Welcome to the new QMRA online platform! Our content is currently being reviewed and updated.

Visit the old wiki

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: 

  1. Statistically acceptable fit (fail to reject goodness of fit, p > 0.05)
  2. Human subjects, or animal models that mimic human pathophysiology well
  3. Infection as the response, rather than disease, symptoms, or death
  4. Exposure route similar/identical to the exposure route of natural infection
  5. Pathogen strain is similar to strains causing natural infection
  6. 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)
  7. Low ID50/LD50 (to obtain a conservative risk estimate)
Title # of Doses Agent Strain Dose Units Host type Μodel Optimized parameters Reference
Adenovirus
Experiments
4 type 4 TCID50 human exponential
k = 6.07E-01
LD50/ID50 = 1.14E+00

Bacillus anthracis
Experiments
4 Vollum spores guinea pig exponential
k = 1.65E-05
LD50/ID50 = 4.2E+04

Burkholderia mallei
Experiments
10 KHW,316c CFU C57BL/6 mice and diabetic rat beta-Poisson a = 3.28E-01

LD50/ID50 = 5.43E+03
N50 = 5.43E+03
Coxiella burnetii
Experiments
10 phase I Ohio PFU C57BL/1OScN mice beta-Poisson a = 3.57E-01

LD50/ID50 = 4.93E+08
N50 = 4.93E+08
Cryptosporidium hominis
Experiments
4 TAMU isolate oocysts human exponential
k = 5.72E-02
LD50/ID50 = 1.21E+01

Cryptosporidium parvum
Experiments
5 From an infected human Cysts human beta-Poisson a = 1.01E-01

LD50/ID50 = 3.41E+02
N50 = 3.41E+02
Echovirus
Experiments
4 strain 12 PFU human beta-Poisson a = 1.06E+00

LD50/ID50 = 9.22E+02
N50 = 9.22E+02
Enterovirus
Experiments
3 porcine, PE7-05i PFU pig exponential
k = 3.74E-03
LD50/ID50 = 1.85E+02

Escherichia coli
Experiments
3 EIEC 1624 CFU human beta-Poisson a = 1.55E-01

LD50/ID50 = 2.11E+06
N50 = 2.11E+06
Francisella tularensis
Experiments
4 SCHU S-4 CFU monkey exponential
k = 4.73E-02
LD50/ID50 = 1.46E+01

Giardia duodenalis
Experiments
8 From an infected human Cysts human exponential
k = 1.99E-02
LD50/ID50 = 3.48E+01

Influenza
Experiments
9 H1N1,A/California/10/78 attenuated strain,H3N2,A/Washington/897/80 attenuated strain TCID50 human beta-Poisson a = 5.81E-01

LD50/ID50 = 9.45E+05
N50 = 9.45E+05
Lassa virus
Experiments
6 Josiah strain PFU guinea pig exponential
k = 2.95E+00
LD50/ID50 = 2.35E-01

Legionella pneumophila
Experiments
4 Philadelphia 1 CFU guinea pig exponential
k = 5.99E-02
LD50/ID50 = 1.16E+01

Mycobacterium avium
Experiments
3 sub sp. Paratuberculosis Bovine CFU deer exponential
k = 6.93E-04
LD50/ID50 = 1000

Naegleria fowleri
Experiments
7 LEE strain no of trophozoites mice exponential
k = 3.42E-07
LD50/ID50 = 2.03E+06

Poliovirus
Experiments
3 type 1,attenuated PD50 (mouse paralytic doses) human exponential
k = 4.91E-01
LD50/ID50 = 1.41E+00

Prion
Experiments
5 scrapie strain 263k LD50 i.c. hamsters beta-Poisson a = 1.76E+00

LD50/ID50 = 1.04E+05
N50 = 1.04E+05
Pseudomonas aeruginosa
Experiments
10 CFU white rabbit beta-Poisson a = 1.9E-01

LD50/ID50 = 1.85E+04
N50 = 1.85E+04
Pseudomonas aeruginosa
Experiments
12 ATCC 19660 CFU Swiss webster mice (5day old) exponential
k = 1.05E-04
LD50/ID50 = 6.61E+03

Pseudomonas aeruginosa
Experiments
10 CFU white rabbit beta-Poisson a = 1.9E-01

LD50/ID50 = 1.85E+04
N50 = 1.85E+04
Pseudomonas aeruginosa
Experiments
12 ATCC 19660 CFU Swiss webster mice (5day old) exponential
k = 1.05E-04
LD50/ID50 = 6.61E+03

Rhinovirus
Experiments
6 type 39 TCID50 human beta-Poisson a = 2.21E-01

LD50/ID50 = 1.81E+00
N50 = 1.81E+00
Rickettsia rickettsi
Experiments
27 R1 and Sheila Smith CFU pooled beta-Poisson a = 7.77E-01

LD50/ID50 = 2.13E+01
N50 = 2.13E+01
Rotavirus
Experiments
8 FFU human beta-Poisson a = 2.53E-0.2

LD50/ID50 = 6.17E+00
N50 = 6.17E+00
Salmonella anatum
Experiments
16 strain I CFU human beta-Poisson a = 3.18E-01

LD50/ID50 = 3.71E+04
N50 = 3.71E+04
Salmonella meleagridis
Experiments
11 strain I CFU human beta-Poisson a = 3.89E-01

LD50/ID50 = 1.68E+04
N50 = 1.68E+04
Salmonella newport
Experiments
3 *Salmonella newport* CFU human exponential
k = 3.97E-06
LD50/ID50 = 1.74E+05

Salmonella nontyphoid
Experiments
10 strain 216 and 219 CFU mice beta-Poisson a = 2.1E-01

LD50/ID50 = 4.98E+01
N50 = 4.98E+01
Salmonella typhi
Experiments
8 Quailes CFU human beta-Poisson a = 1.75E-01

LD50/ID50 = 1.11E+06
N50 = 1.11E+06
SARS
Experiments
0 rSARS-CoV PFU mice hACE-2 and A/J exponential
k = 2.46E-03
LD50/ID50 = 2.82E+02

Shigella flexneri
Experiments
4 2a (strain 2457T) CFU human beta-Poisson a = 2.65E-01

LD50/ID50 = 1.48E+03
N50 = 1.48E+03
Staphylococcus aureus
Experiments
6 CFU/cm2 human exponential
k = 7.64E-08
LD50/ID50 = 9.08E+06

Vibrio cholerae
Experiments
6 Inaba 569B CFU human beta-Poisson a = 2.50E-01

LD50/ID50 = 2.43E+02
N50 = 2.43E+02
Yersinia pestis
Experiments
4 CO92 CFU mice exponential
k = 1.63E-03
LD50/ID50 = 4.26E+02