Cryptosporidium infection as a cause of calf diarrhea

Giardiasis and cryptosporidiosis in ruminants

Although they differ considerably with respect to their biology, both Giardia duodenalis and Cryptosporidium parvum are common in ruminants, whereas Cryptosporidium andersoni is not. G. duodenalis infections are acquired during the first few months of life, tend to be chronic, and may be a production-limiting disease of ruminants. C. parvum infections remain an important cause of diarrhea in neonatal ruminants. Abomasal cryptosporidiosis, caused by C. andersoni, is an emerging disease of cattle that may affect both beef and dairy herds. This article reviews the life cycles, production impacts, treatments, controls, and zoonotic potentials of these important ruminant parasites.

Prevalence of Giardia sp. Cryptosporidium parvum and Cryptosporidium andersoni (syn. C. muris) [correction of Cryptosporidium parvum and Cryptosporidium muris (C. andersoni)] in 109 dairy herds in five counties of southeastern New York

A cross-sectional study was undertaken to determine the prevalence of Giardia sp. (G. duodenalis group), Cryptosporidium parvum and Cryptosporidium andersoni (C. muris) [corrected] in dairy cattle in three different age groups, and to evaluate the association of age and season with prevalence. One hundred and nine dairy farms, from a total of 212 farms, in five counties of southeastern New York volunteered to participate. On these farms, 2943 fecal samples were collected from three defined age groups. The farms were randomly assigned for sampling within the four seasons of the year. Each farm was visited once during the study period from March 1993 to June 1994 to collect fecal samples. Demographic data on the study population was collected at the time of sampling by interviewing the farm owner or manager. At collection, fecal samples were scored as diarrheic or non-diarrheic, and each condition was later related to positive or negative infection with these parasites. Fecal samples were processed using a quantitative centrifugation concentration flotation technique and enumerated using bright field and phase contrast microscopy. In this study, the overall population prevalence for Giardia sp. was 8.9%; C. parvum, 0.9%; and C. muris, 1.1%. When considering animals most at the risk of infection (those younger than 6 months of age) Giardia sp. and C. parvum was found in 20.1 and 2.4% of the animals, respectively. Giardia sp. and C. muris were found in all age groups. There was no significant seasonal pattern of infection for any of these parasites.

Cryptosporidia on dairy farms and the role these farms may have in contaminating surface water supplies in the northeastern United States

The prevalence and risk factors for shedding of cryptosporidia by dairy cattle and calves and the prevalence and risk factors for cryptosporidia in surface waters associated with dairy farms were determined for a well-defined watershed in the northeastern United States. Eleven dairy farms were enrolled in the study and subjected to monthly sampling over a 6-month period. Animal-, water-, and manure-management practices were determined by survey and fecal, on-farm water, and stream samples were obtained monthly and evaluated for the presence of cryptosporidia. Ninety-one percent of the dairy farms in our study had Cryptosporidium on their premises. Fifteen percent of the sampled calves 0-3 weeks of age were shedding cryptosporidia. The risk factors for calves shedding cryptosporidia were contact between calves and frequent bedding changes. The probability of shedding cryptosporidia decreased with age. Nine percent of farm-associated stream samples were cryptosporidia-positive. The single risk factor for detecting cryptosporidia in surface water was increasing frequency of spreading of manure on fields. The probability of detecting cryptosporidia in streams decreased as 5-day cumulative precipitation increased. There were no animal-associated or barnyard-management features associated with detecting cryptosporidia in farm-impacted streams.

Risk factors associated with Cryptosporidium parvum infection in dairy cattle in southeastern New York State

An observational analytical epidemiologic study was carried out to identify factors associated with the risk of infection with Cryptosporidium parvum in dairy herds in southeastern New York state. A random sample of 2943 cattle on 109 farms was selected from the target population. Fecal samples were collected from animals in three different age groups and examined for the presence of C. parvum using a quantitative centrifugation concentration flotation method. Data on intrinsic, preweaning, postweaning, maternity, and general management factors were collected and evaluated for their association with the risk of infection with C. parvum. Indices for each of these categories of management were developed from factors significantly associated with the risk of infection with C. parvum. Significant factors were identified using the logistic regression statistical technique. A final analysis, including the indices, age, and season, was performed to identify factors significantly associated with the risk of infection with C. parvum while simultaneously controlling for the effect of other factors. The farm effect was evaluated using a mixed effect model. Preweaning factors found to be significantly associated with a decreased risk of infection were: use of ventilation in calf rearing areas, daily addition of bedding, feeding of milk replacer, daily disposal and cleaning of bedding, and use of antibiotics. Postweaning factors such as moving of the animals after weaning, cleaning of soiled bedding, and use of antibiotics and ionophores as preventive measures were significantly associated with the decreased risk of an infection with C. parvum. Consideration of maternity management factors showed that winter housing of cows individually within 2 months of calving, use of fresh colostrum to feed calves, and having a concrete floor in the calving area were significantly associated with decreased risk of C. parvum infection. The total number of dairy cattle, total number of other species of agricultural animals on the farm, and the distance of the barn water source from the septic system were found to be significantly associated with increased risk of C. parvum infection. In the final analysis, the risk of infection with C. parvum was significantly decreased with an increased value of the maternity management index score. The general management significantly affected the risk of infection with C. parvum where the risk increased with the increase of the value of the index. The risk of infection significantly decreased with increase in the age of the animal.

