Microbial exposures that establish immunoregulation are compatible with targeted hygiene.

It is often suggested that hygiene is not compatible with the microbial exposures that are necessary for establishment of the immune system in early life. However, when we analyze the microbial exposures of modern humans in the context of human evolution and history, it becomes evident that whereas children need exposure to the microbiotas of their mothers, other family members, and the natural environment, exposure to the unnatural microbiota of the modern home is less relevant. In addition, any benefits of exposure to the infections of childhood within their household setting are at least partly replaced by the recently revealed nonspecific effects of vaccines. This article shows how targeting hygiene practices at key risk moments and sites can maximize protection against infection while minimizing any impact on essential microbial exposures. Moreover, this targeting must aim to reduce direct exposure of children to cleaning agents because those agents probably exert TH2-adjuvant effects that trigger allergic responses to normally innocuous antigens. Finally, we need to halt the flow of publications in the scientific literature and the media that blame hygiene for the increases in immunoregulatory disorders. Appropriately targeted hygiene behavior is compatible with a healthy lifestyle that promotes exposure to essential microorganisms.

The Washing Machine as a Reservoir for Transmission of Extended-Spectrum-Beta-Lactamase (CTX-M-15)-Producing Klebsiella oxytoca ST201 to Newborns.

During the period from April 2012 to May 2013, 13 newborns (1 to 4 weeks of age) and 1 child in a pediatric hospital ward in Germany were colonized with Klebsiella oxytoca producing an extended-spectrum beta-lactamase (ESBL) (CTX-M-15). A microbiological source-tracking analysis with human and environmental samples was carried out to identify the source and transmission pathways of the K. oxytoca clone. In addition, different hygienic intervention methods were evaluated. K. oxytoca isolates were detected in the detergent drawer and on the rubber door seal of a domestic washer-extractor machine that was used in the same ward to wash laundry for the newborns, as well as in two sinks. These strains were typed using pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing. The environmental findings were compared with those for the human strains and the isolates detected on clothing. The results from both techniques showed that the strains were identical (sequence type 201 and PFGE type 00531, a clone specific to this hospital and not previously isolated in Germany), emphasizing the washing machine as a reservoir and fomite for the transmission of these multidrug-resistant bacteria. After the washing machine was taken out of use, no further colonizations were detected during the subsequent 4-year period.IMPORTANCE Washing machines should be further investigated as possible sites for horizontal gene transfer (ESBL genes) and cross-contamination with clinically important Gram-negative strains. Particularly in the health care sector, the knowledge of possible (re-)contamination of laundry (patients' clothes and staff uniforms) with multidrug-resistant Gram-negative bacteria could help to prevent and to control nosocomial infections. This report describes an outbreak with a single strain of a multidrug-resistant bacterium (Klebsiella oxytoca sequence type 201) in a neonatal intensive care unit that was terminated only when the washing machine was removed. In addition, the study implies that changes in washing machine design and processing are required to prevent accumulation of residual water where microbial growth can occur and contaminate clothes.

Developing resilience against the threat of infectious diseases and anti-microbial resistance: Putting targeted hygiene into practice in home and everyday lives.

Objectives: COVID-19 has highlighted the importance of hygiene in home and everyday life (HEDL) to build population resilience against ongoing infectious disease threats. Despite having high awareness of hygiene, people have relatively poor understanding of hygiene risk which compromises their ability to follow advice. This paper combines new insights into hygiene science and hygiene behaviour to propose a framework for achieving more effective behavior. It is aimed at supporting government initiatives to build hygiene resilience within the UK population. Study design: Non-systematic narrative review. Methods: The review is based on findings of recent consensus reviews, prepared by acknowledged hygiene experts. It also draws on studies of hygiene understanding, drivers for behaviour change and behaviour change models. Results: To build hygiene resilience, HEDL hygiene requires a risk management approach where practices combine to reduce infection risk in community populations to an acceptable level. Using this we construct a framework showing when, where and how to practice hygiene. Based on visualization, it gives clear practical guidance and develops better hygiene understanding. Promoting this approach using health belief models ensures behaviours that are embedded are fit for purpose. Conclusions: A risk management approach to hygiene, promoted through behaviour change models, provides a framework for developing effective resilient hygiene behaviour. To achieve this, however, the separate aspects of HEDL hygiene (food, healthcare, pandemic preparedness) must be combined and communicated in a user-centric manner. Leadership teams must also be established with sole responsibility for HEDL hygiene, and the power to drive change.

Modeling COVID-19 infection risks for a single hand-to-fomite scenario and potential risk reductions offered by surface disinfection.

