Determination of hand surface area by sex and body shape using alginate

Development and Implementation of an Ultraviolet-Dye-Based Qualification Procedure for Hand Washing and Disinfection to Improve Quality Assurance of Pharmacy Preparations and Compounding, Especially in Cleanrooms: A Pilot Study

Even though, nowadays, most medicines are manufactured industrially, patients may have medical needs that can only be met by a tailor-made approach. This requires the availability of pharmacy preparations made under Good Manufacturing Practice (GMP) conditions. An efficient hand hygiene practice is essential herewith, especially if sterile products that are prepared in a cleanroom are concerned. The effectiveness of hand washing and hand disinfection procedures greatly relies on adequate training. We carried out an observational cross-sectional pilot study aimed at optimizing hand hygiene training with objective and measurable quality assessments using an ultraviolet (UV) dye. Practical acceptance criteria for qualifying personnel through this method were set and evaluated. In total, 25 GMP-qualified cleanroom operators washed and disinfected their hands with UV dye hand wash lotion and UV dye hand alcohol, respectively. To obtain a proof-of-concept, the results were judged based on adherence to the WHO six-step protocol and associated acceptance criteria. Commonly missed areas were brought to light, and the influence of procedure duration was investigated. UV-dye-based assessments appeared to be more valuable in hand disinfection than in hand washing. In both procedures, the back of the hands and the thumbs were frequently missed. This underpins the need for enhanced and repeated education on hand washing and disinfection. Additionally, a dry skin gave rise to extra cleaning challenges. From this pharmacy practice pilot study with a focus on pharmaceutical product care, it may be concluded that the application of UV-dye-based assessments offers valuable insights for pharmacists to optimize hand hygiene, thereby increasing the safety of tailor-made medicines and on-site preparations.

Eye infection risks from Pseudomonas aeruginosa via hand soap and eye drops

Eye infections from bacterial contamination of bulk-refillable liquid soap dispensers and artificial tear eye drops continue to occur, resulting in adverse health outcomes that include impaired vision or eye enucleation. Pseudomonas aeruginosa (P. aeruginosa), a common cause of eye infections, can grow in eye drop containers and refillable soap dispensers to high numbers. To assess the risk of eye infection, a quantitative microbial risk assessment for P. aeruginosa was conducted to predict the probability of an eye infection for two potential exposure scenarios: (i) individuals using bacteria-contaminated eye drops and (ii) contact lens wearers washing their hands with bacteria-contaminated liquid soap prior to placing the lens. The median risk of an eye infection using contaminated eye drops and hand soap for both single and multiple exposure events (per day) ranged from 10-1 to 10-4, with contaminated eye drops having the greater risk. The concentration of P. aeruginosa was identified as the parameter contributing the greatest variance on eye infection risk; therefore, the prevalence and level of bacterial contamination of the product would have the greatest influence on health risk. Using eye drops in a single-use container or with preservatives can mitigate bacterial growth, and using non-refillable soap dispensers is recommended to reduce contamination of hand soap. Given the opportunistic nature of P. aeruginosa and its ability to thrive in unique environments, additional safeguards to mitigate bacterial growth and exposure are warranted.IMPORTANCEPseudomonas aeruginosa (P. aeruginosa) is a pathogen that can persist in a variety of unusual environments and continues to pose a significant risk for public health. This quantitative microbial risk assessment (QMRA) estimates the potential human health risks, specifically for eye infections, associated with exposure to P. aeruginosa in bacteria-contaminated artificial tear eye drops and hand soap. This study applies the risk assessment framework of QMRA to evaluate eye infection risks through both consumer products. The study examines the prevalence of this pathogen in eye drops and soap, as well as the critical need to implement measures that will mitigate bacterial exposure (e.g., single-use soap dispensers and eye drops with preservatives). Additionally, limitations and challenges are discussed, including the need to incorporate data regarding consumer practices, which may improve exposure assessments and health risk estimates.

Cream versus ointment: Randomized single-blinded study on the adherence to treatment with topical methylprednisolone aceponate

BACKGROUND

Overall adherence in the treatment of chronic dermatoses is poor. Textbooks state an adherence dependence on galenics.

TRIAL DESIGN

Prospective, randomized, parallel-grouped, single-blinded (investigator), monocentric clinical trial (phase IV) on the adherence to treatment of chronic mild to moderate hand eczema with topical methylprednisolone aceponate (MPA, Advantan®) in different vehicles.

OBJECTIVES AND ENDPOINTS

Primary objective was the assessment of the adherence depending on vehicle type in patients with chronic hand eczema. Secondary objective was improvement after a 4-week treatment period. Primary Endpoint Adherence is defined as the percentage of patients applying at least aimed daily dose. Prescribed daily dose was defined as the planned number of applications per day (1) * surface (measured) * aimed amount per application (mg/cm2 ). Truly applicated daily dose was evaluated as individual mean amount per dose * individual mean number of applications per day. Adherence was assumed, if truly applicated daily dose is at least 75% of the prescribed daily dose and the individual mean number of applications per day is at least 0.85. Secondary Endpoint Efficacy was measured by improvement of Hand Eczema Severity Index (HECSI) and Investigator's Global Assessment (IGA) after a 4-week treatment period and in addition to Quality of Life in Hand Eczema Questionnaire (QOLHEQ) and Visual Analogue Scale (VAS) to assess pruritus.

