The aim of this study was to determine the distribution of porcine circovirus in the Austrian swine population. The starting point was the comparison of routine molecular diagnostic methods for the detection of porcine circovirus type 2 (PCV2). Among all available methods, PCR and in situ hybridization (ISH) were chosen. From the beginning of the year 2000, all pigs submitted to the 2nd Medical Clinic for Ruminants and Swine of the University for Veterinary Medicine in Vienna were tested by PCR for porcine circovirus type 1 (PCV1) and PCV2.
A total number of 422 animals was tested by PCR, and within this group 27 animals (6.4 %) were positive for PCV1, 158 animals (37.4 %) were PCR-positive for PCV2, 31 animals (7.4 %) were positive for both PCV1 and PCV2, and 206 animals (48.8 %) tested negative for both PCV1 and PCV2. PCV1 and PCV2 PCR positive pigs were also evaluated microscopically and tested by ISH. A total of 216 pigs were tested by means of ISH. Eight pigs (3.7 %) displayed characteristic microscopic lesions, and PCV2 nucleic acids were demonstrated within these lesions confirming a diagnosis of PMWS. The pigs suffering from PMWS came from one farm and showed typical clinical symptoms (wasting) and gross lesions characterized by enlargement of lymph nodes.
The PCV2 viruses isolated from eight geographically different farms in Austria were sequenced and compared to 35 isolates obtained from the GenBank. The results of phylogenetic analysis showed no uniform PCV2 type in Austria but a variety of different subtypes. The nucleotide sequence homology among these isolates was 95 %, and all the isolates could be identified as PCV-2.
porcine circovirus type 2 (PCV2), postweaning multisystemic wasting syndrome (PMWS), PCR, in situ hybridization (ISH), Austria