Chemical disinfection to interrupt transfer of rhinovirus type 14 from environmental surfaces to hands

The Surgical Instrument Sterilization Process: What Every Surgeon Should Know

» The phases of the sterilization process for surgical equipment are cleaning, disinfection, and sterilization.» Following manufacturer and regulatory guidelines will minimize contamination throughout the sterilization process.» Immediate use steam sterilization, when used appropriately, is a reasonably safe option to be used at the discretion of the operating surgeon.

Transmittance and Survival of SARS-CoV-2 in Global Trade: The Role of Supply Chain and Packaging

We are living in uncertain times and facing a paradigm shift in human health and sustainability. The number of SARS-CoV-2 victims is rising daily and all nations are going through dramatic effects and exploring various solutions to this imminent calamity facing the humanity. The world is confronting a public health issue that has forced it to come to a halt and evaluate the future of our modern society and our way of living. It can be stated that the sustainability of our societies inextricably depends on the performance of our global trade and supply chains. This review article is the first published assessment on the global trade and especially packaging’s role in the transmittance of SARS-CoV-2 virus. Surprisingly, based on our findings, the lack of knowledge on transmittance and survival of SARS-CoV-2 in supply chain and packaging is substantial. Although there are several existing and available technologies that can be used for the risk mitigation, our assessment shows a major and timely need for broad conceptual advancements and necessary understanding of the supply chain risks associated with the viral surface transmittances. The specificity to the current and possibly future pandemics demands an increasing amount of multidisciplinary research and involvement of public and private sectors. This proposed erudition is imminent and may be highly critical in safeguarding and the sustainability of the critical supply chains in our society now and in the future.

Risk Assessment of Healthcare Workers at the Frontline against COVID-19

The novel coronavirus disease 2019 (COVID-19) is a global pandemic. Healthcare workers (HCWs) are on the frontline of treating patients infected with COVID-19. However, data related to its infection rate among HCWs are limited. The aim was to present evidence associated with the number of HCWs being infected with COVID-19 from most viral affected countries (Italy, China, United States, Spain, and France). Furthermore, we looked into the reasons for HCWs COVID 19 infections and strategies to overcome this problem. Early available evidence suggested that HCWs are being increasingly infected with the novel infection ranging from 15% to 18% and in some cases up to 20% of the infected population. Major factors for infection among HCWs include lack of understanding of the disease, inadequate use and availability of Personal Protective Equipment (PPE), uncertain diagnostic criteria, unavailability of diagnostic tests and psychological stress. Therefore the protection of HCWs by authorities should be prioritized through education and training, the readiness of staff, incentives, availability of PPEs, and psychological support.

Transmission of Influenza A in a Student Office Based on Realistic Person-to-Person Contact and Surface Touch Behaviour

Influenza A viruses result in the deaths of hundreds of thousands of individuals worldwide each year. In this study, influenza A transmission in a graduate student office is simulated via long-range airborne, fomite, and close contact routes based on real data from more than 3500 person-to-person contacts and 127,000 surface touches obtained by video-camera. The long-range airborne, fomite and close contact routes contribute to 54.3%, 4.2% and 44.5% of influenza A infections, respectively. For the fomite route, 59.8%, 38.1% and 2.1% of viruses are transmitted to the hands of students from private surfaces around the infected students, the students themselves and other susceptible students, respectively. The intranasal dose via fomites of the students' bodies, belongings, computers, desks, chairs and public facilities are 8.0%, 6.8%, 13.2%, 57.8%, 9.3% and 4.9%, respectively. The intranasal dose does not monotonously increase or decrease with the virus transfer rate between hands and surfaces. Mask wearing is much more useful than hand washing for control of influenza A in the tested office setting. Regular cleaning of high-touch surfaces, which can reduce the infection risk by 2.14%, is recommended and is much more efficient than hand-washing.

Reduction of microbial contamination on the surfaces of layer houses using slightly acidic electrolyzed water

