A standardized procedure for quantitative evaluation of residual viral activity on antiviral treated textiles

Abstract

The SARS-CoV-2 pandemic has increased the demand for antiviral technologies to mitigate or prevent the risk of viral transmission. Antiviral treated textiles have the potential to save lives, especially in healthcare settings that rely on reusable patient-care textiles and personal protective equipment. Currently, little is known about the role of textiles in cross-contamination and pathogen transmission, despite the wealth of information on hard surfaces and fomites harboring viruses that remain viable in certain circumstances. In addition, there is no international standard method for evaluating residual viral activity on textiles, which would allow a thorough investigation of the efficacy of antiviral textile products. Therefore, this pilot study aims to develop and refine a standardized protocol to quantitatively evaluate residual viral activity on antiviral textiles. Specifically, we focused on general textiles, such as bed linens, commonly used in healthcare settings for patient care. The Tissue Culture Infectious Dose 50 (TCID50) method is frequently used to quantitatively evaluate viral infectivity on textiles, but has not been established as a standard. This procedure involves observing the cytopathic effect of a given virus on cells grown in a 96-well plate after several days of incubation to determine the infectivity titer. We used HCoV-229E and Huh-7 human liver cancer cells for this investigation. We worked to improve the TCID50 method through variations of different steps within the protocol to attain reproducible results. Our proposed optimized hybrid protocol has shown evidence that the protocol is technically simpler and more efficient, and provides successful, consistent results. The analysis showed a significant difference between the treated fabric compared with controls.