EFFECT OF CHEMICAL AND PHYSICAL TREATMENTS ON THE INACTIVATION OF STRIPED JACK NERVOUS NECROSIS VIRUS (SJNNV)

The effects of some chemical disinfectants, organic solvents, hydrogen ions, heat, ultraviolet (UV) irradiation and ozone on the inactivatio n of striped jack nervous necrosis virus (SJNNV) were investigated. SJ NNV was inactivated by contact with a final concentration of 50 ppm of sodium hypochlorite, calcium hypochlorite, benzalkonium chloride and iodine for 10 min at 20 degrees C. Cresol concentrations of more than 10000 ppm were required to inactivate SJNNV, and no inactivation of SJ NNV by formalin was detected at any concentration tested. The effectiv e concentrations of ethanol and methanol were 60% and 50%, respectivel y, but SJNNV was resistant to ether and chloroform. SJNNV was inactiva ted by high alkalinity, pH 12 for 10 min at 20 degrees C, and also ina ctivated by heat treatment at 60 degrees C for 30 min. Inactivation of SJNNV by UV irradiation was observed at an intensity of 410 mu W cm(- 2) for 244 s. Ozone at 0.1 0.1 mu g ml(-1) as a total residual oxidant was required to inactivate SJNNV for 2.5 min. Washing fertilized eggs and the treatment of sea water with ozone decreased the rate of occur rence of VNN.