Toilets dominate environmental detection of severe acute respiratory syndrome coronavirus 2 in a hospital

Abstract

Respiratory and fecal aerosols play confirmed and suspected roles, respectively, in transmitting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). An extensive environmental sampling campaign of both toilet and non-toilet environments was performed in a dedicated hospital building for patients with coronavirus disease 2019 (COVID-19), and the associated environmental factors were analyzed. In total, 107 surface samples, 46 air samples, two exhaled condensate samples, and two expired air samples were collected within and beyond four three-bed isolation rooms. The data of the COVID-19 patients were collected. The building environmental design and the cleaning routines were reviewed. Field measurements of airflow and CO 2 concentrations were conducted. The 107 surface samples comprised 37 from toilets, 34 from other surfaces in isolation rooms, and 36 from other surfaces outside the 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. Three were weakly positive, namely one bathroom toilet seat, one bathroom washbasin tap lever, and one bathroom ceiling exhaust louver. Of the 46 air samples, one collected from a corridor was weakly positive. The two exhaled condensate samples and the two expired air samples were negative. The fecal-derived aerosols in patients' toilets contained most of the detected SARS-CoV-2 in the hospital, highlighting the importance of surface and hand hygiene for intervention.

Detection of SARS-CoV-2 within the healthcare environment: a multi-centre 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 I) rather than differences in cleaning product or protocol. 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 J o u r n a l P r e -p r o o f workload, the routine cleaning performed by the nursing and domestic staff across all eight hospitals was effective.…”

“…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]…”

“…Similarly, SARS-CoV-2 RNA has been detected on patient-contact sites outside the immediate bed J o u r n a l P r e -p r o o f space [13,17] and, in the current study, outside of cohort bays; specifically, toilet door handles. The presence of SARS-CoV-2 RNA on door handles has been reported previously [13,14,20] and the contact area between the hand and handle and the pressure of grip likely facilitates transfer to and from the hands. In this study, the amount of SARS-CoV-2 RNA detected on one door handle was 2•2 x 10 5 genomic copies/swab implying significant transfer from a contaminated hand.…”

“…Reported positivity rates range from 0•8% to over 70% with those studies reporting a comparatively higher level of airborne contamination also detecting widespread surface contamination [18,21]. In many cases, sampling was performed before routine cleaning, but the efficacy of cleaning was not assessed [11,13,15]. When comparative samples were taken, SARS-CoV-2 RNA was detected on 61% of surfaces sampled prior to cleaning but was not detected on any surface after it had been cleaned [17].…”

SARS-CoV-2 and Health Care Worker Protection in Low-Risk Settings: a Review of Modes of Transmission and a Novel Airborne Model Involving Inhalable Particles

“…Endoscopic studies also found RNA in the esophagi, stomachs, duodena, and recta of patients with severe gastrointestinal symptoms (151). Finally, two studies showed the toilet was among the most contaminated areas in indoor settings (152,153): interestingly, the patient who's toilet air sample was positive had a negative exhaled breath sample, warranting the consideration that detectable airborne SARS-CoV-2 could originate from fecal rather than respiratory aerosols. As with air, a limited number of studies have been able to culture infectious viruses from stools (154,155), supporting infectivity.…”