Viral replication occurs at both 15 °C and 28 °C in cell line derived from snakehead and carp, although the optimal temperature range for viral replication is between 28 °C and 31 °C. Stability SHRV has been demonstrated to become inactivated following treatment with acid (pH = 3), chloroform (50%), and heat (56 °C). SHRV in distilled water can be completely inactivated by less than five minutes of exposure to 12.5 ppm chlorine, 50 ppm iodine, or a 1:2000 dilution of peroxygen disinfectant. Exposure of infective virions in cell culture material to 2% formalin reduced infectivity by 99.9% after 5 minutes, and completely after 30 minutes. However, exposure of infectious cell culture material to 0.025% formalin for 60 minutes caused only a negligible reduction in infectivity, and more than 50 ppm chlorine was needed to inactivate the virus Also in cell culture fluids, exposure to 500 ppm iodine for 30 minutes did not reduce infectivity. The virus does not lose infectivity when exposed in cell culture fluids to malachite green for 6 hours at 5 ppm. Experimental Infections Snakehead Infections Infection studies with SHNV did not produce disease in exposed healthy snakehead murrels. Zebrafish Infections The first experimental infections conducted with SHRV in zebrafish demonstrated that the NV gene played no important role in the pathogenesis of infection. Subsequent experimental infections exposed zebrafish embryos, juveniles, and adults to SHRV by immersion and/or intraperitoneal (IP) injection. Whereas embryos and larvae were susceptible to infection by immersion, adult zebrafish were only susceptible to infection by IP injection. Histopathology of infected embryos and juvenile fish revealed vascular monocyte accumulation, accumulation of cellular debris in the gas bladder, necrosis of hepatocytes, and necrosis of pharyngeal epithelial cells. SHRV induced interferon (IFN) and orthomyxovirus resistance (Mx) gene expression in zebrafish at levels dependent on route of inoculation and fish age. References Fish viral diseases Novirhabdoviruses