The objective of this study was to evaluate the effectiveness of slightly acidic electrolyzed water (SAEW) in reducing pathogens on pure cultures and on cotton fabric surfaces in the presence of organic matter and estimate its efficacy in comparison with povidone iodine solution for reducing pathogenic microorganisms on internal surfaces of layer houses. Pure cultures of E.coli, S.enteritidis, and S.aureus and cotton fabric surfaces inoculated with these strains were treated with SAEW in the presence of bovine serum albumin (BSA). In the absence of BSA, complete inactivation of all strains in pure cultures and on cotton fabric surfaces was observed after 2.5 and 5 min treatment with SAEW at 40 mg/L of available chlorine concentration (ACC), respectively. The bactericidal efficiency of SAEW increased with increasing ACC, but decreased with increasing BSA concentration. Then, the surfaces of the layer houses were sprayed with SAEW at 60, 80, and 100 mg/L of ACC and povidone iodine using the automated disinfection system at a rate of 110 mL/m(2), respectively. Samples from the floor, wall, feed trough, and egg conveyor belt surfaces were collected with sterile cotton swabs before and after spraying disinfection. Compared to tap water, SAEW and povidone iodine significantly reduced microbial populations on each surface of the layer houses. SAEW with 80 or 100 mg/L of ACC showed significantly higher efficacy than povidone iodine for total aerobic bacteria, staphylococci, coliforms, or yeasts and moulds on the floor and feed trough surfaces (P < 0.05). SAEW was more effective than povidone iodine at reducing total aerobic bacteria, coliforms, and yeasts and moulds on the wall surface. Additionally, SAEW had similar bactericidal activity with povidone iodine on the surface of the egg conveyor belt. Results suggest that SAEW exerts a higher or equivalent bactericidal efficiency for the surfaces compared to povidone iodine, and it may be used as an effective alternative for reducing microbial contamination on surfaces in layer houses.

Rhinovirus infections and adenoidal hypertrophy: do they interact with atopy in children?

Modern diagnostic methods allow the evaluation of the connection between rhinoviruses and atopy. Recent studies suggest that rhinoviruses are present in the adenoids at higher titers than in other specific sites, after inoculation of nasal mucosa or conjunctiva in volunteers. Therefore, it is possible that they might be responsible for specific local changes, while such changes may be influenced by atopy. This review focuses on the interactions between rhinoviral infection, the host's immune status and adenoidal disease.

Role of the Microbial Burden in the Acquisition and Control of Healthcare Associated Infections: The Utility of Solid Copper Surfaces

For more than a century, healthcare has been challenged to keep environmental surfaces clean to control microbes and improve patient outcomes. However despite an annual cost exceeding ten billion dollars cleaning with disinfection has done little to reduce the incidence of healthcare-associated infections (HAI). This chapter will review the scientific evidence delineating the role that the environment and healthcare workers play in the acquisition and movement of the microbes implicated in HAI and how through controlling the microbial burden of the built clinical environment it is possible to mitigate the rate of HAI acquisition. Specifically evidence demonstrating the effectiveness of solid copper surfaces for its ability to continuously limit the concentration of bacteria found on surfaces and objects within the built environment will be reviewed in concert with a discussion of how through the mitigation of the environmental burden copper surfaces are able to concomitantly reduce the incidence of HAI. Insights provided by this chapter are intended to facilitate an understanding and importance of the need to use a comprehensive or systems based approach to fight healthcare associated infections.

Control and mitigation of healthcare-acquired infections: designing clinical trials to evaluate new materials and technologies

Hospitals clean environmental surfaces to lower microbial contamination and reduce the likelihood of transmitting infections. Despite current cleaning and hand hygiene protocols, hospital-acquired infections (HAIs) continue to result in a significant loss of life and cost the U.S. healthcare system an estimated $45 billion annually. Stainless steel and chrome are often selected for hospital touch surfaces for their "clean appearance," comparatively smooth finish, resistance to standard cleaners, and relative effectiveness for removing visible dirt during normal cleaning. Designers use wood surfaces for aesthetics; plastic surfaces have become increasingly endemic for their relative lower initial cost; and "antimicrobial agents" are being incorporated into a variety of surface finishes.This paper concentrates on environmental surface materials with a history of bactericidal control of infectious agents and focuses on the methods necessary to validate their effectiveness in healthcare situations. Research shows copper-based metals to have innate abilities to kill bacteria in laboratory settings, but their effectiveness in patient care environments has not been adequately investigated. This article presents a research methodology to expand the evidence base from the laboratory to the built environment. For such research to have a meaningful impact on the design/specifying community, it should assess typical levels of environmental pathogens (i.e., surface "cleanliness") as measured by microbial burden (MB); evaluate the extent to which an intervention with copper-based materials in a randomized clinical trial affects the level of contamination; and correlate how the levels of MB affect the incidence of infections acquired during hospital stays.

Upper Respiratory Infections and Acute Bronchitis

Upper respiratory infections include the following: uncomplicated upper respiratory infections also known as the “common cold,” acute otitis media, pharyngitis/tonsillitis, and acute sinusitis. These conditions, along with acute bronchitis, are very common illnesses that are commonly seen in outpatient settings and are widely treated with antibiotics. In fact, these conditions are the primary indications for outpatient antibiotic prescriptions. These conditions tend to have overlapping clinical characteristics yet evidence regarding the utility of antimicrobial treatments varies across conditions.

