The transmission and spreading routes of Aujeszky′s disease in swine population

Abstract

Aujeszky′s disease (MA) is an infectious viral disease, caused by suid alpha herpes virus 1, which displays a very broad host range, except humans and primates. Pigs are the only animal species that can survive the infection with the MA virus, which accounts for its ability to be latently infected. Although pigs are considered a natural host and the main reservoar of the virus, the spreading and transmission mechanism cannot be always detected. The aim of the paper was to evaluate the routes of transmission and spread of MA virus in the swine population with different immunological stutus i.e. depending on the vaccinal status. The material for this research consisted of the samples from four swine farms, with health disorders i.e. clinical signs suggesting MA disease. The applied research methods included: epidemiological and clinical evaluation, pathomorphological examination, virology testing of tissues originating from the dead animals and serological testing in order to evaluate the specific antibodies against MA. The obtained results indicate that purchasing breeding animals with different or unknown health status regarding MA, represents the main route of transmission and spreading of the infection. Besides vaccination, which represents one of the measure in MA eradication, it is necessary to apply strict trade control and checking the health status of herds from where breeding animals are purchased.

Current Swine Respiratory Diseases Morphology in Intensive Swine Production in Serbia

“…Typically, depending on days post infection, exudative conjunctivitis, serous to fi brinonecrotic rhinitis, laryngitis and necrotizing tonsillitis may be present. Gross lesions in the lower respiratory tract are more common in weaners and fi nishers: pulmonary edema, scattered foci of hemorrhage (Figure 3e) or even broncho-interstitial pneumonia [9,23,24]. In uncomplicated cases, microscopical alveolar edema could be observed (Figure 3f).…”

“…Some systemic pathogens which do not primarily target the respiratory tract may also cause severe respiratory clinical signs, such as Classical swine fever virus and Pseudorabies virus [3]. It is important to indicate that besides the above mentioned etiological agents, some infectious diseases are endemically present in Serbia for decades, for example, Morbus Aujeszky Disease (AD, Psudorabies) [23,24]. Also, the control of some other important viral infectious diseases in Serbia differs from the Member States of the European Union (EU) [25,26].…”

“…Today, despite the introduction of modern vaccines against the most important agents causing respiratory diseases of swine (for example M. hyopneumoniae, PCV-2, PRRSV) and all efforts implemented from the production aspect in the technology in the swine industry, the situation is even more complicated [29,[32][33][34]. It is a well-known fact that various infectious agents could quite often be introduced into the swine herd after purchasing latently infected animals from another farm with a different health status, causing an outbreak of infectious disease [23,35,36]. Indeed, results of analysis of the multiple swine respiratory diseases outbreaks in Serbia, indicated that purchasing of breeding animals, with different or unknown health status, represented the most important route of transmission and spreading of the infection to other farms, or different state regions [9,20,23,24,33].…”

“…It is a well-known fact that various infectious agents could quite often be introduced into the swine herd after purchasing latently infected animals from another farm with a different health status, causing an outbreak of infectious disease [23,35,36]. Indeed, results of analysis of the multiple swine respiratory diseases outbreaks in Serbia, indicated that purchasing of breeding animals, with different or unknown health status, represented the most important route of transmission and spreading of the infection to other farms, or different state regions [9,20,23,24,33]. Intensifying of swine production increases the incidence and economic importance of respiratory diseases despite the applied measures for their suppression and eradication [9,23,35].…”

“…Indeed, results of analysis of the multiple swine respiratory diseases outbreaks in Serbia, indicated that purchasing of breeding animals, with different or unknown health status, represented the most important route of transmission and spreading of the infection to other farms, or different state regions [9,20,23,24,33]. Intensifying of swine production increases the incidence and economic importance of respiratory diseases despite the applied measures for their suppression and eradication [9,23,35]. Considering the complexity of the etiology, respiratory diseases in pigs are often referred to as porcine respiratory disease complex (PRDC) [30,37].…”