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Experiment ID
79
Pathogen
Salmonella typhi
Agent Strain
Quailes
Contains Preferred Model
No
Reference
Hornick, R. B., Greisman, S. ., Woodward, T. E., DuPont, H. L., Dawkins, A. T., & Snyder, M. J. (1970). Typhoid fever: pathogenesis and immunologic control. The New England Journal of Medicine, 283, 13.
Exposure Route
oral (in milk)
Response
disease
Host type
human
# of Doses
3.00
Dose Units
CFU
Μodel
beta-Poisson
a
1.11E-01
N50
3.45E+06
LD50/ID50
3.45E+06"
Description
Model data for S. Typhi (Quailes) in humans
Dose Disease No disease Total
1E+05 28 76 104
1E+07 15 15 30
1E+09 4 0 4

 

Goodness of fit and model selection
Model Deviance Δ Degrees 
of freedom		 χ20.95,1 
p-value 		χ20.95,m-k 
p-value
Exponential 124 121 2 3.84 
0 		5.99 
0
Beta Poisson 2.87 1 3.84 
0.0905
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 1.11E-01 3.19E-02 4.80E-02 5.49E-02 1.96E-01 2.17E-01 2.59E-01
N50 3.45E+06 4.81E+05 6.95E+05 8.50E+05 9.53E+07 2.24E+08 4.19E+09

 

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