Relative contributions of four exposure pathways to influenza infection risk

The relative contribution of four influenza virus exposure pathways-(1) virus-contaminated hand contact with facial membranes, (2) inhalation of respirable cough particles, (3) inhalation of inspirable cough particles, and (4) spray of cough droplets onto facial membranes-must be quantified to determine the potential efficacy of nonpharmaceutical interventions of transmission. We used a mathematical model to estimate the relative contributions of the four pathways to infection risk in the context of a person attending a bed-ridden family member ill with influenza. Considering the uncertainties in the sparse human subject influenza dose-response data, we assumed alternative ratios of 3,200:1 and 1:1 for the infectivity of inhaled respirable virus to intranasally instilled virus. For the 3,200:1 ratio, pathways (1), (2), and (4) contribute substantially to influenza risk: at a virus saliva concentration of 10(6) mL(-1), pathways (1), (2), (3), and (4) contribute, respectively, 31%, 17%, 0.52%, and 52% of the infection risk. With increasing virus concentrations, pathway (2) increases in importance, while pathway (4) decreases in importance. In contrast, for the 1:1 infectivity ratio, pathway (1) is the most important overall: at a virus saliva concentration of 10(6) mL(-1), pathways (1), (2), (3), and (4) contribute, respectively, 93%, 0.037%, 3.3%, and 3.7% of the infection risk. With increasing virus concentrations, pathway (3) increases in importance, while pathway (4) decreases in importance. Given the sparse knowledge concerning influenza dose and infectivity via different exposure pathways, nonpharmaceutical interventions for influenza should simultaneously address potential exposure via hand contact to the face, inhalation, and droplet spray.

A new Sephadex-based method for removing microbicidal and cytotoxic residues when testing antiseptics against viruses: Experiments with a human coronavirus as a model

The relative lack of efficient methods for evaluating antiseptic antiviral activity, together with weaknesses in the existing European Standard (i.e. NF EN 14476+A1), underlines the need to seek a new method which could allow a more precise evaluation of the antiseptic antiviral activity of chemical agents.

This protocol is based on an original gel-based filtration method, using “in-house” G-25 and G-10 Sephadex™ columns. This method allows the neutralization of both the activity and the cytotoxicity of a large range of molecules, according to their molecular size, in only 1 min.

The viral model used was the human coronavirus (HCoV) 229E chosen for (i) its increasing medical interest, (ii) its potential resistance and (iii) its representing enveloped viruses mentioned in the European Standard.

First, the protocol was validated and it was demonstrated that it was fully operational for evaluating antiviral antiseptic potentiality and useful to screen potentially antiseptic molecules.

Second, chlorhexidine (CHX) and hexamidine (HXM) were assessed for their potential anti-HCoV 229E antiseptic activities. It was demonstrated clearly that (i) HXM had no activity on the HCoV 229E and (ii) CHX showed a moderate anti-HCoV 229E activity but insufficient to be antiseptic.

Development of a method to measure bacterial transfer from hands

A method was developed to investigate the transfer of bacteria from the hands of healthcare workers (HCWs). The method involved standardised hand contact between the HCW and a recipient wearing sterile gloves, followed by sampling of the bare hands of the HCW and the gloved hands of the recipient by the glove juice method. The duration of contact, degree of friction and dryness of the hands could be varied. We investigated the applicability of the method for measuring transfer from hands artificially contaminated with Escherichia coli as well as from naturally contaminated hands following a 30s contact time with moderate friction and dry hands. Only a small proportion of bacteria on donor hands was recovered from the recipient: 0.15% for E. coli and 0.07% for natural hand flora. A smaller proportion of E. coli was recovered from bare skin compared with gloves, suggesting reduced survival of bacteria as a result of contact with natural skin. We suggest that these data are clinically relevant, and may indicate low transfer of bacteria during short contact with dry hands. This method is suitable to investigate the effect of potential risk factors for ineffective hand hygiene and the effect of hand hygiene procedures on contact transmission in clinical studies with large numbers of HCWs.

Development of a test system to apply virus-containing particles to filtering facepiece respirators for the evaluation of decontamination procedures

