Infection Prevention and Control/Surface Decontamination

Surface Disinfection for SARS-CoV-2

Ultraviolet Germicidal Irradiation

UV-C air disinfection was been explored extensively in the context of TB infection prevention and control by the South African scientific community in association with international experts. Protocols, guidelines and testing capacity for application of upper-room UVGI in airborne transmission has been somewhat established. This experience has provided important basic knowledge and key insights into the underpinning science and theory as well as application constraints, albeit for a different application. A short discussion and resources on UVGI for TB infection prevention and control is contained in Appendix A

Introduction

The coronavirus, SARSs-CoV-2, is understood to be transmitted primarily by contact and droplet spread. Covid-19 is highly contagious and spreads more rapidly than its predecessors Severe Acute Respiratory Syndrome (SARS-Cov-1) and Middle East Respiratory Syndrome (MERS), so any residual contamination can pose a public health threat. COVID-19 transmission remains controversial as researchers across the globe remain conflicted about droplet and airborne as modes of transmission. Clarifying the transmission routes and survival of viruses on frequently used surfaces is essential for containment of the outbreak. Research has successfully demonstrated that the virus has the potential to be aerosolised [2], and therefore can theoretically opportunistically through airborne transmit through the air, it is understood that, except in aerosolising procedures, risk of coronavirus transmission via the airborne route [3] is low. Similarly, risk via water and wastewater is low [4]. Persistence of the virus on a variety of surfaces has been demonstrated [2], underpinning concern that SARS-CoV-2 may be transmitted from infected (even asymptomatic) persons to others from touching common surfaces, even after the infector has departed for several hours [5, 6]. Efforts to contain the coronavirus, to stem the pandemic, should therefore primarily focus on contact and droplet transmission. Contact and droplet transmission is of concern in public transport situations, such as trains and mini-bus taxis which convey very large, transient populations in inevitably congested conditions. Transfer of Covid-19 suspected or confirmed patients in planned transport or emergency service vehicles pose a potential risk since studies show that conventional decontamination procedures may be incomplete [7]. In a pandemic, and under already constrained infrastructure, overcrowding and proximity of infectious and susceptible individuals will become inevitable in healthcare settings, intensifying risk of Covid-19 transmission in these settings. The risk of temporary stock-outs of essential personal protective equipment for infection prevention and control during the outbreak is high. In the South African context reduction of exposure to Covid-19 is a priority, in order to: • reduce and delay occupational exposure of frontline workers especially healthcare and transport services workers; • reduce exposure to public health risk, especially to the most vulnerable, such as PLHIV and persons with TB who are the principal users of public transport; • contribute to the strategy of “flattening the curve”; and

• preserve and protect the healthcare service so as to ensure continued service.