Impact of different hand-drying methods on surrounding environment: aerosolization of virus and bacteria, and transfer to surfaces.

BACKGROUND: In recent years, hand drying has been highlighted as a key step in appropriate hand hygiene, as moisture on hands can increase the transfer of micro-organisms from hands to surfaces and vice versa. AIM: To understand bacterial and viral aerosolization following hand drying, and study the transfer of micro-organisms from hands to surfaces after drying using different methods. METHODS: Groups of five volunteers had their hands pre-washed with soap, rinsed and dried, then inoculated with a concentrated mixture of Pseudomonas fluorescens and MS2 bacteriophage. Volunteers entered an empty washroom, one at a time, and rinsed their hands with water or washed their hands with soap prior to drying with a jet dryer or paper towels. Each volunteer applied one hand successively to various surfaces, while their other hand was sampled using the glove juice method. Both residual bacteria and viruses were quantified from the washroom air, surface swabs and hand samples. FINDINGS: P. fluorescens and MS2 bacteriophages were rarely aerosolized while drying hands for any of the drying methods studied. Results also showed limited, and similar, transfer of both micro-organisms studied on to surfaces for all drying methods. CONCLUSION: The use of jet dryers or paper towels produces low levels of aerosolization when drying hands in a washroom. Similarly, all drying methods result in low transfer to surfaces. While the coronavirus disease 2019 pandemic raised concerns regarding public washrooms, this study shows that all methods tested are hygienic solutions for dry washed hands.

The Potential for Transmission of Coronaviruses via Sports Equipment; A Cricket Case Study.

A review of literature on the role of fomites in transmission of coronaviruses informed the development of a framework which was used to qualitatively analyse a cricket case study, where equipment is shared and passed around, and identify potential mitigation strategies. A range of pathways were identified that might in theory allow coronavirus transmission from an infected person to a non-infected person via communal or personal equipment fomites or both. Eighteen percent of potential fomite based interactions were found to be non-essential to play including all contact with another persons equipment. Six opportunities to interrupt the transmission pathway were identified, including the recommendation to screen participants for symptoms prior to play. Social distancing between participants and avoiding unnecessary surface contact provides two opportunities; firstly to avoid equipment exposure to infected respiratory droplets and secondly to avoid uninfected participants touching potential fomites. Hand sanitisation and equipment sanitisation provide two further opportunities by directly inactivating coronavirus. Preventing players from touching their mucosal membranes with their hands represents the sixth potential interruption. Whilst potential fomite transmission pathways were identified, evidence suggests that viral load will be substantially reduced during surface transfer. Mitigation strategies could further reduce potential fomites, suggesting that by comparison, direct airborne transmission presents the greater risk in cricket.

Disinfection of gloved hands during the COVID-19 pandemic.

BACKGROUND: Disinfection of gloves can be used during a pandemic situation when performing various procedures on the same patient or when removing personal protective equipment. If performing glove disinfection, there is a need to check the compatibility of gloves with the disinfectant product used. AIM: To test the resistance of nitrile gloves to various disinfectant solutions. METHODS: One hundred percent powder-free nitrile gloves, composed of nitrile butadiene rubber compounds, were exposed to various disinfectants to analyse resistance. The seven most commonly used disinfectant solutions in the healthcare field were selected for testing. The effects of each disinfectant were analysed in comparison with the control group (untreated glove). For tensile testing, the thickness of each test specimen was measured with a micrometer. FINDINGS: Bleach solution decreased the breaking load of gloves, although to a lesser extent than disinfectants that contained ethanol. CONCLUSION: Disinfectants that contain alcohol decrease the breaking load of nitrile gloves.

Prediction of Potential Respiratory Tract Infection from SARS-CoV-2 Through Hand-to-face Contact Transmission.

OBJECTIVE: The Ministry of Health of China reported a cluster of severe pneumonia cases of unknown etiology in Wuhan city, the cause of which was later identified as a novel coronavirus. However, the risk of infection through indirect transmission routes remains unclear. METHODS: A mathematical modeling approach was used to estimate the risk of infection through hand-to-face contact. The probability of infection for various routes of transmission through face-touching behavior was then calculated. RESULTS: The probabilities of infection through hand-to-mouth transmission from nonporous and porous environments had log-normal (LN) distributions with geometric means (GMs) of 0.0116 and 0.0002, geometric deviations (GDs) of 2.9822 and 3.5560, and medians of 0.0127 and 0.0002, respectively, while those through hand-to-nose transmission from nonporous and porous environments had LN distributions with GMs of 0.0006 and 0.0000, GDs of 43.2310 and 47.3372, and medians of 0.0009 and 0.0000, respectively. The probability of infection through hand-to-eye transmission from a nonporous environment had a beta distribution with α = 2.38803, ß = 13.60457, a minimum of 0.0045, a maximum of 0.9021, and a median of 0.1179, while that from a porous environment had a Weibull distribution with a scale parameter of 0.0030, a shape parameter of 1.323, and a median of 0.0023. CONCLUSION: SARS-CoV-2 infection will occur through hand-to-face contact via contaminated environment.