A chamber to apply aerosolized virus-containing particles to air-permeable substrates (coupons) was constructed and validated as part of a method to assess the virucidal efficacy of decontamination procedures for filtering facepiece respirators. Coliphage MS2 was used as a surrogate for pathogenic viruses for confirmation of the efficacy of the bioaerosol respirator test system. The distribution of virus applied onto and within the coupons was characterized, and the repeatability of applying a targeted virus load was examined. The average viable virus loaded onto 90 coupons over the course of 5 days was found to be 5.09 +/- 0.19 log(10) PFU/coupon (relative standard deviation, 4%). To determine the ability to differentiate the effectiveness of disinfecting procedures with different levels of performance, sodium hypochlorite and steam treatments were tested in experiments by varying the dose and time, respectively. The role of protective factors was assessed by aerosolizing the virus with various concentrations of the aerosol-generating medium. A sodium hypochlorite (bleach) concentration of 0.6% and steam treatments of 45 s and longer resulted in log reductions (>4 logs) which reached the detection limits for both levels of protective factors. Organic matter (ATCC medium 271) as a protective factor afforded some protection to the virus in the sodium hypochlorite experiments but was not a factor in the steam experiments. The evaluation of the bioaerosol respirator test system demonstrated a repeatable method for applying a targeted viral load onto respirator coupons and provided insight into the properties of aerosols that are of importance to the development of disinfection assays for air-permeable materials.

Biometric fingerprinting for visa application: device and procedure are risk factors for infection transmission

BACKGROUND

Biometric fingerprint identity verification is currently introduced in visa application and entry screening at border control. The system implies physical contact between the skin and the surface of the fingerprint-capturing and reading devices.

AIM

To assess the risk of infection transmission through fingerprinting.

METHODS

The medical literature was reviewed for the potential of microorganisms to be carried on the skin of hands in the community, to be transferred from hands to inanimate surfaces, to survive on surfaces, and to be transferred in doses exceeding the infectious dose. The fingerprinting procedures as currently applied were reviewed.

RESULTS

Factors that favor transfer of microorganisms are large skin-surface contact between flat fingers (2 x 20 cm(2)) and fingerprint-capturing device, nonporous contact surface, large overlap of contact surface and short turnaround time between successive applicants, high contact pressure, and difficulties to disinfect devices. Transmission risk exists for enteric viruses (rotavirus, norovirus, and hepatitis A virus), respiratory viruses (respiratory syncytial virus, rhinovirus, influenza virus, etc.), and enteropathogenic bacteria with low infectious doses (Shigella dysenteriae, Enterohemorrhagic Escherichia coli, etc.). Using Monte Carlo risk analysis on US data, transmission of human rotavirus is estimated at 191 [95% credible intervals (CI) 0-289] per million fingerprint-capturing procedures. Application of 70% isopropyl hand rub and 85% ethanol hand gel reduces the risk to 77 (95% CI 0-118) and 0.3 (95% CI 0-0.3) transmissions per million procedures, respectively.

CONCLUSIONS

The fingerprinting procedure as currently used is associated with a risk of infection transmission. Simple hygienic measures can considerably reduce this transmission risk.

Antimicrobial strategies: an option to treat allergy?

Respiratory infections by bacteria and viruses often trigger symptoms of asthma in both adults and children. This observation and subsequent mechanistic studies have demonstrated important interactions among allergens, microbes and the atopic host. The mechanisms responsible for microbe-induced asthma exacerbations are only incompletely understood. A focal point of current research is the inflammatory response of the host following an encounter with a pathogenic microbe, including variations in chemokine and cytokine production and resulting in changes in bronchial hyper-responsiveness and lung function. Direct bronchial infection, exposure of nerves with resulting neurogenic inflammation and a deviated host immune response are among the mechanisms underlying these functional disorders. Lately, suboptimal innate immune responses, expressed as defective interferon production, have gained attention as they might be amenable to intervention. This review describes the suggested mechanisms involved in the complex interactions between 'asthmagenic' microbes, the immune system and atopy, based on in-vitro and in-vivo experimental models and epidemiological evidence. In addition, it provides a synopsis of potential therapeutic strategies either directly against the microorganisms or in respect to the associated inflammation.

Involvement of radical species in inactivation of Vibrio parahaemolyticus in saline solutions by direct-current electric treatment

The effect of pulsed low-direct-current (DC) electric treatment on the viability of Vibrio parahaemolyticus in artificial seawater and 3.0% (w/v) NaCl solution was studied as a function of available chlorine (AC) concentration. The amount of AC generated during the DC electric treatment increased in proportion to the amount of passed DC. The survival fraction of V. parahaemolyticus cells decreased depending on AC concentration. When the generated AC components were completely reduced in the presence of sufficient sodium thiosulfate, no inactivation of V. parahaemolyticus in the NaCl solution was observed during the DC electric treatment. Based on the AC concentration, the inactivation efficacies of the DC electric treatment of the seawater and NaCl solution were approximately 4-fold and 30-fold that of the exogenous addition of sodium hypochlorite, respectively. Fluorometric analysis using 2-[6-(4'-hydroxy)phenoxy-3H-xanthen-3-on-9-yl]benzoic acid showed that the generation of highly reactive radical species such as hydroxyl radical in the seawater and NaCl solution occurred during the DC electric treatment. The amount of generated radical species depended on the amount of passed DC. It is concluded that pulsed low-DC electric treatment of saline solutions exerts superior inactivation efficacy against V. parahaemolyticus to sodium hypochlorite owing to the generation of radical species.

