Investigation And Pathological Observation Of PEDV And Coinfection With Four Virus In Sichuan

Piglet diarrhea is the most serious disease which caused a huge economic loss in China. Porcine epidemic diarrhea virus (PEDV) causes acute, contagious and high infectious digestive tract disease named porcine epidemic diarrhea (PED) with symptoms of acute diarrhea, vomiting, dehydration and led a highly mortality rate in neonatal piglets. In this study, epidemiological investigation of PEDV and its coinfection with CSFV, PRRSV, PCV-2 and PRV firstly and pathology observation and analysis of typical sick piglets executed from 2014 to 2016 in Sichuan province provide evidence for mastering the pathogenic causes of diarrhea piglets and prevention of these diseases in Sichuan province.1 Coinfection investigation of PEDV and four porcine viruses in Sichuan by PCRA total of 349 clinical samples of sick piglets from 17 cities in Sichuan province were detected by diagnostic method of PEDV, CSFV, PCV-2 and PRV established by our own laboratory and National standard diagnostic method of PRRSV (GB/T 27517-2011). The results showed that the positive rate was 70.49% (246/349) for PEDV. Analysis of the onset time showed that proportional morbidity ratio of PED was 10.57% for spring (26/246),19.92% for summer (49/246),12.20% for autumnn (30/246),57.32% for winter (141/246). Results suggested that there was a high mobidity and widely prevalent of PED in Sichuan province; not only winter, but also spring, summer and autumnn had high morbidity, therefore, PED could happen throughout the year.In the PEDV positve case, there was a result that the positive rate was 47.15% for PEDV simple infection,25.61% for CSFV,23.98% for PRRSV,30.08% for PCV-2,15.04% for PRV,3.65% for CSFV simple coinfection,4.07% for PRRSV simple coinfection,8.13% for PCV-2 simple coinfection,5.28% for PRV simple coinfection,2.03% for PCV-2 and PRRSV coinfection,3.25% for CSFV and PCV-2 coinfection,8.54% for CSFV and PRV coinfection,5.28% for PCV-2 and PRV coinfection,2.44% for PRRSV and PRV coinfection,1.63% for CSFV, PRRSV and PCV-2 coinfection,4.88% for CSFV, PRRSV and PRV coinfection,3.65% for CSFV, PCV-2 and PRV coinfection. In conclusion, although there was PEDV simple infection, PEDV coinfection with other viruses was widespread in Sichuan province.2 Clinical pathological characteristics observation of diarrhea piglets in SichuanOn the basis of etiology detection, pathological characteristics of four clinical typical cases from four farms, including clinical behavior, dissection, tistopatho-logic slide, was observed, and four samples were diagnosed by PCR. In results, these cases not only showed pathological features of PED, but also had their own symptoms respectively, typical case from Mianyang (PEDV, PCV-2, PRV) had pathologic character, such as diffuse interstitial pneumonia, yellow liver, kidney with white necrosis, swollen inguinal lymph node with hemosiderin, degeneration and dissociation of mucous epithelium in large intestine. Typical case from Santai (PEDV, CSFV, PCV-2, PRV) had pathologic character, such as hypermia and hemorrhage of heart and choke, diffuse interstitial pneumonia, liver with white necrosis, infarcted focus in margin of spleen, hemorrhage and necrosis in kidney, swollen lymph node, degeneration of mucous epithelium in large intestine, broadening and hemorrhage of submusoca in large intestine. Typical case from Qionglai (PEDV, CSFV, PRV) had pathologic character, such as hypermia and hemorrhage of heart and choke, partial necrosis of liver, red and yellow kidney with white necrosis, renal papillae hyperaemia, infarcted focus in margin of spleen, swollen lymph node, degeneration of mucous epithelium in large intestine, hemorrhage of submusoca in large intestine. Typical case from Xinjin (PEDV, PRRSV) had pathologic character, such as myocardial cell necrosis, diffuse interstitial pneumonia, partial yellow liver, glomerulonephritis, swollen lymph node, degeneration of mucous epithelium in large intestine, broadening of submusoca in large intestine. Difference of clinical symptoms, dissection and histopathologic slide between mixed infection cases and PEDV simple infection provide references in diagnosis of porcine diarrhea disease with coinfection.