Virucidal activity of three ethanol-based hand rubs against murine norovirus in a hand hygiene clinical simulation study.

Aim: We evaluated the efficacy of three ethanol-based hand rubs against murine norovirus in a proposed clinical simulation test (prEN 17430). Materials & methods: Virucidal activity was determined in 18 volunteers using three hand rubs: ethanol 72.4 and 89.5% v/v solutions, and 86% v/v gel. Subjects underwent testing with each product (3/6 ml for 15/30 s) and a reference solution (6 ml 70% v/v ethanol for 60 s). Results: Against murine norovirus, the reduction factors (RF; RF mean ± standard deviation log10 reduction of postsampling) for ethanol gel 86% v/v (RF 1.96 ± 0.64), ethanol 89.5% v/v (RF 2.49 ± 0.59) and ethanol 72.4% v/v (RF 2.61 ± 0.50), were all significantly superior to that of the reference solution. Conclusion: All three hand rubs passed the criteria set out in prEN 17430 and exhibited excellent virucidal efficacy.

COVID-19 and hand hygiene: the vital importance of hand drying.

The significance of hand hygiene for preventing the transmission of microorganisms and reducing the spread of infection has been brought into sharp focus following the global coronavirus (COVID-19) pandemic. In the months since the initial outbreak, international public health campaigns and practitioner education has concentrated on hand washing and hand sanitising, with very little reference to hand drying, if any at all. However, hand drying is integral to effective hand hygiene, and is important in controlling the spread of microorganisms and maintaining healthy skin integrity. This research commentary will focus on two issues of importance with regards to hand drying: microbial transmission and skin irritation, with implications for healthcare practitioners and practice considered. It is argued that a more holistic approach to hand hygiene must be the ambition if health professional and public behaviour is to become embedded and sustained.

Hand Infections Associated with Systemic Conditions.

Systemic conditions are associated with higher rates of hand and upper extremity infections, leading to more severe and atypical presentations. Understanding the unique problems associated with some of the most common systemic conditions, including human immunodeficiency virus, diabetes mellitus, and rheumatoid arthritis, can assist the hand surgeon in diagnosing and treating infection in these patients. This article reviews the most common presentation of hand infections for these patients and summarizes current approaches to the management of hand infections for patients with common immunocompromising conditions.

Comparison of estimated norovirus infection risk reductions for a single fomite contact scenario with residual and nonresidual hand sanitizers.

BACKGROUND: The purpose of this study was to relate experimentally measured log10 human norovirus reductions for a nonresidual (60% ethanol) and a residual (quaternary ammonium-based) hand sanitizer to infection risk reductions. METHODS: Human norovirus log10 reductions on hands for both sanitizers were experimentally measured using the ASTM International Standard E1838-10 method, with modification. Scenarios included product application to: (1) inoculated fingerpads with 30- and 60-second contact times, and (2) hands followed by inoculation with human norovirus immediately and 4 hours later. Hand sanitizer efficacies were used in a mathematical model estimating norovirus infection risk from a single hand-to-fomite contact under low and high environmental contamination conditions. RESULTS: The largest log10 reductions for the residual and nonresidual hand sanitizers were for a 60-second contact time, reducing infection risk by approximately 99% and 85%, respectively. Four hours after application, the residual hand sanitizer reduced infection risks by 78.5% under high contamination conditions, whereas the nonresidual hand sanitizer offered no reduction. DISCUSSION: Log10 virus and infection risk reductions were consistently greater for the residual hand sanitizer under all scenarios. Further data describing residual hand sanitizer efficacy with additional contamination or tactile events are needed. CONCLUSIONS: Residual antinoroviral hand sanitizers may reduce infection risks for up to 4 hours.

Respiratory viruses on personal protective equipment and bodies of healthcare workers.

