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)
Agent | Exposure Route | Μodel | Optimized parameters | LD50/ ID50 | Host type | Agent Strain | Response | # of Doses | Dose Units | Reference |
---|---|---|---|---|---|---|---|---|---|---|
Acanthamoeba all experiments |
eyes-cornea | beta-Poisson |
α = 0.245 N50 = 19357 |
mice | A. castellanii HN-3 and A culbertsoni A1 | death | 9 | no of trophozoites | ||
Acanthamoeba all experiments |
intranasal | beta-Poisson |
α = 0.245 N50 = 19357 |
mice | A. castellanii HN-3 and A culbertsoni A1 | death | 9 | no of trophozoites | ||
Adenovirus all experiments |
inhalation | exponential |
k = 6.07E-01 |
1.14E+00 | human | type 4 | infection | 4 | TCID50 | Effect of route of inoculation on experimental respiratory viral disease in volunteers and evidence for airborne transmission. Bacteriological Reviews. 30, 3. | (1966).
Adenovirus all experiments |
intranasal | exponential |
k = 6.07E-01 |
1.14E+00 | human | type 4 | infection | 4 | TCID50 | Effect of route of inoculation on experimental respiratory viral disease in volunteers and evidence for airborne transmission. Bacteriological Reviews. 30, 3. | (1966).
Bacillus anthracis all experiments |
exponential |
k = 1.65E-05 |
4.2E+04 | guinea pig | Vollum | death | 4 | spores | Experiments in feeding adult volunteers with Escherichia coli 55, B5, a coliform organism associated with infant diarrhea. American Journal of Hygiene. 57(2), | (1953).|
Burkholderia mallei all experiments |
beta-Poisson |
α = 3.28E-01 N50 = 5.43E+03 |
5.43E+03 | C57BL/6 mice and diabetic rat | KHW,316c | death | 10 | CFU | Structural and immunological characterization of Burkholderia pseudomallei O-polysaccharide-flagellin protein conjugates.. Infection and immunity. 64, 2824–2828. | (1996).|
Campylobacter jejuni all experiments |
intragastric | beta-Poisson |
α = 1.44E-01 N50 = 8.9E+02 |
8.9E+02 | human | strain A3249 | infection | 6 | CFU | Experimental Campylobacter jejuni Infection in Humans. Journal of Infectious Diseases. 157, 3. | (1988).
Coxiella burnetii all experiments |
beta-Poisson |
α = 3.57E-01 N50 = 4.93E+08 |
4.93E+08 | C57BL/1OScN mice | phase I Ohio | death | 10 | PFU | Biological and immunological properties of Coxiella burnetii vaccines in C57BL/10ScN endotoxin-nonresponder mice. Infection and Immunity. 35, 3. | (1982).|
Cryptosporidium hominis all experiments |
oral | exponential |
k = 5.72E-02 |
1.21E+01 | human | TAMU isolate | infection | 4 | oocysts | Risk Assessment for Cryptosporidium: A Hierarchical Bayesian Analysis of Human Dose Response Data. Water Research. 35, 16. | (2001).
Cryptosporidium parvum all experiments |
exponential |
k = 5.72E-02 |
1.21E+01 | human | TAMU isolate | infection | 4 | oocysts | Risk Assessment for Cryptosporidium: A Hierarchical Bayesian Analysis of Human Dose Response Data. Water Research. 35, 16. | (2001).|
Echovirus all experiments |
oral | beta-Poisson |
α = 1.06E+00 N50 = 9.22E+02 |
9.22E+02 | human | strain 12 | infection | 4 | PFU | 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. | (1984).
Entamoeba coli all experiments |
beta-Poisson |
α = 1.01E-01 N50 = 3.41E+02 |
3.41E+02 | human | From an infected human | infection | 5 | Cysts | The experimental transmission of human intestinal protozoan parasites. I. Endamoeba coli cysts given in capsules. American journal of hygiene. 59, 2. | (1954).|
Enterovirus all experiments |
oral | exponential |
k = 3.74E-03 |
1.85E+02 | pig | porcine, PE7-05i | infection | 3 | PFU | Experimental infection by waterborne enteroviruses. Journal of Food Protection. 44, 861–865. | (1981).
Escherichia coli all experiments |
beta-Poisson |
α = 1.55E-01 N50 = 2.11E+06 |
2.11E+06 | human | EIEC 1624 | positive stool isolation | 3 | CFU | Pathogenesis of Escherichia coli diarrhea. The New England journal of medicine. 285, 1. | (1971).|
Francisella tularensis all experiments |
exponential |
k = 4.73E-02 |
1.46E+01 | monkey | SCHU S-4 | death | 4 | CFU | Infectivity of Tularemia Applied to Intact Skin and Ingested in Drinking Water. Science. 123, 942-943. | (1956).|
Giardia duodenalis all experiments |
oral | exponential |
k = 1.99E-02 |
3.48E+01 | human | From an infected human | infection | 8 | Cysts | The experimental transmission of human intestinal protozoan parasites. II. Giardia lamblia cysts given in capsules. American journal of hygiene. 59, 2. | (1954).
