Biegunki świń wywoływane przez wirusy warunkowo chorobotwórcze

The paper reviews literature that evaluates the importance of the following groups of viruses in the etiology of diarrhea in pigs, that occur mostly from birth to weaning. These are as follows: Adenoviruses, Rotaviruses, Reoviruses, Picornaviruses, Enteroviruses, Caliciviruses and Astroviruses. Their common properties are: usually low and facultative pathogenicity, dependent on the level of innate immunity of the animal; participation as one of the factors of a multifactorial etiology, usually together with several taxonomically different viruses; contribution to the emergence of clinical symptoms in pigs, together with an unsatisfactory level of welfare which frequently occurs in large farms based on industrial technologies; very often occurring symptomless infections and carriership of these opportunistic microorganisms in healthy animals. These microorganisms predominantly represent RNA viruses and express a high frequency of variability of their genomes. As a consequence this may contribute to the emergence of new species, quasi-species, or variants in the enumerated groups of viruses, in addition to variants also pathogenic for humans. At present it is difficult to define which species or variants of the mentioned groups of viruses - besides the mentioned environmental factors - initiate the multifactorial, enteric disease of pigs. However it may not be excluded that Torque teno or PCV2 viruses and some bacterial enteropathogens, particularly E. coli serotypes pathogenic for swine, may be taken into account.