Transmission of COVID-19 and other infectious diseases in public washrooms: A systematic review

Sotiris Vardoulakis; Daniela A Espinoza Oyarce; Erica Donner

doi:10.1016/j.scitotenv.2021.149932

Transmission of COVID-19 and other infectious diseases in public washrooms: A systematic review

Sci Total Environ. 2022 Jan 10:803:149932. doi: 10.1016/j.scitotenv.2021.149932. Epub 2021 Aug 27.

Authors

Sotiris Vardoulakis¹, Daniela A Espinoza Oyarce², Erica Donner³

Affiliations

¹ National Centre for Epidemiology and Population Health, Research School of Population Health, Australian National University, Canberra, ACT 2601, Australia. Electronic address: sotiris.vardoulakis@anu.edu.au.
² National Centre for Epidemiology and Population Health, Research School of Population Health, Australian National University, Canberra, ACT 2601, Australia.
³ Future Industries Institute, University of South Australia, Mawson Lakes, SA 5095, Australia.

Abstract

Background: The risk of infectious disease transmission in public washrooms causes concern particularly in the context of the COVID-19 pandemic. This systematic review aims to assess the risk of transmission of viral or bacterial infections through inhalation, surface contact, and faecal-oral routes in public washrooms in healthcare and non-healthcare environments.

Methods: We systematically reviewed environmental sampling, laboratory, and epidemiological studies on viral and bacterial infection transmission in washrooms using PubMed and Scopus. The review focused on indoor, publicly accessible washrooms.

Results: Thirty-eight studies from 13 countries were identified, including 14 studies carried out in healthcare settings, 10 in laboratories or experimental chambers, and 14 studies in restaurants, workplaces, commercial and academic environments. Thirty-three studies involved surface sampling, 15 air sampling, 8 water sampling, and 5 studies were risk assessments or outbreak investigations. Infectious disease transmission was studied in relation with: (a) toilets with flushing mechanisms; (b) hand drying systems; and (c) water taps, sinks and drains. A wide range of enteric, skin and soil bacteria and enteric and respiratory viruses were identified in public washrooms, potentially posing a risk of infection transmission. Studies on COVID-19 transmission only examined washroom contamination in healthcare settings.

Conclusion: Open-lid toilet flushing, ineffective handwashing or hand drying, substandard or infrequent surface cleaning, blocked drains, and uncovered rubbish bins can result in widespread bacterial and/or viral contamination in washrooms. However, only a few cases of infectious diseases mostly related to faecal-oral transmission originating from washrooms in restaurants were reported. Although there is a risk of microbial aerosolisation from toilet flushing and the use of hand drying systems, we found no evidence of airborne transmission of enteric or respiratory pathogens, including COVID-19, in public washrooms. Appropriate hand hygiene, surface cleaning and disinfection, and washroom maintenance and ventilation are likely to minimise the risk of infectious disease transmission.

Keywords: Aerosol; Bacterial and viral contamination; Environmental exposure; Hand drying; Public toilet; SARS-CoV-2.

Publication types

Review
Systematic Review

MeSH terms

COVID-19*
Communicable Diseases*
Humans
Pandemics
SARS-CoV-2
Toilet Facilities