Use of a novel soil tilting table apparatus to demonstrate the horizontal and vertical movement of the protozoan pathogen Cryptosporidium parvum in soil

Mawdsley, J. L.; Brooks, A.E.; Merry, R. J.; Pain, B. F.

doi:10.1007/s003740050163

Cited by 30 publications

(41 citation statements)

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“…3,6,10,29 The biologic source(s) for C. parvum infection and the exact routes of transmission during these wetter months have not been well described, but the impact of rainfall has been shown to mobilize and transport C. parvum oocysts out of fresh fecal material and fecal slurries and across vegetated soil surfaces and through soil columns. [30][31][32][33] Increased numbers of cases of C. parvum infection in Fortaleza and Lusaka during the rainy season were associated with contaminated drinking water supplied to these population, 3,6 but source of drinking water and mode of water disinfection were not associated with the odds of C. parvum infection among our study population. Because the 50% infectious dose is relatively low for C. parvum, ranging from approximately 10 to 1,000 for healthy humans, 34 oocysts could be transmitted through low levels of contaminated water or food, followed by person-to-person transmission, especially among household members.…”

Section: Discussionmentioning

confidence: 85%

Intra-familial and extra-familial risk factors associated with Cryptosporidium parvum infection among children hospitalized for diarrhea in Goiânia, Goiás, Brazil.

Pereira¹,

Atwill²,

Barbosa³

et al. 2002

The American Journal of Tropical Medicine and Hygiene

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Abstract.A cross-sectional study was conducted for assessing the prevalence of and risk factors associated with Cryptosporidium parvum in diarrheic children who were hospitalized in Goiânia, capital of Goiás State in Brazil. A crude prevalence of 14.4% (64 of 445) was observed using a direct immunfluorescent assay (DFA), but the true prevalence was 18.7% (83 of 445) when a gold standard of immunomagnetic separation was used in combination with the DFA. Infection was more predominant in children less than 24 months old (odds ratio [OR] ‫ס‬ 0.50, 90% confidence interval [CI] ‫ס‬ 0.36-0.68, P ‫ס‬ 0.0001), and males were 2.2 times more at risk for infection when compared with females (OR ‫ס‬ 2.2, 90% CI ‫ס‬ 0.13-3.8, P ‫ס‬ 0.01). The socioeconomic, intra-familial, and environmental factors associated with cryptosporidiosis were day care attendance, household children with diarrhea up to 30 days prior to the interview, contact with surface water within past 30 days prior to the interview, dwelling distance from a body of water, and the late rainy season (P < 0.10). C. parvum was not associated with the parent's occupation, household sleeping arrangements, number of caregivers, breast-fed children, diet and type of food hygiene, source and type of treatment of drinking water, presence of sewage, and animal exposure (P > 0.10). Although weight was not found to be associated with infection, children infected with C. parvum weighed on average 2.0% less than children not infected with C. parvum (P > 0.10). Thus, C. parvum is an important etiologic agent of childhood diarrhea and should be identified in routine parasitologic tests of diarrheal stool samples.

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Section: Discussionmentioning

confidence: 85%

Intra-familial and extra-familial risk factors associated with Cryptosporidium parvum infection among children hospitalized for diarrhea in Goiânia, Goiás, Brazil.

Pereira¹,

Atwill²,

Barbosa³

et al. 2002

The American Journal of Tropical Medicine and Hygiene

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“…Brush et al (5) and Harter et al (12) have described the leaching of oocysts through sands and sediments as convective dispersion transport in conjunction with sorption-desorption processes. Laboratory studies have also demonstrated the potential for oocyst runoff (2) or leaching (16,17), although oocyst numbers in runoff or leachate were dramatically attenuated by soils.…”

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confidence: 99%

Effect of Bovine Manure onCryptosporidium parvumOocyst Attachment to Soil

Kuczynska

Shelton

Pachepsky

2005

Appl Environ Microbiol

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The objective of this work was to assess the effect of dilute bovine manure (1.0% and 0.1%) versus that of no manure on attachment and subsequent detachment of Cryptosporidium parvum oocysts to soil. Manure enhanced the attachment of oocysts to soil particles; the maximum attachment was observed with 0.1% manure. Oocyst attachment was partially reversible; maximum detachment was observed with dilute manure. These results indicate that oocyst attachment to soil is substantially affected by bovine manure in a complex manner and should have implications for how oocysts may be transported through or over soils.

