Abalone herpes virus stability in sea water and susceptibility to chemical disinfectants

Experimental infection models using immersion and injection challenges were developed to investigate the effects of various physicochemical treatments on the abalone herpes virus (AbHV), an emerging virus causing viral ganglioneuritis in abalone in Australia. To determine stability at different temperatures, the virus was held at 4, 15, or 25 °C for 1, 5, and 12 days prior to immersion challenge of naïve abalone. Mortality curves indicated that when held for 1 day in sea water at 4 °C and 15 °C the virus remained infectious and highly pathogenic. In addition, the virus retained partial infectivity after 5 days held at 4 °C. Histological examination of abalone tissues following viral exposure confirmed the presence of lesions typical of abalone viral ganglioneuritis in animals showing morbidity signs. An additional experiment was performed to determine the virucidal efficacy of three disinfectants (calcium hypochlorite, Buffodine and the non-ionic surfactant Impress). The disinfectants were used at various doses and durations to treat AbHV prior to injection and immersion challenges. Results showed that Buffodine and the non-ionic surfactant Impress were effective at inactivating the virus with no detectable adverse effects on the abalone's health. In addition, calcium hypochlorite showed a virucidal effect when used on lower titres of virus prior to immersion challenge.

► We evaluated the effect of physicochemical treatments on the stability of AbHV. ► Higher sea water temperatures reduce AbHV pathogenicity. ► Calcium hypochlorite, Buffodine and a non-ionic surfactant inactivate AbHV.