Spatial risk assessment of herd sero-status of Aujeszky's disease in a county in Hungary

Abstract

A Geographic Information System (VetEpiGIS) was used to analyze the ADV (Aujeszky's disease virus) sero-status in large-scale pig units regarding certain geographical features in a county of southern Hungary. The ADV sero-statuses were collected from all swine units in Csongrád county in 1998–2000. The units’ coordinates were combined with a vector graphical digital map of the county, with a resolution of 1:100,000. Logistic regression tested the associations between sero-status of large-scale units and presence of topographical features, other units and villages in the neighborhood. “Neighborhood” was defined by circular zones with radius 1–10 km around the unit (in 1 km increments; one logistic regression for each radius). The following topographical features showed significant positive association with the ADV seropositivity: lake (3 km OR: 5.7; 5 km OR: 7.5; 6 km OR: 6.1; 10 km OR: 5.4) and highway (5 km OR: 4.2; 6 km OR: 5.3). Other features had negative association with ADV seropositivity: forest (3 km OR: 0.13; 4 km OR: 0.15; 5 km OR: 0.15; 6 km OR: 0.10; 7 km OR: 0.10; 8 km OR: 0.23) and uninfected large-scale unit (4 km OR: 0.07; 5 km OR: 0.27; 6 km OR: 0.32; 7 km OR: 0.31).