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Experiment ID
43
Pathogen
Escherichia coli
Contains Preferred Model
0
Reference
Experiments on Feeding Adult Volunteers with Escherichia Coli 111, B4, a Coliform Organism Associated with Infant Diarrhea
Host type
human
# of Doses
4.00
Μodel
beta-Poisson
a
2.63E-01
N50
3.56E+06
LD50/ID50
3.56E+06
Dose Units
CFU
Response
slight to severe illness
Agent Strain
ETEC O111 (in paper as "E. coli 111, B4")
Exposure Route
oral
Experiment Dataset
Description: 
Escherichia coli (ETEC O111 (in paper as “E. coli 111, B4”)) in the human model data [1]
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

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

 

References

  1. 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.