Porcine circovirus 4 status of domestic pigs and wild animals in Poland.

INTRODUCTION: Given the threat that porcine circovirus (PCV) 2 and PCV3 pose to the pig industry, the epidemiology of emerging PCV4 warrants further investigation. Until 2023, PCV4 had only been confirmed in Asia, with the majority of reports originating from China. More recently, PCV4 DNA has also been detected in samples from Spain and the United States, indicating a potentially broader geographic distribution. Furthermore, PCV4 DNA has been identified in samples from other animal species. This study aimed to evaluate the presence of PCV4 in samples collected from domestic pigs, wild boars and wild ruminants in Poland using its Rep (replicase) gene.

MATERIAL AND METHODS: A total of 474 serum samples from domestic pigs and 226 blood and internal organ samples (lymph nodes, spleen and lungs) from 20 wild boars, 33 fallow deer, 4 red deer and 6 roe deer were tested using qPCR to detect the presence of PCV4 DNA.

RESULTS: No PCV4 was detected in any of the samples.

CONCLUSION: The presence of PCV4 in other populations or regions of Poland cannot be excluded. Further research is needed to monitor the epidemiological situation in the country, particularly in light of emerging reports confirming the presence of the virus in Europe.