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“…One strategy being advocated for minimizing the transport potential of C. parvum oocysts from animal manure to surface water is to place vegetated buffer strips between animal agricultural operations and vulnerable surface water supplies (10,12,15,32,38,51,59,60). Optimal design criteria for on-farm vegetated buffer strips currently do not exist for waterborne microbial contaminants.…”

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confidence: 99%

Transport ofCryptosporidium parvumOocysts through Vegetated Buffer Strips and Estimated Filtration Efficiency

Atwill

Hou

Karle

et al. 2002

Appl Environ Microbiol

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Vegetated buffer strips were evaluated for their ability to remove waterborne Cryptosporidium parvum from surface and shallow subsurface flow during simulated rainfall rates of 15 or 40 mm/h for 4 h. Log 10 reductions for spiked C. parvum oocysts ranged from 1.0 to 3.1 per m of vegetated buffer, with buffers set at 5 to 20% slope, 85 to 99% fescue cover, soil textures of either silty clay (19:47:34 sand-silt-clay), loam (45:37:18), or sandy loam (70:25:5), and bulk densities of between 0.6 to 1.7 g/cm 3 . Vegetated buffers constructed with sandy loam or higher soil bulk densities were less effective at removing waterborne C. parvum (1-to 2-log 10 reduction/m) compared to buffers constructed with silty clay or loam or at lower bulk densities (2-to 3-log 10 reduction/m). The effect of slope on filtration efficiency was conditional on soil texture and soil bulk density. Based on these results, a vegetated buffer strip comprised of similar soils at a slope of <20% and a length of >3 m should function to remove >99.9% of C. parvum oocysts from agricultural runoff generated during events involving mild to moderate precipitation.Cryptosporidium parvum has emerged as a widespread and persistent waterborne microbial pathogen, with specific genotypes able to be transmitted ambidirectionally between livestock and humans (e.g., amphixenotic) (6,42,46,54). Although we still do not know the percentage of annual cases of human cryptosporidiosis that are attributable to livestock-derived waterborne C. parvum (39), reducing the likelihood that animal agricultural operations will contaminate surface water with infective C. parvum oocysts will help safeguard both water quality and public health (51). Several strategies exist for minimizing the likelihood that an animal agricultural operation contaminates surface water with infective C. parvum oocysts. For example, one such strategy is to reduce the incidence of C. parvum infection or the intensity of fecal shedding of C. parvum oocysts by livestock populations, thereby reducing the rate of environmental loading of C. parvum per livestock unit (26,36). These herd-health efforts remain hampered by our poor understanding of the medical ecology of C. parvum within livestock populations (3,4,16,40), how to interrupt transmission between the biological reservoir and susceptible animals (3, 40), and the lack of an affordable vaccine that has been proven to be efficacious in commercial agricultural settings (23,47).A second strategy is to manage the manure produced by livestock so that the survivability and off-site transport of infective C. parvum are substantially reduced (3,20,30,53,55). One strategy being advocated for minimizing the transport potential of C. parvum oocysts from animal manure to surface water is to place vegetated buffer strips between animal agricultural operations and vulnerable surface water supplies (10,12,15,32,38,51,59,60). Optimal design criteria for on-farm vegetated buffer strips currently do not exist for waterborne microbial contaminants. Moreover, studies ...

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Use of a novel soil tilting table apparatus to demonstrate the horizontal and vertical movement of the protozoan pathogen Cryptosporidium parvum in soil

Cited by 30 publications

References 0 publications

Intra-familial and extra-familial risk factors associated with Cryptosporidium parvum infection among children hospitalized for diarrhea in Goiânia, Goiás, Brazil.

Intra-familial and extra-familial risk factors associated with Cryptosporidium parvum infection among children hospitalized for diarrhea in Goiânia, Goiás, Brazil.

Effect of Bovine Manure onCryptosporidium parvumOocyst Attachment to Soil

Transport ofCryptosporidium parvumOocysts through Vegetated Buffer Strips and Estimated Filtration Efficiency

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