Virus susceptibility to biocides: an understanding

Abstract

The term ‘biocide’ is widely used to denote a chemical agent that possesses antiseptic, disinfectant or preservative activity. Viruses are not the most resistant microorganisms to biocides and it is generally accepted that the presence or absence of a lipid envelope and virus size play a important role in their sensitivity to these agents. Overall, the viricidal activity of biocides is generally less well documented than their bactericidal, sporicidal or fungicidal efficacy. Furthermore, the lack of a standard testing protocol, the complexity of studying virus survival after disinfection and the range of viral models and markers used, make the analysis of information difficult. Consequently, information obtained with other microorganisms such as bacteria, spores and yeast are often used as the basis of explaining the viricidal activity of biocides. From the comparatively few studies undertaken on the mechanisms of action of viricides, it has emerged that although most act by altering viral capsid structure, few damage viral nucleic acid. In addition, the alteration of viral markers, such as antigenic structure and DNA polymerase, as well as structural damage to the capsid do not always reflect loss of viral infectivity. As for viral resistance to disinfection, only a few mechanisms have been identified; the formation of viral aggregates being probably the most important. Yet, the clinical relevance of viral resistance to biocides remains to be determined.