key: cord-0858479-6sjmbtfh
authors: Jones, J.P.; Norton, K.
title: 222-nm ultraviolet light inactivates dried inocula of human rhinovirus and human coronavirus on a glass carrier
date: 2021-08-14
journal: J Hosp Infect
DOI: 10.1016/j.jhin.2021.08.003
sha: 793728d46d90d8de758bc227f96e73cca51e396c
doc_id: 858479
cord_uid: 6sjmbtfh

nan

Narita et al. demonstrated strong germicidal effects of 254-nm and 222-nm ultraviolet C (UVC) light against various suspensions of pathogenic bacteria, yeasts, an enveloped virus (influenza A), and a non-enveloped virus (feline calcivirus, a surrogate of the human norovirus) [1] . UVC light strongly inactivated influenza A, but inactivation was less pronounced on the nonenveloped or naked FCV. Dried inocula of other naked viruses have been shown to be infectious for weeks compared to the dried inocula of enveloped viruses influenza A and herpes simplex type 1, which were infectious for fewer than five days [2] . This study explored the germicidal impact of different amounts of far-UVC irradiation (222-nm) against dried inocula of a naked human rhinovirus (HRV) type 37 and an enveloped human coronavirus (HCoV) 229E on a glass carrier. (Table 1) . Dosages were measured using the ILT2400 radiometer (International Light Technologies, Peabody, MA, USA). Following exposure, test carriers were resuspended, serial 10-fold dilutions made, and dilutions assayed for infectivity (TCID 50 ). Control carriers were exposed to ambient air for same amounts of time as treated carriers. A test-substance cytotoxicity control was run concurrently and exposed to ambient air for 243 seconds. Infectivity of controls was determined using the same method as test carriers.

Dried inocula of HRV and HCoV on glass carriers were increasingly inactivated in response to greater dosages of 222-nm UVC light (Table 1) ; however, the naked HRV may be more stable at low dosages (i.e., 0.9 mJ/cm 2 ). HRV accounts for 50-66% of common colds, and HCoV is the second leading cause of this illness [3, 4] , resulting in billions of indirect and direct costs each year [5] . Paradoxically, the common cold may protect persons from contracting Sars-CoV-2 [6] and the influenza virus [7] through viral competition. Although excimer far-UVC lamps that emit 222-nm light are now commercially available and can be a powerful prophylactic against HRV and HCoV, additional research is needed to optimize the use of 222-nm UVC light for best health outcomes. 

Ultraviolet C light with wavelength of 222 nm inactivates a wide spectrum of microbial pathogens

Survival of Enveloped and Non-Enveloped Viruses on Inanimate Surfaces, Microbes Environ

Frequency and natural history of rhinovirus infections in adults during autumn

Viruses and Bacteria in the Etiology of the Common Cold

The Economic Burden of Non-Influenza-Related Viral Respiratory Tract Infection in the United States

Prior presumed coronavirus infection reduces COVID-19 risk: A cohort study

Do rhinoviruses reduce the probability of viral co-detection during acute respiratory tract infections?

The authors recognize Matthew Sathe, B.S., Principal Microbiologist, Thomas Breyen, B.S., Virologist, and their teams at Element Materials Technology Minneapolis-Eagan Inc. (Eagan, MN, USA) for implementing the protocol, analyzing data, and writing the methods. The authors also recognize Jessica Knight for editing and manuscript preparation support.

None declared.

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.