[Paper Review] Fomite transmission and disinfection strategies for SARS-CoV-2 and related viruses

Nuria Devesa Castaño, Seth C. Cordts+6 more|arXiv (Cornell University)|May 23, 2020

Infection Control and Ventilation197 references17 citations

TL;DR

This review synthesizes current knowledge on fomite transmission of SARS-CoV-2 and related viruses, emphasizing physicochemical mechanisms of viral adsorption, transfer, and inactivation on surfaces. It evaluates disinfection strategies, identifies key knowledge gaps, and provides a framework for developing effective surface hygiene interventions to reduce transmission risk.

ABSTRACT

Contaminated objects or surfaces, referred to as fomites, play a critical role in the spread of viruses, including SARS-CoV-2, the virus responsible for the COVID-19 pandemic. The long persistence of viruses (hours to days) on surfaces calls for an urgent need for surface disinfection strategies to intercept virus transmission and the spread of the disease. Elucidating the physicochemical processes and surface science underlying the adsorption and transfer of virus between surfaces, as well as their inactivation, are important in understanding how the disease is transmitted, and in developing effective interception strategies. This review aims to summarize the current knowledge and underlying physicochemical processes of virus transmission, in particular via fomites, and common disinfection approaches. Gaps in knowledge and needs for further research are also identified. The review focuses on SARS-CoV-2, but will supplement the discussions with related viruses.

Motivation & Objective

• To understand the role of fomites in the environmental transmission of SARS-CoV-2 and related viruses.
• To analyze the physicochemical processes governing viral adsorption, stability, and transfer between surfaces.
• To evaluate the efficacy of common disinfection strategies in inactivating SARS-CoV-2 on fomites.
• To identify critical knowledge gaps in surface virology and disinfection science for future research.
• To provide a science-based framework for optimizing surface disinfection protocols during viral outbreaks.

Proposed method

• Systematic review of existing experimental studies on viral persistence on various surfaces under different environmental conditions.
• Analysis of surface science principles, including surface energy, zeta potential, and hydrophobicity, affecting viral adhesion and desorption.
• Evaluation of disinfection mechanisms using chemical agents (e.g., alcohol, quaternary ammonium compounds) and physical methods (e.g., UV light).
• Comparison of inactivation kinetics across SARS-CoV-2 and related coronaviruses using data from in vitro studies.
• Integration of virological, physicochemical, and engineering data to model transmission risk via fomites.
• Use of quantitative models to assess the impact of disinfection frequency and contact duration on transmission reduction.

Experimental results

Research questions

• RQ1 How long can SARS-CoV-2 remain infectious on different types of surfaces under typical environmental conditions?
• RQ2 What physicochemical factors govern the adsorption and transfer of SARS-CoV-2 from contaminated surfaces to hands or mucosal surfaces?
• RQ3 How effective are common disinfectants in inactivating SARS-CoV-2 on fomites, and what are the critical parameters influencing their efficacy?
• RQ4 How do environmental factors such as temperature, humidity, and surface material affect viral stability and transmission risk?
• RQ5 What are the key knowledge gaps in fomite transmission and disinfection that require further experimental and modeling research?

Key findings

• SARS-CoV-2 can remain viable on non-porous surfaces such as stainless steel and plastic for up to 72 hours under controlled laboratory conditions.
• Viral transfer efficiency from surfaces to hands or other surfaces is significantly influenced by surface energy, hydrophobicity, and contact time.
• Alcohol-based disinfectants (e.g., 60–70% ethanol) achieve rapid inactivation of SARS-CoV-2 within seconds, with >99.9% reduction in viral titer.
• Quaternary ammonium compounds show moderate efficacy but require longer contact times and are less effective on organic soil or high humidity.
• UV-C light exposure (254 nm) can inactivate SARS-CoV-2 on surfaces within minutes, but effectiveness depends on intensity, exposure duration, and shadowing effects.
• The review identifies a lack of standardized protocols for measuring fomite transmission and disinfection efficacy, highlighting the need for harmonized testing methods.