Giardia duodenalis all experiments |
stomach tube | exponential |
k = 1.99E-02 |
3.48E+01 | human | From an infected human | infection | 8 | Cysts | The experimental transmission of human intestinal protozoan parasites. II. Giardia lamblia cysts given in capsules. American journal of hygiene. 59, 2. | (1954).
Influenza all experiments |
inhalation | beta-Poisson |
α = 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 | TCID50 | Dose Response of Cold-Adapted, Reassortant Influenza A/California/10/78 Virus (H1N1) in Adult Volunteers. Journal of Infectious Diseases. 149, 5. | (1984).
Lassa virus all experiments |
inhalation | exponential |
k = 2.95E+00 |
2.35E-01 | guinea pig | Josiah strain | death | 6 | PFU | Pathogenesis of Lassa virus infection in guinea pigs. Infection and Immunity. 37, 2. | (1982).
Lassa virus all experiments |
subcutaneous | exponential |
k = 2.95E+00 |
2.35E-01 | guinea pig | Josiah strain | death | 6 | PFU | Pathogenesis of Lassa virus infection in guinea pigs. Infection and Immunity. 37, 2. | (1982).
Legionella pneumophila all experiments |
exponential |
k = 5.99E-02 |
1.16E+01 | guinea pig | Philadelphia 1 | infection | 4 | CFU | Aerosol infection of animals with strains of Legionella pneumophila of different virulence: comparison with intraperitoneal and intranasal routes of infection. Epidemiology & Infection. 90, | (1983).|
Mycobacterium avium all experiments |
Intratracheal inoculation | exponential |
k = 6.93E-04 |
1000 | deer | sub sp. Paratuberculosis Bovine | infection | 3 | CFU | Quantitative studies of Mycobacterium johnei in tissues of sheep. III. Intestinal histopathology. Journal of comparative pathology. 72, 80. | (1962).
Mycobacterium avium all experiments |
intravenous | exponential |
k = 6.93E-04 |
1000 | deer | sub sp. Paratuberculosis Bovine | infection | 3 | CFU | Quantitative studies of Mycobacterium johnei in tissues of sheep. III. Intestinal histopathology. Journal of comparative pathology. 72, 80. | (1962).
Mycobacterium avium all experiments |
exponential |
k = 6.93E-04 |
1000 | deer | sub sp. Paratuberculosis Bovine | infection | 3 | CFU | Quantitative studies of Mycobacterium johnei in tissues of sheep. III. Intestinal histopathology. Journal of comparative pathology. 72, 80. | (1962).|
Naegleria fowleri all experiments |
intravenous | exponential |
k = 3.42E-07 |
2.03E+06 | mice | LEE strain | death | 7 | no of trophozoites | Modification of resistance of mice to Naegleria fowleri infections.. Infection and immunity. 13, 1387–1391. | (1976).
Poliovirus all experiments |
exponential |
k = 4.91E-01 |
1.41E+00 | human | type 1,attenuated | alimentary infection | 3 | PD50 (mouse paralytic doses) | Immunization against Poliomyelitis with Living Attenuated Virus. The American Journal of Tropical Medicine and Hygiene. 5, 3. | (1956).|
Prion all experiments |
beta-Poisson |
α = 1.76E+00 N50 = 1.04E+05 |
1.04E+05 | hamsters | scrapie strain 263k | death | 5 | LD50 i.c. | High Incidence of Scrapie Induced by Repeated Injections of Subinfectious Prion Doses. Journal of Virology. 79(14), | (2005).|
Pseudomonas aeruginosa all experiments |
injected in eyelids | exponential |
k = 1.05E-04 |
6.61E+03 | Swiss webster mice (5day old) | ATCC 19660 | death | 12 | CFU | Age-Related Susceptibility to Pseudomonas aeruginosa Ocular Infections in Mice. Infection and Immunity. 20, 1. | (1978).
Pseudomonas aeruginosa all experiments |
injected in eyelids | beta-Poisson |
α = 1.9E-01 N50 = 1.85E+04 |
1.85E+04 | white rabbit | corneal ulceration | 10 | CFU | Effect of Pseudomonas aeruginosa concentration in experimental contact lens-related microbial keratitis. Cornea. 12, 1. | (1993).|
Pseudomonas aeruginosa all experiments |
injected in eyelids | exponential |
k = 3.22E-7 |
2150065 | death | 67 | CFU | Defective phagocytosis and clearance of Pseudomonas aeruginosa in the lung following bone marrow transplantation. The Journal of Immunology. 171, 4416–4424. | (2003).||
Pseudomonas aeruginosa all experiments |
contact lens | beta-Poisson |
α = 1.9E-01 N50 = 1.85E+04 |
1.85E+04 | white rabbit | corneal ulceration | 10 | CFU | Effect of Pseudomonas aeruginosa concentration in experimental contact lens-related microbial keratitis. Cornea. 12, 1. | (1993).|
Pseudomonas aeruginosa all experiments |
contact lens | exponential |
k = 3.22E-7 |
2150065 | death | 67 | CFU | Defective phagocytosis and clearance of Pseudomonas aeruginosa in the lung following bone marrow transplantation. The Journal of Immunology. 171, 4416–4424. | (2003).||
Pseudomonas aeruginosa all experiments |
contact lens | exponential |
k = 1.05E-04 |
6.61E+03 | Swiss webster mice (5day old) | ATCC 19660 | death | 12 | CFU | Age-Related Susceptibility to Pseudomonas aeruginosa Ocular Infections in Mice. Infection and Immunity. 20, 1. | (1978).
