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Experiment ID
141
Pathogen
Cryptosporidium hominis
Cryptosporidium parvum
Agent Strain
UCP isolate
Contains Preferred Model
No
Reference
Coster, T. S., Wolf, M. K., Hall, E. R., Cassels, F. J., Taylor, D. N., Liu, C. T., … McQueen, C. E. (2007). Immune response, ciprofloxacin activity, and gender differences after human experimental challenge by two strains of enterotoxigenic Escherichia coli. Infection and Immunity, 75, 1.
Exposure Route
oral
Response
infection
Host type
human
# of Doses
4.00
Dose Units
oocysts
Μodel
beta-Poisson
a
1.45E-01
N50
1.79E+02
LD50/ID50
1.79E+02
Description
UCP isolate 
Dose Infected Non-infected Total
500 3 2 5
1000 2 1 3
5000 2 3 5
1E+04 4 0 4

 

Goodness of fit and model selection
Model Deviance Δ Degrees 
of freedom		 χ20.95,1 
p-value 		χ20.95,m-k 
p-value
Exponential 11.5 6.99 3 3.84 
0.0082 		7.81 
0.00945
Beta Poisson 4.48 2 5.99 
0.107
Beta-Poisson fits better than exponential; cannot reject good fit for beta-Poisson.

 

Optimized parameters for the beta-Poisson model, from 10000 bootstrap iterations
Parameter MLE estimate Percentiles
0.5% 2.5% 5% 95% 97.5% 99.5%
α 1.45E-01 9.81E-04 4.63E-03 9.53E-03 1.27E+00 1.46E+02 9.10E+02
N50 1.79E+02 2.74E-13 7.60E-10 4.54E-09 2.62E+03 3.22E+03 6.10E+03

Parameter scatter plot for beta Poisson model ellipses signify the 0.9, 0.95 and 0.99 confidence of the parameters.

beta Poisson model plot, with confidence bounds around optimized model

References

  • Messner, M. J., Chappell, C. L., & Okhuysen, P. C. (2001). Risk Assessment for Cryptosporidium: A Hierarchical Bayesian Analysis of Human Dose Response Data. Water Research, 35, 16. Retrieved from https://www.sciencedirect.com/science/article/pii/S0043135401001191