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Paddy EN, Afolabi OOD, Sohail M. Exploring toilet plume bioaerosol exposure dynamics in public toilets using a Design of Experiments approach. Sci Rep 2024; 14:10665. [PMID: 38724540 PMCID: PMC11082142 DOI: 10.1038/s41598-024-61039-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Accepted: 04/30/2024] [Indexed: 05/12/2024] Open
Abstract
Bioaerosols generated during toilet flushing can contribute to the spread of airborne pathogens and cross-contamination in indoor environments. This presents an increased risk of fomite-mediated or aerosol disease transmission. This study systematically investigated the factors contributing to increased bioaerosol exposure following toilet flushing and developed an empirical model for predicting the exposure-relevant bioaerosol concentration. Air in a toilet cubicle was sampled by impaction after seeding with Clostridium difficile spores. Design of Experiments (DoE) main effects screening and full factorial design approaches were then employed to investigate the significant factors that heighten the risk of exposure to bioaerosols post-flush. Our findings reveal that the inoculated bacterial concentration (C), time elapsed after flushing (t), lateral distance (d), and mechanical ventilation (v) are significant predictors of bioaerosol concentration, with p-values < 0.05. The interaction term, C × d showed a marked increase in bioaerosol concentration up to 232 CFU/m3 at the closest proximity and highest pathogen load. The interplay of C and t (C × t) demonstrated a time-dependent attenuation of bioaerosol viability, with concentrations peaking at 241 CFU/m3 immediately post-flush and notably diminishing over time. The lateral distance and time post-flush (d × t) interaction also revealed a gradual decrease in bioaerosol concentration, highlighting the effectiveness of spatial and temporal dilution in mitigating bioaerosol exposure risks. Furthermore, there is an immediate rise in relative humidity levels post-flush, impacting the air quality in the toilet environment. This study not only advances our understanding of exposure pathways in determining bioaerosol exposure, but also offers pivotal insights for designing targeted interventions to reduce bioaerosol exposure. Recommendations include designing public toilets with antimicrobial surfaces, optimizing ventilation, and initiating timely disinfection protocols to prioritise surfaces closest to the toilet bowl during peak exposure periods, thereby promoting healthier indoor environments and safeguarding public health in high-traffic toilet settings.
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Affiliation(s)
- Elizabeth N Paddy
- School of Architecture, Building and Civil Engineering, Loughborough University, Loughborough, Leicestershire, UK.
| | - Oluwasola O D Afolabi
- School of Architecture, Building and Civil Engineering, Loughborough University, Loughborough, Leicestershire, UK
| | - M Sohail
- School of Architecture, Building and Civil Engineering, Loughborough University, Loughborough, Leicestershire, UK
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2
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Eisenberg S, Walton A, Connor TH. The Occupational and Environmental Hazards of Uncovered Toilets. Am J Nurs 2024; 124:55-60. [PMID: 38511713 DOI: 10.1097/01.naj.0001010592.45177.43] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/22/2024]
Abstract
ABSTRACT Substantial evidence demonstrates that plumes from uncovered toilets potentially expose nurses and other health care workers to aerosols containing infectious agents and hazardous drugs, including antineoplastic drugs. Most hospitals in the United States utilize flushometer-type toilets, which operate under high pressure and do not have a permanently attached closure or lid, which is known to reduce the aerosols generated by flushing. This article aims to raise awareness among nurses of the potential exposure risks associated with toilet plume aerosols, so they can educate other health care workers and take part in initiatives to address these risks.
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Affiliation(s)
- Seth Eisenberg
- Seth Eisenberg is an oncology nursing consultant and the former professional practice coordinator of infusion services at the Fred Hutchinson Cancer Center, Seattle. AnnMarie Walton is an associate professor at the Duke University School of Nursing, Durham, NC. Thomas Harry Connor is a retired hazardous drug researcher for the National Institute for Occupational Safety and Health and a former associate professor at the University of Texas Health Science Center at Houston. Contact author: Thomas Harry Connor, . The authors have disclosed no potential conflicts of interest, financial or otherwise
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Abney SE, Higham CA, Wilson AM, Ijaz MK, McKinney J, Reynolds KA, Gerba CP. Transmission of Viruses from Restroom Use: A Quantitative Microbial Risk Assessment. FOOD AND ENVIRONMENTAL VIROLOGY 2024; 16:65-78. [PMID: 38372960 DOI: 10.1007/s12560-023-09580-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 12/30/2023] [Indexed: 02/20/2024]
Abstract
Restroom use has been implicated in a number of viral outbreaks. In this study, we apply quantitative microbial risk assessment to quantify the risk of viral transmission by contaminated restroom fomites. We estimate risk from high-touch fomite surfaces (entrance/exit door, toilet seat) for three viruses of interest (SARS-CoV-2, adenovirus, norovirus) through eight exposure scenarios involving differing user behaviors, and the use of hand sanitizer following each scenario. We assessed the impacts of several sequences of fomite contacts in the restroom, reflecting the variability of human behavior, on infection risks for these viruses. Touching of the toilet seat was assumed to model adjustment of the seat (open vs. closed), a common touch point in single-user restrooms (home, small business, hospital). A Monte Carlo simulation was conducted for each exposure scenario (10,000 simulations each). Norovirus resulted in the highest probability of infection for all exposure scenarios with fomite surfaces. Post-restroom automatic-dispensing hand sanitizer use reduced the probability of infection for each virus by up to 99.75%. Handwashing within the restroom, an important risk-reduction intervention, was not found to be as effective as use of a non-touch hand sanitizer dispenser for reducing risk to near or below 1/1,000,000, a commonly used risk threshold for comparison.
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Affiliation(s)
- Sarah E Abney
- Department of Environmental Science, University of Arizona, Tucson, AZ, USA
| | - Ciara A Higham
- EPSRC Centre for Doctoral Training in Fluid Dynamics, University of Leeds, Leeds, UK
| | - Amanda M Wilson
- Department of Community, Environment, & Policy, Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ, USA
| | - M Khalid Ijaz
- Global Research & Development for Lysol and Dettol, Reckitt Benckiser LLC, Montvale, NJ, USA
| | - Julie McKinney
- Global Research & Development for Lysol and Dettol, Reckitt Benckiser LLC, Montvale, NJ, USA
| | - Kelly A Reynolds
- Department of Environmental Science, University of Arizona, Tucson, AZ, USA
- Department of Community, Environment, & Policy, Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ, USA
| | - Charles P Gerba
- Department of Environmental Science, University of Arizona, Tucson, AZ, USA.
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Tan M, Tian Y, Zhang D, Wang Q, Gao Z. Aerosol Transmission of Norovirus. Viruses 2024; 16:151. [PMID: 38275961 PMCID: PMC10818780 DOI: 10.3390/v16010151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 01/16/2024] [Accepted: 01/18/2024] [Indexed: 01/27/2024] Open
Abstract
Norovirus (NoV) is a major cause of acute gastroenteritis outbreaks worldwide. A comprehensive understanding of the transmission mode is of great significance for the prevention and control of the NoV infection. Currently, the transmission modes of NoV include contact, food-borne, water-borne and aerosol transmission. The first three modes are more common, while aerosol transmission is seldom reported. In this paper, the source, generation mechanism, infectivity, sampling and related outbreaks of NoV aerosol are summarized and discussed.
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Affiliation(s)
- Mengdi Tan
- School of Public Health, China Medical University, Shenyang 110122, China
| | - Yi Tian
- Institute for the Control of Infectious and Endemic Diseases, Beijing Center for Disease Prevention and Control, Beijing 100013, China
| | - Daitao Zhang
- Institute for the Control of Infectious and Endemic Diseases, Beijing Center for Disease Prevention and Control, Beijing 100013, China
| | - Quanyi Wang
- Institute for the Control of Infectious and Endemic Diseases, Beijing Center for Disease Prevention and Control, Beijing 100013, China
| | - Zhiyong Gao
- School of Public Health, China Medical University, Shenyang 110122, China
- Institute for the Control of Infectious and Endemic Diseases, Beijing Center for Disease Prevention and Control, Beijing 100013, China
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Valzano F, Coda ARD, Marangi M, La Bella G, Liso A, Arena F. Activity of a foam in preventing rebound of vancomycin-resistant Enterococcus faecium-containing droplets generated from the toilet bowl. Arch Microbiol 2024; 206:57. [PMID: 38189992 PMCID: PMC10774183 DOI: 10.1007/s00203-023-03775-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 11/10/2023] [Accepted: 11/27/2023] [Indexed: 01/09/2024]
Abstract
In hospital environments, droplets generated by urination within shared toilets may represent a route of dissemination for bacteria such as vancomycin-resistant Enterococcus faecium (VREfm), which contributes significantly to the burden of hospital-acquired infections. We investigated the potential activity of a foam in preventing the generation of droplets containing Enterococcus spp. during urination. A uniform layer of foam was deposited in the inner walls and at the bottom of an experimental toilet contaminated with suspensions of Enterococcus strains (including a VREfm strain). Human urination was simulated, and colonies of Enterococcus were recovered through a toilet lid where agar plates had been placed. Results showed that the foam was able to suppress production of droplets containing Enterococcus spp. generated by a liquid hitting inner toilet walls. Conversely, Enterococcus colonies were recovered in absence of foam. Moreover, the foam did not show antibacterial activity. We propose a new non-antimicrobial approach aimed at limiting transmission of multidrug-resistant bacteria, particularly in healthcare settings.
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Affiliation(s)
- Felice Valzano
- Department of Clinical and Experimental Medicine, University of Foggia, Via Napoli 20, 71122, Foggia, Italy
| | - Anna Rita Daniela Coda
- Department of Medical and Surgical Sciences, University of Foggia, Via Napoli 20, 71122, Foggia, Italy
| | - Marianna Marangi
- Department of Clinical and Experimental Medicine, University of Foggia, Via Napoli 20, 71122, Foggia, Italy
| | - Gianfranco La Bella
- Department of Clinical and Experimental Medicine, University of Foggia, Via Napoli 20, 71122, Foggia, Italy
- Istituto Zooprofilattico Sperimentale Della Puglia E Della Basilicata, Via Manfredonia 20, 71121, Foggia, Italy
| | - Arcangelo Liso
- Department of Medical and Surgical Sciences, University of Foggia, Via Napoli 20, 71122, Foggia, Italy
| | - Fabio Arena
- Department of Clinical and Experimental Medicine, University of Foggia, Via Napoli 20, 71122, Foggia, Italy.
- IRCCS Don Carlo Gnocchi Foundation, Via Di Scandicci 269, 50143, Florence, Italy.
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Goforth MP, Boone SA, Clark J, Valenzuela PB, McKinney J, Ijaz MK, Gerba CP. Impacts of lid closure during toilet flushing and of toilet bowl cleaning on viral contamination of surfaces in United States restrooms. Am J Infect Control 2023; 52:S0196-6553(23)00820-9. [PMID: 38276944 DOI: 10.1016/j.ajic.2023.11.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 11/25/2023] [Accepted: 11/27/2023] [Indexed: 01/27/2024]
Abstract
BACKGROUND Viral aerosols generated during toilet flushing represent a potential route of pathogen transmission. The goal of this study was to determine the impact of toilet lid closure prior to flushing on the generation of viral aerosols and cross-contamination of restroom fomites. METHODS A surrogate for human enteric viruses (bacteriophage MS2) was added to household and public toilet bowls and flushed. The resulting viral contamination of the toilet and other restroom surfaces was then determined. RESULTS After flushing the inoculated toilets, toilet seat bottoms averaged >107 PFU/100 cm2. Viral contamination of restroom surfaces did not depend on toilet lid position (up or down). After toilet bowls were cleaned using a bowl brush with or without a commercial product (hydrochloric acid), a >4 log10 (>99.99%) reduction in contamination of the toilet bowl water was observed versus no product. Bowl brush contamination was reduced by 1.6 log10 (97.64%) when the product was used versus no product. CONCLUSIONS These results demonstrate that closing the toilet lid prior to flushing does not mitigate the risk of contaminating bathroom surfaces and that disinfection of all restroom surfaces (ie, toilet rim, floors) may be necessary after flushing or after toilet brush used for the reduction of virus cross-contamination.
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Affiliation(s)
- Madison P Goforth
- Department of Environmental Science, University of Arizona, Tucson, AZ
| | - Stephanie A Boone
- Department of Environmental Science, University of Arizona, Tucson, AZ.
| | - Justin Clark
- Department of Environmental Science, University of Arizona, Tucson, AZ
| | | | - Julie McKinney
- Global Research and Development for Lysol and Dettol, Reckitt Benckiser LLC, Montvale, NJ
| | - M Khalid Ijaz
- Global Research and Development for Lysol and Dettol, Reckitt Benckiser LLC, Montvale, NJ
| | - Charles P Gerba
- Department of Environmental Science, University of Arizona, Tucson, AZ
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Paddy EN, Afolabi OOD, Sohail M. Toilet plume bioaerosols in health care and hospitality settings: A systematic review. Am J Infect Control 2023; 51:324-333. [PMID: 35870658 DOI: 10.1016/j.ajic.2022.07.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 07/07/2022] [Accepted: 07/08/2022] [Indexed: 11/30/2022]
Abstract
BACKGROUND The spread of some respiratory and gastro-intestinal infections has been linked to the exposure to infectious bioaerosols released after toilet flushing. This represents a health hazard and infection risk for immunocompromised patients, health workers and the public, particularly within the health care and hospitality settings. This systematic review provides current knowledge and identifies gaps in the evidence regarding toilet plume bioaerosols and the potential contributory role in spreading infections in health care and hospitality settings. METHODS The PRISMA guidelines were used. Searches were run in PubMed, Scopus, and Google Scholar from 1950 to 30th June 2021. Searches of global and regional reports and updates from relevant international and governmental organizations were also conducted. RESULTS AND CONCLUSION The search yielded 712 results, and 37 studies were finally selected for this review. There is a lack of national and international bioaerosol sampling and exposure standards for health care and hospitality settings. Toilet plume bioaerosols are complex in nature, thus, measured bioaerosol concentrations in these settings depend on many variables and may differ for every pathogen responsible for a particular infectious disease. The contact and airborne transmission risks posed by toilet plume bioaerosols also remain unquantified. They are an important pathway that can increase the exposure to enteric and airborne pathogens. Hence, quantitative risk assessment and related research are needed to investigate these transmission risks.
