BACKGROUND: The protozoancryptosporidiumisan important intestinal parasitic infection in domestic ruminants that has the potential for transmission between humans and livestock throughout the world and Iran. OBJECTIVES: The present study was undertaken to determine cryptosporidiuminfection in different age groupsof cattle and water buffaloesin farms of Mahabad suburb, Iran. METHODS: For this purpose, a total number of 248 fresh fecal samples were randomly collected from rectum of cattle and water buffaloesin farms of 4 villages from May2016 to May 2017. The fecal samples were subjected to floatation technique andcryptosporidiumoocysts were collected using Sucrose Gradient and Percole flotation technique and stained with modified Ziehl-Neelsen technique. RESULTS: Overall prevalence of cryptosporidiuminfection was 50% (124/248). The highest rate of infection was significant in female calves (30.65%) less than one year-old. The highest infection rate was significantly found in summer (20.16%). Cryptosporidium parvum and C. andersoni were identified in 40.32% (100/248) and 9.68% (24/248) of examined cattle, respectively. Mixed infection was 8.47%. CONCLUSIONS: The results of this study indicated that C.parvum was prevalent in cattle of the region, therefore, further molecular studies are recommended to determine the genotypes of the parasiteas a potential zoonotic agent.

BACKGROUND: Cryptosporidium parvum is a protozoan parasite which belongs to apicomplexa phylum. The parasite infects both wild and domesticated animals and human beings as well. OBJECTIVES: The purpose of the present study was to detect oocyst shedding and diarrhea pattern in experimental cryptosporidiosis and their correlation with weight loss in neonatal calves. METHODS: Twelve Holstein calves of both sexes were obtained at birth from dairy farm and randomly divided into two groups of 6 calves. Six calves were orally infected with 107 C.Parvum oocysts at the 12h post parturition. The control group was not infected. Clinical signs were examined and fecal samples were collected by the rectal examination twice a day. All calves were weighed from day 0 to day 30 with 3 days intervals to determine effects of cryptosporidiosis on weight gain. RESULTS: All infected calves were noticeably depressed and had a decreased appetite from 3 days post inoculation (DPI) while they received colostrum. Subsequently, watery diarrhea with clumps of mucus and yellow or pale changes of feces color were observed. The infected calves have had diarrhea for 5-8 days that remarkably had got dehydrated. The most severity of diarrhea was 4-6 DPI. Oocyst excretion started 4 DPI, peaked at 6 DPI (60.48×106±9.03oocysts/g feces) and continued until 11 DPI. Control calves had no diarrhea and other clinical signs during the whole period of the trial. The mean weight gain of control group was significantly higher than inoculated group during experiment (p<0.001). The Weight of the infected calves was retarded until 9 days old and then risen subsequently. CONCLUSIONS: Present study showed the role of C.Parvum as the primary cause of diarrhea and weight loss among neonatal calves.

Cryptosporidium infection is one of the most common causes of parasitic diarrhoea worldwide in cattle and humans. In developing countries, human cryptosporidiosis is most prevalent during early childhood and links between zoonotic infection and animal related activities have been demonstrated. This study investigated the prevalence and species/genotype distribution of Cryptosporidium among children (< 5 years) and calves (< 6 months) living in a rural farming area adjacent to the Kruger National Park in South Africa, where interactions between humans and wild and domestic animals are known to occur. Cryptosporidium oocysts were detected in 8/143 stool samples of children recruited within the hospital system (5.6%; 95% CI 2.4%, 10.7%) and in 2/352 faecal samples of calves (0.6%; 95% CI 0.1%, 2.0%) using the modified Ziehl–Neelsen (MZN) staining technique. Microscopy positive samples from children were further analysed by PCR targeting the 18S rRNA gene and identified as Cryptosporidium hominis (3/4) and Cryptosporidium meleagridis (1/4). Regardless of the microscopy outcome, randomly selected samples (n = 36) from calves 0–4 months of age were amplified and sequenced at the 18S rRNA gene using nested PCR. Two calves tested positive (5.6%; 95% CI 1.7%, 18.7%), and revealed the presence of Cryptosporidium parvum and Cryptosporidium bovis. The detection of only two zoonotic species (C. parvum in one calf and C. meleagridis in one child) suggests that zoonotic cryptosporidiosis is not currently widespread in our study area; however, the potential exists for amplification of transmission in an immunocompromised population. (Résumé d'auteur)

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We investigate the resistance of Cryptosporidium (C.) parvum oocysts to commercial bleach treatment. The viability and infectivity of C. parvum oocysts suspended in 100, 50, 25, 12.5, 6.3 or 3.2% aqueous commercial bleach for 10, 30, 60, 120 or 180 min at room temperature were assessed by nucleic acid Syto-9 staining, histologic examination of ileum and infectivity to immunosuppressed neonatal C57BL/6N mice. Although the viability was decreased compared with normal oocysts, all oocysts in contact with serially diluted commercial bleach for 180 min were alive by nucleic acid dye Syto-9 staining. And, microscopic examination of ileum sections revealed developmental stages of C. parvum in all mice. The oocyst shedding patterns between mice infected with oocysts contacted with commercial bleach and normal control mice were not significantly different each other. Although commercial bleach is widely used as a bacterial and viral disinfectant, the present findings indicate that it is not an effective disinfectant for C. parvum oocysts under practical conditions. Authors conclude that, therefore, it is undesirable to recommend commercial bleach as a disinfectant for C. parvum oocysts.

