one organism must survive the digestive process
and reach a target site within the host.
o The exponential dose–response model has
been found to characterise the dose–
response relationship for Cryptosporidium
and Giardia well (Teunis et al., 1996).
o This model can be expressed as:
n Pinf =1exp(rl)
n where r is the dose–response parameter,
and can be interpreted to be the
probability of one cyst/oocyst/organism
surviving to initiate an infection.