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Affiliation(s)
- Elizabeth N Paddy
- School of Architecture, Building and Civil Engineering, Loughborough University, Loughborough, Leicestershire, United Kingdom.
| | - Oluwasola O D Afolabi
- School of Architecture, Building and Civil Engineering, Loughborough University, Loughborough, Leicestershire, United Kingdom
| | - M Sohail
- School of Architecture, Building and Civil Engineering, Loughborough University, Loughborough, Leicestershire, United Kingdom
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Chadwick PR, Trainor E, Marsden GL, Mills S, Chadwick C, O'Brien SJ, Evans CM, Mullender C, Strazds P, Turner S, Weston V, Toleman MS, de Barros C, Kontkowski G, Bak A. Guidelines for the management of norovirus outbreaks in acute and community health and social care settings. J Hosp Infect 2023:S0195-6701(23)00043-9. [PMID: 36796728 DOI: 10.1016/j.jhin.2023.01.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 01/19/2023] [Accepted: 01/22/2023] [Indexed: 02/17/2023]
Affiliation(s)
| | - Eamonn Trainor
- Northern Care Alliance NHS Foundation Trust, Greater Manchester, UK.
| | - Gemma L Marsden
- Healthcare Infection Society, London, UK; Royal College of General Practitioners, London, UK
| | - Samuel Mills
- British Infection Association, Seafield, West Lothian, UK; Oxford University NHS Foundation Trust, Oxford, UK
| | | | | | - Cariad M Evans
- Sheffield Teaching Hospital NHS Foundation Trust, Sheffield, UK
| | | | - Pixy Strazds
- Infection Prevention Society, London, UK; St Andrew's Healthcare, Northampton, UK
| | - Sarah Turner
- Infection Prevention Society, London, UK; Stockport Council, Stockport, UK
| | - Valya Weston
- Healthcare Infection Society, London, UK; Infection Prevention Society, London, UK; NHS England, London, UK
| | - Michelle S Toleman
- Healthcare Infection Society, London, UK; Cambridge University Hospitals NHS Trust, Cambridge, UK
| | | | | | - Aggie Bak
- Healthcare Infection Society, London, UK
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Joseph J, Baby HM, Zhao S, Li X, Cheung K, Swain K, Agus E, Ranganathan S, Gao J, Luo JN, Joshi N. Role of bioaerosol in virus transmission and material-based countermeasures. EXPLORATION (BEIJING, CHINA) 2022; 2:20210038. [PMID: 37324804 PMCID: PMC10190935 DOI: 10.1002/exp.20210038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 04/15/2022] [Indexed: 06/17/2023]
Abstract
Respiratory pathogens transmit primarily through particles such as droplets and aerosols. Although often overlooked, the resuspension of settled droplets is also a key facilitator of disease transmission. In this review, we discuss the three main mechanisms of aerosol generation: direct generation such as coughing and sneezing, indirect generation such as medical procedures, and resuspension of settled droplets and aerosols. The size of particles and environmental factors influence their airborne lifetime and ability to cause infection. Specifically, humidity and temperature are key factors controlling the evaporation of suspended droplets, consequently affecting the duration in which particles remain airborne. We also suggest material-based approaches for effective prevention of disease transmission. These approaches include electrostatically charged virucidal agents and surface coatings, which have been shown to be highly effective in deactivating and reducing resuspension of pathogen-laden aerosols.
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Affiliation(s)
- John Joseph
- Center for Nanomedicine, Department of AnesthesiologyPerioperative and Pain Medicine, Brigham and Women's HospitalBostonMassachusettsUSA
- Harvard Medical SchoolBostonMassachusettsUSA
| | - Helna Mary Baby
- Center for Nanomedicine, Department of AnesthesiologyPerioperative and Pain Medicine, Brigham and Women's HospitalBostonMassachusettsUSA
| | - Spencer Zhao
- Center for Nanomedicine, Department of AnesthesiologyPerioperative and Pain Medicine, Brigham and Women's HospitalBostonMassachusettsUSA
| | - Xiang‐Ling Li
- Center for Nanomedicine, Department of AnesthesiologyPerioperative and Pain Medicine, Brigham and Women's HospitalBostonMassachusettsUSA
| | - Krisco‐Cheuk Cheung
- Center for Nanomedicine, Department of AnesthesiologyPerioperative and Pain Medicine, Brigham and Women's HospitalBostonMassachusettsUSA
| | - Kabir Swain
- Center for Nanomedicine, Department of AnesthesiologyPerioperative and Pain Medicine, Brigham and Women's HospitalBostonMassachusettsUSA
| | - Eli Agus
- Center for Nanomedicine, Department of AnesthesiologyPerioperative and Pain Medicine, Brigham and Women's HospitalBostonMassachusettsUSA
| | - Sruthi Ranganathan
- Center for Nanomedicine, Department of AnesthesiologyPerioperative and Pain Medicine, Brigham and Women's HospitalBostonMassachusettsUSA
| | - Jingjing Gao
- Center for Nanomedicine, Department of AnesthesiologyPerioperative and Pain Medicine, Brigham and Women's HospitalBostonMassachusettsUSA
- Harvard Medical SchoolBostonMassachusettsUSA
| | - James N Luo
- Harvard Medical SchoolBostonMassachusettsUSA
- Department of SurgeryBrigham and Women's HospitalBostonMassachusettsUSA
| | - Nitin Joshi
- Center for Nanomedicine, Department of AnesthesiologyPerioperative and Pain Medicine, Brigham and Women's HospitalBostonMassachusettsUSA
- Harvard Medical SchoolBostonMassachusettsUSA
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Abney SE, Wilson AM, Ijaz MK, McKinney J, Reynolds KA, Gerba CP. Minding the matrix: The importance of inoculum suspensions on finger transfer efficiency of virus. J Appl Microbiol 2022; 133:3083-3093. [PMID: 35916494 DOI: 10.1111/jam.15758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 07/27/2022] [Accepted: 07/29/2022] [Indexed: 01/07/2023]
Abstract
AIMS The aim of this study was to determine how the transfer efficiency of MS-2 coliphage from the toilet seat to hands and fingertip to lip differs according to the suspension of the inoculum. METHODS AND RESULTS Hands were sampled after lifting a toilet seat which was inoculated with MS-2 on the underneath side. MS-2 was suspended in a spectrum of proteinaceous and non-proteinaceous solutions. Transfer efficiencies were greatest with the ASTM tripartite soil load (3.02% ± 4.03) and lowest with phosphate-buffered saline (PBS) (1.10% ± 0.81) for hand-to-toilet seat contacts. Finger-to-lip transfer rates were significantly different (p < 0.05) depending on suspension matrix, with PBS yielding the highest transfer (52.53% ± 4.48%) and tryptose soy broth (TSB) the lowest (23.15% ± 24.27%). Quantitative microbial risk assessment was used to estimate the probability of infection from adenovirus and norovirus from finger contact with a toilet seat. CONCLUSIONS The greatest transfer as well as the largest variation of transfer were measured for finger-to-lip contacts as opposed to toilet seat-to-finger contacts. These factors influence the estimation of the probability of infection from micro-activity, that is, toilet seat adjustment. SIGNIFICANCE AND IMPACT Viruses may be transferred from various human excreta with differing transfer efficiencies, depending on the protein content.
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Affiliation(s)
- Sarah E Abney
- Department of Environmental Science, University of Arizona, Tucson, Arizona, USA
| | - Amanda M Wilson
- Department of Community, Environment, and Policy, University of Arizona, Tucson, Arizona, USA
| | - M Khalid Ijaz
- Global Research & Development for Lysol and Dettol, Reckitt Benckiser LLC, Montvale, New Jersey, USA.,Department of Biology, Medgar Evers College of the City University of New York (CUNY), Brooklyn, New York, USA
| | - Julie McKinney
- Global Research & Development for Lysol and Dettol, Reckitt Benckiser LLC, Montvale, New Jersey, USA
| | - Kelly A Reynolds
- Department of Environmental Science, University of Arizona, Tucson, Arizona, USA.,Department of Community, Environment, and Policy, University of Arizona, Tucson, Arizona, USA
| | - Charles P Gerba
- Department of Environmental Science, University of Arizona, Tucson, Arizona, USA
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Xu J, Xu X, Sun KS, Wu D, Lam TP, Zhou X. Changes in residents' hygiene awareness and behaviors in public toilets before and during the COVID-19 pandemic in Hangzhou, China: a two-round cross-sectional study. BMC Public Health 2022; 22:1690. [PMID: 36068533 PMCID: PMC9447962 DOI: 10.1186/s12889-022-14114-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 08/30/2022] [Indexed: 11/17/2022] Open
Abstract
Background Hygiene behaviors in public toilets are important to prevent the transmission of infectious diseases, especially during the pandemic. All through the novel coronavirus (COVID-19) pandemic, governments in many countries published guidance on personal hygiene for the general population to prevent disease transmission. This study aimed to investigate improvements in residents’ hygiene awareness and behaviors in public toilets before and during the pandemic. Methods We recruited 316 residents between November and December 2018 before the pandemic, and 314 residents between December 2020 and January 2021 during the pandemic in the same study sites in Hangzhou, a well-developed city in China. Residents’ hygiene behaviors in public toilets, hygiene awareness, risk perception, and sociodemographic factors were collected. Bivariate analysis and multivariable logistic regressions were used to test the differences between the two rounds. We conducted an observational study to record the provision of hygiene amenities at toilets during the pandemic. Results After controlling for sociodemographic factors (gender, marital status, age, education level, and monthly household income), compared with respondents recruited before the pandemic, respondents recruited during the pandemic were more likely to perceive the risks of infection when using public toilets (aOR = 1.77, 95%CI [1.20, 2.60]), and were more likely to be aware of the risks of touching contaminated toilet facilities (aOR = 1.72, 95%CI [1.17, 2.54]) and the risks of not using soap to wash one’s hands after using the toilet (aOR = 1.93, 95%CI [1.38, 2.72]). They were more likely to always clean their toilet seat with alcohol (aOR = 1.88, 95%CI [1.01, 3.51]), wash hands with soap (aOR = 1.52, 95%CI [1.09, 2.10]) and dry their hands with a dryer (aOR = 1.78, 95%CI [1.16, 2.71]), but they were less likely to always wash their hands after using the toilets (aOR = 0.57, 95%CI [0.32, 1.00]). Among 70 public toilets observed, 9 provided alcohol for toilet seat disinfection, 52 provided soap, 33 provided paper towels, and 41 had working hand dryers. Conclusions Despite the overall improvement, residents’ hygiene behaviors in public toilets and the supply of hygiene amenities were still suboptimal during the pandemic. Further hygiene education and an adequate supply of hygiene amenities in public toilets are needed to promote residents’ hygiene behaviors.
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Affiliation(s)
- Jiayao Xu
- Institute of Social Medicine, School of Medicine, Zhejiang University, 866 Yuhangtang Road, Hangzhou, China
| | - Xin Xu
- Institute of Social Medicine, School of Medicine, Zhejiang University, 866 Yuhangtang Road, Hangzhou, China
| | - Kai Sing Sun
- JC School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China
| | - Dan Wu
- Department of Clinical Research, London School of Hygiene & Tropical Medicine, London, UK
| | - Tai Pong Lam
- Department of Family Medicine and Primary Care, The University of Hong Kong, Pokfulam, Hong Kong, China.
| | - Xudong Zhou
- Institute of Social Medicine, School of Medicine, Zhejiang University, 866 Yuhangtang Road, Hangzhou, China. .,The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.
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12
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Digital Twin Evaluation of Environment and Health of Public Toilet Ventilation Design Based on Building Information Modeling. BUILDINGS 2022. [DOI: 10.3390/buildings12040470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Poor indoor air quality reduces the comfort experienced in the environment and can also harm our physical health. Mechanical ventilation design plays an important role in improving the indoor environment and the safety of public toilets. Therefore, in this study, we aimed to evaluate public toilet ventilation design schemes through a digital twin to determine the most effective scheme for reducing indoor pollutant concentrations. In this study, we used Autodesk Revit to create a digital twin BIM of different ventilation systems. We simulated the diffusion of pollutants in these models using computational fluid dynamics (CFD)-based methods, and we used DesignBuilder to simulate building energy consumption. From the perspective of architectural design, we determined measures important for reducing the concentration of air pollutants by increasing the number and volume of air exchanges and controlling the installation height of exhaust vents. The results show that the ventilation design of an all-air air conditioning system with an exhaust height of 400 mm can remarkably improve the indoor environmental health and ventilation efficiency of public toilets, while consuming 20.4% less energy and reducing carbon emissions by 30,681 kg CO2.
