Evaluation of the virucidal efficacy of two chemical disinfectants against avian influenza virus A at different temperatures

Two commercial disinfectants (Venno FF super, Venno Vet 1 super) which were registered in the list of the German Veterinary Association (DVG) as suitable disinfectants against enveloped and non-enveloped viruses were tested for their efficacy against avian influenza A virus (IVA). The guidelines of the DVG served as methodical basis for own experiments. The experiments were performed in suspension tests without and with protein load (40% foetal calf serum (FCS)) and poplar wood carrier tests also loaded with FCS, at 20 degreesC and reaction times of 15 to 120 min. Additionally the tests were carried out at 10 an 4 degreesC and reaction times of 5 and 10 min. Both disinfectants tested exhibited significantly good basic effect against IVA, but showed losses of efficacy when organic load increased and temperature decreased. For short time disinfection (5 min) at 20 and 10 degreesC only disinfectant Venno Vet I super was efficient against IVA, while at 4 degreesC none of the both preparations inactivated the virus in that time. However, it could be demonstrated that they were not only suitable at 20 degreesC, but also 10 degreesC if they were used according to DVG recommendation (Venno FF super: 1% for 60 min, Venno Vet 1 super: 1% for 30 min). For achievement of safe inactivation of IVA at 4 degreesC the contact time should be extended up to 120 min for both disinfectants.