We used a quantitative microbial risk assessment approach to relate log10 disinfection reductions of SARS-CoV-2 bioburden to COVID-19 infection risks. Under low viral bioburden, minimal log10 reductions may be needed to reduce infection risks for a single hand-to-fomite touch to levels lower than 1:1,000,000, as a risk comparison point. For higher viral bioburden conditions, log10 reductions of more than 2 may be needed to achieve median infection risks of less than 1:1,000,000.

Reducing antibiotic prescribing and addressing the global problem of antibiotic resistance by targeted hygiene in the home and everyday life settings: A position paper.

Antimicrobial resistance (AMR) continues to threaten global health. Although global and national AMR action plans are in place, infection prevention and control is primarily discussed in the context of health care facilities with home and everyday life settings barely addressed. As seen with the recent global SARS-CoV-2 pandemic, everyday hygiene measures can play an important role in containing the threat from infectious microorganisms. This position paper has been developed following a meeting of global experts in London, 2019. It presents evidence that home and community settings are important for infection transmission and also the acquisition and spread of AMR. It also demonstrates that the targeted hygiene approach offers a framework for maximizing protection against colonization and infections, thereby reducing antibiotic prescribing and minimizing selection pressure for the development of antibiotic resistance. If combined with the provision of clean water and sanitation, targeted hygiene can reduce the circulation of resistant bacteria in homes and communities, regardless of a country's Human Development Index (overall social and economic development). Achieving a reduction of AMR strains in health care settings requires a mirrored reduction in the community. The authors call upon national and international policy makers, health agencies, and health care professionals to further recognize the importance of targeted hygiene in the home and everyday life settings for preventing and controlling infection, in a unified quest to tackle AMR.

Methicillin-resistant Staphylococcus aureus, Clostridium difficile, and extended-spectrum beta-lactamase-producing Escherichia coli in the community: assessing the problem and controlling the spread.

Although health care-associated methicillin resistant staphylococcus aureus and clostridium difficile strains are primarily a risk to hospital patients, people are increasingly concerned about their potential to circulate in the community and the home. They are thus looking for support in order to understand the extent of the risk, and guidance on how to deal with situations where preventing infection from these species becomes their responsibility. A further concern are the community-acquired MRSA and C. difficile strains, and other antibiotic resistant strains circulating in the community such as the Extended-spectrum beta-lactamase (ESBL) Escherichia coli. In response to concerns about such organisms in the community, the International Scientific Forum on Home Hygiene has produced a report evaluating MRSA, C. difficile, and ESBL-producing E. coli from a community viewpoint. The report summarizes what is known about their prevalence in the community, their mode of transmission in the home, and the extent to which they represent a risk. It also includes "advice sheets" giving practical guidance on what to do when there is a risk of infection transmission in the home.

A unified framework for developing effective hygiene procedures for hands, environmental surfaces and laundry in healthcare, domestic, food handling and other settings.

Hygiene procedures for hands, surfaces and fabrics are central to preventing spread of infection in settings including healthcare, food production, catering, agriculture, public settings, and home and everyday life. They are used in situations including hand hygiene, clinical procedures, decontamination of environmental surfaces, respiratory hygiene, food handling, laundry hygiene, toilet hygiene and so on. Although the principles are common to all, approaches currently used in different settings are inconsistent. A concern is the use of inconsistent terminology which is misleading, especially to people we need to communicate with such as the public or cleaning professionals. This paper reviews the data on current approaches, alongside new insights to developing hygiene procedures. Using this data, we propose a more scientifically-grounded framework for developing procedures that maximize protection against infection, based on consistent principles and terminology, and applicable across all settings. A key feature is use of test models which assess the state of surfaces after treatment rather than product performance alone. This allows procedures that rely on removal of microbes to be compared with those employing chemical or thermal inactivation. This makes it possible to ensure that a consistent "safety target level" is achieved regardless of the type of procedure used, and allows us deliver maximum health benefit whilst ensuring prudent usage of antimicrobial agents, detergents, water and energy.

Time to abandon the hygiene hypothesis: new perspectives on allergic disease, the human microbiome, infectious disease prevention and the role of targeted hygiene.

