Experiment ID
81
Pathogen
Agent Strain
M 131
Contains Preferred Model
No
Reference
DuPont, H. L., Hornick, R. B., Dawkins, A. T., Snyder, M. J., & Formal, S. B. (1969). The Response of Man to Virulent Shigella flexneri 2a. Journal of Infectious Diseases, 119, 3.
Exposure Route
oral (in milk)
Response
illness
Host type
human
# of Doses
4.00
Dose Units
CFU
Μodel
beta-Poisson
a
2.77E-01
N50
2.38E+02
LD50/ID50
2.38E+02
Experiment Dataset
Description
Model data for Shigella dysenteriae (M 131) in the human 
Dose Illness Not illness Total
10 1 9 10
200 2 2 4
2000 7 3 10
1E+04 5 1 6

 

Goodness of fit and model selection
Model Deviance Δ Degrees 
of freedom
χ20.95,1 
p-value
χ20.95,m-k 
p-value
Exponential 13.2 13.2 3 3.84 
0.000283
7.81 
0.0042
Beta Poisson 0.0315 2 5.99 
0.984
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 2.77E-01 5.24E-03 1.10E-01 1.34E-01 1.63E+00 1.88E+01 1.72E+03
N50 2.38E+02 1.35E+01 4.73E+01 6.36E+01 1.42E+03 2.02E+03 5.89E+03

 

Parameter scatter plot for beta Poisson model ellipses signify the 0.9, 0.95 and 0.99 confidence of the parameters
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
beta Poisson model plot, with confidence bounds around optimized model

References