Assessment of the bacterial contamination of hand air dryer in washrooms

Indoor particle dispersion due to hand dryer in public washroom: an in silico study

Hand dryer in public washroom has been reported likely to be a reservoir of drug-resistant bacteria. When a hand dryer being used, the high-velocity air jet from the dryer outlet can carry aerosol particles to hand surfaces, the user, and indoor space. This in silico study considered the effect of different airflow speed of hand dryers on the dispersion of particles in different diameters with and without the user. The aim of this study was to apply the computational fluid dynamics (CFD) method based on the discrete phase model to investigate the trajectory of indoor particles from the hand dryer in public washroom. The CFD results showed that, when the user was using the hand dryer, 42.3% of the particles were distributed on the wall against the user, and 31.6% were distributed on the user's body, including their hands. When no one was standing in front of the hand dryer, 87.6% of the particles fell on the ground. The blocking of user's hand dispersed the particles to a wide range, particularly for the larger diameter particles which were scattered on the user's body or on the ground. In addition, the dispersion proportion of particles did not vary with the speed of airflow, but the area of particles distribution became larger as the speed increased. Our findings suggest that the contamination of the indoor environment caused by the hand dryer could not be ignored, incorporating filters into hand dryers is essential. Furthermore, our work offers valuable insights for optimizing the design of hand dryers.

Assessment of the effect of hand dryers used in shopping malls on hand hygiene

BACKGROUND

Hand drying is one of the most important factors affect hand hygiene. This study was conducted to investigate the effect of hand dryers used in the restrooms located on the food court floors in shopping malls in Turkey on hand hygiene.

METHODS

Hands were washed for at least 20 seconds by following hygienic hand washing procedures of the World Health Organization. Swab samples were taken from the wet hands after hand washing, then from the dry hands, which were dried under the hand dryers and from the air blowing part of the hand dryers. Samples were cultured on agar plates that were directly exposed to the air-blowing part of the hand dryers.

RESULTS

It was found that total coliform bacteria were 0.000 colony-forming unit (CFU)/petri in wet and dried hand, 3.437 CFU/petri in blown air and 5.250 CFU/petri in swab samples. Staphylococcus aureus was found to be 0.125, 64.125, 26.375, and 388.750 CFU/petri, respectively. Total bacteria count was found to be 0.687, 48.750, 35.625, and 595.000 CFU/petri, respectively. S. aureus and the total bacterial load were higher in the blower outlet of the hand dryers than washed hand, blown air and dried hand (P < .05). The bacteria count in the unfiltered hand dryers was higher than that in the filtered hand dryers (P < .05).

CONCLUSIONS

Using hand dryers would negatively affect hand hygiene even if hands were washed following hygienic hand washing procedures.

Transmission of COVID-19 and other infectious diseases in public washrooms: A systematic review

BACKGROUND

The risk of infectious disease transmission in public washrooms causes concern particularly in the context of the COVID-19 pandemic. This systematic review aims to assess the risk of transmission of viral or bacterial infections through inhalation, surface contact, and faecal-oral routes in public washrooms in healthcare and non-healthcare environments.

METHODS

We systematically reviewed environmental sampling, laboratory, and epidemiological studies on viral and bacterial infection transmission in washrooms using PubMed and Scopus. The review focused on indoor, publicly accessible washrooms.

RESULTS

Thirty-eight studies from 13 countries were identified, including 14 studies carried out in healthcare settings, 10 in laboratories or experimental chambers, and 14 studies in restaurants, workplaces, commercial and academic environments. Thirty-three studies involved surface sampling, 15 air sampling, 8 water sampling, and 5 studies were risk assessments or outbreak investigations. Infectious disease transmission was studied in relation with: (a) toilets with flushing mechanisms; (b) hand drying systems; and (c) water taps, sinks and drains. A wide range of enteric, skin and soil bacteria and enteric and respiratory viruses were identified in public washrooms, potentially posing a risk of infection transmission. Studies on COVID-19 transmission only examined washroom contamination in healthcare settings.