An integrated model of infection risk in a health-care environment

Certain respiratory tract infections can be transmitted by hand-to-mucous-membrane contact, inhalation, and/or direct respiratory droplet spray. In a room occupied by a patient with such a transmissible infection, pathogens present on textile and nontextile surfaces, and pathogens present in the air, provide sources of exposure for an attending health-care worker (HCW); in addition, close contact with the patient when the latter coughs allows for droplet spray exposure. We present an integrated model of pertinent source-environment-receptor pathways, and represent physical elements in these pathways as "states" in a discrete-time Markov chain model. We estimate the rates of transfer at various steps in the pathways, and their relationship to the probability that a pathogen in one state has moved to another state by the end of a specified time interval. Given initial pathogen loads on textile and nontextile surfaces and in room air, we use the model to estimate the expected pathogen dose to a HCW's mucous membranes and respiratory tract. In turn, using a nonthreshold infectious dose model, we relate the expected dose to infection risk. The system is illustrated with a hypothetical but plausible scenario involving a viral pathogen emitted via coughing. We also use the model to show that a biocidal finish on textile surfaces has the potential to substantially reduce infection risk via the hand-to-mucous-membrane exposure pathway.

Hand hygiene: simple and complex

This review gives an overview of hand hygiene in healthcare and in the community, including some aspects which have attracted little attention, such as hand drying and cultural issues determining hand hygiene behaviour. Hand hygiene is the most effective measure for interrupting the transmission of microorganisms which cause infection both in the community and in the healthcare setting. Using hand hygiene as a sole measure to reduce infection is unlikely to be successful when other factors in infection control, such as environmental hygiene, crowding, staffing levels and education are inadequate. Hand hygiene must be part of an integrated approach to infection control. Compliance with hand hygiene recommendations is poor worldwide. While the techniques involved in hand hygiene are simple, the complex interdependence of factors which determine hand hygiene behaviour makes the study of hand hygiene complex. It is now recognised that improving compliance with hand hygiene recommendations depends on altering human behaviour. Input from behavioural and social sciences is essential when designing studies to investigate compliance. Interventions to increase compliance with hand hygiene practices must be appropriate for different cultural and social needs. New strategies to promote hand hygiene worldwide include the formation of public-private partnerships.

Household cleaning and surface disinfection: new insights and strategies

Recently, new insights into the persistence of pathogens, their transfer from inanimate surfaces to humans and the risk of contamination and dissemination of pathogens by detergents have been gained. Furthermore, new experimental data on the interruption of chains of infection by disinfectants as well as results of outbreak-control studies are now available. Hence it has become necessary to reassess the potential benefits using disinfectants to prevent and control nosocomial infections. Based on the new findings and in view of the increasing incidence of nosocomial infections and antibiotic resistances, the German Robert-Koch-Institut has issued completely revised recommendations on Household Cleaning and Surface Disinfection. With respect to these recommendations we developed a new test method, which allows comparison of the efficacy of disinfection in reducing the microbial loads and their dissemination with that of cleaning procedures under practical conditions. In a multi-factor approach, mechanical properties (wet mop technique), utensils (different mop materials) and active agents (disinfectant, detergent) were taken into consideration. We found that under the given conditions, dissemination of the test organism Staphylococcus aureus did not take place when using aldehydes and peroxides, it did take place, however, when water, surfactants, and the disinfectants glycol derivatives, quaternary ammonium compounds and alkylamines were used.

Effect of antibacterial home cleaning and handwashing products on infectious disease symptoms: a randomized, double-blind trial

BACKGROUND

Despite the widespread household use of cleaning and personal hygiene products containing antibacterial ingredients, their effects on the incidence of infectious disease symptoms have not been studied.

OBJECTIVE

To evaluate the effect of antibacterial cleaning and handwashing products for consumers on the occurrence of infectious disease symptoms in households.

DESIGN

Randomized, double-blind clinical trial.

SETTING

Northern Manhattan inner-city neighborhood, New York.

PARTICIPANTS

238 primarily Hispanic households (1178 persons) that included at least one preschool-age child.

INTERVENTIONS

Households were randomly assigned to use either antibacterial or nonantibacterial products for general cleaning, laundry, and handwashing. All products were commercially available, but the packaging was blinded and the products were provided free to participants.

MEASUREMENTS

Hygiene practices and infectious disease symptoms were monitored by weekly telephone calls, monthly home visits, and quarterly interviews for 48 weeks.

