Bioaerosol concentrations generated from toilet flushing in a hospital-based patient care setting

Abstract

BackgroundIn the United States, 1.7 million immunocompromised patients contract a healthcare-associated infection, annually. These infections increase morbidity, mortality and costs of care. A relatively unexplored route of transmission is the generation of bioaerosols during patient care. Transmission of pathogenic microorganisms may result from inhalation or surface contamination of bioaerosols. The toilet flushing of patient fecal waste may be a source of bioaerosols. To date, no study has investigated bioaerosol concentrations from flushing fecal wastes during patient care.MethodsParticle and bioaerosol concentrations were measured in hospital bathrooms across three sampling conditions; no waste no flush, no waste with flush, and fecal waste with flush. Particle and bioaerosol concentrations were measured with a particle counter bioaerosol sampler both before after a toilet flushing event at distances of 0.15, 0.5, and 1 m from the toilet for 5, 10, 15 min.ResultsParticle concentrations measured before and after the flush were found to be significantly different (0.3–10 μm). Bioaerosol concentrations when flushing fecal waste were found to be significantly greater than background concentrations (p-value = 0.005). However, the bioaerosol concentrations were not different across time (p-value = 0.977) or distance (p-value = 0.911) from the toilet, suggesting that aerosols generated may remain for longer than 30 min post flush. Toilets produce aerosol particles when flushed, with the majority of the particles being 0.3 μm in diameter. The particles aerosolized include microorganisms remaining from previous use or from fecal wastes. Differences in bioaerosol concentrations across conditions also suggest that toilet flushing is a source of bioaerosols that may result in transmission of pathogenic microorganisms.ConclusionsThis study is the first to quantify particles and bioaerosols produced from flushing a hospital toilet during routine patient care. Future studies are needed targeting pathogens associated with gastrointestinal illness and evaluating aerosol exposure reduction interventions.

Persistent viral shedding of SARS-CoV-2 in faeces - a rapid review

“…Similar patterns of virus isolation from stool and faeco-oral transmission were observed for other coronaviruses including SARS-CoV-1 [33]. Bio-aerosol generation of viral particles as a result of flushing of toilets as well as the impact of disinfection on these have also been studied before [34,35] along with the persistence of coronaviruses on surfaces [36]. A review performed by Tian et al summarised the evidence on the importance of identifying gastrointestinal symptoms in addition to the respiratory symptoms of COVID-19 based on data from China [37].…”

Persistent viral shedding of SARS‐CoV‐2 in faeces – a rapid review

“…Similar patterns of virus isolation from stool and faeco‐oral transmission were observed for other coronaviruses including SARS‐CoV‐1 [34]. Bio‐aerosol generation of viral particles as a result of toilet flushing, the impact of disinfection on this [35,36] and the persistence of coronaviruses on surfaces has been studied before [37]. Other indirect evidence of microbial exposure and contamination of the operator’s face during endoscopy [38] and laboratory evidence of SARS‐CoV‐2 infection of the gastrointestinal tract and mechanisms [39,40] add to the evidence for plausibility of transmission.…”

Current knowledge of COVID-19 and infection prevention and control strategies in healthcare settings: A global analysis

“…One study detected pathogenic microorganisms in air samples collected from hospital toilets, and the pathogen may remain viable in the air for at least 30 minutes after flushing suggest the possibility of fecal-droplet transmission. 93 Specific recommendations are needed regarding the prevention of fecal-oral or fecal-droplet transmission in hospital settings.…”