Environmental microorganisms and infection transmission in healthcare buildings
Lead Research Organisation:
University of Leeds
Department Name: Civil Engineering
Abstract
Healthcare acquired infection (HCAI) remains a problem worldwide and antibiotic resistance means that treating infections is becoming increasingly challenging. There is increasing evidence that the built environment plays an important role in the transmission pathway for infections. In particular, contact transmission can be influenced by the contamination of surfaces in the hospital environment, which is also influenced by the prevalence of microorganisms in the air. While there is growing awareness of the relationships between the environment and microbial contamination, there is very little quantitative data to assess the interactions between air and surface contamination. Moreover the majority of studies have been conducted from a microbiology or clinical perspective and do not fully characterise the physical environment or the activities that are taking place. As such there is not sufficient data to be confident in relationships and to understand how this varies with time.
This project aims to fill this gap in knowledge by establishing quantitative relationships between microogansmisms in hospitals and the design and operation of the hospital environment. This will lead to new approaches to assess the role of the environment on infection risk, supporting both future design and actions such as cleaning. The PhD is aligned to the EPSRC HECOIRA Healthcare Impact Partnership Project EP/P023312/1.
The key objectives of the study are:
Quantify the relationships between microorgansims on the air and on surfaces over time under controlled conditions. This will involve bioaerosol chamber studies for a range of conditions including bioaerosol source, microorganism species, ventilation flow rate, and temperature and humidity, to quantify concentration and viability of microorganisms with time and establish deposition, evaporation and survival rates.
Characterise transient relationships between air and surface microbial burden in a hospital environment. This will involve substantial microbial and environmental sampling and activity monitoring studies in two hospital wards to develop time series variations in air and surface contamination with time, physical conditions and activity.
Apply empirical relationships within mathematical models of infection risk to evaluate the relationships between cleaning procedures, hand hygiene and the environment on potential infection risks for specific events in hospital ward settings.
The project aligns to EPSRC priorities in Built Environment and Healthcare Technology. By integrating microbial methodologies with data on the physical environment and its operation, the project will give new insights to inform future healthcare estates design and operation as well as support clinical decisions over patient care.
This project aims to fill this gap in knowledge by establishing quantitative relationships between microogansmisms in hospitals and the design and operation of the hospital environment. This will lead to new approaches to assess the role of the environment on infection risk, supporting both future design and actions such as cleaning. The PhD is aligned to the EPSRC HECOIRA Healthcare Impact Partnership Project EP/P023312/1.
The key objectives of the study are:
Quantify the relationships between microorgansims on the air and on surfaces over time under controlled conditions. This will involve bioaerosol chamber studies for a range of conditions including bioaerosol source, microorganism species, ventilation flow rate, and temperature and humidity, to quantify concentration and viability of microorganisms with time and establish deposition, evaporation and survival rates.
Characterise transient relationships between air and surface microbial burden in a hospital environment. This will involve substantial microbial and environmental sampling and activity monitoring studies in two hospital wards to develop time series variations in air and surface contamination with time, physical conditions and activity.
Apply empirical relationships within mathematical models of infection risk to evaluate the relationships between cleaning procedures, hand hygiene and the environment on potential infection risks for specific events in hospital ward settings.
The project aligns to EPSRC priorities in Built Environment and Healthcare Technology. By integrating microbial methodologies with data on the physical environment and its operation, the project will give new insights to inform future healthcare estates design and operation as well as support clinical decisions over patient care.
People |
ORCID iD |
| Catherine Noakes (Primary Supervisor) | |
| Waseem Hiwar (Student) |
Publications
King MF
(2020)
Bacterial transfer to fingertips during sequential surface contacts with and without gloves.