METHODS

Number of participants randomized to each group 40, 80 total. Group 1 MPA-C: Methylprednisolone aceponate 0.1% cream and barrier repair emollient (Bepanthen® Sensiderm). Group 2 MPA-FO: Methylprednisolone aceponate 0.1% fatty ointment and barrier repair emollient (Bepanthen® Sensiderm). Adherence to treatment was compared via Fisher's exact test.

RESULTS

Of the patients, 48% were adherent according to our definition. There was no significant difference between MPA-C (42.1%) and MPA-FO (54.1%; p = 0.36; group difference-12.0%, 95% CI-34.3%-11.5%). Generalized-linear-model-analysis of adherence to study treatment with factors emollient use, treatment, time and treatment-time interaction showed a parallel between adherence and amount of emollient use (odds ratio 1.74, p = 0.0038; 95% CI-1.22-2.52). Improvement of hand eczema was seen according to clinical scores without remarkable differences between the groups.

CONCLUSIONS

No dependence of adherence on galenics of topical treatment of chronic hand eczema could be proved. Patients who use more emollient tend to be more adherent to the topical treatment.

Soft computing applications in the field of human factors and ergonomics: A review of the past decade of research

The main objectives of this study were to 1) review the literature on the applications of soft computing concepts to the field of human factors and ergonomics (HFE) between 2013 and 2022 and 2) highlight future developments and trends. Multiple soft computing methods and techniques have been investigated for their ability to address various applications in HFE effectively. These techniques include fuzzy logic, artificial neural networks, genetic algorithms, and their combinations. Applications of these methods in HFE have been highlighted in one hundred and four articles selected from 406 papers. The results of this study help address the challenges of complexity, vagueness, and imprecision in human factors and ergonomics research through the application of soft computing methodologies.

Comparison of aggregated exposure to perfluorooctanoic acid (PFOA) from diet and personal care products with concentrations in blood using a PBPK model - Results from the Norwegian biomonitoring study in EuroMix

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) constitute a large group of compounds that are water, stain, and oil repellent. Numerous sources contribute to the blood levels of PFAS in the European population. The main contributor for perfluorooctanoic acid (PFOA) is food, house dust, consumer products and personal care products (PCPs).

OBJECTIVES

The purpose of the present work is to calculate the dietary and dermal external exposure to PFOA, estimate the aggregated internal exposure from diet and PCPs using a PBPK model, and compare estimates with measured concentrations.

METHODS

Detailed information on diet and PCP use from the EuroMix study is combined with concentration data of PFOA in food and PCPs in a probabilistic exposure assessment. A physiologically based pharmacokinetic model (PBPK) was further refined by incorporating a dermal exposure pathway, and changes in the kidney and faecal excretion.

RESULTS

The aggregated internal exposure using the PBPK model shows that the major contributor to the internal exposure is diet for both males and females. The estimated internal exposure of PFOA for the EuroMix population was in the same range but lower than the measured blood concentrations using the lower bound (LB) external exposure estimates, showing that the LB estimates are underestimations. For seven females the internal exposure of PFOA were higher from PCPs than from diet.

CONCLUSION

PCPs and diet contributed in the same range to the internal PFOA exposure for several women participating in EuroMix. This calls for additional studies on exposure to PFOA and possibly other PFAS from PCPs, especially for women. Overall, PBPK modelling was shown as valuable tool in understanding the sources of PFOA exposure and in guiding risk assessments and regulatory decisions.

Spatial summation of thermal sensitivity is limited to small areas: Comparisons of the forehead, forearm, abdomen, and foot

The purpose of the present study was to examine if spatial summation in thermal sensitivity exists when stimulating areas larger than about 1% of body surface area (BSA) (approximately 200 cm2). We hypothesized that spatial summation would exist within a limited area and the effect would be insignificant for over the 1%BSA. Fifteen young males participated in this study and we measured their warmth and hot sensation thresholds on the four body regions (the forehead, forearm, abdomen, and instep) using the three sizes of radiant film heaters (10 × 10, 15 × 15, and 20 × 20 cm2 heating film area). The heating panel was kept at a distance of 10 cm from the skin and the surface temperature of the heating panel increased by 1 °C·s-1. The results showed that warmth and hot sensation thresholds were higher for the 100 cm2 condition than the 225 or 400 cm2 conditions (P < 0.05), but no differences were found between the 225 and 400 cm2 conditions. Secondly, the instep was most insensitive to the gradual increase of radiant heat among the four body regions for all three stimulating film sizes, even though the hot threshold was lowest for the instep because the initial foot temperature was lower than other skin temperatures. In summary, spatial summation in thermal sensitivity was found for the 100 and 225 cm 2 conditions, but not for the 225 and 400 cm2 conditions. These results suggest that spatial summation exists but limited to small stimulating areas, smaller than approximately 1% BSA.

