Efficacy of Calcium Hypochlorite as a Disinfectant against the Shrimp VirusBaculovirus penaei

Abstract Various concentrations and contact periods of total residual chlorine affected the infectivity of Baculovirus penaei (BP) to larval shrimp Penaeus vannamei in a bioassay. Test shrimp were sampled 46 and 96 h after exposure to calcium hypochlorite-treated BP and examined by light microscopy for patent infections. The virus was completely inactivated by chlorine concentrations of 200 mg/L when treated for 1 h and by 1,600 mg/L when treated for as short as 20 s. Other concentrations and periods of contact either reduced the prevalence of infection or extended the prepatency period, but they did not inactivate all virus.