Evidence of Porcine Circovirus Infection in Pigs with Wasting Disease Syndrome from 1985 to 1999 in Hokkaido, Japan.

Abstract

ABSTRACT. An epizootiological survey with histopathological methods was conducted for porcine circovirus in 220 diseased pigs (1-200 days old) in 49 farms from 1985 to 1999. Histopathological lesions containing PCV antigen were detected mainly in the lymphoid tissues from 42 of 189 diseased pigs (22.2%) in 4 of 45 farms (8.9%) from 1990 to 1999. The rate of positive pigs gradually increased from 1997 onward and PCV infection was found in 50% of diseased pigs in 1999. Histopathologically, the lesions in the lymphoid tissues (including lymph nodes, Peyer's patches, tonsil and spleen) were highly correlated with the presence of numerous spherical basophilic intracytoplasmic inclusion bodies with PCV antigen, and consisted of lymphocellular depletion and infiltration of macrophages. Although most affected cells showed cytoplasmic reactivity for PCV, intranuclear antigen was also seen in the lymphocytes, macrophages and ileal epithelial cells. Ultrastructurally, macrophages and giant cells contained electron-dense, round to ovoid lysosomal bodies, in which there were concentric circle or paracrystalline arrays of small nonenveloped icosahedral viral particles, approximately 15-17 nm in diameter. Other consistent infectious agents were present in 90.5% of cases, and porcine reproductive and respiratory syndrome virus infection was in 52.4% of the cases with PCV. The histopathological findings suggested that PCV induced systemic immunosuppression in the infected pigs and made them more susceptible to infection of the organisms. Because of the presence of PCV antigens in the intestinal epithelium, feces may play a significant role in dissemination of PCV.-KEY WORDS: epizootiological survey, porcine, porcine circovirus, postweaning multisystemic wasting syndrome.

A Novel Porcine Circovirus Distantly Related to Known Circoviruses Is Associated with Porcine Dermatitis and Nephropathy Syndrome and Reproductive Failure

“…Epidemics of severe systemic disease, clinically presenting as wasting and failure to thrive, were subsequently observed in Europe and Asia, followed by North America (7,(9)(10)(11)(12)(13)(14)(15). Histologic lesions typified by lymphoid depletion and lymphohistiocytic or granulomatous inflammation of multiple organs were described.…”

Modified Indirect Porcine Circovirus (PCV) Type 2-Based and Recombinant Capsid Protein (ORF2)-Based Enzyme-Linked Immunosorbent Assays for Detection of Antibodies to PCV

“…In a more recent study, injection of an immunostimulant into PCV2-infected pigs enhanced replication of PCV2 and induced clinical signs and lesions typical of PMWS (25), confirming the role of PCV2 as an essential cause of PMWS. The occurrence of PMWS has been reported worldwide (7,9,10,20,23,36,38,39,42,43,49).…”

Surto de Circovirose (Síndrome Definhante Multissistêmica de Suínos Desmamados) no estado do Rio de Janeiro

“…Em nosso estudo, os órgãos dos Suínos 2, 3, 4 e 5 permaneceram por mais de 6 meses em formalina, o que pode ter prejudicado a detecção pelo PCR dessas amostras. A ausência ou menor quantidade de DNA ou Ag vírico, observada em algumas amostras, também pode estar associada ao estágio da doença (Sato et al 2000, Zanella & Morés 2003 e, até mesmo, a diferentes cepas do PCV-2 (Sato et al 2000, Zanella & Morés 2003. Embora DNA de PCV-2 não tenha sido amplificado a partir do material de todos os animais de um surto, o resultado positivo pelo PCR de parte dos animais e as lesões histológicas típicas, juntos, são considerados consistentes para o diagnóstico de SDMSD nesse episódio (Zanella & Morés, 2003).…”