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13
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Ramlal PS, Lin J, Buckley CA, Stenström TA, Amoah ID. An assessment of the health risks associated with shared sanitation: a case study of the community ablution blocks in Durban, South Africa. ENVIRONMENTAL MONITORING AND ASSESSMENT 2022; 194:166. [PMID: 35142880 PMCID: PMC9035208 DOI: 10.1007/s10661-022-09815-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Accepted: 01/22/2022] [Indexed: 06/14/2023]
Abstract
Shared sanitation facilities have been hailed as an innovative approach to solve the challenge with sanitation access. However, these facilities may act as hotspots for disease transmission due to unhygienic conditions. In this study we used quantitative (based on Escherichia coli contamination) techniques to assess the health risks associated with the use of community ablution blocks (CABs). The most contaminated surfaces were the cistern handle (5.7 Log10 cfu/cm2) and internal pull latch (5.8 Log10 cfu/cm2). Based on the E. coli contamination, at least two people out of 100 CAB users might be potentially infected when they touch "hot" surfaces. These risks were modelled assuming transfer of potentially pathogenic E. coli from these surfaces to the mouth. The incorporation of risk-reduction measures, such as wiping of these surfaces or washing of hands, could potentially result in significant reduction of infection risks. The most significant risk-reduction intervention was determined to be wiping of the contact surfaces, especially twice prior to contact. A combination of risk-reduction interventions could further reduce the risks. This study shows that contamination of contact surfaces within shared CABs could lead to increased risks of infections, requiring measures aimed at reducing the associated risks. The risk assessment framework used in this study could therefore be applied in similar settings to estimate associated health risks with the use of such facilities.
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Affiliation(s)
- Preshod S Ramlal
- eThekwini Municipality Health Department, 9 Archie Gumede Place, 4001, Durban, South Africa.
- School of Life Sciences, University of KwaZulu-Natal, KwaZulu-Natal, 4001, Durban, South Africa.
| | - Johnson Lin
- School of Life Sciences, University of KwaZulu-Natal, KwaZulu-Natal, 4001, Durban, South Africa
| | - Christopher A Buckley
- WASH Research and Development Centre, University of KwaZulu-Natal, KwaZulu-Natal, 4001, Durban, South Africa
| | - Thor Axel Stenström
- Institute for Water and Wastewater Technology, Durban University of Technology, KwaZulu-Natal, Durban, South Africa
| | - Isaac D Amoah
- Institute for Water and Wastewater Technology, Durban University of Technology, KwaZulu-Natal, Durban, South Africa
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14
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Denpetkul T, Pumkaew M, Sittipunsakda O, Leaungwutiwong P, Mongkolsuk S, Sirikanchana K. Effects of face masks and ventilation on the risk of SARS-CoV-2 respiratory transmission in public toilets: a quantitative microbial risk assessment. JOURNAL OF WATER AND HEALTH 2022; 20:300-313. [PMID: 36366988 DOI: 10.2166/wh.2022.190] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Public toilets may increase the risk of COVID-19 infection via airborne transmission; however, related research is limited. We aimed to estimate SARS-CoV-2 infection risk through respiratory transmission using a quantitative microbial risk assessment framework by retrieving SARS-CoV-2 concentrations from the swab tests of 251 Thai patients. Three virus-generating scenarios were investigated: an infector breathing, breathing with a cough, and breathing with a sneeze. The infection risk (95th percentile) was as high as 10-1 with breathing and increased to 1 with a cough or a sneeze. No significant gender differences for toilet users (receptors) were noted. The highest risk scenario, namely breathing with a sneeze, was further evaluated for risk mitigation measures. Mitigation to a lower risk under 10-3 succeeded only when the infector and the receptor both wore N95 respirators or surgical masks. Ventilation of up to 20 air changes per hour (ACH) did not decrease the risk. However, an extended waiting time of 10 min between an infector and a receptor resulted in approximately 1.0-log10 further risk reduction when both wore masks with the WHO-recommended 12 ACH. The volume of expelled droplets, virus concentrations, and receptor dwell time were identified as the main contributors to transmission risk.
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Affiliation(s)
- Thammanitchpol Denpetkul
- Department of Social and Environmental Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
| | - Monchai Pumkaew
- Environmental Engineering and Disaster Management Program, School of Multidisciplinary, Mahidol University, Kanchanaburi Campus, Sai Yok, Kanchanaburi 71150, Thailand
| | - Oranoot Sittipunsakda
- Department of Social and Environmental Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
| | - Pornsawan Leaungwutiwong
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand 10400
| | - Skorn Mongkolsuk
- Research Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok 10210, Thailand E-mail: ; Center of Excellence on Environmental Health and Toxicology (EHT), OPS, MHESI, Thailand
| | - Kwanrawee Sirikanchana
- Research Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok 10210, Thailand E-mail: ; Center of Excellence on Environmental Health and Toxicology (EHT), OPS, MHESI, Thailand
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15
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Vardoulakis S, Espinoza Oyarce DA, Donner E. Transmission of COVID-19 and other infectious diseases in public washrooms: A systematic review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 803:149932. [PMID: 34525681 PMCID: PMC8390098 DOI: 10.1016/j.scitotenv.2021.149932] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 08/13/2021] [Accepted: 08/23/2021] [Indexed: 05/03/2023]
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.
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Affiliation(s)
- Sotiris Vardoulakis
- National Centre for Epidemiology and Population Health, Research School of Population Health, Australian National University, Canberra, ACT 2601, Australia.
| | - Daniela A Espinoza Oyarce
- National Centre for Epidemiology and Population Health, Research School of Population Health, Australian National University, Canberra, ACT 2601, Australia
| | - Erica Donner
- Future Industries Institute, University of South Australia, Mawson Lakes, SA 5095, Australia
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16
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Phi 6 recovery from inoculated fingerpads based on elution buffer and methodology. J Virol Methods 2022; 299:114307. [PMID: 34606796 PMCID: PMC9757907 DOI: 10.1016/j.jviromet.2021.114307] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Revised: 08/24/2021] [Accepted: 09/09/2021] [Indexed: 11/22/2022]
Abstract
Phi 6 (Φ6) bacteriophage is a proposed surrogate to study pathogenic enveloped viruses including SARS-CoV-2-the causative agent of COVID-19-based on structural similarities, BSL-1 status, and ease of use. To determine the role of virus-contaminated hands in disease transmission, an enhanced understanding of buffer and method performance for Φ6 recovery needs to be determined. Four buffer types and three methodologies were investigated for the recovery of Φ6 from human fingerpads over a 30 min duration. Phosphate buffered saline (PBS), PBS + 0.1 % Tween, 0.1 M glycine + 3% beef extract, and viral transport medium were evaluated as buffers for recovery of Φ6 via a dish, modified glove juice, and vigorous swabbing method. Φ6 concentrations on fingerpads were determined at 0-, 5-, 10-, and 30-min post-inoculation. While there were observed differences in virus recovery across buffer and method types depending on the time point, log PFU recovery based on buffer type or methodology was not significantly different at any time point (P > 0.05). The results presented in this study will allow for future work on Φ6 persistence, transfer between hands and surfaces, and efficacy of hand hygiene methods to be performed using a well-characterized and validated recovery method.
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Boles C, Brown G, Nonnenmann M. Determination of murine norovirus aerosol concentration during toilet flushing. Sci Rep 2021; 11:23558. [PMID: 34876637 PMCID: PMC8651634 DOI: 10.1038/s41598-021-02938-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 11/24/2021] [Indexed: 11/14/2022] Open
Abstract
Murine norovirus (MNV) was used as a surrogate for human viral pathogens (e.g., norovirus) to determine if toilet flushing resulted in the aerosolization of virus. A flushometer type toilet was seeded with a viral solution of 105 and 106 PFU mL-1 of MNV and then flushed. Upon flushing, two bioaerosol samplers were activated to collect aerosolized MNV. Prior to the experiment, two optical particle counters monitored particle size and number distribution of aerosol produced from flushing a toilet across height, position, and side. The location with the highest mean particle concentration, was behind the toilet and 0.15 m above the toilet bowl rim, which is where bioaerosol sampling occurred. Bioaerosol and toilet water samples were collected, extracted and then quantified using RT-ddPCR. The concentration of MNV collected after seeding the toilet water ranged from 2.18 × 105 to 9.65 × 106 total copies of MNV. Positive samples of airborne MNV were detected with collected concentrations ranging from 383 to 684 RNA copies/m3 of air. This study provides evidence that viral pathogens may be aerosolized when a toilet is flushed. Furthermore, the MNV used in this study is a model organism for human norovirus and may be generalizable to other viral pathogens (e.g., coronavirus). This study suggests that virus is aerosolized from toilet flushing and may contribute to human exposure to viral pathogens.
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Affiliation(s)
| | - Grant Brown
- College of Public Health, University of Iowa, Iowa City, IA, USA
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18
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Childhood Rotavirus Infection Associated with Temperature and Particulate Matter 2.5 µm: A Retrospective Cohort Study. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph182312570. [PMID: 34886295 PMCID: PMC8656776 DOI: 10.3390/ijerph182312570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 11/22/2021] [Accepted: 11/24/2021] [Indexed: 11/18/2022]
Abstract
No study has ever investigated how ambient temperature and PM2.5 mediate rotavirus infection (RvI) in children. We used insurance claims data from Taiwan in 2006–2012 to evaluate the RvI characteristics in children aged ≤ 9. The RvI incidence rates were higher in colder months, reaching the highest in March (117.0/100 days), and then declining to the lowest in July (29.2/100 days). The age–sex-specific average incident cases were all higher in boys than in girls. Stratified analysis by temperature (<20, 20–24, and ≥25 °C) and PM2.5 (<17.5, 17.5–31.4, 31.5–41.9, and ≥42.0 μg/m3) showed that the highest incidence was 16.4/100 days at average temperatures of <20 °C and PM2.5 of 31.5–41.9 μg/m3, with Poisson regression analysis estimating an adjusted relative risk (aRR) of 1.26 (95% confidence interval (CI) = 1.11–1.43), compared to the incidence at the reference condition (<20 °C and PM2.5 < 17.5 μg/m3). As the temperature increased, the incident RvI cases reduced to 4.84 cases/100 days (aRR = 0.40, 95% CI = 0.35–0.45) when it was >25 °C with PM2.5 < 17.5 μg/m3, or to 9.84/100 days (aRR = 0.81, 95% CI = 0.77–0.93) when it was >25 °C with PM2.5 > 42 μg/m3. The seasonal RvI is associated with frequent indoor personal contact among children in the cold months. The association with PM2.5 could be an alternative assessment due to temperature inversion.
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19
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Abstract
The lavatory is a fertile area for the transmission of infectious disease through bioaerosols between its users. In this study, we built a generic compact lavatory model with a vacuum toilet, and computational fluid dynamics (CFD) is used to evaluate the effects of ventilation and user behaviors on the airflow patterns, and the resulting fates of bioaerosols. Fecal aerosols are readily released into the lavatory during toilet flush. Their concentration rapidly decays in the first 20 s after flushing by deposition or dilution. It takes about 315 s to 348 s for fine bioaerosols (<10 µm in diameter) to decrease to 5% of the initial concentration, while it takes 50 and 100 µm bioaerosols approximately 11 and <1 s, respectively, to completely deposit. The most contaminated surfaces by aerosol deposition include the toilet seat, the bowl, and the nearby walls. The 10 µm aerosols tend to deposit on horizontal surfaces, while the 50 and 100 µm bioaerosols almost always deposit on the bowl. In the presence of a standing thermal manikin, the rising thermal plume alters the flow field and more bioaerosols are carried out from the toilet; a large fraction of aerosols deposit on the manikin’s legs. The respiratory droplets generated by a seated coughing manikin tend to deposit on the floor, legs, and feet of the manikin. In summary, this study reveals the bioaerosol dilution time and the easily contaminated surfaces in a compact lavatory, which will aid the development of control measures against infectious diseases.
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20
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Short-Term Impacts of Meteorology, Air Pollution, and Internet Search Data on Viral Diarrhea Infection among Children in Jilin Province, China. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph182111615. [PMID: 34770125 PMCID: PMC8582928 DOI: 10.3390/ijerph182111615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Revised: 10/29/2021] [Accepted: 11/03/2021] [Indexed: 01/08/2023]
Abstract
The influence of natural environmental factors and social factors on children’s viral diarrhea remains inconclusive. This study aimed to evaluate the short-term effects of temperature, precipitation, air quality, and social attention on children’s viral diarrhea in temperate regions of China by using the distribution lag nonlinear model (DLNM). We found that low temperature affected the increase in children’s viral diarrhea infection for about 1 week, while high temperature and heavy precipitation affected the increase in children’s viral diarrhea infection risk for at least 3 weeks. As the increase of the air pollution index may change the daily life of the public, the infection of children’s viral diarrhea can be restrained within 10 days, but the risk of infection will increase after 2 weeks. The extreme network search may reflect the local outbreak of viral diarrhea, which will significantly improve the infection risk. The above factors can help the departments of epidemic prevention and control create early warnings of high-risk outbreaks in time and assist the public to deal with the outbreak of children’s viral diarrhea.