CONCLUSION

Open-lid toilet flushing, ineffective handwashing or hand drying, substandard or infrequent surface cleaning, blocked drains, and uncovered rubbish bins can result in widespread bacterial and/or viral contamination in washrooms. However, only a few cases of infectious diseases mostly related to faecal-oral transmission originating from washrooms in restaurants were reported. Although there is a risk of microbial aerosolisation from toilet flushing and the use of hand drying systems, we found no evidence of airborne transmission of enteric or respiratory pathogens, including COVID-19, in public washrooms. Appropriate hand hygiene, surface cleaning and disinfection, and washroom maintenance and ventilation are likely to minimise the risk of infectious disease transmission.

An Evaluation of the Hand Hygiene Behaviour and Compliance of the General Public When Using Public Restrooms in Northern Ireland (NI) during the Initial Weeks of the Novel Coronavirus (COVID-19) Pandemic

BACKGROUND

The ongoing novel coronavirus (COVID-19) global pandemic has resulted in significant levels of morbidity and mortality worldwide, particularly among the elderly and immuno-suppressed groups. Although adequate hand hygiene (HH) behaviour and compliance is widely accepted as being the most effective self-protective measure in preventing the spread of diseases like COVID-19, previous research suggests that normal hand hygiene compliance is poor, but generally improves during a disease pandemic. This research aimed to evaluate the hand hygiene behaviour and compliance of the general public in the initial weeks of the COVID-19 pandemic in Northern Ireland (NI).

METHODS

This cross-sectional study involved the use of infrared-imaging cameras to observe the hand hygiene behaviour and compliance of the general public when using one set of male and female public restrooms.

RESULTS

The findings of this study indicated that the level of hand hygiene compliance of the general public was poor in the initial weeks, with 82.93% overall not washing their hands adequately.

CONCLUSIONS

Inadequate HH behaviour and compliance may have added significantly to the rapid rate of spread of COVID-19 in the initial weeks of the pandemic in NI. Current public health campaigns do not appear, based on this study, to have the desired impact and may need to be reviewed or re-enforced in order to achieve the levels of hand hygiene compliance required to slow the spread of COVID-19 and other communicable diseases in the future.

Degree of bacterial contamination in barbershops using hair dryers in Riyadh

Barbershops provide areas for the growth and transfer of bacterial pathogens and thereby have an impact on public health. Barbershops are ideal places for the interactive spread of infections, including community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA). Here, the work determines the degree of bacterial contamination of hair dryers used in barbershops. The samples were collected in the city of Riyadh, the Kingdom of Saudi Arabia on March 2019. Significant bacterial contamination was seen, with total bacterial count increasing when the hair dryers were run for 20 instead of 10 s. The study shows a high level of bacterial contamination barbershops using hair dryers, with MRSA being isolated in some. The results suggest that high quality filters should be used inside hair dryers and filters, and theses should be cleaned frequently.

An Investigation of the General Population's Self-Reported Hand Hygiene Behaviour and Compliance in a Cross-European Setting

Every year, thousands of people from the UK travel to other countries for work and leisure. Europe, and particularly Spain, is one of the most popular travel destinations for people from the UK. However, it is known that travel to other countries can enhance the risk of communicable disease transmission from person to person, especially when a new one emerges. Adequate hand hygiene behaviour and compliance is widely accepted as being a simple, effective method in preventing the spread of communicable diseases that may be contracted during travel abroad. There is a well-established body of work investigating hand hygiene practice and compliance in community settings, but no recent studies have examined the hand hygiene practice and compliance of the general population when travelling abroad or in a cross-European context. The findings of this study indicated that most UK members of the general population when travelling abroad have a good level of understanding of the importance of adequate hand hygiene practice and compliance and its role regarding communicable disease prevention and control. As such, self-reported levels of compliance were high. Similar findings were made for Spanish members of the general population. However, while self-reported perceptions of adequacy of hand hygiene performance were relatively high, particularly among UK respondents, this was not supported by responses specifically focused on hand hygiene behaviour. However, differences in self-reported adequacy regarding the importance of handwashing versus hand drying, the number of steps that should be followed and the length of time that should be spent washing and drying hands were found for each group. This suggests that self-reported compliance may reflect intention to practice hand hygiene rather than true compliance. It also suggests that there are gaps in knowledge regarding the adequate method of hand hygiene among the cohort as a whole, and indeed these differences may account be a factor in for the high transmission rates of communicable disease when travelling abroad.

