Viricidal activity of several disinfectants against African swine fever virus

Prevention of African swine fever, a disease caused by African swine fever virus (ASFV), requires maintenance of high biosecurity standards, which principally relies on disinfection. Finding the perfect disinfectant against ASFV is difficult because of the lack of relevant data. Therefore, we aimed to find the most effective disinfectant and to optimise its concentration as well as contact time to confirm the viricidal effect against ASFV in vitro. We evaluated the viricidal activity of three concentrations each of six common disinfectants against ASFV using immersion disinfection assay (IDA) and spray disinfection assay (SDA); the concentrations of these disinfectants at which complete viral inactivation occurred were almost same as the manufacturer-recommended concentrations, but the exposure times for viral inactivation are different. The following disinfectants (assay: concentration, exposure time) showed complete inactivation: iodine and acid mixed solution (IDA/SDA: 0.5%, 10 min); compound potassium peroxymonosulfate (IDA: 0.25%, 30 min; SDA: 0.25%, 60 min); citric acid (IDA: 0.25%, 60 min; SDA: 0.5%, 60 min); sodium dichloroisocyanurate (IDA: 0.125%, 60 min; SDA: 0.25%, 60 min); and glutaral ang deciquam (IDA/SDA: 0.2%, 60 min); and deciquam (IDA/SDA: 0.5%, 60 min). However, in the presence of organic material contamination, disinfectants did not show a marked inactivation effect. Therefore, disinfection procedures should be performed in two steps: thorough mechanical cleaning followed by application of disinfectant. In conclusion, all the tested disinfectants can inactivate ASFV; these can be used as alternative disinfectants to enhance biosecurity.