OBJECTIVE: To characterize the magnitude of virus contamination on personal protective equipment (PPE), skin, and clothing of healthcare workers (HCWs) who cared for patients having acute viral infections. DESIGN: Prospective observational study. SETTING: Acute-care academic hospital. PARTICIPANTS: A total of 59 HCWs agreed to have their PPE, clothing, and/or skin swabbed for virus measurement. METHODS: The PPE worn by HCW participants, including glove, face mask, gown, and personal stethoscope, were swabbed with Copan swabs. After PPE doffing, bodies and clothing of HCWs were sampled with Copan swabs: hand, face, and scrubs. Preamplification and quantitative polymerase chain reaction (qPCR) methods were used to quantify viral RNA copies in the swab samples. RESULTS: Overall, 31% of glove samples, 21% of gown samples, and 12% of face mask samples were positive for virus. Among the body and clothing sites, 21% of bare hand samples, 11% of scrub samples, and 7% of face samples were positive for virus. Virus concentrations on PPE were not statistically significantly different than concentrations on skin and clothing under PPE. Virus concentrations on the personal stethoscopes and on the gowns were positively correlated with the number of torso contacts (P < .05). Virus concentrations on face masks were positively correlated with the number of face mask contacts and patient contacts (P < .05). CONCLUSIONS: Healthcare workers are routinely contaminated with respiratory viruses after patient care, indicating the need to ensure that HCWs complete hand hygiene and use other PPE to prevent dissemination of virus to other areas of the hospital. Modifying self-contact behaviors may decrease the presence of virus on HCWs.

Environmental Contact and Self-contact Patterns of Healthcare Workers: Implications for Infection Prevention and Control.

BACKGROUND: Respiratory viruses on fomites can be transferred to sites susceptible to infection via contact by hands or other fomites. METHODS: Care for hospitalized patients with viral respiratory infections was observed in the patient room for 3-hour periods at an acute care academic medical center for over a 2 year period. One trained observer recorded the healthcare activities performed, contacts with fomites, and self-contacts made by healthcare workers (HCWs), while another observer recorded fomite contacts of patients during the encounter using predefined checklists. RESULTS: The surface contacted by HCWs during the majority of visits was the patient (90%). Environmental surfaces contacted by HCWs frequently during healthcare activities included the tray table (48%), bed surface (41%), bed rail (41%), computer station (37%), and intravenous pole (32%). HCWs touched their own torso and mask in 32% and 29% of the visits, respectively. HCWs' self-contacts differed significantly among HCW job roles, with providers and respiratory therapists contacting themselves significantly more times than nurses and nurse technicians (P < .05). When HCWs performed only 1 care activity, there were significant differences in the number of patient contacts and self-contacts that HCWs made during performance of multiple care activities (P < .05). CONCLUSIONS: HCWs regularly contact environmental surfaces, patients, and themselves while providing care to patients with infectious diseases, varying among care activities and HCW job roles. These contacts may facilitate the transmission of infection to HCWs and susceptible patients.

Mittens and Booties Syndrome: A Unique Manifestation of Human Parechovirus Infection in Infants.

We describe the first 2 cases from the United States, of human parechovirus infection in infants manifesting a distinct rash of the hands and feet. We propose the term "Mittens and Booties Syndrome" and provide a review of the literature of all published cases.

Validation of a Stochastic Discrete Event Model Predicting Virus Concentration on Nurse Hands.

Understanding healthcare viral disease transmission and the effect of infection control interventions will inform current and future infection control protocols. In this study, a model was developed to predict virus concentration on nurses' hands using data from a bacteriophage tracer study conducted in Tucson, Arizona, in an urgent care facility. Surfaces were swabbed 2 hours, 3.5 hours, and 6 hours postseeding to measure virus spread over time. To estimate the full viral load that would have been present on hands without sampling, virus concentrations were summed across time points for 3.5- and 6-hour measurements. A stochastic discrete event model was developed to predict virus concentrations on nurses' hands, given a distribution of virus concentrations on surfaces and expected frequencies of hand-to-surface and orifice contacts and handwashing. Box plots and statistical hypothesis testing were used to compare the model-predicted and experimentally measured virus concentrations on nurses' hands. The model was validated with the experimental bacteriophage tracer data because the distribution for model-predicted virus concentrations on hands captured all observed value ranges, and interquartile ranges for model and experimental values overlapped for all comparison time points. Wilcoxon rank sum tests showed no significant differences in distributions of model-predicted and experimentally measured virus concentrations on hands. However, limitations in the tracer study indicate that more data are needed to instill more confidence in this validation. Next model development steps include addressing viral concentrations that would be found naturally in healthcare environments and measuring the risk reductions predicted for various infection control interventions.

Hand-to-genital and genital-to-genital transmission of human papillomaviruses between male and female sexual partners (HITCH): a prospective cohort study.