Microbiological Assessment of the Different Hand Drying Methods and Washroom Environment Cross-Contamination

Proper hand drying is a fundamental part of the hand hygiene process looking at optimizing the elimination of potentially pathogenic microbes. This research compared the effectiveness of three different hand drying methods—paper towels, the use of warm air dryers in stationary hands position, and the use of air drying while hand rubbing—and their potential for cross-contamination of other users and the surrounding environment. One hundred sixty samples were collected from finger pads and palms, before and after drying. The outlet of the air dryers, air current emitted from the air dryers, and washroom environment air were also tested. The study reported that paper towels were more successful in eliminating bacteria and lead to less contamination to the washroom environment compared to the air dryers. The average number of bacteria obtained from volunteers using hand air dryer while hand rubbing was significantly higher than drying with air dryer while holding hands stationary. Plates exposed to the turned-off dryer for 5 minutes gave an average of only 25 colonies/plate, while plates exposed to the air outlet of the turned-on warm air dryers provided 292 colonies/plate. Placing Petri dishes at least one meter away from the dryer in the washroom for 30 minutes gave 72.5 colonies/plate. The current research also documented frequent contamination of public washroom environments and showed dissemination of potential pathogens, including Escherichia coli (E. coli), Klebsiella species, Bacillus cereus (B. cereus), Staphylococcus aureus (S. aureus), and coagulase-negative Staphylococci. Over 70.0% of Staphylococci were resistant to at least three antibiotics and 50.0% revealed coresistance to at least four antibiotics including penicillin, erythromycin, clindamycin, and co-trimoxazole. The method of hand drying may serve as a risk factor of cross-contamination from users to the environment and subsequent users and as reservoirs of drug-resistant bacteria in public washrooms.

Blowing in the wind: Bacteria and fungi are spreading from public restroom hand dryers

This study aimed to identify and quantify fungi and bacteria in the airflow of restroom hand dryers in public areas. Airflow from restroom hand dryers in 8 retail locations was tested using three types of culture media, followed by PCR and sequence analysis to identify microbial species. Both bacterial and fungal colonies were detected in all locations. The number of colonies did not vary significantly across different locations, suggesting a similar level of microbial spread by hand dryers between different types of commercial stores. Molecular analysis revealed 24 bacterial species and 40 fungal species. Of these species, 48% (31/64) have been reported to be implicated in various infections in humans, primarily those with underlying medical conditions. This study is the first to demonstrate the spread of fungi by the airflow of restroom hand dryers, and the first to show the prevalence of different fungal and bacterial species spread by restroom hand dryers in common public areas.

Knowledge Level and Hand Hygiene Practice of Nepalese Immigrants and Their Host Country Population: A Comparative Study

Nepali people are one of the ethnic minority immigrants of Hong Kong. This epidemiological investigation aims to determine and compare the knowledge level and hand hygiene (HH) behaviour of the Nepali people and the population of their host country (i.e., native Chinese population of Hong Kong). A total of 1008 questionnaires were collected via an online platform. The overall knowledge level of the native population towards HH was considerably higher than that of the Nepali respondents. Lower levels of knowledge in young and older people were noted. Reduced HH knowledge was also observed in people with low educational level or with comorbid illness(es). Significant differences between groups were noted in the self-reported hand washing behaviours. Regarding hand drying, more Nepalese than native Chinese respondents always/sometimes dried their hands on their clothing irrespective whether after performing handwashing in public washrooms or at home. Misconceptions and suboptimal practices on HH were prevalent in the two populations. The findings of this comparative study offer valuable information for the development of culturally sensitive health educational programs to enhance HH practices for the ethnic minorities and native Chinese population.

A survey of public restrooms microbial contamination in Tehran city, capital of Iran, during 2019

INTRODUCTION

Daily use of public restrooms may have a significant impact on spreading infectious diseases. Human society could be affected by spreading of transitional infectious diseases through feces, urinary tract infection and poor personal hygiene. According to the World Health Organization reports, plenty of people's developed diseases caused by contaminated public restrooms that may result in severe health problems.

