An epidemiological study of Cryptosporidium parvum in two herds of adult beef cattle

Scott, CA; Smith, H. V.; Mtambo, M.M.A.; Gibbs, H. A.

doi:10.1016/0304-4017(94)00694-8

Cited by 84 publications

(42 citation statements)

References 25 publications

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“…In particular, there is a wide range of reported prevalences of fecal shedding of C. parvum for adult beef and dairy cattle. Numerous investigators have reported mean prevalences of fecal shedding from ϳ20 to ϳ70% in groups of clinically healthy adult cattle (23,31,34), yet several large cross-sectional epidemiologic surveys have observed prevalences of only 2% or less in asymptomatic adult cattle populations (4, 20, 41). Some of this variation in the observed prevalence of fecal shedding can be explained by different investigators using diagnostic assays of differing sensitivity and specificity (11,13,15), but much of the variation is the result of studying different populations of cattle (e.g., beef versus dairy), different age distributions within those populations, and groups of cattle under different management practices, especially when only a single farm or a small sample is examined.…”

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confidence: 99%

“…Recent estimates have ranged from 70 to 900 oocysts g of feces Ϫ1 for infected noncalf populations (13,16,19,34), but these values are highly conditional on the underlying age distribution of the population (16,39,41,44) and the sensitivity of the diagnostic test being employed (11,15,19,21,42,43). Increasing the sensitivity of an assay will function to increasingly detect individuals shedding at low intensities, thereby lowering the overall estimated mean intensity of shedding for the infected cohort of a population.…”

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Improved Quantitative Estimates of Low Environmental Loading and Sporadic Periparturient Shedding ofCryptosporidium parvumin Adult Beef Cattle

Atwill

Hoar²,

Pereira

et al. 2003

Appl Environ Microbiol

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Our primary goal was to generate an accurate estimate of the daily environmental loading rate of Cryptosporidium parvum oocysts for adult beef cattle, using immunomagnetic separation coupled with direct immunofluorescence microscopy for a highly sensitive diagnostic assay. An additional goal was to measure the prevalence and intensity of fecal shedding of C. parvum oocysts in pre-and postparturient cows as an indicator of their potential to infect young calves. This diagnostic method could detect with a >90% probability oocyst concentrations as low as 3.2 oocysts g of feces ؊1 , with a 54% probability of detecting just one oocyst g of feces ؊1 . Using this diagnostic method, the overall apparent prevalence of adult beef cattle testing positive for C. parvum was 7.1% (17 of 240), with 8.3 and 5.8% of cattle shedding oocysts during the pre-and postcalving periods, respectively. The mean intensity of oocyst shedding for test-positive cattle was 3.38 oocysts g of feces ؊1 . The estimated environmental loading rate of C. parvum ranged from 3,900 to 9,200 oocysts cow ؊1 day ؊1 , which is substantially less than a previous estimate of 1. . Use of this highly sensitive assay functioned to detect a greater proportion of low-intensity shedders in our population of cattle, which reduced the estimated mean intensity of shedding and thereby reduced the associated environmental loading rate compared to those of previous studies.Cryptosporidium parvum has emerged as a ubiquitous waterborne microbial pathogen, with specific genotypes readily transmitted ambidirectionally between livestock and humans (7,9,12,25,28,36). One of the first steps in designing watershed management programs for minimizing the occurrence of C. parvum in drinking water supplies is to identify significant quantitative sources of this parasite. Adult cattle are often considered potential nonpoint sources of environmental contamination for C. parvum, but there is some disagreement over the relative importance that adult cattle have in loading watersheds with significant amounts of C. parvum oocysts. In particular, there is a wide range of reported prevalences of fecal shedding of C. parvum for adult beef and dairy cattle. Numerous investigators have reported mean prevalences of fecal shedding from ϳ20 to ϳ70% in groups of clinically healthy adult cattle (23,31,34), yet several large cross-sectional epidemiologic surveys have observed prevalences of only 2% or less in asymptomatic adult cattle populations (4, 20, 41). Some of this variation in the observed prevalence of fecal shedding can be explained by different investigators using diagnostic assays of differing sensitivity and specificity (11,13,15), but much of the variation is the result of studying different populations of cattle (e.g., beef versus dairy), different age distributions within those populations, and groups of cattle under different management practices, especially when only a single farm or a small sample is examined. For example, we found in two different studies that calving duration fo...

