Band 55, Heft 5

Changes in recent years mean that preventing infection through hygiene in home and everyday life has become increasingly important. In developing and promoting home and everyday life hygiene, a number of issues which represent a barrier to change need to be addressed and balanced against the need for effective hygiene. These include environmental and toxicity issues, and concerns about antibiotic resistance and whether we have become “too clean”. Education of the public is key, but this can only be achieved if hygiene practice is based on a simple, plausible approach to hygiene, which health professionals and the public can relate to. This in turn needs to be underpinned by an evidence base which demonstrates to health professionals and other hygiene stakeholders who communicate with the public that the procedures and products which they advise are capable of reducing infection risks to an acceptable level, with sustainable use of resource necessary to deliver hygiene such as water, heat, microbiocides etc. The purpose of this paper is to outline a multimodal targeted approach to home and everyday life hygiene based on risk management. This includes a framework for developing effective and sustainable hygiene practices, including hand hygiene, surface hygiene and laundering practices.

The microbiome of the built environment (BE) and its interactions with the human occupants represent a new and highly interdisciplinary research field. The BE is characterized by a great microbial diversity as well as very fluctuating environmental conditions and sharp gradients of physicochemical parameters, which significantly shape the resident microbiomes. A great significance of the BE microbiome for human health is obvious, but far from being fully understood. However, there is a growing body of evidence that antimicrobial and probiotic strategies will have to be balanced in a well-considered manner to successfully manage the BE microbiome in a way that finally is most beneficial for human health.

Each consumer is entitled to have hygienically clean processed dishes and cutlery. Consequently, restaurants, caterers, canteens, nursing homes, kindergartens and hospitals are very concerned to avoid infecting their customers and patients. They are afraid of the spread of diseases by inadequately washed dishes, glasses and cutlery. This study deals with the verification of the hygienic performance of commercial freshwater dishwashers with the aid of bioindicators that are contaminated with the test soil BAMS and two different strains of microorganisms: Micrococcus luteus and Enterococcus faecium . The method used is described in the working paper “WD 00429001 Commercial warewashing machines – Hygiene requirements and testing.” Tests for heat resistance are carried out to check the temperature interval of Micrococcus luteus . Thereby, it is shown that the germ examined still shows vitality at a temperature of 70°C and a holding time of ten minutes. When testing the hygienic performance of the dishwashing programs tested, it is shown that not only temperature, but also the effects of the detergent are recognizable.

In recent years, the aspect of hygiene has become increasingly important in all areas of daily life. Especially in the areas of gastronomy, nursing homes, kindergartens and hospitals, the hygiene aspect is of particular importance. This study deals with the examination of the hygienic performance of commercial dishwashers with a water replacement system (fresh water dishwashers) using Micrococcus luteus DSM 1790 and the carrier material oat flakes as test soil. After rinsing, the soil is detached from the test items using an elution solution. Furthermore, the sump and the back and side walls of the commercial fresh water dishwasher were examined by contact plates to obtain the microbial count. This approach has been tested for functionality in a series of empirical experiments. In addition, the influence of various commercial detergents on results was examined. It was found that the newly developed method emphasizes the difference between the tested programs. Furthermore, it was found that using a program with longer holding times led to a higher germ reduction in the upper basket than in the lower basket.

Even though, temperature and water consumption have decreased in domestic dishwashing cycles in the last years, it is generally agreed that dishwashing programs are efficient enough to remove critical microorganisms. But will the dishwashing process be efficient enough in the future? In the first part of this study, the impact of temperature, time and detergent amounts on microbial reduction of Enterococcus faecium , Micrococcus luteus and Pseudomonas aeruginosa were tested in suspension tests with the aim to select potential test strains for hygiene studies in the dishwasher. Enterococcus faecium and Micrococcus luteus biomonitors were in a second part applied to different low temperature cycles in a household dishwasher. The microbial reduction in the dishwasher was compared with the corresponding results from the suspension tests to get more insight in additional effects on microbial reduction like the mechanical action and rinsing step.

Insufficiently decontaminated textiles could lead to transmission of infections. Thus, laundry hygiene is of particular interest and investigated in numerous studies. However, laundering experiments that use microorganisms to investigate the reduction of microbial loads on textiles are particularly time-consuming and material-intensive and the handling of pathogenic microorganisms is subject to legal regulations. Therefore, alternative methods of investigation are desired. So far, there is no satisfactory solution to assess the antimicrobial efficacy of a laundering process without expensive microbiological investigations. This study introduces an approach to predict the antimicrobial performance of a laundering process by its cleaning performance. It is not possible to conclude immediately from the cleaning index of a washing process to its antimicrobial effect based on stain types used in this study. Also in washing processes with low cleaning indices a high microbial reduction can be achieved. For bleach free liquid detergent, strong, time dependent, positive correlations between microbial reduction and cleaning index for cocoa, soot, and sebum were identified.

Within the course of this investigation five different antibacterial textiles have been tested with four important standards for assessment of antibacterial efficacy (AATCC 147, ASTM E2149, DIN EN ISO 20645 and DIN EN ISO 20743). For some combinations of conducted method and utilized antibacterial textile the results revealed unexpected variations in antibacterial efficacy. This fact could lead to misperception of antibacterial textile efficacy which in turn could result in hygiene deficits for operators or economic losses for manufacturers. Accordingly, there is a strong need for a consistent method for evaluation of antibacterial efficacy so that the comparability of antibacterial textiles and particularly the significance of antibacterial efficacy will be improved.

Using common normative test approaches, it is impossible until now to evaluate how antimicrobial health care equipment contributes to the interruption of infection chains or even to address a benefit-risk-assessment. Therefore, in this study we quantified bacterial transfer and transmission probabilities between surfaces by a stamp assay to assess the performance of antimicrobial equipment under defined conditions. The definition of application-specific parameters is essential to allow the assessment of hygienic relevant surfaces, compared to the normative setups. In a second step, we then fed the determined material-specific data into an integrated mathematical model which enables a discussion about infection risks and a risk-benefit-assessment of antimicrobial surfaces in the health-care environment with practical relevance for the first time.

European domestic laundry habits are changing. Industry's move towards lower/ambient temperature washing and reduced water usage has resulted in lower degrees of microbial control leading to an increased risk to the health and wellbeing of the consumer. One solution targeted at mitigating this risk is the adoption of hygienic rinse-stage disinfectants to reduce the microorganisms in the laundry process. In this study, we evaluated the efficacy of two commercially-available quaternary ammonium compounds (QAC)-based rinse-stage disinfectants using both suspension test methodology and an application test in ASTM E2406 modified to offer a potential solution for the future testing and registration of such products in Europe. In addition, this paper paves the way for further development and validation of testing methodologies while exploring ways to better deploy and optimise antimicrobial actives within the laundry environment.