Highest Quality Models and Parameters

We generally recommend a single dose-response model, and we justify the decision in terms of specific criteria. This decision is somewhat subjective, since dose response datasets seldom meet all of these criteria. If all available models are unsatisfactory, we choose a single model to ‘recommend with reservations’. Our recommended model will seldom (if ever) be the best model for all applications. The user should carefully choose the model that is most appropriate for their particular problem.

Criteria for Model Selection

We prefer dose-response models with the following criteria, in rough order of importance:

Statistically acceptable fit (fail to reject goodness of fit, p > 0.05)
Human subjects, or animal models that mimic human pathophysiology well
Infection as the response, rather than disease, symptoms, or death
Exposure route similar/identical to the exposure route of natural infection
Pathogen strain is similar to strains causing natural infection
Pooled model using data from 2 or more experiments, provided the data sets are statistically similar (fail to reject that datasets are from the same distribution, p > 0.05)
Low ID₅₀/LD₅₀ (to obtain a conservative risk estimate)

Microbial Group

Μodel

Host type

Exposure Route

Response

Agent	Exposure Route	Μodel	Optimized parameters	LD50/ID50	Host type	Agent Strain	Response type	# of Doses	Dose Units	Reference
Acanthamoeba all experiments	intranasal	beta-Poisson	a = 0.245 N₅₀ = 19357		mice	A. castellanii HN-3 and A culbertsoni A1	death	9.00	no of trophozoites
Adenovirus all experiments	inhalation	exponential	k = 6.07E-01	1.14E+00	human	type 4	infection	4.00	TCID50	Couch, R. B., Cate, T. R., Douglas, R. G., Gerone, P. J., & . (1966). Effect of route of inoculation on experimental respiratory viral disease in volunteers and evidence for airborne transmission. Bacteriological Reviews, 30, 3.
Bacillus anthracis all experiments	inhalation	exponential	k = 1.65E-05	4.2E+04	guinea pig	Vollum	death	4.00	spores	June, R. ., Ferguson, W. ., & Worfel, M. . (1953). Experiments in feeding adult volunteers with Escherichia coli 55, B5, a coliform organism associated with infant diarrhea. American Journal of Hygiene, 57(2). https://doi.org/10.1093/oxfordjournals.aje.a119570
Burkholderia mallei all experiments		beta-Poisson	a = 3.28E-01 N₅₀ = 5.43E+03	5.43E+03	C57BL/6 mice and diabetic rat	KHW,316c	death	10.00	CFU	Brett, P. J., & Woods, D. E. (1996). Structural and immunological characterization of Burkholderia pseudomallei O-polysaccharide-flagellin protein conjugates. Infection and Immunity, 64, 2824–2828.
Campylobacter jejuni all experiments	oral	beta-Poisson	a = 1.44E-01 N₅₀ = 8.9E+02	8.9E+02	human	strain A3249	infection	6.00	CFU	Black, R. E., Levine, M. M., Clements, M. L., Hughes, T. P., & Blaser, M. J. (1988). Experimental Campylobacter jejuni Infection in Humans. Journal of Infectious Diseases, 157, 3. https://doi.org/10.1093/infdis/157.3.472
Coxiella burnetii all experiments	intraperitoneal	beta-Poisson	a = 3.57E-01 N₅₀ = 4.93E+08	4.93E+08	C57BL/1OScN mice	phase I Ohio	death	10.00	PFU	Williams, J. C., & Cantrell, J. L. (1982). Biological and immunological properties of Coxiella burnetii vaccines in C57BL/10ScN endotoxin-nonresponder mice. Infection and Immunity, 35, 3.
Cryptosporidium hominis all experiments	oral	exponential	k = 5.72E-02	1.21E+01	human	TAMU isolate	infection	4.00	oocysts	Messner, M. J., Chappell, C. L., & Okhuysen, P. C. (2001). Risk Assessment for Cryptosporidium: A Hierarchical Bayesian Analysis of Human Dose Response Data. Water Research, 35, 16. Retrieved from https://www.sciencedirect.com/science/article/pii/S0043135401001191
Cryptosporidium parvum all experiments	oral	exponential	k = 5.72E-02	1.21E+01	human	TAMU isolate	infection	4.00	oocysts	Messner, M. J., Chappell, C. L., & Okhuysen, P. C. (2001). Risk Assessment for Cryptosporidium: A Hierarchical Bayesian Analysis of Human Dose Response Data. Water Research, 35, 16. Retrieved from https://www.sciencedirect.com/science/article/pii/S0043135401001191