Prevalence, detection and control of Cryptosporidium parvum in food

The role of Cryptosporidium parvum as a foodborne pathogen has not been well documented. Epidemiological features of this parasitic protozoon lead to the assumption that the incidence of cryptosporidiosis due to contaminated food is under-estimated. The high prevalence of C. parvum among dairy herds has increased the spread of oocysts in the farm environment, and their potential presence in raw milk and other raw foods. In October 1993, the first well-documented foodborne outbreak was reported in Maine, USA, and was caused by contaminated hand-pressed apple cider. Although various cases of cryptosporidiosis among humans have pointed to raw milk and other raw foods as possible sources of infection, a conclusive demonstration of foodborne cryptosporidiosis has rarely been established. The limited numbers of oocysts in the suspected samples and the lack of sensitive detection methods adapted for oocyst detection in food contribute to this under-reporting. This review paper discusses various aspects of Cryptosporidium spp. and cryptosporidiosis, including the routes of transmission, the control of oocysts in food, and the available detection methods. The polymerase chain reaction (PCR) combined with DNA probe hybridization is a promising detection method. Recent knowledge on the molecular biology of the parasite for the development of new PCR assays and their potential use in the detection of C. parvum in food are described.

Whole milk and oral rehydration solution for calves with diarrhea of spontaneous origin

Forty-two calves (mean 10 d of age) that spontaneously contracted diarrhea were used to test the therapeutic value of an oral rehydration solution with or without whole milk. Therapy began on the first feeding after a fecal score was > 2 (five-point scale). Amounts (percentages of BW daily) of milk and oral rehydration solution on d 1 and 2, 3 and 4, 5 and 6, and 7 for treatments 1, 2, and 3 were 1) 0 and 10, 5 and 5, 7.5 and 2.5, 10 and 0% (in two feedings); 2) 2.5 and 10, 5 and 7.5, 7.5 and 5, 10 and 0% (in two feedings); 3) 10 and 10, 10 and 5, 10 and 2.5, 10 and 0% (in three feedings). Oral rehydration solution was fed 15 min after milk. Fecal score, rectal temperature, packed cell volume of whole blood, concentrations of glucose and electrolytes in serum, and strong ion difference of serum were unaffected by treatments. Calves given treatment 3 gained BW throughout the experiment, whereas those given treatments 1 and 2 lost BW during the first 3 d of therapy. Fecal cultures indicated that 70% of calves were infected with Cryptosporidium on d 1 of therapy. No mortality occurred. Whole milk and oral rehydration solution fed to calves did not adversely affect calves or prolong or worsen diarrhea but promoted gain of BW.

Treatment of diarrhea of neonatal calves

Therapeutic strategies for the treatment of diarrhea of neonatal calves should be logical and should be targeted at correction of physiologic dysfunction. Appropriate, specific antimicrobial or antiprotozoal therapy should be instituted when colibacillosis, salmonellosis, or giardiasis is confirmed or suspected. All calves with diarrhea should be rehydrated if necessary, and proper nutritional support should be provided. Antisecretory agents such as flunixin meglumine and bismuth subsalicylate may be beneficial for treatment of calves with colibacillosis and salmonellosis. Adsorbants, such as attapulgite and bismuth subsalicylate, also may reduce loss of fluids. Perhaps loperamide or a similar drug will be proven effective in calves in the future. Potentially harmful drugs include several antimicrobial agents when they are administered orally, because they result in malabsorption; kaolin and pectin, which increase loss of ions during diarrhea; and motility modifiers that cause a decrease in all types of intestinal motor function. Finally, success should be measured by indicators of production such as survivability, days treated, weight gained, and net profit. Our goal should be to restore and maintain the health of the calf, not simply to alter the volume and consistency of the feces.

Intestinal protozoa and epithelial cell kinetics, structure and function

Intestinal protozoa are not only common enteric pathogens in the tropics but also the high incidence of infection among immunocompromised patients in northern countries has evoked an increased interest in these parasites. Although enteric protozoa are a major cause of diarrhea and malabsorption in humans and other animals, the pathophysiology of gut disturbances caused by them remains poorly understood. Clinical signs related to enteric protozoan disease commonly involve malabsorption, diarrhea, weight loss or retarded weight gain and anorexua. Since these infections are most prevalent and most severe in the young, this may translate into considerable illness among children and significant loss to the agricultural economy where domestic animals are prone to infection. In this review we describe the effects of intestinal protozoan diseases on the structure, kinetics and function of absorptive intestinal cells and other epithelial cells, and correlate morphological injury with physiological alterations in the parasitized gut. Some of the interactions between immune responses and pathophysiology will be discussed, but in-depth discussion of intestinal immunity has recently been undertaken by other authors.

Enteric coccidial infections. Isospora, Sarcocystis, Cryptosporidium, Besnoitia, and Hammondia

The authors consider coccidial infections of the genera Isospora, Sarcocystis, Cryptosporidium, Besnoitia, and Hammondia.

Cryptosporidium spp. and cryptosporidiosis

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