Role of interfering substances in the survival of coronaviruses on surfaces and their impact on the efficiency of hand and surface disinfection

Contaminated environmental surfaces are considered to represent a significant vector for hospital-acquired viral infections. In this study, we have evaluated the impact of interfering substances on SARS-CoV-2 surface stability and virucidal efficiency of hand sanitizers and surface disinfectant. To this end, surface stability of SARS-CoV-2 was measured on stainless steel in different experimental conditions, with or without an artificial mucus/saliva mixture and compared against that of human coronavirus HCoV-229E and feline coronavirus FCoV. The impact of the mucus/saliva mixture on the virucidal efficiency of 3 commercial alcohol hand sanitizers and 1 surface chemical disinfectant against SARS-CoV-2, HCoV-229E and FCoV was then measured. Our results indicate that mucus/saliva mixture did not demonstrate a beneficial effect on the surface survival of tested viruses, with temperature being an important parameter. In addition, we demonstrated that interfering substances may play an important role in the virucidal efficacy of hand sanitizers and disinfectants, highlighting the need for adapted testing protocols that better reflect current “real life” conditions of use. Highlights ### Competing Interest Statement LS, LD, DB, YM and VM are employees of VirHealth SAS. Other authors declare no conflict of interest. ### Funding Statement LZ is the holder of a CIFRE PhD thesis grant from the Agence Nationale de Recherche Technologique (ANRT). This study was funded by INSERM REACTing (REsearch & ACtion emergING infectious diseases), CNRS, and Merieux research grants. The sponsors had no role in study design, collection, analysis and interpretation of data, manuscript writing, or in the decision to submit the article for publication. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Research that does not necessitate IRB and/or Ethics committee All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes The data associated with this manuscript are available on request. * RH : relative humidity