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Table 1 Description and distribution of input variables for the Paratuberculosis (PTB) survey models.

From: Economic Aspects of Disease Monitoring with Special Reference to Bovine Paratuberculosis

Variable

Description

Distribution

N

Number of herds

Fixed; 24,218

HP

Prevalence of PTB

Fixed; 0.2%

IH

Number of infected herds

Binomial (N, HP)

NHT

Number of herds tested

Fixed; 6000

IHT

Infected herds tested

Hypergeometric (NHT, IH, N)

HS

Herd size

Cumulative (1, 136)

WHP

Within-herd prevalence

BetaPERT (0.01, 0.10, 0.50)

NIT

Number of infected cows tested

Binomial (HS, WHP); Minimum = 1

SE

Test sensitivity

BetaPERT (0.15, 0.45, 0.87)

NID

Number of infected detected

Binomial(NIT, SE)

HSE

Herd test sensitivity

NID/NIT

SP

Test specificity

Uniform (0.99, 0.999)

HSP

Herd test specificity

1-herd false positive percentage

NIHT

Non-infected herds tested

NHT-IHT

NICT

Non-infected cows tested

NIHT * 12

FP

Number of false positive herd tests

Binomial (NIHT, 1-HSP)

FP:TP

False positive: true positive ratio

ΣNID/FP