Letter to the Editor on “An Imperative Need for Research on the Role of Environmental Factors in Transmission of Novel Coronavirus (COVID-19)”, Back to Basics

Abstract

The recent viewpoint article by Qu et al. entitled “An Imperative Need for Research on the Role of Environmental Factors in Transmission of Novel Coronavirus (COVID-19)” highlights an imperative need for research on SARS-CoV-2 in environmental sciences. 1 It is promising that advanced environmental science and technology will identify environmental factors modifying the infectivity of the virus, the severity of COVID-19, and help to control its environmental spread. Here we highlight research showing the importance of basic sanitations to control the spread of infectious diseases applicable to the prevention of COVID-19. SARS-CoV-2 in culture media is easily disinfected with 70% ethanol, 0.05% chlorhexidine, 2% hand soap, 1% bleach, etc. 2 Hence, good hand hygiene is likely to prevent COVID-19 transmission via contacts. Although there has not yet been an intervention study for COVID-19, a previous meta-analysis of the effects of hand hygiene in a community setting showed significant reductions in the spread of gastrointestinal illness of 31% and also in respiratory illness of 21%. 3 Hand hygiene costs using alcohol-based handrubs in intensive care units was estimated at USD 0.025 per application, compared to nosocomial infections resulting in far higher cost implications (e.g., USD 25,546 for a surgical site infection). 4 The aerosol transmission route for SARS-CoV-2 in aerosols 5 means effective ventilation, including both natural and mechanical ventilation, is an important, easy and basic way to reduce risk of transmission. For example, in a study of the common cold (around a quarter caused by ordinary coronaviruses), low ventilation rates in dormitories was shown to increase the risk of infections among students. 6 While exhaust-only mechanical ventilation has an associated cost (e.g., USD 64 annually for a 1780 ft2 home, including annualized cost of installation), 7 natural ventilation (opening windows and doors), provides a comparable efficient exchange of indoor air. 8 A case study of the nosocomial spread of SARS in a Vietnam hospital with 33 SARS patients during the 2003 SARS outbreak demonstrated the effectiveness of face masks, gloves, hand sanitizer, and cross-ventilation in the hospital in reducing cross-infection rates. 9 The cross-infection measures discussed are not state of the art, but remain underutilized in low- and middle-income countries. Although comparisons of the cost-effectiveness of basic versus advanced technologies are not yet available, COVID-19 cases in low- and middle-income countries are rapidly rising. We acknowledge the importance of these basic sanitations and engineering solutions for COVID-19, and encourage preparedness for future infectious diseases.