Teschen disease outbreak in nursery piglets in Southwestern Brazil

This case report details an outbreak on a technified pig farm in the state of São Paulo, Brazil, occurred in June 2022, where nursery piglets presented neurological clinical signs. Three pigs were euthanized, followed by necropsy and sample collections for microbiological, histopathological, and molecular analysis. During the necropsy there were no evident macroscopic lesions, and the microbiological analysis was negative for two of the main causes of neurological signs in nursery piglets: meningoencephalitis caused by Streptococcus suis and Edema Disease caused by F18-STx2e enterotoxigenic Escherichia coli. However, the histopathological analysis indicated a viral etiology. After a comprehensive tissue sample molecular analysis, Porcine Teschovirus (PTV) was detected. The same samples were negative for Astrovirus, Enterovirus and Sapelovirus. These findings highlight the critical importance of collecting central nervous system tissues, particularly brain and spinal cord, in cases presenting compatible neurological clinical signs. In addition, the inclusion of complementary samples, such as cerebrospinal fluid and feces may further improve diagnostic sensitivity. Therefore, PTV should be considered in the differential diagnosis of neurological disease in nursery pigs, especially when clinical and histopathological findings are suggestive of viral infection. In this study, PTV was detected in the absence of co-infection with other picornaviruses commonly reported in similar cases.