Post-weaning multisystemic wasting syndrome (PMWS) is a new emerging disease affecting nursery and growing pigs in worldwide. Porcine circovirus type 2 (PCV-2) is a most important pathogen associated with PMWS. This study was carried out to investigate the pathological changes in the pancreas of pigs diagnosed as PMWS. To detect the PCV-2 antigen and nucleic acid in the tissue, immunohistochemistry and polymerase chain reaction (PCR) was conducted, respectively. 24 pigs of 4-10 weeks old showed clinical signs of PMWS such as chronic wasting, respiratory distress and diarrhea were examined. Histopathologically, interstitial and periductular mononuclear cells infiltration were observed in pancreas. Multifocal to diffuse necrosis of acinar tissues or necrotizing to granulomatous pancreastitis with numerous syncytial cells infiltration were examined in severe cases. PCV-2 nucleic acid was detected from all tested pancreas using PCR. The PCV-2 antigen in 12 pancreas sections was detected by immunohistochemical staining. PCV-2 has a tropism for vascular endothelial cells and infiltrated macrophages. Although gross lesions are uncommon in the pancreas of pigs with PMWS, histopathological changes and the presence of PCV-2 in this tissue may be related to clinical signs associated with digestive disorders.

Este estudo investigou a manifestação do vírus da Anemia Infecciosa das Aves (VAIA) em lotes de frangos que apresentavam retardo no crescimento e aumento da mortalidade observado a partir do quarto dia de idade. Clinicamente, as aves apresentavam depresão, palidez, despigmentação e retardo de crescimento. À necropsia, as aves apresentavam lesões compatíveis com a infecção pelo vírus da Anemia infecciosa das aves (VAIA). Amostras de fígado, baço e timo foram examinadas por PCR que amplifica um frangmento de 675 pb do gene VP-1 do VAIA. Todos os órgãos examinados foram positivos para o vírus da Anemia Infecciosa das Aves. Os demais patógenos, como adenovírus, reovírus, astrovírus, vírus da doença infecciosa bursal e coronavírus aviário não foram detectados pelas diferentes técnicas laboratoriais, como sorologia, PCR ou PAGE. Os resultados mostraram que o vírus da Anemia Infecciosa das Aves (VAIA) pode manifestar-se clinicamente nos primeiros dias de vida dos frangos - um fato ainda não reportado - associado ao vírus vacinal da doença infecciosa bursal (DIB) cepa forte pode induzir um persistente retardo de crescimento, por várias semanas, em frangos. | This survey aimed to investigate chicken anemia virus (CAV) in broilers flocks experimenting retarded growth and increasing mortality since the fourth day of age. Clinically, chickens presented depression, paleness, depigmentation and retarded growth. At necropsy, chickens presented CAV-compatible lesions. Samples from liver, spleen and thymus were tested by PCR for a 675-bp fragment of the CAV VP-1 gene, and all tested samples were positive. Serological and molecular techniques did not detect other pathogens, such as adenovirus, reovirus, astrovirus, infectious bursal disease and avian infectious bronchitis virus. These results showed that chicken anemia virus (CAV) may occur since the first few days of life in broilers - a fact not as yet reported -, associated with high pathogenic Infectious Bursal Disease Virus (IBDV) vaccine strain may induce a persistent growth retarded for several weeks in broilers.