Exploring the Importance of Differentiating Live and Dead Microorganisms to Enhance Cleaning Effectiveness and Reduce Infection Risks in Healthcare Settings.
Infection prevention and control (IPC) is fundamental in healthcare environments, especially within hospital wards, where preventing healthcare-associated infections (HAIs) can save lives. A major part of IPC involves monitoring the cleanliness of surfaces, tools, and devices that come into contact with both patients and staff. However, there is a growing concern over whether current methods truly indicate whether an environment is pathogen-free, specifically focusing on the viability of organisms collected during environmental monitoring. The importance of knowing whether these microorganisms are alive or dead is key to understanding the effectiveness of cleaning and disinfection processes.
The Importance of Effective Environmental Monitoring
Hospital wards are often subjected to rigorous cleaning protocols aimed at minimising the presence of harmful pathogens. Yet, one of the biggest questions remains: “How do you know clean is clean?” Surfaces might appear spotless and test results from certain rapid cleanliness tests may suggest low contamination levels, but does this mean the environment is safe?
Traditional tests like ATP (adenosine triphosphate) measurement are often used to quickly determine the cleanliness of a surface. They detect the presence of organic matter, including living and dead cells. However, this method doesn’t differentiate between viable and non-viable organisms. Therefore, ATP measurements may show the presence of contaminants, but they won’t tell you if the pathogens are alive and capable of causing infections or simply remnants of previously neutralised organisms. This lack of differentiation can lead to unnecessary actions, like ward closures, that may disrupt hospital operations without truly addressing infection risks.
The Limitations of Non-Culture Methods
ATP testing is often used as a screening method for cleaning validation due to its ability to deliver rapid results. However, while it effectively detects the presence of organic matter, it does not differentiate between live and dead microbes. As such, non-culture methods provide an overview of cleanliness but do not give specific insights into whether remaining microorganisms are viable and capable of causing infections. To gain a complete understanding of environmental risks, it is essential to rapid screening methods, such as ATP testing, with culture methods, which allow healthcare professionals to determine if the microorganisms present are still viable and require further intervention (Collins, 2012)
Without further culture testing, it’s impossible to tell if the detected organisms are viable or merely cellular debris. This lack of detailed information can result in unnecessary ward closures, which may impact hospital capacity and patient care, or worse, give a false sense of security when pathogens are still present and active.
The Need to Differentiate Between Viable and Non-Viable Organisms
Knowing whether organisms are alive or dead is crucial when assessing hospital cleaning efficacy. Live organisms pose a risk of transmission, while dead ones do not. ATP measurement, often used for rapid cleanliness checks, detects organic matter but cannot distinguish between viable and non-viable microorganisms. While ATP tests provide immediate feedback on contamination, they don’t reveal whether organisms are capable of causing infections. This can lead to unnecessary interventions or underestimations of risk.
Effective environmental monitoring should focus on methods that differentiate viable microorganisms. Culture-based methods confirm whether remaining pathogens are alive and harmful, allowing healthcare teams to target cleaning efforts and reduce healthcare-associated infections. Combining ATP with culture techniques offers a more accurate infection control strategy.
For example, Clostridium difficile can persist on surfaces for long periods and may become airborne, contributing to cross-contamination (Best, 2012). Without accurate testing, contamination reservoirs like hospital curtains, which can harbour C. difficile despite infrequent cleaning, may be overlooked (Best, 2012).
POLYWIPE™ and NRSII™: Reliable Sampling Tools for Accurate Results
One solution to the challenge of differentiating between viable and non-viable organisms lies in the use of advanced microbial surface sampling methods, such as the POLYWIPE™ and NRSII™ sponge swabs. Both products are designed to collect surface samples and neutralise any cleaning agents present, providing a more accurate representation of the living organisms present on surfaces. Additionally, this method can be standardised using a 10x10cm template, ensuring consistent and reliable sample collection across various areas. By using this standardised approach, healthcare facilities can accurately assess cleaning efficacy, identifying any viable pathogens that may still pose a risk and ensuring targeted infection control measures.
POLYWIPE™ is highly effective in large-area sampling. Its pre-moistened sterile sponge makes it an ideal tool for collecting microbial samples from wide surfaces, such as hospital beds or floors (Collins, 2011). The neutralising agents ensure that any residual cleaning chemicals do not interfere with the microbial count, allowing for a clearer picture of what pathogens remain viable. This ensures that only live organisms are cultured and assessed, giving healthcare providers accurate information to act upon.
For smaller or high-touch areas like doorknobs, bed rails, or tabletops, NRSII™ is an excellent alternative. Tailored for more targeted sampling, NRSII™ captures viable organisms from smaller surfaces that are frequently touched and pose a higher risk of pathogen transmission.
The Role of Culture Testing in Infection Prevention
One of the key advantages of using products like POLYWIPE™ is that they allow healthcare professionals to culture the samples, giving a clear indication of which organisms are alive. By incubating the collected samples in a laboratory setting, viable pathogens such as C. difficile, MRSA, and VRE can be identified and treated appropriately (Collins, 2011; Collins, 2012).
Screening techniques that include culture testing are crucial because they provide conclusive data on the types of organisms present and whether they pose an active threat. This process allows hospitals to implement targeted cleaning measures rather than reacting to inconclusive ATP tests. The added benefit is that cleaning protocols can be adjusted to ensure maximum efficacy, reducing the risk of HAI outbreaks.
Environmental Monitoring Success
Several case studies highlight the importance of effective environmental monitoring, and the difference advanced sampling tools can make. For example, studies have shown that mattresses and curtains in hospital wards can harbour viable pathogens long after routine cleaning, underscoring the need for thorough testing and culture techniques (Collins, 2012; Best, 2012).
In one hospital, POLYWIPE™ sampling during a mattress audit detected C. difficile on surfaces even after standard cleaning procedures, demonstrating the persistence of this pathogen and the need for targeted disinfection (Collins, 2011).
Similarly, research on hospital curtains found that these frequently overlooked items can act as reservoirs for infection when contaminated with airborne spores of C. difficile (Best, 2012). The findings showed that random sampling of small curtain sections could miss true contamination, emphasizing the necessity for comprehensive environmental monitoring.
Infection prevention and control in hospital wards must go beyond superficial cleanliness checks. It requires an in-depth understanding of the living organisms present in the environment. While ATP tests provide a quick overview of contamination, they fall short when it comes to determining whether organisms are alive or dead. Products like POLYWIPE™ and NRSII™, combined with culture testing, offer a more reliable solution for effective environmental monitoring.
References:
- Collins, J. (2012). Collaborative development of a quality assurance programme for the decontamination of hire beds. Newcastle Upon Tyne Hospitals NHS Foundation Trust.
- Collins, J. (2011). Mattress screening using Polywipes and chromogenic Clostridium difficile agar. Newcastle Upon Tyne Hospitals NHS Foundation Trust.
- Best, E. L., Bosomworth, C. E., Pinker, F., Parnell, P., & Wilcox, M. H. (2012). Curtains as a source of Clostridium difficile: The importance of sampling methods. The Leeds Teaching Hospitals NHS Trust.
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Author
Lucy Pulman
Marketing – MWE