Cryptosporidium parvum is the most frequent parasitic agent that causes diarrhoea in AIDS patients in Thailand. Cryptosporidiosis outbreaks in humans may be attributed to contamination of their drinking water from infected dairy pastures. A 23-kDa glycoprotein of C. parvum (CpP23) is a sporozoite surface protein that is geographically conserved among C. parvum isolates. This glycoprotein is a potentially useful candidate antigen for the diagnosis of cryptosporidiosis by enzyme-linked immunosorbent assay. Therefore, we investigated the seroprevalence of C. parvum infection in dairy cows in northern Thailand using an ELISA based on recombinant CpP23 antigen. Sera were randomly collected from 642 dairy cows of 42 small-holder farmers, which had the top three highest number of the dairy cows' population in Northern Thailand, that included Chiang Mai, Chiang Rai and Lumpang provinces. The overall seroprevalence of the infection was 4.4 %, and the seropositive rates for the three provinces were 3.3 % in Chiang Mai, 5.1 % in Chiang Rai and 3 % in Lumpang. These results suggest that cattle could play a role in zoonotic cryptosporidiosis in Thailand.

A calf suffering from diarrhea was admitted to the Animal and Plant Quarantine Agency for diagnostic evaluation. Postmortem examination revealed that the mesenteric lymph node was enlarged and small intestine wall was thin. Microscopically, a large number of small round organisms were attached to the small intestine villi. Villous atrophy and proprial neutrophil infiltration were also observed. Based on modified Ziehl-Neelsen staining, electron microscopy, and ELISA results, the calf was diagnosed with fatal cryptosporidiosis.

Serum retinol, retinyl palmitate, and total vitamin A concentrations, and jejunoileal morphology were examined in neonatal calves infected with Cryptosporidium parvum. Group-1 calves served as noninfected controls and, after an adjustment period, were given 50 ml of saline solution IV every 12 hours for 6 days. Group-2 calves were inoculated with 10(7) C parvum oocysts and, after the onset of diarrhea, were given 50 ml of saline solution IV every 12 hours for 6 days. Group-3 calves were inoculated with 10(7) C parvum oocysts and, after the onset of diarrhea, were treated with difluoromethylornithine (DFMO, 200 mg/kg of body weight IV, q 12 h) for 6 days. Group-4 calves were naturally infected with C parvum. Jejunoileal biopsy specimens were excised from calves of groups 1-3 at 3 and again at 15 to 16 days of age. During the course of diarrhea and 3 days after saline or DFMO administration, water-miscible retinyl palmitate was administered orally (2,750 micrograms/kg) to each calf in each group. Cryptosporidium parvum infection was associated with significant (P < 0.05) reduction in postadministration serum retinol, retinyl palmitate, and total vitamin A concentrations in calves of groups 2, 3, and 4. Cryptosporidium parvum infection caused significant (P < 0.05) reduction in villus height. Decreased villus height, villus blunting and fusion, and attenuation of the intestinal mucosa were associated with reduced absorption of vitamin A, as indicated by lower peak postadministration retinyl palmitate concentration in C parvum-infected calves. Intravenous administration of DFMO to group-3 calves did not improve retinol absorption. Vitamin A should be provided parenterally to young calves with enteric cryptosporidiosis in an attempt to avoid depletion of concurrent low liver vitamin A reserves.

Objective-To identify risk factors associated with Cryptosporidium parvum infection in dairy calves. Animals-108 case animals and 283 control animals. Procedures-Case animals were calves infected with C parvum, and controls were infected with Cryptosporidium bovis (n = 67) or calves not infected with Cryptosporidium spp. Fecal samples were tested via the flotation concentration method for Cryptosporidium spp. Samples were genotyped by sequencing of the 18s rRNA gene. Associations between host, management, geographic, and meteorologic factors and Cryptosporidium genotype were assessed. Results-Younger calves and calves housed in a cow barn were more likely to be infected with both genotypes. Herd size and hay bedding were associated with an increased risk of infection with C parvum, and Jersey breed was a risk factor for C bovis infection. Compared with a flat surface, a steeper slope was significantly associated with a decreased likelihood of infection with both genotypes, and precipitation influenced the risk of C parvum infection only. Conclusions and Clinical Relevance-Risk factors for calf infection with C parvum differed from those for infection with C bovis. Results may be useful to help design measures that reduce animal exposure and decrease public health risk and economic losses associated with C parvum infection in cattle.