First EN carrier test for virucidal efficacy testing published

In September 2014, the first phase 2/step 2 European standard prEN 16777 for virucidal efficacy testing of surface disinfectants on non-porous stainless steel discs was published. With adenovirus type 5 and murine norovirus (MNV) strain S99 as test viruses, the use-recommendations of surface disinfectants will strongly improve because there is a practice-like test method for virucidal efficacy evaluation available.To this day, the EN 14476 (phase 2, step 1) as quantitative suspension test with polio-, adeno- and norovirus serves as the basis for efficacy evaluation of surface disinfectants. The successful inactivation test according to EN 14476 allowed a virucidal claim of the product. But the extent of virus inactivation by chemical means often completely differs when testing in vitro (quantitative suspension test) and in vivo (carrier test). After introduction of the prEN 16777 a test simulating practical conditions is now available which will allow more realistic use-recommendations (virucidal claim) and which will be the basis together with EN 14476 for biocidal product registration in Europe.In this prEN, a test virus suspension together with a soil load (virus inoculum) is dried on a stainless steel disc before the disinfectant is added. After the chosen exposure time has been reached a recovery process is followed to determine residual viral infectivity on the carriers. Our lab is highly experienced in carrier tests and was significantly involved in the development of the method. In 2008, we already started to study the efficacy of various active ingredients of disinfectants against the murine norovirus as new surrogate of human norovirus in the carrier test (Magulski et al. 2009). Furthermore, we participated in the ring trials of DVV with the same topic (Rabenau et al. 2014) and in all European carrier ring trials with MNV and adenovirus type 5. In addition, the lab took part in the OECD ring trial with adenovirus testing PAA based formulations in 2008.