Epidemiologic and Phylogenetic Analysis of Emerging Porcine Parvoviruses in Croatia

Abstract

With the aim of investigating if the emerging porcine parvoviruses (PPVs) exists in Croatia, 83 postmortem samples from different organs were collected from 14 Croatian farms. ORFs of these samples were amplified with PCR and the resulting 279-330 BP products were sequenced. Except PPV1, the classical porcine parvovirus; PPV2, PPV3 and PPV4 were detected, and their prevalence was 12%, 54.2% and 19.2%, respectively. This prevalence showed an increasing trend compared to previous studies by other authors. Besides, thirteen PPV positive samples were detected; each, 3, 7, and 3 of them for PPV2, PPV3 and PPV4, respectively. Unlike in many studies, in this study the prevalence of PPVs in adult pigs was not significantly higher than that in non-adults (fetuses, piglets and gilts), suggesting a possibly high infection in the latter groups. The Croatian sequences for PPV2, PPV3 and PPV4 have respectively shown 91.4-99.5%, 98.2-99.7% and 98.7-100% identities with corresponding PPVs from the GenBank. Generally, these sequences have been more similar to one another than they were to the viruses from the GenBank. However, some Croatian PPV3 sequences have been phylogenetically very similar to such viruses from Germany, Hungary and Romania suggesting a common (point) source (ancestor) for such spread among these countries. Like in previous studies, also in this study, the identity and phylogenetic studies for PPV4 have shown a uniformly very high similarity among these viruses suggesting higher adaptation of the virus compared to PPV2 or PPV3. These results warrant further studies possibly full genome analysis of these strains, their impacts on herd health as well as geographic distribution of the virus for possible prevention measures.