Table 1 Notations used in the model to quantify the probability of freedom from Echinococcus multilocularis in Sweden, Finland and mainland Norway

P* _Sp

Design prevalence at the animal level for species Sp.

s

Sample of animals of the same species tested with the same test during the same year.

Sa _s Se _{Sp, t, y}

Sample sensitivity: The probability of detection of EM in sample s of animals tested of species Sp with test t in year y.

PIntro

The annual probability of introduction and establishment of the infection in the country

PostPFree

The posterior probability of freedom from infection in the country

PriorPInf

Prior probability of infection in the country

Sp

Species: Species of animals (red foxes, raccoon dogs, domestic pigs, wild boars) or animal population (voles) included in the surveillance

SSC

Surveillance system component, the surveillance performed in one species

SSCSe _{Sp, y}

The surveillance system component sensitivity for one species Sp for one year y

SSSe _y

The surveillance system sensitivity: The combined sensitivity for all SSC for year y

Se _t

The sensitivity of an individual test