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21
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Arena F, Coda ARD, Meschini V, Verzicco R, Liso A. Droplets generated from toilets during urination as a possible vehicle of carbapenem-resistant Klebsiella pneumoniae. Antimicrob Resist Infect Control 2021; 10:149. [PMID: 34670621 PMCID: PMC8527778 DOI: 10.1186/s13756-021-01023-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 10/08/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In the health care setting, infection control actions are fundamental for containing the dissemination of multidrug-resistant bacteria (MDR). Carbapenemase-producing Enterobacterales (CPE), especially Klebsiella pneumoniae (CR-KP), can spread among patients, although the dynamics of transmission are not fully known. Since CR-KP is present in wastewater and microorganisms are not completely removed from the toilet bowl by flushing, the risk of transmission in settings where toilets are shared should be addressed. We investigated whether urinating generates droplets that can be a vehicle for bacteria and explored the use of an innovative foam to control and eliminate this phenomenon. METHODS To study droplet formation during urination, we set up an experiment in which different geometrical configurations of toilets could be reproduced and customized. To demonstrate that droplets can mobilize bacteria from the toilet bowl, a standard ceramic toilet was contaminated with a KPC-producing Klebsiella pneumoniae ST101 isolate. Then, we reproduced urination and attached culture dishes to the bottom of the toilet lid for bacterial colony recovery with and without foam. RESULTS Rebound droplets invariably formed, irrespective of the geometrical configuration of the toilet. In microbiological experiments, we demonstrated that bacteria are always mobilized from the toilet bowl (mean value: 0.11 ± 0.05 CFU/cm2) and showed that a specific foam layer can completely suppress mobilization. CONCLUSIONS Our study demonstrated that droplets generated from toilets during urination can be a hidden source of CR-KP transmission in settings where toilets are shared among colonized and noncolonized patients.
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Affiliation(s)
- Fabio Arena
- Department of Clinical and Experimental Medicine, University of Foggia, Via Luigi Pinto, 71122, Foggia, Italy.
- IRCCS Don Carlo Gnocchi Foundation ONLUS, Florence, Italy.
| | | | - Valentina Meschini
- Department of Industrial Engineering, University of Rome 'Tor Vergata', Rome, Italy
- Maths Division, Gran Sasso Science Institute, L'Aquila, Italy
| | - Roberto Verzicco
- Department of Industrial Engineering, University of Rome 'Tor Vergata', Rome, Italy
- Maths Division, Gran Sasso Science Institute, L'Aquila, Italy
| | - Arcangelo Liso
- Department of Medical and Surgical Sciences, University of Foggia, Foggia, Italy
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22
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Dancer SJ, Li Y, Hart A, Tang JW, Jones DL. What is the risk of acquiring SARS-CoV-2 from the use of public toilets? THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 792:148341. [PMID: 34146809 PMCID: PMC8192832 DOI: 10.1016/j.scitotenv.2021.148341] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 06/04/2021] [Accepted: 06/05/2021] [Indexed: 05/18/2023]
Abstract
Public toilets and bathrooms may act as a contact hub point where community transmission of SARS-CoV-2 occurs between users. The mechanism of spread would arise through three mechanisms: inhalation of faecal and/or urinary aerosol from an individual shedding SARS-CoV-2; airborne transmission of respiratory aerosols between users face-to-face or during short periods after use; or from fomite transmission via frequent touch sites such as door handles, sink taps, lota or toilet roll dispenser. In this respect toilets could present a risk comparable with other high throughput enclosed spaces such as public transport and food retail outlets. They are often compact, inadequately ventilated, heavily used and subject to maintenance and cleaning issues. Factors such as these would compound the risks generated by toilet users incubating or symptomatic with SARS-CoV-2. Furthermore, toilets are important public infrastructure since they are vital for the maintenance of accessible, sustainable and comfortable urban spaces. Given the lack of studies on transmission through use of public toilets, comprehensive risk assessment relies upon the compilation of evidence gathered from parallel studies, including work performed in hospitals and prior work on related viruses. This narrative review examines the evidence suggestive of transmission risk through use of public toilets and concludes that such a risk cannot be lightly disregarded. A range of mitigating actions are suggested for both users of public toilets and those that are responsible for their design, maintenance and management.
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Affiliation(s)
- Stephanie J Dancer
- Department of Microbiology, Hairmyres Hospital, NHS, Lanarkshire G75 8RG, Scotland, UK; School of Applied Sciences, Edinburgh Napier University, Edinburgh EH14 1DJ, Scotland, UK.
| | - Yuguo Li
- Department of Mechanical Engineering, University of Hong Kong, Hong Kong, China
| | - Alwyn Hart
- Environment Agency, Research Assessment & Evaluation, Streetsbrook Road, Solihull B91 1QT, West Midlands, England, UK
| | - Julian W Tang
- Respiratory Sciences, University of Leicester, Leicester LE1 7RH, England, UK
| | - Davey L Jones
- Environment Centre Wales, Bangor University, Deiniol Road, Bangor, Gwynedd LL57 2UW, Wales, UK; UWA School of Agriculture and Environment, University of Western Australia, Perth, WA 6009, Australia
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23
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Haji Ali B, Shahin MS, Masoumi Sangani MM, Faghihinezhad M, Baghdadi M. Wastewater aerosols produced during flushing toilets, WWTPs, and irrigation with reclaimed municipal wastewater as indirect exposure to SARS-CoV-2. JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING 2021; 9:106201. [PMID: 34405082 PMCID: PMC8361049 DOI: 10.1016/j.jece.2021.106201] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Revised: 08/05/2021] [Accepted: 08/10/2021] [Indexed: 05/07/2023]
Abstract
The detection of SARS-CoV-2 RNA in raw and treated wastewater can open up a fresh perspective to waterborne and aerosolized wastewater as a new transmission route of SARS-CoV-2 RNA during the current pandemic. The aim of this paper is to discuss the potential transmission of SARS-CoV-2 RNA from wastewater aerosols formed during toilet flushing, plumbing failure, wastewater treatment plants, and municipal wastewater reuse for irrigation. Moreover, how these aerosols might increase the risk of exposure to this novel coronavirus (SARS-CoV-2 RNA). This article supplies a review of the literature on the presence of SARS-CoV-2 RNA in untreated wastewater, as well as the fate and stability of SARS-CoV-2 RNA in wastewater. We also reviewed the existing literatures on generation and transmission of aerosolized wastewater through flush a toilet, house's plumbing networks, WWTPs, wastewater reuse for irrigation of agricultural areas. Finally, the article briefly studies the potential risk of infection with exposure to the fecal bioaerosols of SARS-CoV-2 RNA for the people who might be exposed through flushing toilets or faulty building plumbing systems, operators/workers in wastewater treatment plants, and workers of fields irrigated with treated wastewater - based on current knowledge. Although this review highlights the indirect transmission of SARS-CoV-2 RNA through wastewater aerosols, no research has yet clearly demonstrated the role of aerosolized wastewater in disease transmission regarding the continuation of this pandemic. Therefore, there is a need for additional studies on wastewater aerosols in transmission of COVID-19.
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Affiliation(s)
- Banafsheh Haji Ali
- School of Environment, College of Engineering, University of Tehran, Tehran, Iran
| | | | | | - Mohsen Faghihinezhad
- School of Environment, College of Engineering, University of Tehran, Tehran, Iran
| | - Majid Baghdadi
- School of Environment, College of Engineering, University of Tehran, Tehran, Iran
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24
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Gormley M, Aspray TJ, Kelly DA. Aerosol and bioaerosol particle size and dynamics from defective sanitary plumbing systems. INDOOR AIR 2021; 31:1427-1440. [PMID: 33569864 DOI: 10.1111/ina.12797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 01/05/2021] [Accepted: 01/07/2021] [Indexed: 05/07/2023]
Abstract
Aerosols are readily transported on airstreams through building sanitary plumbing and sewer systems, and those containing microbial pathogens (known as bioaerosols) are recognized as contributors to infection spread within buildings. When a defect occurs in the sanitary plumbing system that affects the system integrity, a cross-transmission route is created that can enable the emission of bioaerosols from the system into the building. These emission occurrences are characterized as short-burst events (typically <1 min in duration) which make them difficult to detect and predict. The characterization of these emission events is the focus of this research. Two methods were used to characterize bioaerosol emission events in a full-scale test rig: (a) an Aerodynamic Particle Sizer (APS) for particle size distribution and concentrations; and (b) a slit-to-agar sampler to enumerate the ingress of a viable tracer microorganism (Pseudomonas putida). The APS data confirmed that most particles (>99.5%) were <5 μm and were therefore considered aerosols. Particles generated within the sanitary plumbing system as a result of a toilet flush leads to emissions into the building during system defect conditions with an equivalence of someone talking loudly for over 6 and a half minutes. There were no particles detected of a size >11 μm anywhere in the system. Particle count was influenced by toilet flush volume, but it was not possible to determine if there was any direct influence from airflow rate since both particle and biological data showed no correlation with upward airflow rates and velocities. Typical emissions resulting from a 6 L toilet flush were in the range of 280-400 particles per second at a concentration of typically 9-12 number per cm3 and a total particle count in the region of 3000 to 4000 particles, whereas the peak emissions from a 1.2 L toilet flush were 60-80 particles per second at a concentration of 2.4-3 number per cm3 and a total particle count in the region of 886 to 1045 particles. The reduction in particles is in direct proportion to the reduction in toilet flush volume. The slit-to-agar sampler was able to provide viable time course CFU data and confirmed the origin of the particles to be the tracer microorganism flushed into the system. The time course data also have characteristics consistent with the unsteady nature of a toilet flush.
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Affiliation(s)
- Michael Gormley
- Institute for Sustainable Building Design, Heriot-Watt University, Edinburgh, UK
| | | | - David A Kelly
- Institute for Sustainable Building Design, Heriot-Watt University, Edinburgh, UK
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25
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Moresco V, Oliver DM, Weidmann M, Matallana-Surget S, Quilliam RS. Survival of human enteric and respiratory viruses on plastics in soil, freshwater, and marine environments. ENVIRONMENTAL RESEARCH 2021; 199:111367. [PMID: 34029551 DOI: 10.1016/j.envres.2021.111367] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 05/12/2021] [Accepted: 05/15/2021] [Indexed: 05/24/2023]
Abstract
The public health significance of plastics and microplastics in different environmental matrices has mainly focused on the toxicological effects of human ingestion. But these pollutants can also harbour pathogenic bacteria as the surfaces of plastics in the environment quickly become colonised by microbial biofilm. This novel microbial habitat has been termed the 'plastisphere' and could facilitate the survival and dissemination of important bacterial and fungal pathogens. Importantly, however, the role of plastic pollution as a secondary pathway for the transmission of human pathogenic viruses has never been addressed. Due to the high prevalence of both enteric and respiratory viruses in the population and in the environment, there is significant potential for human viruses to become associated with the plastisphere. In this review we critically evaluate current knowledge on the interaction of human enteric and respiratory viruses with plastic surfaces and identify the main environmental conditions and plastic characteristics that could affect virus survival and persistence in the environment. Our hypothesis is that the plastisphere can enhance the adhesion, survival and dissemination of human pathogenic viruses and potentially lead to more effective transfer and transmission of viral diseases within the environment. We identify key research questions needed to more fully assess the potential human health risks associated with viruses on plastic surfaces. These include understanding, (1) the mechanisms of viral attachment to either naked or biofilm-colonised plastic (2) how the structural characteristics of viruses (e.g., enveloped, or non-enveloped), affect their persistence in the plastisphere, (3) whether the plastisphere offers protection and increases the persistence of infectious viruses in soil, freshwater, and marine environments.
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Affiliation(s)
- Vanessa Moresco
- Biological and Environmental Sciences, Faculty of Natural Sciences, University of Stirling, Stirling, FK9 4LA, UK.
| | - David M Oliver
- Biological and Environmental Sciences, Faculty of Natural Sciences, University of Stirling, Stirling, FK9 4LA, UK
| | - Manfred Weidmann
- Institute of Microbiology and Virology, Brandenburg Medical School Theodor Fontane, Senftenberg, D-01968, Germany
| | - Sabine Matallana-Surget
- Biological and Environmental Sciences, Faculty of Natural Sciences, University of Stirling, Stirling, FK9 4LA, UK
| | - Richard S Quilliam
- Biological and Environmental Sciences, Faculty of Natural Sciences, University of Stirling, Stirling, FK9 4LA, UK
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England R, Peirce N, Torresi J, Mitchell S, Harland A. The Potential for Transmission of Coronaviruses via Sports Equipment; A Cricket Case Study. Int J Sports Med 2021; 42:1058-1069. [PMID: 34255324 DOI: 10.1055/a-1500-4620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
A review of literature on the role of fomites in transmission of coronaviruses informed the development of a framework which was used to qualitatively analyse a cricket case study, where equipment is shared and passed around, and identify potential mitigation strategies. A range of pathways were identified that might in theory allow coronavirus transmission from an infected person to a non-infected person via communal or personal equipment fomites or both. Eighteen percent of potential fomite based interactions were found to be non-essential to play including all contact with another persons equipment. Six opportunities to interrupt the transmission pathway were identified, including the recommendation to screen participants for symptoms prior to play. Social distancing between participants and avoiding unnecessary surface contact provides two opportunities; firstly to avoid equipment exposure to infected respiratory droplets and secondly to avoid uninfected participants touching potential fomites. Hand sanitisation and equipment sanitisation provide two further opportunities by directly inactivating coronavirus. Preventing players from touching their mucosal membranes with their hands represents the sixth potential interruption. Whilst potential fomite transmission pathways were identified, evidence suggests that viral load will be substantially reduced during surface transfer. Mitigation strategies could further reduce potential fomites, suggesting that by comparison, direct airborne transmission presents the greater risk in cricket.
