Identification of porcine circovirus type 2 in retrospective cases of pigs naturally infected with porcine epidemic diarrhoea virus

The identification of porcine circovirus type 2 (PCV2) was studied in fresh intestinal tissues by polymerase chain reaction (PCR) and in formalin-fixed, paraffin-wax-embedded intestinal tissues by in situ hybridisation. The tissues came from pigs naturally infected with porcine epidemic diarrhoea virus (PEDV). A total of 35 (32.7%) of 107 small intestinal samples from pigs naturally infected with PEDV were found to be positive using PCR. Positive signals for PCV2 were detected in 32 (29.9%) of 107 small intestinal samples from pigs naturally infected with PEDV by in situ hybridisation. The distribution of positive cells in the jejunum and ileum was multifocal or patchy. Distinct positive labelling was found throughout the lamina propria in the small intestines. The results of this study indicate that PCV2 is highly prevalent in pigs naturally infected with PEDV.