BACKGROUND: Hand-to-genital contact is hypothesised to be a transmission mode of human papillomavirus (HPV) of the Alphapapillomavirus genus. We compared the relative importance of hand-to-genital and genital-to-genital HPV transmission between sexual partners. METHODS: In this prospective cohort study, we recruited and followed up female university students aged 18-24 years and their male sexual partners in Montreal, QC, Canada (2005-11). Participants were eligible if they had initiated sexual activity within the past 6 months. Women were examined at clinic visits at baseline and every 4-6 months for up to 24 months. Men had a baseline visit and a single follow-up visit approximately 4 months later. Partners provided hand and genital swab samples, which we tested for DNA of 36 HPV types using PCR. We assessed predictors of incident type-specific HPV detections using Cox proportional hazards models. FINDINGS: Participants were recruited between June 5, 2006, and April 4, 2013. 264 women and 291 men had valid hand samples. The hazard ratio (HR) of incident detection of HPV in genital samples from women was 5·0 (95% CI 1·5-16·4) when her partner was positive for the same HPV type on his hand versus negative, but adjustment for his genital HPV status reduced the HR to 0·5 (0·1-1·8). Similarly, the HR of incident detection of HPV on men's genitals was 17·4 (95% CI 7·9-38·5) when his partner was positive for the same HPV type on her hand versus negative, but adjustment for her genital HPV status reduced the HR to 2·3 (0·9-6·2). Conversely, the HR of type-specific incident detection of HPV in genital samples associated with partner genital HPV positivity was 19·3 (95% CI 11·8-31·8) for women and 28·4 (15·4-52·1) for men after adjustment for their hand HPV status. INTERPRETATION: Clinicians can reassure their patients that HPV transmission is unlikely to occur through hand-to-genital contact. The majority of genital HPV infections are likely to be caused by genital-to-genital sexual transmission. FUNDING: Canadian Institutes for Health Research, National Institutes of Health, Fonds de la Recherche en Santé du Québec, and Merck & Co.

Hand Infections in the Immunocompromised Patient: An Update.

Physicians are increasingly caring for immunocompromised individuals owing, in part, to the improved treatments and the increased life expectancy in these patients. Presentation of a patient with hand infection can vary greatly depending on the patient's underlying immune status. It is important to recognize and treat the infections quickly and effectively owing to the higher morbidity and mortality that may result from ineffective or delayed treatment in this patient population. The purpose of this article is to provide an outline of the most common and some of the more exotic organisms causing hand infections in patients with human immunodeficiency virus/acquired immunodeficiency syndrome, diabetes, and patients on immunosuppressive treatment. We discuss presentation, clinical picture, evidence-based approaches in treatment, and possible complications. It is important to inform surgeons of the atypical presentation of hand infections and systemic infections with hand manifestation in immunocompromised patients in order to shorten time to accurate diagnosis and effective treatment.

Modeling the role of fomites in a norovirus outbreak.

Norovirus accounts for a large portion of the gastroenteritis disease burden, and outbreaks have occurred in a wide variety of environments. Understanding the role of fomites in norovirus transmission will inform behavioral interventions, such as hand washing and surface disinfection. The purpose of this study was to estimate the contribution of fomite-mediated exposures to infection and illness risks in outbreaks. A simulation model in discrete time that accounted for hand-to-porous surfaces, hand-to-nonporous surfaces, hand-to-mouth, -eyes, -nose, and hand washing events was used to predict 17 hr of simulated human behavior. Norovirus concentrations originated from monitoring contamination levels on surfaces during an outbreak on houseboats. To predict infection risk, two dose-response models (fractional Poisson and 2F1 hypergeometric) were used to capture a range of infection risks. A triangular distribution describing the conditional probability of illness given an infection was multiplied by modeled infection risks to estimate illness risks. Infection risks ranged from 70.22% to 72.20% and illness risks ranged from 21.29% to 70.36%. A sensitivity analysis revealed that the number of hand-to-mouth contacts and the number of hand washing events had strong relationships with model-predicted doses. Predicted illness risks overlapped with leisure setting and environmental attack rates reported in the literature. In the outbreak associated with the viral concentrations used in this study, attack rates ranged from 50% to 86%. This model suggests that fomites may have accounted for 25% to 82% of illnesses in this outbreak. Fomite-mediated exposures may contribute to a large portion of total attack rates in outbreaks involving multiple transmission modes. The findings of this study reinforce the importance of frequent fomite cleaning and hand washing, especially when ill persons are present.