Diagnosis And Pathomorphology Observation Of Porcine Hemagglutinating Encephalomyelitis

Porcine hemaglutinating encephalomyelitis by a coronavirus of hemaglutinating encephalomyelitis virus caused an acute infectious disease of swine.The virus generally 1-3 weeks against the nursing piglets. Usually the virus in sub-clinical symptoms. In the majority of the herd was endemic, and immunity. Sows can be immune maternal antibodies passed piglets; pigs can be stage immunity. Therefore, the incidence of the disease is rare. But when the virus enters the susceptibility of birth herd of pigs, morbidity and mortality rates are increased. The experiments of the cases were from the Siping Huaide, the family backyard, sows mainly as the temperature increased, and the consumption decline. Sows producing piglets by a total 83, 5-7 day old piglets were incidence, clinical manifestations: the early stage of sneezing and coughing, vomiting, and others. Piglet disease often crowded together, bowing do not love walking. For the latter part of the realization of constipation and physical decline. Case in piglets died within 20 days postpartum 73, the survival of only 10 sent in the laboratory diagnosis, 3 days died after piglet mortality reached 100%.Pig hemagglutinin encephalomyelitis the general was hidden infection, and did not show typical symptoms, it is difficult in clinical diagnosis. The experiments showed significant clinical vomiting, diarrhea, as well as barriers to movement of the 10 piglets diagnosis, the use of classical swine fever virus (CSFV), and pig hemagglutinin encephalomyelitis virus (HEV), and porcine reproductive and respiratory syndrome virus (PRRSV), swine pseudorabies virus (PRV) multiplex PCR detection of the infected piglets whether one or more of the virus showed that only pig hemagglutinin encephalomyelitis virus of PCR positive results. To the diseased brain tissue after treatment with negative electron microscopy observation, discovered coronavirus. 10 piglets can be confirmed as infected with the hemagglutinin encephalomyelitis virus. On the organizations culture and identification of bacteria and found no bacteria, piglets diagnosed as infected simple hemagglutinin encephalomyelitis virus.Observation of piglets survived the clinical symptoms, manifested as the temperature increased, decreased appetite, vomiting, diarrhea or constipation, movement disorders, such as voice sensitive. To dissect the dead piglets and observation, the pathological changes of meningeal congestion, hemorrhage, cerebral cortex congestion, kidney parenchymatous degeneration, liver enlargement, mild gore and lipid change; histopathological changes in the cerebral cortex that cone cell layer and multi-layer neuron cell edema and mild vascular expansion of neurons week gap expanded. Cell body swelling, Nissl bodies of the dissolution. Nerve cells with deep concentration. In a small pyramidal cell layer see mild gliosis, some small glial cells surround nerve cells and macrophages were nerve phenomenon and satellite phenomenon. Kidney glomerular bleeding, Acute renal tubular epithelial cell swelling, loss. Tubular basement membrane in the glass-like change, thickening of the basement membrane, cell swelling. Liver cells were highly expansion, congestion, sinus expansion, swelling of the liver cells. Villi gastric epithelial cells shed, exfoliated epithelium, focal-lymphocyte infiltration, and glandular cell degeneration, swelling or shrinking. Shedding all of intestinal villi, interstitial edema, intestinal glands from mesenchymal cells instead of connective tissue, connective tissue cells interval gland hyperplasia, the basement membrane of intestinal glands and connective tissue edema, columnar epithelial cells shed, occasionally congestive lamina propria, smooth muscle loose. In immunohistochemical results found in the brain of pyramidal cells, cerebellum Puken cell have shown a positive expression. HEV from the experimental results in the distribution of piglets in their nervous system and cause damage.Piglet's brain tissue will be grinding, supernatants from infected mice after treatment, the clinical symptoms in mice, for the spirit of sluggish performance, sitting posture like a dog, hair against the legislation, sensitive to excessive noise, screams, body shuddering. Organization of the mice after treatment by RT-PCR, the mice brain and kidney results were positive; mice histological mainly for the brain nerve cells coagulation and necrosis, acute renal tubular epithelial cell swelling, and cytoplasm coagulation necrosis, and the pathological changes similar to piglets. Thus, mice can return to the basic HEV infection symptoms, that is, through experiments in mice can be successfully reproduced on the virus to prove that the consumption of vomiting encephalomyelitis viruses against the main body of the nervous system, the organ also has a certain impact. This type of vomiting hemagglutinin encephalomyelitis virus laid the foundation for the study, the pathogenic mechanism for HEV; drug screening studies have important significance.