METHODS

This descriptive cross-sectional study was conducted on 7,482 samples that were collected randomly in 6 months (spring and summer 2019) in different regions of Tehran. The Data were obtained by analyzing 804 restroom's indoor and outdoor handles, 1062 toilet faucet, 826 washbasin taps, 1,062 toilet hoses, 804 flush tank levers, 643 soap dispenser bottoms, 643 liquid soaps, 99 bar soaps, 169 toilet papers and paper towels, and 50 hand dryer machines. Samples which were tested, based on bacteriology standard methods.

RESULT

7,482 samples were gathered of which 6,678 contaminated cases (89.25%) were observed and 804 cases (10.75%) were found non-contaminated. Escherichia coli with 28.48% and Pseudomonas with 0.39% were the most and the least common bacteria, respectively, in this study.

CONCLUSION

The required tests to identify the bacteria that cause contamination through the use of public restrooms have been done. It is essential to inform the public of the mentioned items and teach how to prevent infectious diseases.

The Effectiveness of a Poster Intervention on Hand Hygiene Practice and Compliance When Using Public Restrooms in a University Setting

Background: Most research on hand hygiene compliance in community settings indicates that compliance is poor. It is not conclusive as to whether poster interventions are effective at improving compliance. Methods: An independent, self-designed poster intervention was installed in one set of male and female public restrooms in a university campus in the UK. The hand hygiene practice and compliance of the university population was measured via indirect observation over a 60 day period. Results: During the pre-intervention observation period, 51.09% of the university population practiced basic hand hygiene compliance (washed hands with water, soap and dried afterwards), and 7.88% practiced adequate hand hygiene compliance (washed hands with water and soap for 20 s or more and dried afterwards for 20 s or more). During the post-intervention observation period, 55.39% of the university population were observed practicing basic hand hygiene compliance, and 7.97% practicing adequate hand hygiene compliance. Gender differences revealed that more females practiced basic hand hygiene in the post-intervention observation period (62.81%) than during the pre-intervention period (49.23%) and this was statistically significant (χ² = 13.49, p = < 0.01). Discussion: The poster intervention had a limited effect on improving the basic and adequate hand hygiene compliance of the general population when using public restrooms. The use of independent, self-designed posters to improve hand hygiene practice and compliance is largely ineffective in the short term and should be used with caution in future intervention strategies.

Epidemiological investigation on hand hygiene knowledge and behaviour: a cross-sectional study on gender disparity

Background

The hand hygiene (HH) behaviour of the general public and its effect on illnesses are issues of growing importance. Gender is associated with HH behaviour. HH efficiency is a combination of washing efficiency and hand drying, but information about the knowledge level and HH behaviour of the general public is relatively limited. The findings of this cross-sectional study can substantially contribute to the understanding on the knowledge gap and public behaviour towards HH, thereby providing information on gender-specific health promotion activities and campaigns to improve HH compliance.

Methods

An epidemiological investigation by using a cross-sectional study design on the general public was conducted either via an online platform (SurveyMonkey) or paper-and-pen methods. The hand-washing and -drying questionnaire was used for data collection.

Results

A total of 815 valid questionnaires were collected. Majority of the respondents can differentiate the diseases that can or cannot be transmitted with poor HH, but the HH knowledge of the respondents was relatively inadequate. The female respondents had a significantly better HH knowledge than male respondents. The multiple regression analysis results also indicated that females had a significantly higher knowledge score by 0.288 towards HH than males after adjusting for age and education level. Although the majority of the respondents indicated that they performed hand cleaning under different specific situations, they admitted only using water instead of washing their hands with soap. More males than females dried their hands on their own clothing, whereas more females dried their hands through air evaporation. The average time of using warm hand dryers was generally inadequate amongst the respondents.

Conclusions

Being a female, middle-aged and having tertiary education level are protective factors to improve HH knowledge. Misconceptions related to the concepts associated with HH were noted amongst the public. Self-reported practice on hand drying methods indicated that additional education was needed. The findings of this study can provide information on gender-specific health promotion activities and creative campaigns to achieve sustained improvement in HH practices.