AIMS: To review the burden of allergic and infectious diseases and the evidence for a link to microbial exposure, the human microbiome and immune system, and to assess whether we could develop lifestyles which reconnect us with exposures which could reduce the risk of allergic disease while also protecting against infectious disease. METHODS: Using methodology based on the Delphi technique, six experts in infectious and allergic disease were surveyed to allow for elicitation of group judgement and consensus view on issues pertinent to the aim. RESULTS: Key themes emerged where evidence shows that interaction with microbes that inhabit the natural environment and human microbiome plays an essential role in immune regulation. Changes in lifestyle and environmental exposure, rapid urbanisation, altered diet and antibiotic use have had profound effects on the human microbiome, leading to failure of immunotolerance and increased risk of allergic disease. Although evidence supports the concept of immune regulation driven by microbe-host interactions, the term 'hygiene hypothesis' is a misleading misnomer. There is no good evidence that hygiene, as the public understands, is responsible for the clinically relevant changes to microbial exposures. CONCLUSION: Evidence suggests a combination of strategies, including natural childbirth, breast feeding, increased social exposure through sport, other outdoor activities, less time spent indoors, diet and appropriate antibiotic use, may help restore the microbiome and perhaps reduce risks of allergic disease. Preventive efforts must focus on early life. The term 'hygiene hypothesis' must be abandoned. Promotion of a risk assessment approach (targeted hygiene) provides a framework for maximising protection against pathogen exposure while allowing spread of essential microbes between family members. To build on these findings, we must change public, public health and professional perceptions about the microbiome and about hygiene. We need to restore public understanding of hygiene as a means to prevent infectious disease.

Home hygiene: a risk approach.

The need to place "prevention through hygiene" at the core of strategies for infection prevention has been emphasised by recent events. Indications are that re-evaluation of current practice and the promotion of improved hygiene in the domestic setting could have a significant impact in reducing infectious disease. If the public are to play a part however they must be properly informed. Encouraging the concept of the home as a setting in which the whole range of activities occur, including food hygiene, personal hygiene and hygiene related to medical care, provides the opportunity for a rational approach to home hygiene based on risk assessment. In the home surfaces (including hand surfaces) and other sites play an important part in the transmission of infection, especially food-borne infections. From an assessment of the frequency of occurrence of pathogens and potential pathogens at reservoirs, disseminators and hand and food contact sites together with the potential for transfer within the home, the risks of exposure can be assessed. This can be used to develop a rational approach in which effective hygiene procedures involving cleaning and disinfection as appropriate are targeted at these sites to reduce risks of cross contamination. This approach is consistent with the view that good home hygiene is not about "getting rid of household germs" but about targeting hygiene measures appropriately to reduce exposure to germs and thereby prevent cross infection. In motivating change, education programmes must take account of concerns related to antimicrobial resistance, the environment and the "health" of the immune system.

A risk assessment approach to use of antimicrobials in the home to prevent spread of infection.

Home and everyday life hygiene is a key part of the public health strategy to reduce infectious disease, but an effective code of practice is required. This short review summarizes the basic scientific principles of a risk-based approach to home hygiene where hygiene procedures are applied at critical points at appropriate times. It suggests that, although detergent-based cleaning can be used to break the chain of infection, in some cases an antimicrobial agent is required.

Importance of disinfection as a means of prevention in our changing world hygiene and the home.

Contrary to expectation, the risks of infection are growing rather than declining, even in everyday life. After all, who is able to make a distinction between cleanliness and hygiene? This situation is further compounded by the growing number of persons who are susceptible to infections. If one wants to combat infectious diseases in an economically feasible and consistent manner, public support must be sought. In turn, the public have a right to be informed in a proper and responsible manner. The difference between "dirt" and "contamination" must be highlighted once again.To create a forum for everyday hygiene, an international expert working group was set up (http://www.ifh-homehygiene.org). The hallmark of this group is its holistic view of hygiene in the family setting, something that is not true in the case of most public health sectors. Based on the latest study results, the International Forum for Hygiene (IFH) has coined a new motto "Selective Hygiene", and evaluates the causes of infection so as to be able to react in an appropriate manner. The aim cannot be routine, daily repetitive decontamination of all potentially dangerous microbes that are found in a normal household, but rather selective reaction to important transmission processes, i.e. hands and foodstuffs, kitchen, bathroom and toilet. The motto can be summarized as follows: "Do the right thing at the right time". This, however, calls for an understanding of the risks and of effective procedures for microbial reduction. Depending on the respective circumstances, hands can be washed with running water or by using a hand disinfectant. Even experts must learn that hygiene in the home must be evaluated differently from that of the hospital setting. The comparatively lower risk is offset by markedly less awareness of the risks involved. These risks can be significantly increased by any members of the household who are ill. Hence in some cases it is advisable to use disinfectants in the home too - even if it is claimed in certain quarters that we have become "too clean", and have thus lower immunity. Study data demonstrate that disinfectants have become indispensable in the household in the context of "selective hygiene strategies" so as to prevent infectious diseases.