Optimization Output for Exp. 108 | QMRA wiki

Basic information

Experiment ID	108
Pathogen	Cryptosporidium hominis Cryptosporidium parvum
Agent Strain	Iowa strain
Contains Preferred Model	No
Reference	DuPont, H. L., Chappell, C. L., Sterling, C. R., Okhuysen, P. C., Rose, J. B., & Jakubowski, W. . (1995). The infectivity of Cryptosporidium parvum in healthy volunteers. The New England Journal of Medicine, 332, 13. Retrieved from https://www.nejm.org/doi/full/10.1056/NEJM199503303321304
Exposure Route	oral
Response	infection

Detailed information

Host type

human

# of Doses

8.00

Dose Units

oocysts

Μodel

exponential

k

4.19E-03

LD50/ID50

1.65E+02

Experiment Dataset

Description

**Iowa strain data**
Dose	Infected	Non-infected	Total
30	1	4	5
100	3	5	8
300	2	1	3
500	5	1	6
1000	2	0	2
1E+04	3	0	3
1E+05	1	0	1
1E+06	1	0	1

**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	0.503	0.131	7	3.84 0.717	14.1 0.999
Beta Poisson	0.372	0.131	6	3.84 0.717	12.6 0.999
Exponential is preferred to beta-Poisson; cannot reject good fit for exponential.

**Optimized k parameter for the exponential model, from 10000 bootstrap iterations**
Parameter	MLE estimate	Percentiles
Parameter	MLE estimate	0.5%	2.5%	5%	95%	97.5%	99.5%
k	4.19E-03	1.80E-03	2.22E-03	2.46E-03	7.52E-03	8.52E-03	1.12E-02
ID50/LD50/ETC*	1.65E+02	6.17E+01	8.14E+01	9.22E+01	2.82E+02	3.12E+02	3.84E+02
*Not a parameter of the exponential model; however, it facilitates comparison with other models.

Parameter histogram for exponential model (uncertainty of the parameter)

Exponential model plot, with confidence bounds around optimized model

References