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Experiment ID
79, 80
Pathogen
Salmonella typhi
Contains Preferred Model
1
Reference
Study of induced typhoid fever in man. I. Evaluation of vaccine effectiveness
Host type
human
# of Doses
8.00
Μodel
beta-Poisson
a
1.75E-01
N50
1.11E+06
LD50/ID50
1.11E+06
Dose Units
CFU
Response
disease
Agent Strain
Quailes
Exposure Route
oral (in milk)
Experiment Dataset
Description: 
Model data for S. Typhi (Quailes) in humans [1] [2]
Dose Disease No disease Total
1000 0 14 14
1E+05 28 76 104
1E+05 32 84 116
1E+07 15 15 30
1E+07 16 16 32
1E+08 8 1 9
1E+09 4 0 4
1E+09 40 2 42

 

Goodness of fit and model selection
Model Deviance Δ Degrees 
of freedom		 χ20.95,1 
p-value		 χ20.95,m-k 
p-value
Exponential 419 406 7 3.84 
0		 14.1 
0
Beta Poisson 13.8 6 12.6 
0.0321
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 1.75E-01 1.21E-01 1.32E-01 1.39E-01 2.23E-01 2.34E-01 2.58E-01
N50 1.11E+06 5.13E+05 6.10E+05 6.72E+05 2.00E+06 2.28E+06 2.95E+06

 

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