Release assessments
The probability Pre was estimated with 2
conditional probabilities: The probability of ASFV infection in a
country o (P1 ) and the probability of
selecting an ASFV contaminated meat during the month m before
detection of the infection (P2 ). Probability of
an ASFV infection in the country o (P1 )
was modelled using a beta distribution (α1, α2), where the α1 was the
number of months with at least one undetected ASF outbreak in the
country and α2 was the number of months considered for the analysis
(OIE, 2019).
The P2 was also estimated with a beta
distribution (α3, α4), where α3 was the quantity (kg) of potentially
infected pig products in the country o in the month m(Qim ) and α4 was the quantity of pig products produced in countryo in the month m (Nm ). The quantity of infected pig
products in the country o (Qim ) was calculated with 3 parameters:
(NI ) estimated number of infected pigs in the country which was
calculated by multiplying the number of undetected outbreaks
(Ou ), average herd size (To ), and intraherd prevalence
(Hp ) similar to the assessment of the ASF introduction by live
pig imported legally during the HRP, (Pm ) the probability that an
ASFV infected pig is transformed into meat and (Mp ) the average
weight of the products (kg) obtained per slaughtered pig. The
probability Pm was estimated as follows:
Pm = P3 × P4 ×Psm × Pus
In this formula, P3 is the probability that a pig
survives ASFV infection; P4 is the probability
that the ASFV infected pig survives the transportation;Psm is the probability of a pig going to a
slaughterhouse during a specific month based on the pig census and
monthly proportion of pigs slaughtered on average (EUROSTAT, 2014) and;Pus is the probability that an ASFV-infected pig
is undetected during the clinical checks in the slaughterhouse.