RESULTS

Symptoms were primarily respiratory: During 26.2% (717 of 2736) of household-months, 23.3% (640 of 2737) of household-months, and 10.2% (278 of 2737) of household-months, one or more members of the household had a runny nose, cough, or sore throat, respectively. Fever was present during 11% (301 of 2737) of household-months, vomiting was present in 2.2% (61 of 2737), diarrhea was present in 2.5% (69 of 2737), and boils or conjunctivitis were present in 0.77% (21 of 2737). Differences between intervention and control groups were not significant for any symptoms (all unadjusted and adjusted relative risks included 1.0) or for numbers of symptoms (overall incidence density ratio, 0.96 [95% CI, 0.82 to 1.12]).

CONCLUSIONS

The tested antibacterial products did not reduce the risk for symptoms of viral infectious diseases in households that included essentially healthy persons. This does not preclude the potential contribution of these products to reducing symptoms of bacterial diseases in the home.

Disinfection and the prevention of infectious disease

This article reviews published literature to determine the role environmental disinfection plays in the prevention of infectious disease. Health benefits from disinfection have been established through studies of applications such as critical instrument sterilization, water treatment, and food production. Guidelines by the Centers for Disease Control and Prevention, the Food and Drug Administration, the Environmental Protection Agency, and the International Scientific Forum on Home Hygiene acknowledge the incidence of disease due to insufficient disinfection and that one of the means for prevention of disease is through proper disinfection. Studies conducted in day care centers, long-term care facilities, and laboratories show that disinfectants containing a variety of active ingredients demonstrated efficacy against a broad spectrum of pathogens and interrupted microbial transmission and that the use of disinfectants results in public health benefits.

Infection control recommendations for patients with cystic fibrosis: microbiology, important pathogens, and infection control practices to prevent patient-to-patient transmission

Infection Control Recommendations for Patients With Cystic Fibrosis: Microbiology, Important Pathogens, and Infection Control Practices to Prevent Patient-to-Patient Transmissionupdates, expands, and replaces the consensus statement,Microbiology and Infectious Disease in Cystic Fibrosispublished in 1994. This consensus document presents background data and evidence-based recommendations for practices that are intended to decrease the risk of transmission of respiratory pathogens among CF patients from contaminated respiratory therapy equipment or the contaminated environment and thereby reduce the burden of respiratory illness. Included are recommendations applicable in the acute care hospital, ambulatory, home care, and selected non-healthcare settings. The target audience includes all healthcare workers who provide care to CF patients. Antimicrobial management is beyond the scope of this document.

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.

The role of the home environment in the transmission of infectious diseases

The purpose of this paper is to examine current health care literature (1980-2000) regarding the microbiology of the home environment, to summarize evidence of transmission within the home, and to assess effectiveness of cleaning practices and products. The home environment, particularly the kitchen and bathroom, serves as a reservoir of large numbers of microorganisms, particularly Enterobacteriacae, and infectious disease transmission has been demonstrated to occur in 6-60% of households in which one member is ill. Current food preparation and cleaning practices provide multiple opportunities for intra-household member spread. Routine cleaning is often sufficient, but in cases of household infection, may not adequately reduce environmental contamination. The effectiveness of disinfectants varies considerably and depends on how they are used as well as their intrinsic efficacy. The behavioral aspects of infection prevention in the home (e.g., foodhandling and cleaning practices) warrant increased public attention and education.

Surface disinfection: should we do it?

The effective use of disinfectants constitutes an important factor in preventing hospital-acquired infections. Surfaces are considered non-critical items as they come in contact with intact skin. Use of non-critical items or contact with non-critical surfaces carries little risk of transmitting a pathogen to patients. Thus, the routine use of disinfectants to disinfect hospital floors and other non-critical items is controversial. However, surfaces may potentially contribute to cross-transmission by acquisition of transient hand carriage by health care personnel due to contact with a contaminated surface or by patient contact with contaminated surfaces or medical equipment. This paper reviews the epidemiological and microbiological data regarding the use of disinfectants on non-critical surfaces. It concludes that while non-critical surfaces are uncommonly associated with transmission of infections to patients, one should clean and disinfect surfaces on a regularly scheduled basis.