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Affiliation(s)
- Rory England
- Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough, United Kingdom of Great Britain and Northern Ireland
| | - Nicholas Peirce
- Sport Science & Medicine, England and Wales Cricket Board, Loughborough, United Kingdom of Great Britain and Northern Ireland
| | - Joseph Torresi
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, Australia
| | - Sean Mitchell
- Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough, United Kingdom of Great Britain and Northern Ireland
| | - Andy Harland
- Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough, United Kingdom of Great Britain and Northern Ireland
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Detection of SARS-CoV-2 RNA on contact surfaces within shared sanitation facilities. Int J Hyg Environ Health 2021; 236:113807. [PMID: 34265632 PMCID: PMC8270751 DOI: 10.1016/j.ijheh.2021.113807] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 07/07/2021] [Accepted: 07/08/2021] [Indexed: 01/22/2023]
Abstract
Contamination of contact surfaces with SARS-CoV-2 has been reported as a potential route for the transmission of COVID-19. This could be a major issue in developing countries where access to basic sanitation is poor, leading to the sharing of toilet facilities. In this study, we report SARS-CoV-2 contamination of key contact surfaces in shared toilets and the probabilistic risks of COVID-19 infections based on detection and quantification of the nucleic acid on the surfaces. We observed that 54-69% of the contact surfaces were contaminated, with SARS-CoV-2 loads ranging from 28.1 to 132.7 gene copies per cm2. Toilet seats had the highest contamination, which could be attributed to shedding of the virus in feces and urine. We observed a significant reduction in viral loads on the contaminated surfaces after cleaning, showing the potential of effective cleaning on the reduction of contamination. The pattern of contamination indicates that the most contaminated surfaces are those that are either commonly touched by users of the shared toilets or easily contaminated with feces and urine. These surfaces were the toilet seats, cistern handles and tap handles. The likelihood (probability) of infection with COVID-19 on these surfaces was highest on the toilet seat (1.76 × 10-4(1.58 × 10-6)) for one time use of the toilet. These findings highlight the potential risks for COVID-19 infections in the event that intact infectious viral particles are deposited on these contact surfaces. Therefore, this study shows that shared toilet facilities in densely populated areas could lead to an increase in risks of COVID-19 infections. This calls for the implementation of risk reduction measures, such as regular washing of hands with soap, strict adherence to wearing face masks, and effective and regular cleaning of shared facilities.
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28
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Kuzniewski S. Prevalence, environmental fate, treatment strategies, and future challenges for wastewater contaminated with SARS-CoV-2. REMEDIATION (NEW YORK, N.Y.) 2021; 31:97-110. [PMID: 34539159 PMCID: PMC8441782 DOI: 10.1002/rem.21691] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been detected in untreated and treated wastewater and studies have shown that the concentration of SARS-CoV-2 is proportional to the prevalence of the coronavirus disease 2019 (COVID-19) in communities. This article presents a literature review of the prevalence of SARS-CoV-2 in wastewater, its environmental fate, recommended treatment strategies for contaminated wastewater, and treatment challenges to be faced in the future. The environmental fate of SARS-CoV-2 in wastewater is not straightforward because it can be a source of infection when present in the treated wastewater depending on the permeability of the wastewater treatment plant containment area, and can also leach into aquifers, which may serve as drinking water supplies. Secondly, there are different practices that can mitigate the SARS-CoV-2 infection rate from infected feces and urine. The World Health Organization has recommended the use of ultraviolet radiation (UV), disinfection, and filtration for wastewater contaminated with SARS-CoV-2, processes also common in wastewater treatment facilities. This article discusses these strategies referencing studies performed with surrogate viruses and shows that SARS-CoV-2 treatment can be complicated due to the interference from other aqueous chemical and physical factors. Considering that COVID-19 is not the first and certainly not the last pandemic, it is imperative to develop an effective multitreatment strategy for wastewater contaminated with contagious viruses and, preferably, those that are compatible with current wastewater treatment methods.
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29
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Amoah ID, Pillay L, Deepnarian N, Awolusi O, Pillay K, Ramlal P, Kumari S, Bux F. Detection of SARS-CoV-2 RNA on contact surfaces within shared sanitation facilities. Int J Hyg Environ Health 2021; 236:113807. [PMID: 34265632 DOI: 10.21203/rs.3.rs-89199/v1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 07/07/2021] [Accepted: 07/08/2021] [Indexed: 05/28/2023]
Abstract
Contamination of contact surfaces with SARS-CoV-2 has been reported as a potential route for the transmission of COVID-19. This could be a major issue in developing countries where access to basic sanitation is poor, leading to the sharing of toilet facilities. In this study, we report SARS-CoV-2 contamination of key contact surfaces in shared toilets and the probabilistic risks of COVID-19 infections based on detection and quantification of the nucleic acid on the surfaces. We observed that 54-69% of the contact surfaces were contaminated, with SARS-CoV-2 loads ranging from 28.1 to 132.7 gene copies per cm2. Toilet seats had the highest contamination, which could be attributed to shedding of the virus in feces and urine. We observed a significant reduction in viral loads on the contaminated surfaces after cleaning, showing the potential of effective cleaning on the reduction of contamination. The pattern of contamination indicates that the most contaminated surfaces are those that are either commonly touched by users of the shared toilets or easily contaminated with feces and urine. These surfaces were the toilet seats, cistern handles and tap handles. The likelihood (probability) of infection with COVID-19 on these surfaces was highest on the toilet seat (1.76 × 10-4(1.58 × 10-6)) for one time use of the toilet. These findings highlight the potential risks for COVID-19 infections in the event that intact infectious viral particles are deposited on these contact surfaces. Therefore, this study shows that shared toilet facilities in densely populated areas could lead to an increase in risks of COVID-19 infections. This calls for the implementation of risk reduction measures, such as regular washing of hands with soap, strict adherence to wearing face masks, and effective and regular cleaning of shared facilities.
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Affiliation(s)
- Isaac Dennis Amoah
- Institute for Water and Wastewater Technology, Durban University of Technology, P.O. Box 1334, Durban, 4000, South Africa
| | - Leanne Pillay
- Institute for Water and Wastewater Technology, Durban University of Technology, P.O. Box 1334, Durban, 4000, South Africa
| | - Nashia Deepnarian
- Institute for Water and Wastewater Technology, Durban University of Technology, P.O. Box 1334, Durban, 4000, South Africa
| | - Oluyemi Awolusi
- Institute for Water and Wastewater Technology, Durban University of Technology, P.O. Box 1334, Durban, 4000, South Africa
| | - Kriveshin Pillay
- Institute for Water and Wastewater Technology, Durban University of Technology, P.O. Box 1334, Durban, 4000, South Africa
| | - Preshod Ramlal
- School of Life Sciences, University of KwaZulu-Natal, Durban, KwaZulu-Natal, 4001, South Africa; eThekwini Health Department, eThekwini Municipality, KwaZulu-Natal, 4001, South Africa
| | - Sheena Kumari
- Institute for Water and Wastewater Technology, Durban University of Technology, P.O. Box 1334, Durban, 4000, South Africa
| | - Faizal Bux
- Institute for Water and Wastewater Technology, Durban University of Technology, P.O. Box 1334, Durban, 4000, South Africa.
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30
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Abney SE, Bright KR, McKinney J, Ijaz MK, Gerba CP. Toilet hygiene-review and research needs. J Appl Microbiol 2021; 131:2705-2714. [PMID: 33899991 PMCID: PMC9292268 DOI: 10.1111/jam.15121] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 03/26/2021] [Accepted: 04/21/2021] [Indexed: 11/26/2022]
Abstract
The goal of good toilet hygiene is minimizing the potential for pathogen transmission. Control of odours is also socially important and believed to be a societal measure of cleanliness. Understanding the need for good cleaning and disinfecting is even more important today considering the potential spread of emerging pathogens such as SARS‐CoV‐2 virus. While the flush toilet was a major advancement in achieving these objectives, exposure to pathogens can occur from failure to clean and disinfect areas within a restroom, as well as poor hand hygiene. The build‐up of biofilm within a toilet bowl/urinal including sink can result in the persistence of pathogens and odours. During flushing, pathogens can be ejected from the toilet bowl/urinal/sink and be transmitted by inhalation and contaminated fomites. Use of automatic toilet bowl cleaners can reduce the number of microorganisms ejected during a flush. Salmonella bacteria can colonize the underside of the rim of toilets and persist up to 50 days. Pathogenic enteric bacteria appear in greater numbers in the biofilm found in toilets than in the water. Source tracking of bacteria in homes has demonstrated that during cleaning enteric bacteria are transferred from the toilet to the bathroom sinks and that these same bacteria colonize cleaning tools used in the restroom. Quantitative microbial risk assessment has shown that significant risks exist from both aerosols and fomites in restrooms. Cleaning with soaps and detergents without the use of disinfectants in public restrooms may spread bacteria and viruses throughout the restroom. Odours in restrooms are largely controlled by ventilation and flushing volume in toilet/urinals. However, this results in increased energy and water usage. Contamination of both the air and surfaces in restrooms is well documented. Better quantification of the risks of infection are needed as this will help determine what interventions will minimize these risks.
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Affiliation(s)
- S E Abney
- Department of Environmental Science, University of Arizona, Tucson, AZ, USA
| | - K R Bright
- Department of Environmental Science, University of Arizona, Tucson, AZ, USA
| | - J McKinney
- Global Research and Development for Lysol and Dettol, Reckitt Benckiser LLC, Montvale, NJ, USA
| | - M Khalid Ijaz
- Global Research and Development for Lysol and Dettol, Reckitt Benckiser LLC, Montvale, NJ, USA.,Department of Biology, Medgar Evers College of the City University of New York (CUNY), Brooklyn, NY, USA
| | - C P Gerba
- Department of Environmental Science, University of Arizona, Tucson, AZ, USA
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31
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Lai ACK, Nunayon SS. A new UVC-LED system for disinfection of pathogens generated by toilet flushing. INDOOR AIR 2021; 31:324-334. [PMID: 32989792 PMCID: PMC7537215 DOI: 10.1111/ina.12752] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 08/27/2020] [Accepted: 09/15/2020] [Indexed: 06/11/2023]
Abstract
A new disinfection system utilizing UVC-LED irradiation was developed. The system was affixed to the toilet seat, and it was challenged by three bacteria strains. Different configurations were tested: 3-LEDs, 5-LEDs (two variants), and 8-LEDs. To determine the arrangement designs of LEDs with the optimum efficacy, two variants of 5-LEDs configurations were additionally considered-uniform and concentrated (2-sided) distributions. It was noticed that disinfection efficacy initially increased with the number of LEDs, but with 8-LEDs, the trend became almost non-obvious for surface disinfection and just marginally increased for airborne disinfection. The mean efficiencies for the surface disinfection ranged from 55.17 ± 23.89% to 72.80 ± 4.13% for E. coli; 36.65 ± 2.99% to 50.05 ± 13.38% for S. typhimurium; and 8.81 ± 3.23% to 39.43 ± 9.33% for S. epidermidis. Likewise, the mean efficiencies for airborne disinfection ranged from 42.17 ± 8.18% to 70.70 ± 4.80%; 40.40 ± 17.90% to 58.31 ± 13.87%; and 24.16 ± 3.81% to 42.79 ± 10.20% for E. coli; S. typhimurium; and S. epidermidis, respectively. Furthermore, the efficacy of the uniform irradiation was nearly twice that of the concentrated irradiation for surface disinfection and 17.70% higher for airborne disinfection, when tested against E coli. Collectively, these very promising results showcased that this compact, sustainable, and localized disinfection system has a high potential for the next generation of disinfection devices.
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Affiliation(s)
- Alvin C. K. Lai
- Department of Architecture and Civil EngineeringCity University of Hong KongKowloon TongHong Kong
| | - Sunday S. Nunayon
- Department of Architecture and Civil EngineeringCity University of Hong KongKowloon TongHong Kong
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32
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Sun KS, Lam TP, Tang WS, Chan HY, Lam KF, Chow ECY, Wu D, Zhou XD, Xu JY, Ho PL. Improving Public Toilet Environment and Hygiene Practices in an Asian City: Voices From Hong Kong Residents. Asia Pac J Public Health 2021; 33:378-387. [PMID: 33593075 DOI: 10.1177/1010539521993685] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Toilet hygiene is an important preventive measure for infectious diseases, including severe acute respiratory syndrome (SARS) and COVID-19. This study explored public's opinions on improving toilet environment and hygiene practices in Hong Kong. A mixed-method approach was applied. We conducted 4 focus groups plus 3 individual interviews among the Hong Kong Chinese, followed by a questionnaire survey with 300 respondents recruited from various districts. Difference in response distributions between groups with different demographics was tested by Pearson χ2 test. Instead of advocating for advanced toilet facilities, respondents were mostly concerned about basic hygiene issues. Malfunctioning facilities resulting from poor toilet management, such as clogged toilets, stained facilities, and problematic flushing systems, were most cited as barriers to toilet hygiene practices. Three quarters of the survey respondents expressed concerns over worn and poorly maintained toilets, shortage of janitors, and cleansing supplies. However, respondents who were older (P < .001), less educated (P < .001), and had lower income (P = .001) were significantly more likely to find hygiene conditions in public toilets satisfactory. The findings reflected the substandard of the current provisions as a developed city in Asia. Enhanced efforts by the government to maintain basic toilet supplies and facilities is the key to improving public compliance to toilet hygiene practices.
