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

Abstract

The first outbreak of swine circoviruse infection which occurred in the State of Rio de Janeiro was described. The disease which affects mainly weaned pigs, about 4 months old, caused the death of at least 14 animals. The property where the outbreak occurred, had inadequate sanitary and management conditions. Clinically the disease was characterized by wasting, poor development, coughing, tachypnoea, dispnoea, ataxia , tremors after simulation, decubitus and convulsions. The course of the disease was acute to subacute. The most important post-mortem findings were paleness of the body, enlarged lymphnodes, non-colapsed lungs, with consolidated áreas mainly in the cranial lobes. Histological lesions consisted mainly of lymphohistiocytic infiltration with multinucleate giant cells cells in lymph nodes, spleen, Peyer’s patches, kidney, lungs and liver, depletion and/or lymphoid hyperplasia, as well as lymphohistiocytic intersticial pneumonia and areas of secondary broncopneumonia. The diagnosis was established through observations of the symptoms and typical lesions of Postweaning Multisystemic Wasting Syndrome (PMWS), and was confirmed by immunohistochemical examination and PCR. The objective of this study was to characterize the epidemiological and clinical-pathological aspects of na outbreak of PMWS in Rio de Janeiro, because of its severe direct or indirect economical losses to the world pig industry.