Inactivation of infectious salmon anaemia virus, viral haemorrhagic septicaemia virus and infectious pancreatic necrosis virus in water using UVC irradiation

Abstract

The UVC irradiation doses necessary for a 99.9% (3-log) inactivation of 3 different fish pathogenic viruses diluted in freshwater/seawater and wastewater from a fish processing plant were determined. The results showed that both infectious salmon anaemia virus (ISAV) and viral haemorrhagic septicaemia virus (VHSV) were very sensitive to UVC irradiation, showing a 3-log reduction of infectivity in freshwater of 33 ± 3.5 and 7.9 ± 1.5 J m-2, respectively, while that of infectious pancreatic necrosis virus (IPNV) was substantially higher, 1188 ± 57 J m-2. Using ISAV as a model, a comparison of the effect of UVC irradiation on virus isolation versus reverse transcription polymerase chain reaction (RT-PCR) showed that considerably higher UVC doses, depending on the length of the amplified product, were necessary to abolish RT-PCR detection of viral RNA.