Experiment ID
232
Pathogen
Agent Strain
strain I
Contains Preferred Model
No
Reference
McCullough, N. ., & Elsele, C. . (1951). Experimental Human Salmonellosis: I. Pathogenicity of Strains of Salmonella Meleagridis and Salmonella Anatum Obtained from Spray-Dried Whole Egg. Oxford Journal of Infectious Diseases, 88(3). https://doi.org/https://doi.org/10.1093/infdis/88.3.278
Exposure Route
oral (with eggnog)
Response
positive stool culture
Host type
human
# of Doses
8.00
Dose Units
CFU
Μodel
beta-Poisson
a
2.91E-01
N50
4.44E+04
LD50/ID50
4.44E+04
Description
Human / Salmonella anatum strain I data
Dose Positive stool culture No positive stool culture Total
12000 2 3 5
24000 3 3 6
66000 4 2 6
93000 1 5 6
141000 3 3 6
256000 5 1 6
587000 4 2 6
860000 6 0 6

 

Goodness of fit and model selection
Model Deviance Δ Degrees 
of freedom
χ20.95,1 
p-value
χ20.95,m-k 
p-value
Exponential 20.5 11 7 3.84 
0.000922
14.1 
0.00457
Beta Poisson 9.53 6 12.6 
0.146
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 2.91E-01 9.77E-04 9.77E-04 4.11E-02 1.68E+00 5.36E+00 1.20E+03
N50 4.44E+04 6.74E-02 8.03E+02 4.15E+03 1.64E+05 6.89E+06 9.07E+07

 

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