Echovirus all experiments	oral	beta-Poisson	a = 1.06E+00 N₅₀ = 9.22E+02	9.22E+02	human	strain 12	infection	4.00	PFU	Schiff, G. M., Stefanović, G. M., Young, E. C., Sander, D. S., Pennekamp, J. K., & Ward, R. L. (1984). Studies of echovirus-12 in volunteers: determination of minimal infectious dose and the effect of previous infection on infectious dose. The Journal of Infectious Diseases, 150, 6. Retrieved from https://academic.oup.com/jid/article-abstract/150/6/858/880281
Entamoeba coli all experiments	oral	beta-Poisson	a = 1.01E-01 N₅₀ = 3.41E+02	3.41E+02	human	From an infected human	infection	5.00	Cysts	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
Enterovirus all experiments	oral	exponential	k = 3.74E-03	1.85E+02	pig	porcine, PE7-05i	infection	3.00	PFU	Cliver, D. O. (1981). Experimental infection by waterborne enteroviruses. Journal of Food Protection, 44, 861–865. Retrieved from http://www.jfoodprotection.org/doi/abs/10.4315/0362-028X-44.11.861?code=fopr-site
Escherichia coli all experiments	oral (in milk)	beta-Poisson	a = 1.55E-01 N₅₀ = 2.11E+06	2.11E+06	human	EIEC 1624	positive stool isolation	3.00	CFU	DuPont, H. L., Formal, S. B., Hornick, R. B., Snyder, M. J., Libonati, J. P., Sheahan, D. G., … Kalas, J. P. (1971). Pathogenesis of Escherichia coli diarrhea. The New England Journal of Medicine, 285, 1.
Francisella tularensis all experiments	inhalation	exponential	k = 4.73E-02	1.46E+01	monkey	SCHU S-4	death	4.00	CFU	Quan, S. F., McManus, A. G., & von Fintel, H. . (1956). Infectivity of Tularemia Applied to Intact Skin and Ingested in Drinking Water. Science, 123, 942-943.
Giardia duodenalis all experiments	oral	exponential	k = 1.99E-02	3.48E+01	human	From an infected human	infection	8.00	Cysts	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
Influenza all experiments	intranasal	beta-Poisson	a = 5.81E-01 N₅₀ = 9.45E+05	9.45E+05	human	H1N1,A/California/10/78 attenuated strain,H3N2,A/Washington/897/80 attenuated strain	infection	9.00	TCID50	Murphy, B. R., Clements, M. L., Madore, H. P., Steinberg, J. ., O’Donnell, S. ., Betts, R. ., … Maassab, H. F. (1984). Dose Response of Cold-Adapted, Reassortant Influenza A/California/10/78 Virus (H1N1) in Adult Volunteers. Journal of Infectious Diseases, 149, 5. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/6726007
Lassa virus all experiments	subcutaneous	exponential	k = 2.95E+00	2.35E-01	guinea pig	Josiah strain	death	6.00	PFU	Jahrling, P. B., Smith, S. ., Hesse, R. A., & Rhoderick, J. B. (1982). Pathogenesis of Lassa virus infection in guinea pigs. Infection and Immunity, 37, 2. Retrieved from http://iai.asm.org/content/37/2/771.abstract
Legionella pneumophila all experiments	inhalation	exponential	k = 5.99E-02	1.16E+01	guinea pig	Philadelphia 1	infection	4.00	CFU	Fitzgeorge, R. B., Baskerville, A. ., Broster, M. ., Hambleton, P. ., & Dennis, P. J. (1983). Aerosol infection of animals with strains of Legionella pneumophila of different virulence: comparison with intraperitoneal and intranasal routes of infection. Epidemiology & Infection, 90.
Mycobacterium avium all experiments all experiments	oral	exponential	k = 6.93E-04	1000	deer	sub sp. Paratuberculosis Bovine	infection	3.00	CFU	Nisbet, D. I., Gilmour, N. J., & Brotherston, J. G. (1962). Quantitative studies of Mycobacterium johnei in tissues of sheep. III. Intestinal histopathology. Journal of Comparative Pathology, 72, 80.
Naegleria fowleri all experiments	intravenous	exponential	k = 3.42E-07	2.03E+06	mice	LEE strain	death	7.00	no of trophozoites	Adams, A. C., John, D. T., & Bradley, S. G. (1976). Modification of resistance of mice to Naegleria fowleri infections. Infection and Immunity, 13, 1387–1391. Retrieved from http://iai.asm.org/content/13/5/1387.full.pdf+html
Poliovirus all experiments	oral (capsule)	exponential	k = 4.91E-01	1.41E+00	human	type 1,attenuated	alimentary infection	3.00	PD50 (mouse paralytic doses)	Koprowski, H. . (1956). Immunization against Poliomyelitis with Living Attenuated Virus. The American Journal of Tropical Medicine and Hygiene, 5, 3.
Prion all experiments	oral	beta-Poisson	a = 1.76E+00 N₅₀ = 1.04E+05	1.04E+05	hamsters	scrapie strain 263k	death	5.00	LD50 i.c.	Jacquemot, C. ., Cuche, C. ., Dormont, D. ., & Lazarini, F. . (2005). High Incidence of Scrapie Induced by Repeated Injections of Subinfectious Prion Doses. Journal of Virology, 79(14). https://doi.org/10.1128/JVI.79.14.8904-8908.2005
