Piscine Orthoreovirus-1 (PRV-1) Has Been Present in Chilean Salmon Aquaculture since at Least 1994

Heart and skeletal muscle inflammation (HSMI) caused by Piscine orthoreovirus (PRV) was first described in farmed Atlantic salmon Chile 2011. However, as PRV induces long-lasting infections, it is not known when Chilean may have started to show positivity. This study aimed evaluate the presence/absence of PRV-1 formalin-fixed, paraffin-embedded heart tissues (FFPE) cultured during 1992 1999. The most frequent histopathological findings 42 FFPE blocks were mild focal cardiomyocyte degeneration (57.1%) a mononuclear inflammatory infiltrate (21.4%) ventricular stratum spongiosum heart. One samples analyzed RT-qPCR positive for (2.4%). All negative other viral bacterial pathogens that can induce similar histological changes Taken together, our results has been present Chile—as low-virulence genogroup—since at least 1994, 17 years before HSMI outbreak Finally, archaeovirology be valid alternative contribute understanding epidemiology diseases aquaculture.