Host type
# of Doses
4.00
Μodel
a
1.35E-01
N50
3.11E+03
LD50/ID50
3.11E+03
Dose Units
Response
Agent Strain
2a (strain 2457T)
Exposure Route
Experiment Dataset
Description: 
Model data for Shigella flexneri (2a, strain 2457T) in the human [1]
Dose Illness Not illness Total
180 9 27 36
5000 28 21 49
1E+04 52 36 88
1E+05 14 10 24

 

Goodness of fit and model selection
Model Deviance Δ Degrees 
of freedom
χ20.95,1 
p-value
χ20.95,m-k 
p-value
Exponential 154 153 3 3.84 
0
7.81 
0
Beta Poisson 1.69 2 5.99 
0.429
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 1.35E-01 9.86E-04 1.22E-02 6.85E-02 2.06E-01 2.22E-01 2.58E-01
N50 3.11E+03 5.09E+01 4.31E+02 9.64E+02 7.49E+03 9.14E+03 1.89E+04

 

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

  1. Immunity in shigellosis. I. Response of man to attenuated strains of Shigella, DuPont, Herbert L., and , Journal of Infectious Diseases, Volume 125, Number 1, p.5-11, (1972)