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Experiment ID
42
Pathogen
Escherichia coli
Contains Preferred Model
0
Reference
Experiments in feeding adult volunteers with Escherichia coli 55, B5, a coliform organism associated with infant diarrhea
Host type
human
# of Doses
4.00
Μodel
beta-Poisson
a
8.7E-02
N50
2.05E+05
LD50/ID50
2.05E+05
Dose Units
CFU
Response
slight to severe illness
Agent Strain
ETEC O55 (in paper as “type 55, B5”)
Exposure Route
oral
Experiment Dataset
Description: 
Escherichia coli (ETEC O55 (in paper as “type 55, B5”)) in the human model data [1]
Dose Slight to severe illness No slight to severe illness Total
1.43E+08 6 2 8
1.73E+09 5 2 7
5.33E+09 6 2 8
1.6E+10 7 1 8

 

Goodness of fit and model selection
Model Deviance Δ Degrees 
of freedom		 χ20.95,1 
p-value		 χ20.95,m-k 
p-value
Exponential 35 34.5 3 3.84 
4.2e-09		 7.81 
1.21e-07
Beta Poisson 0.486 2 5.99 
0.784
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 8.7E-02 9.87E-04 1.02E-03 1.67E-02 3.57E-01 4.67E-01 7.83E-01
N50 2.05E+05 3.40E-09 4.31E-06 2.31E-04 1.30E+08 2.09E+08 5.13E+08

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