Proceedings of the 10th International Colloquium on Paratuberculosis

#114 Epidemiological characteristics <strong>of</strong> MAP-infected population <strong>of</strong> wild hares cropped in
sou<strong>the</strong>rn Chile
Gustavo Enrique Monti, Miguel Angel Salgado, Sergio Eugenio Gallardo, Armin Fabian Mella, Manuel Ignacio
Ruiz, Juan Kruze
Universidad Austral de Chile, Chile
Although infected cattle are <strong>the</strong> main source <strong>of</strong> infection, previous studies suggested that <strong>the</strong> rabbit possess
<strong>the</strong> greatest risk <strong>of</strong> transmission to domestic livestock. However, in sou<strong>the</strong>rn Chile <strong>the</strong> hare is more common
than rabbits and it is considered a plague. The aims <strong>of</strong> this study were to provide evidence that hares might be
infected with Map, to assess <strong>the</strong> prevalence <strong>of</strong> infected hares, and to assess association between individual
characteristics and risk <strong>of</strong> infection in a hare population cropped in sou<strong>the</strong>rn Chile.
A cross-sectional study was designed using 385 wild hares randomly selected from cropped animals
in two provinces <strong>of</strong> sou<strong>the</strong>rn Chile. Samples were stratified by geographical area based on <strong>the</strong>ir location at
<strong>the</strong> time <strong>of</strong> capture and information about <strong>the</strong> individuals and <strong>the</strong> place <strong>of</strong> capture were collected. Faecal
samples, mesenteric lymph nodes and representative tissue <strong>of</strong> <strong>the</strong> small intestine were aseptically collected
once a week, transferred to sterile containers, and transported to <strong>the</strong> laboratory for bacteriological analysis by
liquid culture (MGIT) and PCR confirmation. The true prevalence was estimated using a Bayesian approach,
assuming a Sensitivity = 60% and Specificity = 99%. Associations between characteristics <strong>of</strong> hares and
disease status were assessed by logistic regression (LR).
Apparent prevalence was 12.7%. The median <strong>of</strong> <strong>the</strong> estimated posterior for <strong>the</strong> true prevalence was
14.1% (95% credibility interval 0.0; 0.20). From LR model, we estimated that hares captured in <strong>the</strong> Osorno
province were 2.1 times (95% CI 1.1; 4.1) more likely to be infected compared to those from Valdivia province.
Hares younger than one year were 2.2 times (95% CI 1.1; 4.5) more likely to be infected compared to older
ones.
This study provides <strong>the</strong> first evidence that Map infection is common in wild hares in sou<strong>the</strong>rn Chile and it
seems that have a heterogeneous spatially and age-risk distribution.
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