in Indoor air
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| EP/N509681/1 | 01/10/2016 | 30/09/2021 | |||
| 1955605 | Studentship | EP/N509681/1 | 01/10/2017 | 30/09/2021 | Waseem Hiwar |
| Description | The quantitative relationship between airborne and surface bioburden can be measured and predicted, which can lead to minimising the risk of hospital-acquired infection by providing a standardised plan to perform cleaning and disinfection procedure. The findings support the importance of controlling the ventilation and the environmental parameters to mitigate both air and surface infection risks in the hospital environment. |
| Exploitation Route | This work can be of tremendous advantage to researchers as it provides quantitative studies and meta-analyses in addition to a novel device that can help and standardise the sampling of airborne microbial deposition on surfaces. It also presents an intensive systematic review of academic papers in this field and summarizes the key findings saving months-worth of work for new researchers. More importantly, this work shows that the feasible action of controlling ventilation rate can affect the deposition rate of airborne microorganisms and possibly mitigate the infection risk. |
| Sectors | Environment,Healthcare |
| Title | Automated Multi-Plate Air Sampler (AMPAS) |
| Description | In a controlled chamber with an aerosolised microorganism that could be pathogenic, it is not possible for a person to enter the room. In a real-world environment, it can also be challenging to physically access the room and change the plates manually in a timely manner without causing inconvenience to the patient or for safety reasons where a patient may have a contagious disease. I created a novel Automated Multi-Plate Air Sampler (AMPAS) for surface sampling purposes to obtain accurate results, and to collect samples at precise intervals with minimal human intervention. This device allows us to capture the transient effects without human intervention. To the best of our knowledge, there is no commercial equivalent to this device. The implementation included building (from scratch) the electrical and electronic circuit, the mechanical aspects including motors and shafts, and the programming and configuration of the device using an Arduino controller. I have performed extensive testing and validation for the device in different environments (controlled environment, office environment, and hospital environment) simultaneously performing air sampling to optimize the efficiency of the device and to obtain accurate and reliable data in terms of both timing and data collection. |
| Type Of Material | Biological samples |
| Year Produced | 2021 |
| Provided To Others? | Yes |
| Impact | This device enabled us to quantify the deposition rate of airborne microorganisms on surfaces in both controlled and real-world environments where there is a risk involved with human intervention. It also enabled us to determine the effect of environmental parameters that can be controlled like ventilation, HEPA filter unit, UV device, air conditioning, etc on the deposition rate onto surfaces. This provides clear scientific progress if these techniques can affect the quantitative samples of deposited microorganisms on surfaces. |
| URL | https://scholar.google.co.uk/citations?view_op=view_citation&hl=en&user=l0q3A3gAAAAJ&citation_for_vi... |
| Description | Far-UVC (222 nm) efficiently inactivates an airborne pathogen in a room-sized chamber |
| Organisation | NHS Scotland |
| Department | NHS 24 |
| Country | United Kingdom |
| Sector | Public |
| PI Contribution | I conducted an investigation to demonstrate the performance of the Far-UVC devices at reducing the concentration of microorganisms in the air and on surfaces under different environmental conditions. I have also contributed to the design and planning of these experiments. |
| Collaborator Contribution | The University of Dundee provided the means for performing CFD analyses and led the progress of the project. The NHS Scotland provided the experiment setup and the geometry of the testing areas. |
| Impact | This collaboration is multi-disciplinary involving Civil engineering, Biology, Medicine, Physics and Astronomy. - Eadie, E., Hiwar, W., Fletcher, L., Tidswell, E., O'Mahoney, P., Buonanno, M., Welch, D., Adamson, C.S., Brenner, D.J., Noakes, C. and Wood, K., 2021. Far-UVC efficiently inactivates an airborne pathogen in a room-sized chamber. Scientific Reports SREP 8462 pp.9-17 |
| Start Year | 2021 |
| Description | Far-UVC (222 nm) efficiently inactivates an airborne pathogen in a room-sized chamber |
| Organisation | University of Dundee |
| Department | Radiology Dundee |
| Country | United Kingdom |
| Sector | Academic/University |
| PI Contribution | I conducted an investigation to demonstrate the performance of the Far-UVC devices at reducing the concentration of microorganisms in the air and on surfaces under different environmental conditions. I have also contributed to the design and planning of these experiments. |
| Collaborator Contribution | The University of Dundee provided the means for performing CFD analyses and led the progress of the project. The NHS Scotland provided the experiment setup and the geometry of the testing areas. |
| Impact | This collaboration is multi-disciplinary involving Civil engineering, Biology, Medicine, Physics and Astronomy. - Eadie, E., Hiwar, W., Fletcher, L., Tidswell, E., O'Mahoney, P., Buonanno, M., Welch, D., Adamson, C.S., Brenner, D.J., Noakes, C. and Wood, K., 2021. Far-UVC efficiently inactivates an airborne pathogen in a room-sized chamber. Scientific Reports SREP 8462 pp.9-17 |
| Start Year | 2021 |