Evaluation and declaration of effectiveness of disinfectants against viruses. Position of the Virucide Study Group of the Robert Koch Institute (RKI) and the "Virus Disinfection" Professional Committee of the German Society for Control of "Virus Infections" and the Disinfectant Committee of the German Society of Public Health and Microbiology - Robert Koch-Institut, Deutsche Gesellschaft zur Bekämpfung der Viruskrankheiten, Desinfektionsmittelkommission der Deutschen Gesellschaft für Hygiene und Mikrobiologie (Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz, 2004)