Proceedings of the 10th International Colloquium on Paratuberculosis

Latium Region Viterbo districts
RESULTS
At animal level <strong>the</strong> AP was in <strong>the</strong> range 1.6 -4.3 % with a total prevalence <strong>of</strong> 3%. The TP was
in <strong>the</strong> range 0.26 -7.3 % with a total prevalence <strong>of</strong> 3.9% . Among <strong>the</strong> flocks <strong>the</strong> HAP was
from 20% to 50% and <strong>the</strong> HTP was from 0% to 72%. The results <strong>of</strong> herd prevalence are
influenced from <strong>the</strong> low sensitivity <strong>of</strong> <strong>the</strong> test.
We calculated also <strong>the</strong> confidence interval (CI). Instead <strong>of</strong> estimating <strong>the</strong> parameter by
a single value, an interval likely to include <strong>the</strong> parameter is given. Thus, confidence intervals
are used to indicate <strong>the</strong> reliability <strong>of</strong> an estimate.
Minimum requirements
(according to Nielsen and T<strong>of</strong>t,
2009)
LATIUM
region
Viterbo Rieti
ROMA
Latina
Our data
Region and country Lazio /Viterbo, Italy
Year <strong>of</strong> study 2005
Animal species Sheep
Test used ELISA Pourquier
Age >1 year
Number <strong>of</strong> animals studied 1500
Number <strong>of</strong> herds studied 50
Number <strong>of</strong> animals positive 45
Number <strong>of</strong> herds positive 20
Sampling strategy 50 sheep flocks, randomly selected and proportionally
allocated according to <strong>the</strong> 5 sanitary districts <strong>of</strong> <strong>the</strong> Viterbo
province
Animal prevalence
District Animals
tested (n)
Frosinone
ELISA
positive
Prevalence
(AP)%
AP 95%
konfidence
interval
TP%
Vt1 300 13 4.3 2-6.5 7.3
Vt2 300 7 2.3 0.6-4 2.1
Vt3 300 10 3.8 1.6-6 6
Vt4 300 10 3.8 1.6-6 6
Vt5 300 5 1.6 0.19-3 0.26
Total 1500 45 3 2.1-3.8 3.9
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