Surgical hand preparation with chlorhexidine soap or povidone iodine: new methods to increase immediate and residual effectiveness, and provide a safe alternative to alcohol solutions

Alcohol-Based Chlorhexidine and Potassium Sorbate Rub Strengthens the Effectiveness of Traditional Hand Scrubbing and Improves Long-Lasting Effectiveness-Evaluation of Hand Preparation Protocols According to EN 12791

Despite the advantages of surgical handrub in terms of the ease of application and effectiveness, chlorhexidine (CHG)-based hand scrubbing remains the preferred method for surgical hand preparation. However, it does not systematically meet the non-inferiority requirement of the European norm (EN) 12791 with respect to n-propanol (the reference product) and does not provide the sustained efficacy expected for these long-lasting agents. Commercially available alcohol-based products have also failed to demonstrate sustained efficacy according to EN 12791. Multi-step protocols enhance the efficacy of hand scrubbing, yet their extended disinfection duration might diminish their allure for healthcare professionals. In this study, we show that hand scrubbing with CHG 4% followed by a 1 min rubbing with the novel formulation of ethanol (Et) 70%/CHG 3% plus 0.3% potassium sorbate food additive (PS) meets the non-inferiority requirement and demonstrates sustained efficacy when tested according to EN 12791. The immediate and 3 h effect of this protocol was significantly higher than that of n-propanol and the homologous disinfection protocol without PS (CHG 4% hand scrub plus Et 70%/CHG 3% rub), demonstrating that the inclusion of PS confers a notable residual effect. We speculate that this non-volatile ingredient acts synergistically with CHG. This promising combination represents an alternative method for the development of new disinfection strategies.

The application of normative documents for determination of biocidal activity of disinfectants and antiseptics dedicated for medical area: a narrative review

Disinfectants and antiseptics are important weapons to reduce the number of microorganisms and thus to limit the number of infections. Different methods of antimicrobial activity testing, often not standardised, without appropriate controls and not validated are applied. To address these issues, several European Standards (EN) have been developed, describing the test methods to determine whether chemical disinfectants or antiseptic products have appropriate bactericidal, sporicidal, mycobactericidal or tuberculocidal activity; fungicidal or yeasticidal activity; or virucidal activity. In this narrative review, the 17 EN concerning evaluation of the above-mentioned antimicrobial activity of preparations dedicated to the medical area are briefly reviewed, together with recent publications on this topic. Suspension and carrier tests have been performed in clean and dirty conditions simulating the medical area. In addition, a wide range of applications of these standards has been presented in the research of biocides for hand antisepsis, surfaces disinfection, including airborne disinfection as well as medical device and medical textile disinfection. The role of normative documents in the investigation of antimicrobial activity of disinfectants and antiseptics to limit infections has been underestimated. This narrative review aims to persuade researchers to conduct antimicrobial activity testing in line with validated EN and highlights an existing gap in ongoing research. It also aims to raise awareness of the wide range of biocidal activity tests with standardised methods in medical area. We also pay attention to the recently developed European Pharmacopoeia monography concerning the testing of bactericidal and fungicidal activity of antiseptics classified as medicinal products.

Evaluation of the Residual Disinfection Effects of Commonly Used Skin Disinfectants against Viruses: An Innovative Contact Transmission Control Method

Lasting disinfection effects, that is, the residual disinfection effects (RDEs), of skin-coated disinfectants have rarely been considered for infection control owing to the challenges involved in the accurate evaluation of RDEs. In this study, we constructed a new skin evaluation model and determined the RDEs of existing disinfectants against viruses. Our results showed that ethanol and isopropanol had no RDE, whereas povidone-iodine, chlorhexidine gluconate, and benzalkonium chloride (BAC) exhibited RDEs, with 10% povidone-iodine and 0.2% BAC showing particularly strong RDEs. The RDE of 0.2% BAC was strong enough to reduce the median survival times of severe acute respiratory syndrome coronavirus-2, human coronavirus-OC43, and influenza virus from 670 to 5.2, 1300 to 12, and 120 to 4.2 min, respectively. Additionally, this strong RDE was maintained even 4 h after coating the skin. Clinical data also showed that the strong RDE of 0.2% BAC was maintained for more than 2 h. Thus, applying disinfectants with strong RDEs on the skin correlates with a reduction in virus survival time and appears to create a skin surface environment that is not conducive to virus survival. A prolonged reduction in virus survival decreases the contact transmission risk, thereby enabling stronger infection control.

Controlled release of iodine from cross-linked cyclodextrin metal-organic frameworks for prolonged periodontal pocket therapy

Effective therapeutic system to periodontitis was designed using cross-linked cyclodextrin metal-organic framework (COF) as carrier for iodine and further suspended in hydroxyethyl cellulose gel as I2@COF-HEC hydrogel. Inclusion of iodine within the COF was demonstrated by SR-FTIR spectral and characteristic DSC and TGA changes. Molecular modelling identified the interaction of iodine with both COF central cavity and individual cyclodextrin moieties of COF. In vitro results of study demonstrated that iodine release in artificial saliva from I2@COF-HEC hydrogel could be extended up to 5 days, which was slower than I2@COF particles. Using an in vivo rat model of periodontitis, micro-computed tomography of alveolar bone morphology demonstrated that I2@COF-HEC hydrogel showed similar effects in decreasing periodontal pocket depth and alveolar bone resorption to minocycline ointment, a periodontitis antibiotic. The I2@COF-HEC hydrogel is a novel local delivery device of iodine as a broad spectrum antimicrobial use for treatment of periodontitis.

