ORIGINAL PAPER Mycoplasma hyopneumoniae temporal trends of infection and pathological effects in wild boar populations Mario Chiari & Nicola Ferrari & Mariagrazia Zanoni & Loris Alborali Received: 10 July 2013 /Revised: 7 August 2013 /Accepted: 9 September 2013 # Springer-Verlag Berlin Heidelberg 2013 Abstract Mycoplasma hyopneumoniae (Mhyo) is the princi- pal etiological agent of enzootic pneumonia (EP), one of the most economically important diseases in the pig production industry worldwide. Although swine and wild boars (Sus scrofa ) share susceptibility to Mhyo infection, information regarding the dynamics of Mhyo infections and pathology in wild boars is currently limited. Therefore, the aim of this study was to determine the spatiotemporal dynamics of Mhyo in- fections in free-living wild boars through serological ELISA testing. Additionally, the presence of EP-like gross lesions and their association with the presence of Mhyo, based on a PCR assay, were assessed. Over a period of 5 years, antibodies against Mhyo were detected in 655 (30.0 %) of the 2,177 analyzed wild boars. A generalized temporal increase of sero- prevalence coupled with an increase of mean antibody titers of seropositive individuals was found. Moreover, a similar sero- prevalence between age classes associated with higher anti- body titers of younger individuals indicated the wild boars were infected during the early stages of their life. Out of 99 lungs tested, 43 showed EP-like lesions and 45 were PCR positive for the presence of Mhyo DNA. The lung lesion scores were related to the sex and age of the wild boars, with young individuals having higher lung scores than others, and there was a positive association with the Mhyo PCR-positive status. The temporal increase of the Mhyo seroprevalence and infection association with EP-like lesions, when coupled with the spreading of wild boar populations, raises concerns on the epidemiological role of this species. Keywords Mycoplasma hyopneumoniae . Wild boar . Enzootic pneumonia . Italy Introduction In the last decade, the Eurasian wild boar (Sus scrofa ) has shown a remarkable population increase coupled with an ex- pansion of its distribution throughout Europe, driven by rural abandonment, changes in agricultural production, and changes in game management (Acevedo et al. 2011). This continuing expansion raises concerns regarding the control of pathogens shared with livestock and humans (Meng and Lindsay 2009; Chiari et al. 2013; Martinelli et al. 2013). Therefore, the study of these pathogens in wild boars and the role of this species as pathogen reservoir is of interest, not only for public health, but also because of its economic implications on livestock farms (Wyckoff et al. 2009). Swine and wild boars share a suscepti- bility to the main etiological agent of enzootic pneumonia (EP), Mycoplasma hyopneumoniae (Mhyo), which, despite the low mortality rates, is one of the most economically im- portant diseases in the pig production industry (Sibila et al. 2010). In the infected animals, this chronic respiratory disease is characterized by purple to gray areas of cranio-ventral con- solidation generally located at the ventral portion of the cranial and middle lobes, the accessory lobe, and the cranial portion of the caudal lobes of the lungs (Ross 1999). Information about Mhyo prevalence, infection, and macro- scopic lesions in wild boars is currently limited. The seroprev- alence of antibodies against Mhyo in wild boars ranged from 21 % in Slovenia and Spain to 58 % in France (Vengust et al. 2006; Marois et al. 2007; Sibila et al. 2010). Evidence of Mhyo infections, through PCR, was reported in France and in Spain with a prevalence of about 8 % (Marois et al. 2006; Sibila et al. 2010), but none of the tested animals showed EP- like gross lesions. However, the lack of data on the serological Communicated by C. Gortázar M. Chiari (*) : N. Ferrari : M. Zanoni : L. Alborali Istituto Zooprofilattico Sperimentale della Lombardia e dell’Emilia Romagna (IZSLER) “Bruno Ubertini”, Via Bianchi 7/9, 25124 Brescia, Italy e-mail: mario.chiari@izsler.it Eur J Wildl Res DOI 10.1007/s10344-013-0763-2