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Affiliation(s)
| | | | | | | | - Kwok Fai Lam
- The University of Hong Kong, Hong Kong, China.,Duke-NUS Medical School, Singapore
| | | | - Dan Wu
- The University of Hong Kong, Hong Kong, China.,London School of Hygiene and Tropical Medicine, London, UK
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33
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Lou M, Liu S, Gu C, Hu H, Tang Z, Zhang Y, Xu C, Li F. The bioaerosols emitted from toilet and wastewater treatment plant: a literature review. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:2509-2521. [PMID: 33098562 PMCID: PMC7585356 DOI: 10.1007/s11356-020-11297-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 10/18/2020] [Indexed: 05/05/2023]
Abstract
The aerosols harboring microorganisms and viruses released from the wastewater system into the air have greatly threatened the health and safety of human beings. The wastewater systems, including toilet and wastewater treatment plant (WWTP), are the major locations of epidemic infections due to the extensive sources of aerosols, as well as multifarious germs and microorganisms. Viruses and microorganisms may transport from both toilet and hospital into municipal pipes and subsequently into WWTP, which accounts for the main source of bioaerosols dispersed in the air of the wastewater system. This review aims to elaborate the generation, transmission, and diffusion processes of bioaerosols at toilet and WWTP. Moreover, the main factors affecting bioaerosol transmission and the corresponding prevention strategies for the airborne and inhaled bioaerosols are also discussed. Collectively, this review highlights the importance of managing bioaerosol occurrence in the wastewater system, which has aroused increasing concern from the public.
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Affiliation(s)
- Mengmeng Lou
- College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China
| | - Shuai Liu
- College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China
| | - Chunjie Gu
- College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China
| | - Huimin Hu
- College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China
| | - Zhengkun Tang
- College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China
| | - Yaopeng Zhang
- College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China
| | - Chenye Xu
- College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China.
- State Environmental Science and Engineering Centre for Pollution Treatment and Control in Textile Industry, Shanghai, 201620, China.
| | - Fang Li
- College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China.
- State Environmental Science and Engineering Centre for Pollution Treatment and Control in Textile Industry, Shanghai, 201620, China.
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34
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Duda-Chodak A, Lukasiewicz M, Zięć G, Florkiewicz A, Filipiak-Florkiewicz A. Covid-19 pandemic and food: Present knowledge, risks, consumers fears and safety. Trends Food Sci Technol 2020; 105:145-160. [PMID: 32921922 PMCID: PMC7480472 DOI: 10.1016/j.tifs.2020.08.020] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 08/04/2020] [Accepted: 08/29/2020] [Indexed: 12/15/2022]
Abstract
BACKGROUND COVID-19 is a pandemic disease that has paralyzed social life and the economy around the world since the end of 2019, and which has so far killed nearly 600,000 people. The rapidity of its spread and the lack of detailed research on the course and methods of transmission significantly impede both its eradication and prevention. SCOPE AND APPROACH Due to the high transmission rate and fatality resulting from COVID-19 disease, the paper focuses on analyzing the current state of knowledge about SARS-CoV-2 as well as its potential connection with food as a source of pathogen and infection. KEY FINDINGS AND CONCLUSIONS There is currently no evidence (scientific publications, WHO, EFSA etc.) that COVID-19 disease can spread directly through food and the human digestive system. However, according to the hypothesis regarding the primary transmission of the virus, the source of which was food of animal origin (meat of wild animals), as well as the fact that food is a basic necessity for humans, it is worth emphasizing that food can, if not directly, be a carrier of the virus. Particular attention should be paid to this indirect pathway when considering the potential for the spread of an epidemic and the development of prevention principles.
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35
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Dennler-Church TE, Butz JC, McKinley JE, Keim EK, Hall MC, Meschke JS, Mulligan JM, Williams JF, Robins LI. Modification of Major Contributors Responsible for Latrine Malodor on Exposure to Hypochlorous Acid: The Potential for Simultaneously Impacting Odor and Infection Hazards to Encourage Latrine Use. Am J Trop Med Hyg 2020; 103:2584-2590. [PMID: 33073749 PMCID: PMC7695106 DOI: 10.4269/ajtmh.20-0553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Open defecation remains a common practice in developing countries and leads to high incidence and prevalence of acute gastroenteritis, which is most often caused by human noroviruses (human NoV). Encouraging the use of toilets and pit latrines is one method of improving sanitation; however, it is often hindered by not only cultural traditions but also from a reluctance to use latrines and toilets due to their odor and impression of uncleanliness. In an effort to establish new means to encourage toilet and latrine use, laboratory experiments tested the ability of hypochlorous acid (HOCl) to modify the malodorous compounds identified in the air in latrines in developing countries (indole, p-cresol, dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS), and butyric acid) and inactivate MS2 bacteriophage, a surrogate for human NoV. After 5 minutes, > 94% of indole, p-cresol, DMDS, and DMTS was modified as determined by high-pressure liquid chromatography in the presence of 100 ppm HOCl. A log10 reduction value (LRV) greater than 6 was seen for MS2 bacteriophage after 5 minutes of exposure to 100 ppm HOCl in solution. Sensory studies indicated that there was a significant difference (P ≤ 0.05) between the untreated and HOCl-treated samples for all five malodorous compounds tested. The findings suggest that introduction of HOCl into the headspace air could encourage latrine and toilet use. Optimization of HOCl dosing in air to accomplish both odor control and reduction of infectious hazards is worthy of further study.
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Affiliation(s)
- Tim E Dennler-Church
- Department of Physical Sciences, University of Washington Bothell, Bothell, Washington
| | - Jeremy C Butz
- Department of Physical Sciences, University of Washington Bothell, Bothell, Washington
| | - Joseph E McKinley
- Department of Physical Sciences, University of Washington Bothell, Bothell, Washington
| | - Erika K Keim
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington
| | - Mary C Hall
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington
| | - John S Meschke
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington
| | - JoAnne M Mulligan
- Department of Physical Sciences, University of Washington Bothell, Bothell, Washington
| | | | - Lori I Robins
- Department of Physical Sciences, University of Washington Bothell, Bothell, Washington
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36
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González-Olmo MJ, Delgado-Ramos B, Ruiz-Guillén A, Romero-Maroto M, Carrillo-Díaz M. Oral hygiene habits and possible transmission of COVID-19 among cohabitants. BMC Oral Health 2020; 20:286. [PMID: 33076880 PMCID: PMC7569355 DOI: 10.1186/s12903-020-01274-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 10/06/2020] [Indexed: 01/22/2023] Open
Abstract
Background To find out whether misuse of dental hygiene, in terms of certain dental habits, may facilitate the spread of COVID-19 among cohabiting individuals. Methods 302 COVID-19 infected (PCR +) subjects cohabiting with someone else at home were selected for an observational cross-sectional study. An anonymous online questionnaire was developed using Google forms to avoid person-to-person contact. The structured questionnaire consisted of questions covering several areas: sociodemographic data, cross transmission to another person living together, oral hygiene habits during confinement, care and disinfection control behaviours in the dental environment like sharing toothbrush, sharing toothbrush container, sharing toothpaste, placing brush vertically, placing cap with hole for brush, disinfecting brush with bleach, closing toilet lid before flushing. Results Tongue brushing was more used in the group where there was no transmission of the disease to other members (p < 0.05). Significant differences were found for shared toothbrush use (p < 0.05), although shared use was a minority in this group (4. 7%), significant differences were also found for the use of the same container (p < 0.01), shared use of toothpaste (p < 0.01), toothbrush disinfection with bleach (p < 0.01), brush change after PCR + (p < 0.05). The women performed significantly more disinfection with toothbrush bleach (p < 0.01), closing the toilet lid (p < 0.05) and changing the brush after PCR + (p < 0.05). Conclusions The use of inappropriate measures in the dental environment could contribute to the indirect transmission of COVID-19 between cohabitants.
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Affiliation(s)
- María José González-Olmo
- Dentistry Department, Rey Juan Carlos University, Avda de Atenas s/n, 28922, Alcorcón, Madrid, Spain
| | | | - Ana Ruiz-Guillén
- Dentistry Department, Rey Juan Carlos University, Avda de Atenas s/n, 28922, Alcorcón, Madrid, Spain
| | - Martín Romero-Maroto
- Dentistry Department, Rey Juan Carlos University, Avda de Atenas s/n, 28922, Alcorcón, Madrid, Spain
| | - María Carrillo-Díaz
- Dentistry Department, Rey Juan Carlos University, Avda de Atenas s/n, 28922, Alcorcón, Madrid, Spain
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37
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Fennelly KP. Particle sizes of infectious aerosols: implications for infection control. THE LANCET. RESPIRATORY MEDICINE 2020; 8:914-924. [PMID: 32717211 PMCID: PMC7380927 DOI: 10.1016/s2213-2600(20)30323-4] [Citation(s) in RCA: 320] [Impact Index Per Article: 80.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 07/06/2020] [Accepted: 07/08/2020] [Indexed: 12/13/2022]
Abstract
The global pandemic of COVID-19 has been associated with infections and deaths among health-care workers. This Viewpoint of infectious aerosols is intended to inform appropriate infection control measures to protect health-care workers. Studies of cough aerosols and of exhaled breath from patients with various respiratory infections have shown striking similarities in aerosol size distributions, with a predominance of pathogens in small particles (<5 μm). These are immediately respirable, suggesting the need for personal respiratory protection (respirators) for individuals in close proximity to patients with potentially virulent pathogens. There is no evidence that some pathogens are carried only in large droplets. Surgical masks might offer some respiratory protection from inhalation of infectious aerosols, but not as much as respirators. However, surgical masks worn by patients reduce exposures to infectious aerosols to health-care workers and other individuals. The variability of infectious aerosol production, with some so-called super-emitters producing much higher amounts of infectious aerosol than most, might help to explain the epidemiology of super-spreading. Airborne infection control measures are indicated for potentially lethal respiratory pathogens such as severe acute respiratory syndrome coronavirus 2.
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Affiliation(s)
- Kevin P Fennelly
- Pulmonary Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA.
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38
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Sevin T, Goldstein V, Lolom I, Lenne F, Gaudonnet Y, Baptiste AL, Bendjelloul G, Armand-Lefevre L, Lucet JC. Bathroom contamination by antibiotic-resistant Enterobacterales (ESBLPE and CPE): an experimental study. J Hosp Infect 2020; 106:271-276. [PMID: 32750383 DOI: 10.1016/j.jhin.2020.07.033] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 07/27/2020] [Indexed: 12/19/2022]
Abstract
BACKGROUND Extended-spectrum β-lactamase-producing Enterobacterales (ESBLPE) and carbapenemase-producing Enterobacterales (CPE) cause serious infections. Their presence in urine may lead to environmental contamination potentially responsible for cross-transmission. AIM To evaluate the level of spraying and contamination after emptying urine in the toilet and rinsing in the sink, a common practice in the healthcare setting. METHODS For each test, the procedure was similar: seat raised, emptying urinal bottle into the toilet at the height of the bowl, rinsing in the sink and flushing. To study splash-drops, water and fluorescein were mixed in the urinal bottle. In each area, the splash-drops frequency and level were assessed with UV. To study contamination, three ESBLPE and one CPE were diluted in saline, 106/mL. Contamination was assessed by sampling before, immediately after and 3 h after the test. The swabs were cultured and the colonies counted and identified. FINDINGS The areas at the highest risk of spraying were the toilet bowl contour (N = 36/36), the underside of the toilet seat (N = 34) and the inside of the sink (N = 34). Except for gloves (N = 14), there was low clothing contamination. The most frequently contaminated areas were inside the sink (40/48), where the highest levels of contamination were found (14/48). CONCLUSION Emptying the urinal bottles in the toilet followed by sink rinsing is associated with a significant risk of projection and contamination, depending on the area (highest risk at the sink), but the bacteria did not survive beyond 3 h. This practice, which carries a risk of cross-transmission, should be reviewed.
