (27%), Trichuris trichiura (24%) and Giardia duodenalis (13%). School food vendors recorded lower prevalence of infection (92%) than the street food vendors (98.7%) (P>0.05) Fifty-two percent (52%) of the food vendors have dewormed in the last four years; Eighty percent (80%) of this were school food vendors. Infections with helminthes were recorded in 63.5% of the dewormed food vendors. Food vendors involved in child care activities were found to be more infected than those not involved in such activities. Toilet facilities available to the vendors were mainly pit latrine and other related structure (75%) while 25% had access to water system closets. During hawking, dung hills were majorly used for defaecation. Hand washing after defaecation did not include the use of soap in the few vendors that were involved in hand washing. There is need to enact food handling policies and implementation of such policies ensured in order to reduce transmission of oral faecal parasites.

PARASITES OF FREE-RANGING SMALL CANIDS AND FELIDS IN THE BOLIVIAN CHACO

Parasite surveys of free-ranging wildlife provide important information for monitoring population health. Between March 2001 and March 2003, we sampled 10 ocelots (Leopardus pardalis), eight Geoffroy's cats (Oncifelis geoffroyi), a jaguarundi (Herpailurus yaguarondi), five pampas foxes (Pseudalopex gymnocercus), and three crab-eating foxes (Cerdocyon thous) at three sites in the Bolivian Chaco. The objective of the study was to survey the parasite fauna of these carnivores and compare prevalence of parasites among the sites. The parasite community of these carnivores was diverse, with representatives from eight genera of nematodes, two families of cestodes, two protozoan species, and six arthropod species. Fecal parasites identified from 12 of the 13 felids and five of the six canids examined included Aelurostrongylus abstrusus, Ancylostoma tubaeforme, Uncinaria sp., Crenosoma sp., Toxocara cati, Spirurida, Capillaria aerophila, Spirometra sp., Taeniidae, and Cystoisospora sp. Four tick species, Amblyomma parvum, A. tigrinum, A. ovale, and A. cajennense, and two flea species, Pulex irritans and Delostichus phyllotis, were identified. Two crab-eating foxes had serologic evidence of heartworm disease (HWD). Antibodies against Toxoplasma gondii were found in 15 of 26 animals. Although HWD was found only in canids inside the national park, parasite prevalence did not appear to differ among sites, and no evidence was found of parasite spillover from domestic to wild carnivores.

Susceptibility of Different Triatomine Species to Trypanosoma rangeli Experimental Infection

Trypanosoma rangeli is a kinetoplastid protozoan parasite that has been found in the majority of Latin American countries, overlapping its distribution area with that of Trypanosoma cruzi, the causative agent of Chagas disease. This parasite shares the same reservoirs and vectors as T. cruzi. Triatomines from genus Rhodnius are considered the most susceptible hosts to infection. In this work, we report the susceptibility of different triatomine species (Rhodnius neglectus, Panstrongylus megistus, Triatoma infestans, T. sordida, T. braziliensis, and T. vitticeps) to experimental infection by T. rangeli isolated from Didelphis albiventris in a highly endemic region for Chagas disease. An intense parasitism was evidenced in feces (56% to 81%) of the majority of the species studied on the 10th day after infection, decreasing during the period of the experiment (30 days). T. vitticeps did not present parasites in feces at any time. All triatomine species presented parasites in the hemolymph. In T. vitticeps and P. megistus, this parasitism was scarce (6.3% and 6.6%, respectively). In the other species, the parasitism was variable (62.5% to 100%). Triatomine mortality varied between 3% to 40%, increasing during the infection in all species studied. The lowest mortality was observed for T. infestans. Also, we showed that only trypomastigotes forms from salivary glands, and hemolymph were infective for mice. We conclude that all triatomine species used were susceptible to infection by T. rangeli at different levels. There was no direct correlation between intensity of parasitism and mortality.

Comparison of fecal microflora in children with atopic eczema/dermatitis syndrome according to IgE sensitization to food

Atopic eczema/dermatitis syndrome (AEDS) commonly often arises during early infancy. In several intervention studies a beneficial influence on AEDS course of certain intestinal bacteria, administered as 'probiotics', has been described. To evaluate the possible role of the natural intestinal microflora in children with allergic eczema/dermatitis syndrome regarding immediate type hypersensitivity to food allergens, children with food allergy (AAEDS, n = 68) have been compared with children without detectable food allergy (NAEDS, n = 25). All children (n = 93) in preschool age, mean age of 2.6 (+/-1.8) years, diagnosed with AEDS who were treated as inpatients in 2003 in a dermatological hospital were included. The correlation between fecal microflora, parasites and specific immunoglobulin E (IgE) antibodies against common food allergens was analyzed. A similar composition of intestinal microflora in children with AAEDS and NAAEDS was found. The food allergens that were most frequently detected were egg white, cow milk, casein, peanut and hazelnut. Furthermore, a significant association between IgE sensitization against important food allergens and components of the fecal microflora could not be demonstrated. With aging changes occur in the intestinal microbiota [Proteus/Klebsiella and age (rho = -0.607) and Enterococcus and age (rho = -0.428)]. In two subjects of the AAEDS group Blastocystis hominis was found. The composition of natural intestinal microflora in children with AAEDS and NAAEDS was similar. Hence, there is no evidence of a role of the intestinal microflora with regard to the development of infant (food) allergy in children with AEDS. The possible consequences for allergic diseases later in life require further investigation.

Concurrent response to challenge infection withCryptosporidium parvumin immunosuppressed C57BL/6N mice

We investigated the response to challenge infection with Cryptosporidium parvum oocysts in immunosuppressed C57BL/6N mice. In the primary infection, fecal oocyst shedding and parasite colonization were greater in immunosuppressed mice than in nonimmunosuppressed mice. Compared with primary infection, challenge infection with C. parvum didn't show any oocyst shedding and parasite colonization. Especially, oocyst shedding and parasite colonization from the mice infected with heat-killed oocysts were not detected. After challenge infection with C. parvum oocysts, however, these mice were shedding small numbers of oocysts and parasite colonization. Except normal control and uninfected groups, the antibody titers of other groups appear similar. Based on the fecal oocyst shedding, parasite colonization of ilea, and antibody titers in the mice, these results suggest that the resistance to challenge infection with C. parvum in immunosuppressed C57BL/6N mice has increased.