Piscine orthoreovirus subtype 3 (PRV-3) causes heart inflammation in rainbow trout ( Oncorhynchus mykiss )

In this study, we conducted a 10-week long experimental infection trial in rainbow trout with purified PRV-3 particles to assess the causal relationship between the virus and development of heart inflammation. The monitoring the PRV-3 load in heart and spleen by RT-qPCR shows a progressive increase of viral RNA to a peak, followed by clearance without a measurable change in haematocrit. The development of characteristic cardiac histopathological findings occurred in the late phase of the trial and was associated with increased expression of CD8+, indicating cytotoxic T cell proliferation. The findings indicate that, under these experimental conditions, PRV-3 infection in rainbow trout act similarly to PRV-1 infection in Atlantic salmon with regards to immunological responses and development of heart pathology, but not in the ability to establish a persistent infection.
Source: Veterinary Research - Category: Veterinary Research Source Type: research