The potential of environmental and demographic factors in prediction of the presence of Aujeszky disease in wild boars (Sus scrofa L.)

Abstract

Aujeszky disease is a viral disease, primarily of suids, caused by Suid-alphaherpesvirus 1, also known as the Aujeszky disease virus. The potential transmission of virus from wild boars to domestic pigs underlines the necessity of studying the epidemiology of Aujeszky disease in wild boars. The aim of this study was to evaluate the potential of demographic, environmental and population management predictors in predicting that ELISA tested animals will be seropositive. We used 222 wild boar blood samples, collected from 10 different hunting grounds and Medvednica Nature Park. In total, 12 predictors were used in this study, three of which were demographic (age category, sex, population density), two represented population management (hunting method, relative hunting bag) and seven environmental characteristics (altitude, watercourses, meadows, scrublands, forests, agricultural area and infrastructure area). The model selection was based on the Akaike Information Criterion, corrected AIC and Akaike weight. The model with the lowest value (ΔAIC<2 units) was selected as representing the better model fit. Predictors were selected using logistic forward stepwise regression. The age of the wild boars proved to be positively correlated with prediction of seropositive animals, while altitude and population density proved to be negatively correlated. The selected models were shown to be able to predict ADV seropositive animals with an average accuracy between 77.12 and 78.67%, and seronegative animals between 82.46 % and 85.09. The odds ratio values ranged between 12.53 and 14.52. Our results are in accordance with previous studies, and the impact of population density in the case of Aujeszky disease in wild boars remains unclear.