Home hygiene practices and infectious disease symptoms among household members

Public health programs are generally targeted to communitywide, population-based prevention strategies, with little attention focused on the home environment as one potential source of transmission of infectious diseases. The purpose of this correlational prevalence survey was to describe the relationship between home hygiene practices and prevalence of infectious disease symptoms among household members. Three hundred and ninety-eight households with 1,662 members in an inner-city population (96.4% Hispanic) were surveyed to examine hygiene practices and determine the presence of transmission of infection, defined as the presence of the same symptom(s) in two or more household members for which at least one individual sought medical attention and received treatment. At least one individual in 78.6% of households reported symptoms of infection in the previous 30 days, and 37.9% of households met the definition of disease transmission. In univariate analyses, five factors were significantly associated with risk of household transmission, but in the logistic regression model, only use of communal laundry (p = 0.009) and lack of bleach use (p = 0.04) were significantly predictive of increased risk of transmission. This is the first comprehensive survey of home hygiene practices and the first study to identify a potential link between laundry and risk of disease transmission in homes. This potential link warrants further study in clinical trials.

Quantification and variability analysis of bacterial cross-contamination rates in common food service tasks

This study investigated bacterial transfer rates between hands and other common surfaces involved in food preparation in the kitchen. Nalidixic acid-resistant Enterobacter aerogenes B199A was used as a surrogate microorganism to follow the cross-contamination events. Samples from at least 30 different participants were collected to determine the statistical distribution of each cross-contamination rate and to quantify the natural variability associated with that rate. The transfer rates among hands, foods, and kitchen surfaces were highly variable, being as low as 0.0005% and as high as 100%. A normal distribution was used to describe the variability in the logarithm of the transfer rates. The mean +/- SD of the normal distributions were, in log percent transfer rate, chicken to hand (0.94 +/- 0.68), cutting board to lettuce (0.90 +/- 0.59), spigot to hand (0.36 +/- 0.90), hand to lettuce (-0.12 +/- 1.07), prewashed hand to postwashed hand (i.e., hand washing efficiency) (-0.20 +/- 1.42), and hand to spigot (-0.80 +/- 1.09). Quantifying the cross-contamination risk associated with various steps in the food preparation process can provide a scientific basis for risk management efforts in both home and food service kitchens.

Overview of Lysol scientific studies

When followed, simple hygienic practices such as handwashing and surface disinfection along with proper food handling techniques can have a positive impact on the health of families and individuals in nonmedical settings like homes, day care and long term care facilities. Several studies have attempted to identify the specific role surface disinfectants can play in this effort. The evidence seems to indicate that these types of products, when properly used, can be beneficial. Because it has been established that environmental surfaces act as intermediates in the transmission of microorganisms throughout the day-care center and in homes, future studies should be developed to quantitate the impact of specific interventions in the reduction of microorganisms.

Transmission of viruses via contact in ahousehold setting: experiments using bacteriophage straight phiX174 as a model virus

Contamination of the environment with pathogens is the prerequisite for contact infections. The aim of this study was to elucidate how viruses can be transmitted from a primary contact person to further individuals. Bacteriophage straight phiX174 was chosen as a model virus. In its stability straight phiX174 is comparable with the most resistant human pathogenic viruses, e.g. polio- or parvoviruses. About 10(7)pfu were applied to exposed contact points such as door handles or the hands of volunteers. After touching of these handles and common social contacts like hand shaking, re-isolation rates were determined from the hands of our test persons. Contaminated door handles and skin surfaces were found to be efficient sources for potential infection. At least 14 persons could be contaminated by horizontal spread, one after the other by touching the same door handle. Successive transmission from one person to another could be followed up to the sixth contact person. These results were confirmed under everyday life conditions in a flat shared by four students. The transmission could not be prevented by the usual standards of hand hygiene, practised in this household. straight phiX174 could be reisolated after 24h from the hands of all persons tested even after normal use and cleaning of their hands. This might be improved by the use of liquid soap dispensers.

Effect of a comprehensive infection control program on the incidence of infections in long-term care facilities

BACKGROUND

Control of infection within the long-term care facility is a daunting problem. Elderly patients are at high risk for contracting infection because of reduced innate immunity, malnutrition, and the presence of chronic medical conditions. This small study tested the effect of developing and implementing a comprehensive preventive infection control program in the long-term care setting and examined the resultant incidence of infections.

METHODS

Eight private, freestanding, long-term care facilities in urban and suburban settings were selected for the study. The 4 test sites had a total of 443 beds; there were 447 beds in 4 matched control sites. Data on infection rates were accrued in both preintervention and intervention years. The control homes maintained their existing infection control policies and procedures. The test homes were provided with an infection control educational program and replaced all currently used germicidal products with single-branded products for a 12-month period. A criteria-based standardized infection control surveillance system was used to monitor and report infections in all facilities.

RESULTS

In the preintervention year, the test sites experienced 743 infections (incidence density rate, 6.33) and the control homes experienced 614 infections (incidence density rate, 3.39). In the intervention year, the test homes reported 621 infections, a decrease of 122 infections (incidence density rate, 4.15); in the control homes, the number of infections increased slightly, to 626 (incidence density rate, 3.15). The greatest reduction in infections in the test homes was in upper respiratory infections (P =.06).

