Toilets dominate environmental detection of SARS-CoV-2 virus in a hospital

Abstract

words)Main text (3372 words) AbstractBackground: Respiratory and faecal aerosols play a suspected role in transmitting the SARS-CoV-2 virus. We performed extensive environmental sampling in a dedicated hospital building for Covid-19 patients in both toilet and non-toilet environments, and analysed the associated environmental factors. Methods:We collected data of the Covid-19 patients. 107 surface samples, 46 air samples, two exhaled condensate samples, and two expired air samples were collected were collected within and beyond the four three-bed isolation rooms. We reviewed the environmental design of the building and the cleaning routines. We conducted field measurement of airflow and CO2 concentrations. Findings:The 107 surface samples comprised 37 from toilets, 34 from other surfaces in isolation rooms (ventilated at 30-60 L/s), and 36 from other surfaces outside isolation rooms in the hospital. Four of these samples were positive, namely two ward door-handles, one bathroom toilet-seat cover and one bathroom door-handle; and three were weakly positive, namely one bathroom toilet seat, one bathroom washbasin tap lever and one bathroom ceiling-exhaust louvre. One of the 46 air samples was weakly positive, and this was a corridor air sample. The two exhaled condensate samples and the two expired air samples were negative.Interpretation: The faecal-derived aerosols in patients' toilets contained most of the detected SARS-CoV-2 virus in the hospital, highlighting the importance of surface and hand hygiene for intervention.

Detection of SARS-CoV-2 within the healthcare environment: a multicentre study conducted during the first wave of the COVID-19 outbreak in England

“…This likely reflects the fact that sampling was carried out on different types of ward occupied by different types of patient requiring different types of care and/or treatment (Table 1). Overall, however, the results are similar to those of other studies 13,15,20 and suggest that, whilst SARS-CoV-2 can contaminate healthcare surfaces, widespread contamination is unlikely. 17 The bacterial load on the majority (89%) of surfaces sampled was < 2•5 cfu/cm 2 suggesting that in general and despite increased pressure on beds and workload, the routine cleaning performed by the nursing and domestic staff across all eight hospitals was effective.…”

“…9 In a rapidly evolving outbreak situation, there is a need to gain quick understanding of certain trends; in this case, the contamination of the healthcare environment. Despite its limitations, this multi-centre study supports the findings of others 13,15,[19][20] is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint…”

“…Patient mobility can contribute greatly to the spread of bacteria within a ward. 25 Similarly, SARS-CoV-2 RNA has been detected on patient-contact sites outside the immediate bed space 13,17 and, in the current study, outside of cohort bays; specifically, toilet door handles.…”

“…The copyright holder for this this version posted September 25, 2020. ; https://doi.org/10.1101/2020.09.24.20191411 doi: medRxiv preprint Several studies, utilising a range of air and surface sampling methods, have been carried out to determine the presence and prevalence of SARS-CoV-2 in the healthcare environment. [11][12][13][14][15][16][17][18][19][20][21] The detection of viral RNA in air samples differs with study with some reporting widespread airborne contamination 14, 18, 21 but many reporting low or non-detectable concentrations 13,15,16,19 even in samples collected 10 cm from the face of positive patients. 12 Surfaces frequently touched by staff and/or patients are often contaminated with bacterial pathogens.…”

Microbicidal actives with virucidal efficacy against SARS-CoV-2 and other beta- and alpha-coronaviruses: implications for future emerging coronaviruses and other enveloped viruses

“…The relatively high risk of the bathroom for deposition of SARS-CoV-2 from patients onto HITES was also highlighted in the study of Ding et al 81 In that study, frequency of sanitization of HITES was twice daily using a chlorine-releasing agent. Out of 107 surface samples and 46 air samples taken from a COVID-19 hospital ward, only seven surface samples (two door handles, one toilet seat, one toilet seat cover, one bathroom washbasin tap handle, one bathroom ceiling exhaust louver, and one bathroom door handle) and one air sample (a corridor air sample) were positive or weakly positive for SARS-CoV-2 RNA 81 .…”