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Affiliation(s)
- T Sevin
- Infection Control Unit, Bichat-Claude Bernard Teaching Hospital, Assistance Publique - Hôpitaux de Paris, Paris, France.
| | - V Goldstein
- Infection Control Unit, Bichat-Claude Bernard Teaching Hospital, Assistance Publique - Hôpitaux de Paris, Paris, France
| | - I Lolom
- Infection Control Unit, Bichat-Claude Bernard Teaching Hospital, Assistance Publique - Hôpitaux de Paris, Paris, France
| | - F Lenne
- Infection Control Unit, Bichat-Claude Bernard Teaching Hospital, Assistance Publique - Hôpitaux de Paris, Paris, France
| | - Y Gaudonnet
- Infection Control Unit, Bichat-Claude Bernard Teaching Hospital, Assistance Publique - Hôpitaux de Paris, Paris, France
| | - A L Baptiste
- Infection Control Unit, Bichat-Claude Bernard Teaching Hospital, Assistance Publique - Hôpitaux de Paris, Paris, France
| | - G Bendjelloul
- Infection Control Unit, Bichat-Claude Bernard Teaching Hospital, Assistance Publique - Hôpitaux de Paris, Paris, France
| | - L Armand-Lefevre
- Bacteriology Laboratory, Bichat-Claude Bernard Teaching Hospital, Assistance Publique - Hôpitaux de Paris, Paris, France; Université de Paris, IAME, INSERM, F-75018 Paris, France
| | - J C Lucet
- Infection Control Unit, Bichat-Claude Bernard Teaching Hospital, Assistance Publique - Hôpitaux de Paris, Paris, France; Université de Paris, IAME, INSERM, F-75018 Paris, France
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Ismail NS, Olive M, Fernandez-Cassi X, Bachmann V, Kohn T. Viral Transfer and Inactivation through Zooplankton Trophic Interactions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:9418-9426. [PMID: 32662638 DOI: 10.1021/acs.est.0c02545] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Waterborne viruses are responsible for numerous diseases and are abundant in aquatic systems. Understanding the fate of viruses in natural systems has important implications for human health. This research quantifies the uptake of the bacteriophage T4 and the enteric virus echovirus 11 when exposed to the filter feeders Tetrahymena pyriformis and Daphnia magna, and also examines the potential of viral transfer due to trophic interactions. Experiments co-incubating each species with the viruses over 72-96 h showed up to a 4 log virus removal for T. pyriformis, while direct viral uptake by D. magna was not observed. However, viral uptake by D. magna occurred indirectly by viral transfer from prey to predator, through D. magna feeding on virus-loaded T. pyriformis. This prey-predator interaction resulted in a 1 log additional virus removal compared to removal by T. pyriformis alone. Incomplete viral inactivation by D. magna was observed through recovery of infective viruses from the daphnid tissue. This research furthers our understanding of the impacts of zooplankton filter feeding on viral inactivation and shows the potential for viral transfer through the food chain. The viral-zooplankton interactions observed in these studies indicate that zooplankton may improve water quality through viral uptake or may serve as vectors for infection by accumulating viruses.
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Affiliation(s)
- Niveen S Ismail
- Picker Engineering Program, Smith College, Northampton, Massachusetts 01063, United States
| | - Margot Olive
- Laboratory of Environmental Chemistry, School of Architecture, Civil and Environmental Engineering (ENAC), École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Xavier Fernandez-Cassi
- Laboratory of Environmental Chemistry, School of Architecture, Civil and Environmental Engineering (ENAC), École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Virginie Bachmann
- Laboratory of Environmental Chemistry, School of Architecture, Civil and Environmental Engineering (ENAC), École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Tamar Kohn
- Laboratory of Environmental Chemistry, School of Architecture, Civil and Environmental Engineering (ENAC), École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
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Park GW, Ng TFF, Freeland AL, Marconi VC, Boom JA, Staat MA, Montmayeur AM, Browne H, Narayanan J, Payne DC, Cardemil CV, Treffiletti A, Vinjé J. CrAssphage as a Novel Tool to Detect Human Fecal Contamination on Environmental Surfaces and Hands. Emerg Infect Dis 2020; 26:1731-1739. [PMID: 32511090 PMCID: PMC7392416 DOI: 10.3201/eid2608.200346] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
CrAssphage is a recently discovered human gut–associated bacteriophage. To validate the potential use of crAssphage for detecting human fecal contamination on environmental surfaces and hands, we tested stool samples (n = 60), hand samples (n = 30), and environmental swab samples (n = 201) from 17 norovirus outbreaks for crAssphage by real-time PCR. In addition, we tested stool samples from healthy persons (n = 173), respiratory samples (n = 113), and animal fecal specimens (n = 68) and further sequenced positive samples. Overall, we detected crAssphage in 71.4% of outbreak stool samples, 48%–68.5% of stool samples from healthy persons, 56.2% of environmental swabs, and 60% of hand rinse samples, but not in human respiratory samples or animal fecal samples. CrAssphage sequences could be grouped into 2 major genetic clusters. Our data suggest that crAssphage could be used to detect human fecal contamination on environmental surfaces and hands.
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Wang X, Han J, Lichtfouse E. Unprotected mothers and infants breastfeeding in public amenities during the COVID-19 pandemic. ENVIRONMENTAL CHEMISTRY LETTERS 2020; 18:1447-1450. [PMID: 32837483 PMCID: PMC7372974 DOI: 10.1007/s10311-020-01054-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Affiliation(s)
- Xue Wang
- Department of Environmental Science and Engineering, Xi’an Jiaotong University, Xi’an, 710049 Shaanxi People’s Republic of China
| | - Jie Han
- Department of Environmental Science and Engineering, Xi’an Jiaotong University, Xi’an, 710049 Shaanxi People’s Republic of China
| | - Eric Lichtfouse
- Aix-Marseille University, CNRS, IRD, INRAE, Coll France, CEREGE, 13100 Aix en Provence, France
- State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, Xi’an, 710049 Shaanxi People’s Republic of China
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Sasaki J, Shiino Y, Kato Y, Kudo D, Fujita M, Miyairi I, Mochizuki T, Okuda H, Nagato T, Nabetani Y, Takahashi T. Checklist for infection control in the emergency department. Acute Med Surg 2020; 7:e540. [PMID: 33364033 PMCID: PMC7751486 DOI: 10.1002/ams2.540] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 06/02/2020] [Indexed: 01/08/2023] Open
Abstract
The risk of encountering human-to-human infections, including emerging infectious diseases, should be adequately and appropriately addressed in the emergency department. However, guidelines based on sufficient evidence on infection control in the emergency department have not been developed anywhere in the world. Each facility examines and implements its own countermeasures. The Japanese Association for Acute Medicine has established the "Committee for Infection Control in the Emergency Department" in cooperation with the Japanese Association for Infectious Diseases, Japanese Society for Infection Prevention and Control, Japanese Society for Emergency Medicine, and Japanese Society for Clinical Microbiology. A joint working group has been established to consider appropriate measures. This group undertook a comprehensive and multifaceted review of infection control measures for emergency outpatients and related matters, and released a checklist for infection control in emergency departments. This checklist has been prepared such that even small emergency departments with few or no emergency physicians can control infection by following the checklist, without committing any major errors. The checklist includes a control system for infection control, education, screening, and vaccination, prompt response to suspected infections, and management of the risk of infection in facilities. In addition, the timing of the check and interval at which the check is carried out are specified as categories. We hope that this checklist will contribute to improving infection control in the emergency department.
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Affiliation(s)
- Junichi Sasaki
- Department of Emergency and Critial Care MedicineKeio University School of MedicineTokyoJapan
| | - Yasukazu Shiino
- Department of Acute MedicineKawasaki Medical SchoolKurashikiJapan
| | - Yasuyuki Kato
- Department of Infectious DiseasesInternational University of Health and Welfare School of MedicineNaritaJapan
| | - Daisuke Kudo
- Division of Emergency and Critical Care MedicineTohoku University Graduate School of MedicineSendaiJapan
| | - Masahisa Fujita
- Infection Control TeamNippon Medical School HospitalTokyoJapan
| | - Isao Miyairi
- Division of Infectious DiseasesNational Center for Child Health and DevelopmentTokyoJapan
| | - Toru Mochizuki
- Infection Control TeamNippon Medical School Musashikosugi HospitalKawasakiJapan
| | - Hiroshi Okuda
- Division of Comprehensive MedicineTohoku University Graduate School of MedicineSendaiJapan
| | - Tadashi Nagato
- Department of Internal MedicineChugoku Central HospitalFukuyamaJapan
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Wu D, Lam TP, Chan HY, Lam KF, Zhou XD, Xu JY, Sun KS, Ho PL. A mixed-methods study on toilet hygiene practices among Chinese in Hong Kong. BMC Public Health 2019; 19:1654. [PMID: 31823757 PMCID: PMC6902477 DOI: 10.1186/s12889-019-8014-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Accepted: 11/28/2019] [Indexed: 11/10/2022] Open
Abstract
Background Public toilets are a common transmission vector of infectious diseases due to environmental contamination. Research on Chinese people’s hygiene practices in public lavatories are lacking. This study examined Chinese people’s hygiene practices in public lavatories in Hong Kong. Methods We conducted qualitative interviews and a self-administered questionnaire survey with local residents from June 2016 to April 2018. Four focus group discussions and three individual interviews informed the design of the questionnaire. We recruited interviewees and survey respondents via social service centers. The interviews and questionnaire focused on the public’s daily practices and hygiene behaviors in public toilets. Content analysis of qualitative data was conducted. Multivariable logistic regressions were used to examine the association between age and toilet hygiene behaviors. Results Our qualitative component revealed a range of handwashing practices, from not washing at all, washing without soap, to washing for a longer time than instructions. Other toilet use practices were identified, such as not covering toilet lid before flushing and stepping on toilet seats due to dirtiness, and spitting into toilet bowls or hand basin. Totally, 300 respondents completed the questionnaire. Among them, 212 (70.9%) were female and 246 (86.1%) were aged 65 or below. More than two thirds always washed hands with soap (68.7%) and dried hands with paper towels (68.4%). Up to 16.2% reported stepping on toilet seats and 43.9% never covered the toilet lid before flushing. Over one fourth (26.4%) spit into squat toilets/ toilet bowl. Regression analyses showed that the elderly group were less likely to report stepping on toilet seats (adjusted odds ratio, AOR = 0.17, 95%CI 0.03–0.88), flushing with the toilet lid closed (AOR = 0.40, 0.16–0.96), but more likely to spit into squat toilets/ toilet bowl (AOR = 4.20, 1.50–11.74). Conclusions Hong Kong Chinese’s compliance to hygiene practices in public toilets is suboptimal. Stepping on toilet seat is a unique Chinese practice due to the dirtiness of toilet seats. Spitting practices may increase the risk of airborne infectious diseases and need improvement. Measures are needed to improve toilet hygiene behaviors, including public education campaigns and keeping toilet environment clean.
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Affiliation(s)
- Dan Wu
- Department of Family Medicine and Primary Care, The University of Hong Kong, Hong Kong, China.,Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Tai Pong Lam
- Department of Family Medicine and Primary Care, The University of Hong Kong, Hong Kong, China.
| | - Hoi Yan Chan
- Department of Family Medicine and Primary Care, The University of Hong Kong, Hong Kong, China
| | - Kwok Fai Lam
- Department of Statistics and Actuarial Science, The University of Hong Kong, Hong Kong, China
| | - Xu Dong Zhou
- School of Public Health, Zhejiang University, Hangzhou, China
| | - Jia Yao Xu
- School of Public Health, Zhejiang University, Hangzhou, China
| | - Kai Sing Sun
- Department of Family Medicine and Primary Care, The University of Hong Kong, Hong Kong, China
| | - Pak Leung Ho
- Department of Microbiology, and Carol Yu Center for Infection, The University of Hong Kong, Hong Kong, China
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Chai PR, Zhang H, Jambaulikar GD, Boyer EW, Shrestha L, Kitmitto L, Wickner PG, Salmasian H, Landman AB. An Internet of Things Buttons to Measure and Respond to Restroom Cleanliness in a Hospital Setting: Descriptive Study. J Med Internet Res 2019; 21:e13588. [PMID: 31219046 PMCID: PMC6607773 DOI: 10.2196/13588] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Revised: 05/20/2019] [Accepted: 05/20/2019] [Indexed: 11/29/2022] Open
Abstract
Background Restroom cleanliness is an important factor in hospital quality. Due to its dynamic process, it can be difficult to detect the presence of dirty restrooms that need to be cleaned. Using an Internet of Things (IoT) button can permit users to designate restrooms that need cleaning and in turn, allow prompt response from housekeeping to maintain real-time restroom cleanliness. Objective This study aimed to describe the deployment of an IoT button–based notification system to measure hospital restroom cleanliness reporting system usage and qualitative feedback from housekeeping staff on IoT button use. Methods We deployed IoT buttons in 16 hospital restrooms. Over an 8-month period, housekeeping staff received real-time notifications and responded to button presses for restroom cleaning. All button presses were recorded. We reported average button usage by hospital area, time of day, and day of week. We also conducted interviews with housekeeping supervisors and staff to understand their acceptance of and experience with the system. Results Over 8 months, 1920 requests to clean restrooms in the main hospital lobby and satellite buildings were received. The hospital lobby IoT buttons received over half (N=1055, 55%) of requests for cleaning. Most requests occurred in afternoon hours from 3 PM to midnight. Requests for cleaning remained stable throughout the work week with fewer requests occurring over weekends. IoT button use was sustained throughout the study period. Interviews with housekeeping supervisors and staff demonstrated acceptance of the IoT buttons; actual use was centered around asynchronous communication between supervisors and staff in response to requests to clean restrooms. Conclusions An IoT button system is a feasible method to generate on-demand request for restroom cleaning that is easy to deploy and that users will consistently engage with. Data from this system have the potential to enable responsive scheduling for restroom service and anticipate periods of high restroom utilization in a hospital.