CONCLUSIONS

This study provides additional evidence that a comprehensive infection control program that includes handwashing and environmental cleaning and disinfecting may help reduce infections among the elderly residing in long-term care settings.

Antimicrobial activity of home disinfectants and natural products against potential human pathogens

OBJECTIVE

To assess the efficacy of both natural products (vinegar, baking soda) and common commercial disinfectants (Vesphene IIse, TBQ, Clorox, Lysol Disinfectant Spray, Lysol Antibacterial Kitchen Cleaner, Mr. Clean Ultra, ethanol) designed for home or institutional use against potential human pathogens, including selected antibiotic-resistant bacteria.

DESIGN

A quantitative suspension test was used to assess the efficacy of selected disinfectants following exposure times of 30 seconds and 5 minutes. Activity was assessed against Staphylococcus aureus, Salmonella choleraesuis, Escherichia coli O157:H7, and Pseudomonas aeruginosa. Selected disinfectants were also tested against poliovirus, vancomycin-susceptible and -resistant Enterococcus species, and methicillin-susceptible and -resistant S. aureus.

RESULTS

The following compounds demonstrated excellent antimicrobial activity (>5.6-8.2 log10 reduction) at both exposure times: TBQ, Vesphene, Clorox, ethanol, and Lysol Antibacterial Kitchen Cleaner. Mr. Clean eliminated 4 to >6 logs10 and Lysol Disinfectant approximately 4 logs10 of pathogenic microorganisms at both exposure times. Vinegar eliminated <3 logs10 of S. aureus and E. coli, and baking soda <3 logs10 of all test pathogens. All tested chemical disinfectants completely inactivated both antibiotic-resistant and -susceptible bacteria at both exposure times. Only two disinfectants, Clorox and Lysol, demonstrated excellent activity (>3 log10 reduction) against poliovirus.

CONCLUSIONS

A variety of commercial household disinfectants were highly effective against potential bacterial pathogens. The natural products were less effective than commercial household disinfectants. Only Clorox and Lysol disinfectant were effective against poliovirus.

Uses of inorganic hypochlorite (bleach) in health-care facilities

Hypochlorite has been used as a disinfectant for more than 100 years. It has many of the properties of an ideal disinfectant, including a broad antimicrobial activity, rapid bactericidal action, reasonable persistence in treated potable water, ease of use, solubility in water, relative stability, relative nontoxicity at use concentrations, no poisonous residuals, no color, no staining, and low cost. The active species is undissociated hypochlorous acid (HOCl). Hypochlorites are lethal to most microbes, although viruses and vegetative bacteria are more susceptible than endospore-forming bacteria, fungi, and protozoa. Activity is reduced by the presence of heavy metal ions, a biofilm, organic material, low temperature, low pH, or UV radiation. Clinical uses in health-care facilities include hyperchlorination of potable water to prevent Legionella colonization, chlorination of water distribution systems used in hemodialysis centers, cleaning of environmental surfaces, disinfection of laundry, local use to decontaminate blood spills, disinfection of equipment, decontamination of medical waste prior to disposal, and dental therapy. Despite the increasing availability of other disinfectants, hypochlorites continue to find wide use in hospitals.

Epidemiology, pathogenesis, and treatment of the common cold

OBJECTIVE

Reading this article will reinforce the reader's knowledge of the pathogenesis of the common cold. The rationale for current and potential therapies for the common cold are reviewed in the context of current concepts of the pathogenesis of these illnesses.

DATA SOURCES AND STUDY SELECTION

A MEDLINE literature search was done using the search terms common cold, rhinovirus, and viral respiratory infection. The search was restricted to the English language. Articles were selected for review if the title and/or abstract suggested the content was relevant to the subject of this review. The bibliographies of selected articles were used as a source of additional literature.

RESULTS

Recent studies suggest that the host response to the virus is an important contributor to the pathogenesis of the common cold. Inflammatory mediators, especially the pro-inflammatory cytokines, appear to be an important component of this response and present an attractive target for new interventions for common cold therapies. Currently available treatments for the common cold have limited efficacy against specific symptoms. These therapies should be selected to treat the specific symptoms that are perceived to be the most bothersome by the patient.

The common cold: current therapy and natural history

Despite its prevalence, the common cold is complicated and can be difficult to treat, even symptomatically. There is still no cure for the myriad of viruses that cause the common cold. Many of the most popular remedies are either ineffective or counterproductive. This paper reviews the causes and course of upper respiratory infections, and discusses treatment options, including a new anticholinergic aqueous formulation for controlling rhinorrhea.