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Experiment ID
46
Pathogen
Giardia duodenalis
Agent Strain
From an infected human
Contains Preferred Model
Yes
Reference
Rendtorff, R. C. (1954). The experimental transmission of human intestinal protozoan parasites. II. Giardia lamblia cysts given in capsules. American Journal of Hygiene, 59, 2. Retrieved from https://academic.oup.com/aje/article-abstract/59/2/196/89318?redirectedFrom=PDF
Exposure Route
oral
Response
infection
Host type
human
# of Doses
8.00
Dose Units
Cysts
Μodel
exponential
k
1.99E-02
LD50/ID50
3.48E+01
Description
Dose response data 
Dose Infected Non-infected Total
1 0 5 5
10 2 0 2
25 6 14 20
100 2 0 2
1E+04 3 0 3
1E+05 3 0 3
3E+05 3 0 3
1E+06 2 0 2

 

Goodness of fit and model selection
Model Deviance Δ Degrees 
of freedom		 χ20.95,1 
p-value 		χ20.95,m-k 
p-value
Exponential 8.37 -0.000469 7 3.84 
1 		14.1 
0.301
Beta Poisson 8.37 6 12.6 
0.212
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
0.5% 2.5% 5% 95% 97.5% 99.5%
k 1.99E-02 8.50E-03 1.05E-02 1.26E-02 2.92E-02 3.29E-02 3.71E-02
ID50/LD50/ETC* 3.48E+01 1.87E+01 2.11E+01 2.38E+01 5.49E+01 6.60E+01 8.15E+01
*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

  • Rendtorff, R. C. (1954). The experimental transmission of human intestinal protozoan parasites. I. Endamoeba coli cysts given in capsules. American Journal of Hygiene, 59, 2. https://doi.org/https://doi.org/10.1093/oxfordjournals.aje.a119633