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Experiment ID
43
Pathogen
Escherichia coli
Agent Strain
ETEC O111 (in paper as "E. coli 111, B4")
Contains Preferred Model
No
Reference
Feeguson, W. W., & June, E. C. (1952). Experiments on Feeding Adult Volunteers with Escherichia Coli 111, B4, a Coliform Organism Associated with Infant Diarrhea. American Journal of Epidemiology, 55, 2.
Exposure Route
oral
Response
slight to severe illness
Host type
human
# of Doses
4.00
Dose Units
CFU
Μodel
beta-Poisson
a
2.63E-01
N50
3.56E+06
LD50/ID50
3.56E+06
Experiment Dataset
Description
Escherichia coli (ETEC O111 (in paper as “E. coli 111, B4”)) in the human model data 
Dose Slight to severe illness No slight to severe illness Total
7E+06 7 4 11
5.31E+08 8 4 12
6.5E+09 11 0 11
9E+09 12 0 12

 

Goodness of fit and model selection
Model Deviance Δ Degrees 
of freedom		 χ20.95,1 
p-value 		χ20.95,m-k 
p-value
Exponential 39.8 33.4 3 3.84 
7.5e-09 		7.81 
1.19e-08
Beta Poisson 6.38 2 5.99 
0.0412
Neither the exponential nor beta-Poisson fits well; beta-Poisson is less bad.

 

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 2.63E-01 9.92E-04 7.95E-02 1.00E-01 4.71E-01 5.53E-01 1.48E+01
N50 3.56E+06 6.89E-01 1.15E+03 2.08E+03 1.85E+07 2.49E+07 4.18E+07
beta Poisson model plot, with confidence bounds around optimized model
beta Poisson model plot, with confidence bounds around optimized model

 

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.

 

 

References