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Affiliation(s)
- Peter R Chai
- Department of Emergency Medicine, Brigham and Women's Hospital, Boston, MA, United States.,The Fenway Institute, Boston, MA, United States.,Harvard Medical School, Boston, MA, United States
| | - Haipeng Zhang
- Harvard Medical School, Boston, MA, United States.,Digital Innovation Hub, Brigham and Women's Hospital, Boston, MA, United States.,Department of Psychosocial Oncology and Palliative Care, Dana Farber Cancer Institute, Boston, MA, United States
| | | | - Edward W Boyer
- Department of Emergency Medicine, Brigham and Women's Hospital, Boston, MA, United States.,The Fenway Institute, Boston, MA, United States.,Harvard Medical School, Boston, MA, United States
| | - Labina Shrestha
- Environmental Services, Brigham and Women's Hospital, Boston, MA, United States
| | - Loay Kitmitto
- Environmental Services, Brigham and Women's Hospital, Boston, MA, United States
| | - Paige G Wickner
- Harvard Medical School, Boston, MA, United States.,Department of Quality and Safety, Brigham and Women's Hospital, Boston, MA, United States
| | - Hojjat Salmasian
- Harvard Medical School, Boston, MA, United States.,Department of Quality and Safety, Brigham and Women's Hospital, Boston, MA, United States
| | - Adam B Landman
- Department of Emergency Medicine, Brigham and Women's Hospital, Boston, MA, United States.,Harvard Medical School, Boston, MA, United States.,Digital Innovation Hub, Brigham and Women's Hospital, Boston, MA, United States
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Farling S, Rogers T, Knee JS, Tilley EA, Brown J, Deshusses MA. Bioaerosol emissions associated with pit latrine emptying operations. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 648:1082-1086. [PMID: 30340254 PMCID: PMC6234106 DOI: 10.1016/j.scitotenv.2018.08.147] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2018] [Revised: 08/10/2018] [Accepted: 08/10/2018] [Indexed: 05/14/2023]
Abstract
Pit latrines are the most common sanitation option in the developing world. They are simple to build but require periodic emptying which results in widespread dispersion of fecal pathogens in the environment. While much is known about the health risks of fecal-oral exposure, little is known about those resulting from the aerosolization of pathogens from fecal material. Bioaerosols were sampled around seven pit latrines before, after, and during emptying in Blantyre, Malawi. Bioaerosols were collected directly onto nutrient and selective medium agar plates using an impact sampler. DNA was extracted from some plates and analyzed for selected enteric pathogens. Total heterotrophic bacteria in the air during active emptying ranged from 198 to >13,000 colony forming units (CFU) per m3, and generally increased above background levels during pit emptying. At about one meter from the pit latrine emptying, E. coli and total coliforms concentrations in air reached up to 350 and 790 CFU m-3, respectively. Additionally, at four out of the seven pit latrines sites sampled, enterotoxigenic E. coli (ETEC) LT/ST was confirmed to be present in bioaerosols. This work demonstrates the potential for airborne dispersion of enteric pathogens during pit latrine emptying operations.
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Affiliation(s)
- Stewart Farling
- Dept. of Civil and Environmental Engineering, Box 90287, Duke University, Durham, NC 27708-0287, USA
| | - Tate Rogers
- Triangle Environmental Health Initiative, 711 N Hyde Park Ave, Durham, NC 27703, USA
| | - Jackie S Knee
- School of Civil and Environmental Engineering, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, GA, 30332, USA
| | - Elizabeth A Tilley
- Department of Environmental Health, University of Malawi, The Polytechnic, Chichiri, Blantyre 3, Malawi; EAWAG: Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, 8600 Dübendorf, Switzerland
| | - Joe Brown
- School of Civil and Environmental Engineering, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, GA, 30332, USA
| | - Marc A Deshusses
- Dept. of Civil and Environmental Engineering, Box 90287, Duke University, Durham, NC 27708-0287, USA.
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Abstract
A gastrointestinal outbreak was reported among 154 diners who attended a Christmas buffet on the 9 and 10 December 2016. A retrospective cohort study was undertaken. Faecal samples, water, ice and an air ventilation device were tested for indicators and routine pathogens. Altogether 26% (24/91) fulfilled the case definition of having typical viral gastrointestinal symptoms. Norovirus genogroup I was detected in faecal samples from three cases. One of these cases tested positive also for sapovirus and had a family member testing positive for both norovirus and sapovirus. A diner who drank water or drinks with ice cubes (risk ratios (RR) 6.5, 95% confidence intervals (CI) 1.5–113.0) or both (RR 8.2, 95% CI 1.7–145.5) had an increased risk in a dose-response manner. Ice cubes from three vending machines had high levels of heterotrophic bacteria. A faulty air ventilation valve in the space where the ice cube machine was located was considered a likely cause of this outbreak. Leaking air ventilation valves may represent a neglected route of transmission in viral gastrointestinal outbreaks.
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Lai ACK, Nunayon SS, Tan TF, Li WS. A pilot study on the disinfection efficacy of localized UV on the flushing-generated spread of pathogens. JOURNAL OF HAZARDOUS MATERIALS 2018; 358:389-396. [PMID: 30005250 PMCID: PMC7116983 DOI: 10.1016/j.jhazmat.2018.07.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 06/25/2018] [Accepted: 07/01/2018] [Indexed: 05/21/2023]
Abstract
The process of toilet-flushing can generate flushing-associated water droplets which can potentially expose humans to pathogen-laden aerosols. Very little is known about such aerosol dissemination or the means for minimizing exposure to these aerosols. This study has evaluated the efficacy of ultraviolet waveband C (UV-C) for disinfection of flushing-generated pathogen-laden aerosols through tests with localized disinfection systems for airborne and surface contaminations. Three types of bacteria were chosen for investigation: Staphylococcus epidermidis, Escherichia coli, and Salmonella typhimurium. Tests were conducted with UV-C tubes of 5 W and 10 W. High levels of disinfection efficacies were observed, ranging from 76% to 97% for bacteria-laden aerosols at sources of emission, and efficiencies of 53% to 79% for surface samples in localized systems. The results from the localized systems were further compared with those obtained with an upper-room ultraviolet germicidal irradiation (UVGI) system. As it is important to note, the UV-C doses and ozone emissions for the localized systems were found well below the limits recommended in current guidelines. This research has shown that the disinfection of flushing-generated pathogen-laden aerosols in proximity to the source of emission was more effective than at the more distant sites where aerosols may be dispersed to the environment.
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Affiliation(s)
- A C K Lai
- Department of Architecture and Civil Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong.
| | - S S Nunayon
- Department of Architecture and Civil Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong
| | - T F Tan
- Shenzhen Key Laboratory for the Sustainable Use of Marine Biodiversity, Research Centre for the Oceans and Human Health, City University of Hong Kong Shenzhen Research Institute, Shenzhen, China
| | - W S Li
- Queen Mary Hospital, Pokfulam Road, Hong Kong; School of Public Health, The University of Hong Kong, Hong Kong
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48
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Evaluation of hospital-grade disinfectants on viral deposition on surfaces after toilet flushing. Am J Infect Control 2018; 46:507-511. [PMID: 29305284 DOI: 10.1016/j.ajic.2017.11.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 11/03/2017] [Accepted: 11/03/2017] [Indexed: 12/21/2022]
Abstract
BACKGROUND Past studies have shown that infectious aerosols created during toilet flushing result in surface contamination of the restroom. The goals of this study were to quantify viral contamination of surfaces in restrooms after flushing and the impact of disinfectants added to the toilet bowl prior to flushing on reducing surface contamination. METHODS The degree of contamination of surfaces in the restroom was assessed with and without the addition of coliphage MS2 to the toilet bowl before flushing. The bowl water and various surfaces in the restroom were subsequently tested for the presence of the virus. RESULTS The toilet bowl rim, toilet seat top, and toilet seat underside were contaminated in all trials without a disinfectant added to the bowl water before flushing. All disinfectants significantly reduced concentrations on surfaces when the contact time was ≥15 minutes. Hydrogen peroxide resulted in very little reduction of virus in the toilet bowl (<1 log10). Peracetic acid and quaternary ammonium had the greatest log reductions on virus in the organic matter in the toilet. CONCLUSIONS Toilet flushing resulted in extensive contamination of surfaces within the restroom. Addition of disinfectant to the toilet bowl prior to flushing reduced the level of contamination in the bowl and fomites after flushing.
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Bing-Yuan, Zhang YH, Leung NH, Cowling BJ, Yang ZF. Role of viral bioaerosols in nosocomial infections and measures for prevention and control. JOURNAL OF AEROSOL SCIENCE 2018; 117:200-211. [PMID: 32226118 PMCID: PMC7094610 DOI: 10.1016/j.jaerosci.2017.11.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2017] [Revised: 11/21/2017] [Accepted: 11/23/2017] [Indexed: 09/21/2023]
Abstract
The presence of patients with diverse pathologies in hospitals results in an environment that can be rich in various microorganisms including respiratory and enteric viruses, leading to outbreaks in hospitals or spillover infections to the community. All hospital patients are at risk of nosocomial viral infections, but vulnerable groups such as older adults, children and immuno-compromised/-suppressed patients are at particular risk of severe outcomes including prolonged hospitalization or death. These pathogens could transmit through direct or indirect physical contact, droplets or aerosols, with increasing evidence suggesting the importance of aerosol transmission in nosocomial infections of respiratory and enteric viruses. Factors affecting the propensity to transmit and the severity of disease transmitted via the aerosol route include the biological characteristics affecting infectivity of the viruses and susceptibility of the host, the physical properties of aerosol particles, and the environmental stresses that alter these properties such as temperature and humidity. Non-specific systematic and individual-based interventions designed to mitigate the aerosol route are available although empirical evidence of their effectiveness in controlling transmission of respiratory and enteric viruses in healthcare settings are sparse. The relative importance of aerosol transmission in healthcare setting is still an on-going debate, with particular challenge being the recovery of infectious viral bioaerosols from real-life settings and the difficulty in delineating transmission events that may also be a result of other modes of transmission. For the prevention and control of nosocomial infections via the aerosol route, more research is needed on identifying settings, medical procedures or equipment that may be associated with an increased risk of aerosol transmission, including defining which procedures are aerosol-generating; and on the effectiveness of systematic interventions on aerosol transmission of respiratory and enteric viruses in healthcare settings.
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Affiliation(s)
- Bing-Yuan
- State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, No. 151, Yanjiangxi Road, Yuexiu District, Guangzhou, Guangdong 510120, China
- Department of Respiration, First People's Hospital of Yunnan Province, 157, Jinbi Road, Kunming, Yunnan 650032, China
| | - Yun-Hui Zhang
- Department of Respiration, First People's Hospital of Yunnan Province, 157, Jinbi Road, Kunming, Yunnan 650032, China
| | - Nancy H.L. Leung
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Patrick Manson Building (North Wing), 7 Sassoon Road, Pokfulam, Hong Kong SAR, China
| | - Benjamin J. Cowling
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Patrick Manson Building (North Wing), 7 Sassoon Road, Pokfulam, Hong Kong SAR, China
| | - Zi-Feng Yang
- State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, No. 151, Yanjiangxi Road, Yuexiu District, Guangzhou, Guangdong 510120, China
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Johnson DL, Lynch RA, Villanella SM, Jones JF, Fang H, Mead KR, Hirst DVL. Persistence of Bowl Water Contamination during Sequential Flushes of Contaminated Toilets. JOURNAL OF ENVIRONMENTAL HEALTH 2017; 80:34-49. [PMID: 29651169 PMCID: PMC5890808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Toilets contaminated with infectious organisms are a recognized contact disease transmission hazard. Previous studies indicate that toilet bowl water can remain contaminated for several flushes after the contamination occurs. This study characterized contamination persistence over an extended series of flushes using both indicator particles and viable bacteria. For this study, toilets were seeded with microbe-size microbial surrogates and with Pseudomonas fluorescens or Clostridium difficile bacteria and flushed up to 24 times. Bowl water samples collected after seeding and after each flush indicated the clearance per flush and residual bowl water contaminant concentration. Toilets exhibited 3 + log10 contaminant reductions with the first flush, only 1-2 logs with the second flush, and less than 1 log thereafter. Contamination still was present 24 flushes post contamination. Clearance was modeled accurately by a two-stage exponential decay process. This study shows that toilet bowl water will remain contaminated many flushes after initial contamination, posing a risk of recurring environmental contamination and associated infection incidence.
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Affiliation(s)
- David L. Johnson
- Department of Occupational and Environmental Health, University of Oklahoma College of Public Health, P.O. Box 26901, Oklahoma City, Oklahoma 72126-0901
| | - Robert A. Lynch
- Department of Occupational and Environmental Health, University of Oklahoma College of Public Health, P.O. Box 26901, Oklahoma City, Oklahoma 72126-0901
| | - Stephanie M. Villanella
- Department of Occupational and Environmental Health, University of Oklahoma College of Public Health, P.O. Box 26901, Oklahoma City, Oklahoma 72126-0901
| | - Jacob F. Jones
- Department of Occupational and Environmental Health, University of Oklahoma College of Public Health, P.O. Box 26901, Oklahoma City, Oklahoma 72126-0901
| | - Haiqin Fang
- Key Laboratory of Food Safety Risk Assessment, China National Center for Food Safety Risk Assessment, Ministry of Health, Beijing 100021, PR China
| | - Kenneth R. Mead
- Division of Applied Research and Technology, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Cincinnati, Ohio 45213
| | - Deborah V. L. Hirst
- Division of Applied Research and Technology, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Cincinnati, Ohio 45213
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