Optimization Output for Exp. 43 | QMRA wiki

Basic information

Experiment ID	43
Pathogen	Escherichia coli
Agent Strain	ETEC O111 (in paper as "E. coli 111, B4")
Contains Preferred Model	No
Reference	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.
Exposure Route	oral
Response	slight to severe illness

Detailed information

Host type

human

# of Doses

4.00

Dose Units

CFU

Μodel

beta-Poisson

a

2.63E-01

N50

3.56E+06

LD50/ID50

3.56E+06

Experiment Dataset

Description

**Escherichia coli** **(ETEC O111 (in paper as “E. coli 111, B4”)) in the human model data**
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	χ²_0.95,1 p-value	χ²_0.95,m-k p-value
Exponential	39.8	33.4	3	3.84 7.5e-09	7.81 1.19e-08
Beta Poisson	6.38	33.4	2	3.84 7.5e-09	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
Parameter	MLE estimate	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

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.