The public washroom - friend or foe? An observational study of washroom cleanliness combined with microbiological investigation of hand hygiene facilities

Background

Many people use handwashing and hand-drying facilities in public washrooms under the impression that these amenities are hygienic. However, such facilities may be potential sites for the transmission of pathogenic bacteria. This study aimed to examine the hygiene facilities provided including handwashing and hand-drying facilities in public washrooms. Total bacterial counts and species identification were determined for hand-drying facilities. Antimicrobial susceptibilities were performed.

Methods

The bacterial contamination levels of 55 public washrooms ranging in category from low class communities to high end establishments, were examined. The hygienic environment and facilities of the washrooms were analysed using an electronic checklist to facilitate immediate data entry. Pre-moistened sterile swabs were used to collect samples from areas around the outlet of paper towel dispensers, air outlet of air dryers, exit door handles and paper towels in the washrooms. Total bacterial counts were performed and isolates identified using matrix-assisted laser desorption ionisation time-of-flight mass spectrometry. Antimicrobial susceptibility was determined by disk diffusion.

Results

The high and middle-income categories washrooms generally had cleaner facilities and environment followed by those in low categories. Fifty-two bacterial species were identified from the 55 investigated washrooms. Over 97% of the pathogenic Staphylococcus spp. tested were resistant to at least one first-line antimicrobial therapeutic agent, including penicillin, cefoxitin, erythromycin, co-trimoxazole, clindamycin and gentamicin, and 22.6% demonstrated co-resistance to at least three antimicrobial agents, with co-resistance to penicillin, erythromycin and clindamycin being the most common.

Conclusion

Our findings suggest that hand-drying facilities in public washrooms can act as reservoirs of drug-resistant bacteria. The importance of frequent cleaning and maintenance of public washrooms to promote safe hand hygiene practices for the public are emphasised.

High-Strength Antibacterial Chitosan-Cellulose Nanocrystal Composite Tissue Paper

A heightened need to control the spread of infectious diseases prompted the current work in which functionalized and innovative antimicrobial tissue paper was developed with a hydrophobic spray-coating of chitosan (Ch) and cellulose nanocrystals (CNCs) composite. It was hypothesized that the hydrophobic nature of chitosan could be counterbalanced by the addition of CNC to maintain fiber formation and water absorbency. Light-weight tissue handsheets were prepared, spray-coated with Ch, CNC, and their composite coating (ChCNC), and tested for antimicrobial activity against Gram-negative bacteria Escherichia coli and a microbial sample from a human hand after using the rest room. Water absorption and strength properties were also analyzed. To activate the surface of cationized tissue paper, an oxygen/helium gas atmospheric plasma treatment was employed on the best performing antimicrobial tissue papers. The highest bactericidal activity was observed with ChCNC-coated tissue paper, inhibiting up to 98% microbial growth. Plasma treatment further improved the antimicrobial activity of the coatings. Water absorption properties were reduced with Ch but increased with CNC. This "self-disinfecting" bactericidal tissue has the potential to be one of the most innovative products for the hygiene industry because it can dry, clean, and resist the infection of surfaces simultaneously, providing significant societal benefits.

The method used to dry washed hands affects the number and type of transient and residential bacteria remaining on the skin

BACKGROUND

Widespread antibiotic resistance has led to fears that we are entering a post-antibiotic era and the relatively simple premise of hand washing to reduce transfer of bacteria and viruses has never been more important. Much of the emphasis has been on hand-washing technique, type of soap, and maintaining compliance but effective drying of the hands is just as important.

AIM

To compare the efficacy of drying washed hands with a jet air dryer or paper towels to remove transient bacterial contamination and to determine the effect on residential flora.

METHODS

Eighty volunteers were recruited. The entire surfaces of volunteers' hands were artificially contaminated with Escherichia coli before being washed and dried; then bacteria remaining on the skin were recovered and enumerated. In the second part of the study the number and types of bacteria comprising the natural flora remaining on washed and dried hands were determined.

