An interesting new article reviews the history and state-of-the-art for surface disinfection in dentistry settings. Historically, aerosols and sprays were the most common approaches to the delivery of disinfectants in dentistry. However, due to occupational exposure concerns, disinfectant wipes are quickly becoming the most common method for surface disinfection in dental settings.
The article spans space and time, beginning with acidic rinses used by ancient Egyptians in 3000 BC, and ending with a review of current disinfection approaches. The article provides a helpful list of chemicals currently used for surface disinfection in dentistry settings. Quaternary-ammonium based disinfectants the most common disinfectant, and wipes are becoming the most common mode of delivery. The article also highlights some of the unique challenges of dentistry settings, with a need for local sterilisation of some items and the associated surface hygiene requirements, x-ray equipment, rapid service user throughput, and limited availability of support staff.
Finally, the article provides some good practice recommendations for surface hygiene in dental settings. These include the need for a local infection control and environmental hygiene policy, a recommendation in favour of using disinfectant wipes, and recommendations around best-practice use of wipes in dental settings along with a visualisation of common high-touch surfaces to target.
Dentistry often includes invasive procedures and infections can be serious and difficult to treat. So it’s vital that the dental environment is kept clean and safe to prevent the transmission of microorganisms that can cause infections.
As we come towards 5th May, it’s time to celebrate global hand hygiene day! This year, the theme for the WHO’s campaign is ‘Clean care for all – it’s in your hands’.
The WHO team in Geneva have published editorials in a range of journals (including one here in Infection Control and Hospital Epidemiology) outlining the details of the campaign. The campaign includes individual calls to action for different staff groups. This is a good message: regardless of your professional background or role, hand hygiene is in your hands! The campaign and also launches a Global Survey on Hand Hygiene (details here).
The idea of ‘Clean care for all’ is broader than just hand hygiene – and encompasses the cleaning and disinfection of surfaces and medical devices in what is a ‘multi-modal’ approach to infection prevention. The transmission of pathogenic micro-organisms between patients occurs through a complex network of vectors and fomites. If we are to prevent the transmission of pathogens that cause HCAI in hospitals, it’s no good just focussing on hand hygiene – otherwise the organisms will ‘choose’ an alternative route (see the Diagram below)!
Diagram: Dynamic transmission routes of microorganisms that can cause HCAI
We blogged last time on the first in a series of articles in the Journal of Infection Prevention about disinfection in healthcare. The first part in the series argues for routine disinfection of the healthcare environment. This second instalment describes the importance of standardised testing of disinfectants for hospitals.
The authors describe the bewildering choice of disinfectant chemistries and formulations that are now available for disinfecting healthcare surfaces. Infection Prevention and Control experts have a key role to play in ensuring that the most appropriate range of disinfectants are available to hospital cleaning teams. The key property of a disinfectant is its ability to kill microorganisms. Therefore, a crucial step in the process of selecting an appropriate disinfectant is ensuring that it has the required level and range of biocidal activity through standardised laboratory testing.
The article describes the family of European testing standards (EN standards) that are currently available, including both suspension testing methods, which test the ability of a disinfectant to kill microorganisms in a liquid suspension, and surface/carrier testing methods, which test the ability of a disinfectant to kill micro-organisms dried onto a surface. Key considerations when considering testing standard include:
On a more practical level, it is vital to perform disinfectant testing in accredited laboratories who are experienced at performing this sort of testing. Otherwise, common pitfalls can occur and efficacy can be over-estimated. Commonly, disinfectant neutralisation is not performed adequately, meaning that the actual contact time is longer than the intended contact time and the efficacy of the disinfectant is over-estimated. For example, many ‘sporicidal’ disinfectants that are on the market do not exhibit meaningful sporicial activity when tested using appropriate laboratory methods. Therefore, when reviewing a disinfectant for use in a hospital, it is wise to ask the following questions:
Biocidal activity is a vital factor in selecting an appropriate disinfectant. However, other factors are also crucial when selecting the right disinfectant, including the mode of application, environmental impact, potential occupational exposure issues, and formulation. These factors must be considered together when selecting the most appropriate hospital disinfectant.
A new review in the Journal of Infection Prevention by Dr Evonne Curran and colleagues sets out the arguments for and against the routine use of disinfectants in the healthcare environment. The review dispels some of the common arguments used against the routine use of disinfectants in the healthcare environment, and presents a novel risk-based scheme for deciding when to use detergent only for cleaning surface in the healthcare environment (which is not very often!).
Historically, the use of detergent cleaning only without the use of a chemical disinfectant has been the favoured model for cleaning the healthcare environment in the UK (whilst other countries have historically taken a more disinfectant-centric approach). However, we now know that detergent cleaning only does not reliably eliminate pathogenic micro-organisms from surfaces, and can inadvertently spread pathogens between surfaces. Therefore, routine use of disinfectants in the healthcare environment is becoming more common.
This review article examines the common arguments against the routine use of disinfectants in the healthcare environment:
The article also makes a case that the traditional approach to risk assessment for when to use a disinfectant and when to use a detergent needs to be re-evaluated in light of modern healthcare, restricting the use of detergent-only cleaning to settings outside of the patient zone when no medical equipment is around.
In summary, the use of disinfectants for cleaning and disinfecting the healthcare environment is evidence based, maximises patient safety, and is likely to be at least cost-neutral if not cost-saving.
Computer keyboards are a potential contamination risk in the hospital setting. A new systematic review of the literature concludes that computer keyboards are frequently contaminated and that more studies are required to understand the risk they pose and effective and practical methods to prevent and reduce contamination.
Computer equipment in hospital settings, such as keyboards, mice, and smartcard readers, frequently become contaminated with pathogens that can cause HCAI and are difficult to clean and disinfect. Furthermore, hand hygiene rarely follows contact with computer equipment in clinical settings. Since computer keyboards are handled by multiple staff groups, and since hand hygiene practice is rarely optimal, pathogenic organisms could be deposited onto keyboards by one staff member, and acquired on the hands of subsequent staff members, fuelling the spread of pathogenic organisms in hospitals.
Improved design and disinfection of computer keyboards has been shown to reduce the level of microbial contamination, and so reduce the risk of transmission. For example, Clinell EasyClean computer keyboards, mice, and smartcard readers have been designed to simplify cleaning procedures and increase compliance.
The review identified 75 studies including data from 2804 individual computer devices. Around one third of these studies also reported on the efficacy of disinfection methods for computer keyboards. The most common organisms found to contaminate keyboards in healthcare settings are, unsurprisingly, skin commensals. However, potential pathogens including MRSA, C. difficile, and VRE have also been identified. Disinfectant wipes were one of the methods found to be effective in tackling contamination of computer keyboards. The review concluded that more studies are required to scale the risk of computer keyboards as a potential fomite for the transmission of pathogens in healthcare settings.