Pseudomonas aeruginosa all experiments	contact lens	beta-Poisson	a = 1.9E-01 N₅₀ = 1.85E+04	1.85E+04	white rabbit		corneal ulceration	10.00	CFU	Lawin-Brüssel, C. A., Refojo, M. F., Leong, F. L., Hanninen, L. ., & Kenyon, K. R. (1993). Effect of Pseudomonas aeruginosa concentration in experimental contact lens-related microbial keratitis. Cornea, 12, 1.
Pseudomonas aeruginosa all experiments	injected in eyelids	exponential	k = 1.05E-04	6.61E+03	Swiss webster mice (5day old)	ATCC 19660	death	12.00	CFU	Hazlett, L. D., Rosen, D. D., & Berk, R. S. (1978). Age-Related Susceptibility to Pseudomonas aeruginosa Ocular Infections in Mice. Infection and Immunity, 20, 1.
Rhinovirus all experiments	intranasal	beta-Poisson	a = 2.21E-01 N₅₀ = 1.81E+00	1.81E+00	human	type 39	infection	6.00	TCID50	Hendley, J. O., Edmondson, W. P., & Gwaltney, J. M. (1972). Relation between Naturally Acquired Immunity and Infectivity of Two Rhinoviruses in Volunteers. Journal of Infectious Diseases, 125, 3.
Rickettsia rickettsi all experiments		beta-Poisson	a = 7.77E-01 N₅₀ = 2.13E+01	2.13E+01	pooled	R1 and Sheila Smith	morbidity	27.00	CFU	Saslaw, S. ., & Carlisle, H. N. (1966). Aerosol infection of monkeys with Rickettsia rickettsii. Bacteriological Reviews, 30, 3.
Salmonella anatum all experiments	oral (with eggnog)	beta-Poisson	a = 3.18E-01 N₅₀ = 3.71E+04	3.71E+04	human	strain I	positive stool culture	16.00	CFU	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
Salmonella meleagridis all experiments	oral (with eggnog)	beta-Poisson	a = 3.89E-01 N₅₀ = 1.68E+04	1.68E+04	human	strain I	infection	11.00	CFU	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
Salmonella newport all experiments	oral	exponential	k = 3.97E-06	1.74E+05	human	Salmonella newport	infection	3.00	CFU	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
Salmonella nontyphoid all experiments	intraperitoneal	beta-Poisson	a = 2.1E-01 N₅₀ = 4.98E+01	4.98E+01	mice	strain 216 and 219	death	10.00	CFU	Meynell, G. G., & Meynell, E. W. (1958). The growth of micro-organisms in vivo with particular reference to the relation between dose and latent period. The Journal of Hygiene, 56(3). https://doi.org/10.1017/s0022172400037827
Salmonella typhi all experiments	oral (in milk)	beta-Poisson	a = 1.75E-01 N₅₀ = 1.11E+06	1.11E+06	human	Quailes	disease	8.00	CFU	Hornick, R. ., Woodward, T. ., McCrumb, F. ., Snyder, M. ., Dawkins, A. ., Bulkeley, J. ., … Corozza, F. . (1966). Study of induced typhoid fever in man. I. Evaluation of vaccine effectiveness. Transactions of the Association of American Physicians, 79, 361-367. Retrieved from https://pubmed.ncbi.nlm.nih.gov/5929469/
SARS all experiments	intranasal	exponential	k = 2.46E-03	2.82E+02	mice hACE-2 and A/J	rSARS-CoV	death	0.00	PFU
Shigella flexneri all experiments	oral (in milk)	beta-Poisson	a = 2.65E-01 N₅₀ = 1.48E+03	1.48E+03	human	2a (strain 2457T)	positive stool isolation	4.00	CFU	DuPont, H. L., Hornick, R. B., Snyder, M. J., Libonati, J. P., Formal, S. B., & Gangarosa, E. J. (1972). Immunity in Shigellosis. I. Response of Man to Attenuated Strains of Shigella. Journal of Infectious Diseases, 125, 1.
Staphylococcus aureus all experiments	subcutaneous	exponential	k = 7.64E-08	9.08E+06	human		infection	6.00	CFU/cm2	Lawin-Brüssel, C. A., Refojo, M. F., Leong, F. L., Hanninen, L. ., & Kenyon, K. R. (1993). Effect of Pseudomonas aeruginosa concentration in experimental contact lens-related microbial keratitis. Cornea, 12, 1.
Vibrio cholerae all experiments	oral (with NaHCO3)	beta-Poisson	a = 2.50E-01 N₅₀ = 2.43E+02	2.43E+02	human	Inaba 569B	infection	6.00	CFU	Diringer, H. ., Roehmel, J. ., & Beekes, M. . (1998). Effect of repeated oral infection of hamsters with scrapie. Journal of General Virology, 79. Retrieved from http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.541.3587&rep=rep1&type=pdf
Yersinia pestis all experiments	intranasal	exponential	k = 1.63E-03	4.26E+02	mice	CO92	death	4.00	CFU	Lathem, W. W., Crosby, S. D., Miller, L. . , V, & Goldman, W. E. (2005). Progression of primary pneumonic plague: A mouse model of infection, pathology, and bacterial transcriptional activity. Proceedings of the National Academy of Sciences of the United States of America, 102, 17786-17791. https://doi.org/10.1073/pnas.0506840102