FINDINGS

Significantly fewer transient and residential bacteria remained on the skin if hands were dried with a jet air dryer (P < 0.001). Drying hands with paper towels increased the number of resident bacteria, including potentially pathogenic species, released from the volunteers' skin, compared to a jet air dryer.

CONCLUSION

The number and types of bacteria remaining on washed hands were affected by the drying method. Hands dried with a jet air dryer harboured fewer viable bacteria, reducing the risk of infection transmission via touch. This could be especially important for healthcare workers who are constantly in contact with large numbers of vulnerable patients.

The neglected element of hand hygiene - significance of hand drying, efficiency of different methods and clinical implication: A review

Hand hygiene is a fundamental strategy for controlling the spread of infection. Careful hand drying is integral to the process of hand hygiene, which aims to optimise the removal of potentially pathogenic microorganisms. Ineffective hand drying results in wet hands that are an infection risk increasing the potential for cross-infection, occupational contact dermatitis for healthcare practitioners, harm to patients and environmental contamination. Evidence indicates that there has been limited research regarding the significance of hand drying and the efficacy and clinical impact of different drying methods. The purpose of this review paper was to scope and evaluate the existing literature pertaining to hand drying; to examine the clinical consequences associated with wet hands for patients, healthcare practitioners and the clinical environment; to assess the efficacy of different drying methods; to consider the impact on patient safety; and to progress the research, debate and practice relating to hand drying. The methodological framework applied in this review was that of Arksey and O'Malley (2007). Twenty-one papers identified from 112 abstracts screened were included in the review. Analysis identified three primary themes emerging from the literature: (1) efficacy of hand drying methods; (2) drying method and microbial translocation, dispersion and environmental contamination; and (3) drying methods and environmental sustainability. This review highlights the equal importance of hand drying in the process of hand hygiene and suggests that the efficacy of hand drying is a critical factor in the prevention of the transfer of microorganisms to the environment, and from person to person following hand washing. In conclusion, this paper argues that greater attention needs to be given to hand drying in terms of practice, policy and research and its importance in clinical settings given greater focus.

Deposition of Bacteria and Bacterial Spores by Bathroom Hot-Air Hand Dryers

Hot-air hand dryers in multiple men's and women's bathrooms in three basic science research areas in an academic health center were screened for their deposition on plates of (i) total bacteria, some of which were identified, and (ii) a kanamycin-resistant Bacillus subtilis strain, PS533, spores of which are produced in large amounts in one basic science research laboratory. Plates exposed to hand dryer air for 30 s averaged 18 to 60 colonies/plate; but interior hand dryer nozzle surfaces had minimal bacterial levels, plates exposed to bathroom air for 2 min with hand dryers off averaged ≤1 colony, and plates exposed to bathroom air moved by a small fan for 20 min had averages of 15 and 12 colonies/plate in two buildings tested. Retrofitting hand dryers with HEPA filters reduced bacterial deposition by hand dryers ∼4-fold, and potential human pathogens were recovered from plates exposed to hand dryer air whether or not a HEPA filter was present and from bathroom air moved by a small fan. Spore-forming colonies, identified as B. subtilis PS533, averaged ∼2.5 to 5% of bacteria deposited by hand dryers throughout the basic research areas examined regardless of distance from the spore-forming laboratory, and these were almost certainly deposited as spores. Comparable results were obtained when bathroom air was sampled for spores. These results indicate that many kinds of bacteria, including potential pathogens and spores, can be deposited on hands exposed to bathroom hand dryers and that spores could be dispersed throughout buildings and deposited on hands by hand dryers.IMPORTANCE While there is evidence that bathroom hand dryers can disperse bacteria from hands or deposit bacteria on surfaces, including recently washed hands, there is less information on (i) the organisms dispersed by hand dryers, (ii) whether hand dryers provide a reservoir of bacteria or simply blow large amounts of bacterially contaminated air, and (iii) whether bacterial spores are deposited on surfaces by hand dryers. Consequently, this study has implications for the control of opportunistic bacterial pathogens and spores in public environments including health care settings. Within a large building, potentially pathogenic bacteria, including bacterial spores, may travel between rooms, and subsequent bacterial/spore deposition by hand dryers is a possible mechanism for spread of infectious bacteria, including spores of potential pathogens if present.