Actualidades en la higiene de manos quirúrgica. Revisión de la literatura

Introducción: La higiene de manos quirúrgica, procedimiento esencial en cirugía; es una técnica que ha evolucionado y se ha ido actualizando tras el surgimiento de evidencia científica. El manual de la Organización Mundial de la Salud (OMS) publicado hace diez años es uno de los documentos que plasman cambios de esta técnica, como dejar de usar el cepillo. Sin embargo, es necesario analizar la evidencia actual con la finalidad de reconocer las nuevas tendencias de acuerdo con los resultados de las investigaciones publicadas. Objetivo: Realizar una revisión actualizada de la literatura sobre la higiene de manos quirúrgica. Desarrollo: El lavado de manos quirúrgico con cepillo es un procedimiento que se realiza en la mayoría de las instituciones hospitalarias de México; pocas han incursionado en la técnica en la que se omite el uso de cepillo. Existen diversos estudios que sustentan que el uso de cepillos debe ser erradicado debido al daño tisular que estos ocasionan. La abrasión dérmica provocada por el uso de cepillos origina que el personal se cepille las superficies de las manos y brazos por menos tiempo que el recomendado y esto a su vez impide un efecto idóneo por parte de los antisépticos. Las sustancias más recomendadas son la clorhexidina y las soluciones a base de alcohol. Conclusiones: La higiene de manos quirúrgica sin cepillo debe ser considerada debido a que disminuye costos hospitalarios, garantiza la efectividad de la descontaminación de manos, ocasiona menos lesiones dérmicas y contribuye a la reducción de las infecciones relacionadas al sitio quirúrgico.

Infectious Disease Management and Control with Povidone Iodine

With reports of vancomycin-resistant enterococci recently emerging in hospital settings, renewed focus is turning to the importance of multifaceted infection prevention efforts. Careful compliance with established hygiene practices by healthcare workers together with effective antiseptic options is essential for the protection of patients from infectious agents. For over 60 years, povidone iodine (PVP-I) formulations have been shown to limit the impact and spread of infectious diseases with potent antiviral, antibacterial and antifungal effects. In addition to a lack of reported resistance, the benefits of PVP-I include an excellent safety profile and a broad spectrum of effect due to its multimodal action. Studies have shown that hand washing with PVP-I-based antiseptics is effective for the decontamination of skin, while PVP-I mouthwashes and gargles significantly reduce viral load in the oral cavity and the oropharynx. The importance of PVP-I has been emphasised by its inclusion in the World Health Organization's list of essential medicines, and high potency for virucidal activity has been observed against viruses of significant global concern, including hepatitis A and influenza, as well as the Middle-East Respiratory Syndrome and Sudden Acute Respiratory Syndrome coronaviruses. Together with its diverse applications in antimicrobial control, broad accessibility across the globe, and outstanding safety and tolerability profile, PVP-I offers an affordable, potent, and widely available antiseptic option.Funding Mundipharma Singapore Holding Pte Limited.

Adaptive bacterial response to low level chlorhexidine exposure and its implications for hand hygiene

Chlorhexidine digluconate (CHG) is commonly used in healthcare, e.g. in skin antiseptics, antimicrobial soaps, alcohol-based hand rubs and oral or wound antiseptics. Aim of the literature review was to evaluate the potential of bacteria to adapt to low level CHG exposure. A maximum 4fold MIC increase to CHG was found after low level exposure in most of the 71 evaluated bacterial species. A strong adaptive mostly stable MIC change was described in strains or isolates of the healthcare-associated species E. coli, S. marcescens and P. aeruginosa (up to 500fold, 128fold or 32fold, respectively). The highest MIC values after adaptation were 2,048 mg/l (S. marcescens) and 1,024 mg/l (P. aeruginosa). A new resistance to tetracycline, gentamicin, meropeneme or triclosan was found in some adapted isolates. In E. coli horizontal gene transfer was induced (sulfonamide resistance by conjugation), pointing out an additional risk of sublethal CHG. The use of CHG in patient care - but also all other settings such as consumer products and households - should therefore be critically assessed and restricted to indications with a proven health benefit or justifiable public health benefits. Additional CHG has no health benefit when used in alcohol-based hand rubs and is not recommended by the WHO. For routine hand washing of soiled hands the use of plain soap is sufficient, CHG in soaps has no health benefit. In surgical hand antisepsis alcohol-based hand rubs should be preferred to CHG soaps. Implementation of these principles will help to reduce avoidable selection pressure.