Outbreak of Porcine Reproductive and Respiratory Syndrome in Gumma Prefecture in 1987

Abstract

In two farms in the same district of Gumma Prefecture, stillbirth, hard labors, and parturition of weak piglets in sow, as well as diarrhea, loss of vigor, and death within 1 week of age in piglets massively occured in 1987. The piglet mortality was over 30%. Histopathology revealed myocarditis, interstitial pneumonia and perivascular cuffing in the brain. Immunohistochemistry showed PRRS viral antigen in the lungs.