Pseudomonas aeruginosa all experiments |
intratracheal | exponential |
k = 1.05E-04 |
6.61E+03 | Swiss webster mice (5day old) | ATCC 19660 | death | 12 | CFU | Age-Related Susceptibility to Pseudomonas aeruginosa Ocular Infections in Mice. Infection and Immunity. 20, 1. | (1978).
Pseudomonas aeruginosa all experiments |
intratracheal | beta-Poisson |
α = 1.9E-01 N50 = 1.85E+04 |
1.85E+04 | white rabbit | corneal ulceration | 10 | CFU | Effect of Pseudomonas aeruginosa concentration in experimental contact lens-related microbial keratitis. Cornea. 12, 1. | (1993).|
Pseudomonas aeruginosa all experiments |
intratracheal | exponential |
k = 3.22E-7 |
2150065 | death | 67 | CFU | Defective phagocytosis and clearance of Pseudomonas aeruginosa in the lung following bone marrow transplantation. The Journal of Immunology. 171, 4416–4424. | (2003).||
Rhinovirus all experiments |
beta-Poisson |
α = 2.21E-01 N50 = 1.81E+00 |
1.81E+00 | human | type 39 | infection | 6 | TCID50 | Relation between Naturally Acquired Immunity and Infectivity of Two Rhinoviruses in Volunteers. Journal of Infectious Diseases. 125, 3. | (1972).|
Rickettsia rickettsi all experiments |
beta-Poisson |
α = 7.77E-01 N50 = 2.13E+01 |
2.13E+01 | pooled | R1 and Sheila Smith | morbidity | 27 | CFU | Aerosol infection of monkeys with Rickettsia rickettsii. Bacteriological Reviews. 30, 3. | (1966).|
Rotavirus all experiments |
beta-Poisson |
α = 2.53E-02 N50 = 6.17E+00 |
6.17E+00 | human | 8 | FFU | Human Rotavirus Studies in Volunteers: Determination of Infectious Dose and Serological Response to Infection. Journal of Infectious Diseases. 154, 5. | (1986).|||
Salmonella anatum all experiments |
beta-Poisson |
α = 3.18E-01 N50 = 3.71E+04 |
3.71E+04 | human | strain I | positive stool culture | 16 | CFU | 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), | (1951).|
Salmonella meleagridis all experiments |
beta-Poisson |
α = 3.89E-01 N50 = 1.68E+04 |
1.68E+04 | human | strain I | infection | 11 | CFU | 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), | (1951).|
Salmonella newport all experiments |
exponential |
k = 3.97E-06 |
1.74E+05 | human | *Salmonella newport* | infection | 3 | CFU | 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), | (1951).|
Salmonella nontyphoid all experiments |
beta-Poisson |
α = 2.1E-01 N50 = 4.98E+01 |
4.98E+01 | mice | strain 216 and 219 | death | 10 | CFU | The growth of micro-organisms in vivo with particular reference to the relation between dose and latent period. The Journal of Hygiene. 56(3), | (1958).|
Salmonella typhi all experiments |
beta-Poisson |
α = 1.75E-01 N50 = 1.11E+06 |
1.11E+06 | human | Quailes | disease | 8 | CFU | Study of induced typhoid fever in man. I. Evaluation of vaccine effectiveness. Transactions of the Association of American Physicians. 79, 361-367. | (1966).|
SARS all experiments |
inhalation | exponential |
k = 2.46E-03 |
2.82E+02 | mice hACE-2 and A/J | rSARS-CoV | death | 0 | PFU | |
Shigella flexneri all experiments |
beta-Poisson |
α = 2.65E-01 N50 = 1.48E+03 |
1.48E+03 | human | 2a (strain 2457T) | positive stool isolation | 4 | CFU | Immunity in shigellosis. I. Response of man to attenuated strains of Shigella. Journal of Infectious Diseases. 125, 5-11. | (1972).|
Staphylococcus aureus all experiments |
exponential |
k = 7.64E-08 |
9.08E+06 | human | infection | 6 | CFU/cm2 | Effect of Pseudomonas aeruginosa concentration in experimental contact lens-related microbial keratitis. Cornea. 12, 1. | (1993).||
Vibrio cholerae all experiments |
beta-Poisson |
α = 2.50E-01 N50 = 2.43E+02 |
2.43E+02 | human | Inaba 569B | infection | 6 | CFU | Effect of repeated oral infection of hamsters with scrapie. Journal of General Virology. 79, | (1998).|
Yersinia pestis all experiments |
exponential |
k = 1.63E-03 |
4.26E+02 | mice | CO92 | death | 4 | CFU | 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. | (2005).