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confidence: 99%

mentioning

confidence: 99%

Improved Quantitative Estimates of Low Environmental Loading and Sporadic Periparturient Shedding ofCryptosporidium parvumin Adult Beef Cattle

Atwill

Hoar²,

Pereira

et al. 2003

Appl Environ Microbiol

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“…Cryptosporidium parvum is also the most widespread enteropathogen identified in neonatal calves. Ninety percent of American dairy farms harbor this coccidian, and 92% of asymptomatic adult cows have specific anti-C. parvum IgG, IgG1, IgG2, and IgM antibodies (1). Neonatal calves experience high morbidity, but low mortality with monoinfections, although mixed infections result in a much greater rate of mortality (2).…”

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Oral Bovine Serum Concentrate Improves Cryptosporidial Enteritis in Calves

Hunt

Armstrong

et al. 2002

Pediatr Res

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Cryptosporidium parvum produces a prolonged watery diarrhea unresponsive to conventional antimicrobials. Because of reported efficacy of antibody-based immunotherapy, we studied the effect of inexpensive, commercially available oral bovine serum concentrate (BSC) in experimental cryptosporidiosis. Twenty-four calves were treated with 57 g/d BSC (n ϭ 12) or soy protein (n ϭ 12) added to their standard whey protein-based milk replacer (227 g/2 L twice daily). Of the 24, 9 were also treated with L-glutamine (GLN), 8 g/L (50 mM) in the milk (5 calves in the BSC group and 4 in the soy group). Animals were inoculated with 10 8 cryptosporidium oocysts per os on d 8 of life and received oral rehydration on d 12-14. Eight uninfected controls were treated with BSC or soy protein. Fecal and urine volume and urinary Cr-EDTA excretion were measured. Animals were killed on d 18 of life. Cryptosporidiosis induced severe watery diarrhea lasting Ͼ9 d and produced a 25% increase in intestinal permeability, a 33% decrease in villous surface area, and a 40% reduction in mucosal lactase specific activity. Glutamine treatment had no effect on the diarrhea or any of the intestinal tests; and therefore pooled data were used to compare the 12 calves treated with BSC with the 12 treated with soy. In animals receiving BSC, peak diarrheal volume and intestinal permeability were reduced 33%, fewer oocysts were shed, intestinal crypts were significantly deeper, and villous surface area returned to normal by 9 d after infection (all p Յ 0.05). BSC should be studied as a treatment for human cryptosporidiosis. Cryptosporidiosis is a major enteric pathogen found globally in infants with acute and chronic diarrhea, and is a cause of persistent diarrhea in 10%-20% of patients with AIDS. Cryptosporidium parvum is also the most widespread enteropathogen identified in neonatal calves. Ninety percent of American dairy farms harbor this coccidian, and 92% of asymptomatic adult cows have specific anti-C. parvum IgG, IgG1, IgG2, and IgM antibodies (1). Neonatal calves experience high morbidity, but low mortality with monoinfections, although mixed infections result in a much greater rate of mortality (2). The epidemic potential of this organism was realized in Milwaukee in 1993, when over 400,000 residents contracted the infection from contaminated municipal water sources (3). Presently, there is no available antimicrobial to kill cryptosporidium; in fact, there is no treatment to stimulate bowel repair from any infectious agent in infants with serious or chronic diarrhea.We have shown that cryptosporidial diarrhea is both malabsorptive and secretory in nature, produced by partial mucosal destruction as well as elevated levels of prostaglandin E 2 and prostacyclin, the latter of which activate enteric secretomotor neurons (4). We have also found beneficial effects of growth factors (present in serum and colostrum) in enhancing bowel repair in rotavirus diarrhea and after intestinal ischemic injury (5, 6). Recently, Lembcke (7) showed in Peruvian children...

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“…The host specificity of Cryptosporidium spp. is broad: it infects a wide range of animals, as well as humans (Nime et al, 1976;Hering et al, 1989;Moore & Zeman, 1991;Lindsay et al, 1991;Ditrich et al, 1991;Scott et al, 1994;Krause étal, 1995;Scott et al, 1995). However it is questio nable whether the Cryptosporidium strains commonly found in animals are the same as those infecting humans.…”

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confidence: 99%

Cryptosporidiuminfections in muskrat (Ondatra zibethica)

1997

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Summary :The faeces of muskrats were examined for Cryptosporidium infections. A total of 121 muskrats trapped in areas close to surface water supplies in two different regions of Germany were examined for the presence of Cryptosporidium spp. oocysts.Faecal samples from these animals were homogenised and processed by sucrose-density-gradient centrifugation, through a 1 M sucrose solution. Separated oocysts were identified by immunofluorescence test assay. 56 animals (46.3 %) were found to be Cryptosporidium positive. These results implicate muskrats as a source of contamination of surface water supplies with

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An epidemiological study of Cryptosporidium parvum in two herds of adult beef cattle

Cited by 84 publications

References 25 publications

Improved Quantitative Estimates of Low Environmental Loading and Sporadic Periparturient Shedding ofCryptosporidium parvumin Adult Beef Cattle

Improved Quantitative Estimates of Low Environmental Loading and Sporadic Periparturient Shedding ofCryptosporidium parvumin Adult Beef Cattle

Oral Bovine Serum Concentrate Improves Cryptosporidial Enteritis in Calves

Cryptosporidiuminfections in muskrat (Ondatra zibethica)

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