One case of swine hepatitis E virus and porcine reproductive and respiratory syndrome virus Co-infection in weaned pigs

BACKGROUND: Using various methods, we analyzed the cause of death among weaned pigs from a pig farm in Hebei Province, China. All 300 piglets (100% fatality) were identified as moribund, with death occurring within 1 month from the onset of clinical signs. RESULTS: A single case exhibited obvious hemorrhagic necrotic changes with massive lymphocytic infiltration in multiple organs, in particular the liver, lungs and intestines. Dysplasia and lymphocyte deterioration were common in lymphatic organs. No visible bacterial colonies from liver and spleen were observed in nutrient, MacConkey, and blood agar plates. Using polymerase chain reaction techniques for this case, we attempted to detect a number of epidemic swine viruses in spleen and liver, including PRRSV, CSF, HEV, and PCV2. We found that this sample was positive for the presence of HEV and PRRSV. CONCLUSIONS: We have detected HEV and PRRSV co-infection in one piglet. Severe pathologic changes were observed. The high mortality of weaned pigs which showed the similar clinical syptom was possibly a result of HEV and PRRSV co-infection, which has rarely been reported previously. We speculated that co-infection with PRRSV and HEV might lead to more serious problems.