RadarSense: Accurate Recognition of Mid-Air Hand Gestures with Radar Sensing and Few Training Examples

Microwave radars bring many benefits to mid-air gesture sensing due to their large field of view and independence from environmental conditions, such as ambient light and occlusion. However, radar signals are highly dimensional and usually require complex deep learning approaches. To understand this landscape, we report results from a systematic literature review of ( N = 118) scientific papers on radar sensing, unveiling a large variety of radar technology of different operating frequencies and bandwidths, antenna configurations, but also various gesture recognition techniques. Although highly accurate, these techniques require a large amount of training data that depend on the type of radar. Therefore, the training results cannot be easily transferred to other radars. To address this aspect, we introduce a new gesture recognition pipeline that implements advanced full-wave electromagnetic modeling and inversion to retrieve physical characteristics of gestures that are radar independent, i.e. , independent of the source, antennas, and radar-hand interactions. Inversion of radar signals further reduces the size of the dataset by several orders of magnitude, while preserving the essential information. This approach is compatible with conventional gesture recognizers, such as those based on template matching, which only need a few training examples to deliver high recognition accuracy rates. To evaluate our gesture recognition pipeline, we conducted user-dependent and user-independent evaluations on a dataset of 16 gesture types collected with the Walabot, a low-cost off-the-shelf array radar. We contrast these results with those obtained for the same gesture types collected with an ultra-wideband radar made of a vector network analyzer with a single horn antenna and with a computer vision sensor, respectively. Based on our findings, we suggest some design implications to support future development in radar-based gesture recognition.

Comparison of two alcohol hand rubbing techniques regarding hand surface coverage among hospital workers: a quasi-randomized controlled trial

BACKGROUND

The adapted 6-step without interlock (A6Sw/oI) hand rub technique, commonly practiced in Japan, adds the "wrist" but omits the "interlock" step compared to the WHO 6-step technique (WHO6S). The first objective of this study was to assess the differences of the two techniques regarding surface coverage. The second objective was to analyze the coverage differences between hand sizes.

METHODS

Hospital workers went under stratified quasi-randomization by glove size. The overall mean coverage, and the coverage of the sections of the hands were evaluated by fluorescent dye-based coverage assessment using a digital device with artificial intelligence technology.

RESULTS

Total of 427 workers were randomly allocated to WHO6S (N = 215) or the A6Sw/oI (N = 212). The overall mean dorsum coverage by WHO6S and A6Sw/oI was 90.6% versus 88.4% (p < 0.01), and the percentage of the participants with insufficient coverage of the backs of the four fingers ranged from 0.0-7.4% versus 28.2-51.4% (p < 0.001). Dorsum coverage varied largely between hand size for both techniques, and significant differences were found between small and large hands.

CONCLUSION

The WHO6S was superior to the locally adapted technique regarding hand surface coverage. Hand size should be considered when assessing coverage differences between procedures. No trial registrations or fundings.

A method to assess dermal absorption dynamics of chemical warfare agents: Finite doses of volatile compounds

Chemical warfare agents are absorbed into the body from various entry routes and may have detrimental effects on human health. As many chemical compounds in this group are lipophilic, the outer layer of the skin is at an elevated risk. This contribution explores the dynamics of skin penetration for risk assessment. A previously validated model was applied to describe how an agent is transported across the stratum corneum following dermal exposure to a finite dose of a chemical. A mathematical construct was implemented for estimating the time constants and the cumulative amount of permeant entering the bloodstream or being released into the environment. Empirical equations were selected to determine the ratio of the steady-state evaporation rate to the steady-state dermal absorption rate and the physicochemical properties of the chemical warfare agents. Wolfram Mathematica was employed to run the simulations. The results from the newly derived expressions for the time constants matched those directly obtained from the validated model. For example, sarin gas had steady-state evaporation to an absorption rate of 991.25, and a total fractional absorption and evaporation of 5.1% and 94.9%, respectively. Combined with occupational exposure limits, the findings can help researchers assess an individual's risk level and develop protection programs.

Defining the Relationship Between Pocket and Breast Implant Surface Area as the Basis for a New Classification System for Capsular Contracture

BACKGROUND

The precise etiology and treatment for capsular contracture remains uncertain at least partially due to the fact that there is no reliable quantitative measurement tool. To address this, it is postulated that the surface area of an implant as defined by the surrounding pocket may provide a quantifiable variable that can be measured to evaluate the degree of capsular contracture.

METHODS

A bench model for capsular contracture was developed. The surface area of a series of spherical test objects and non-contracted and contracted breast implants was measured using a wax coating technique as well as three-dimensional reconstructions created from CT scan images.

RESULTS

Comparison of the mathematically calculated surface areas to the wax and CT results for spheres of known dimension provided nearly identical values documenting the accuracy of the two experimental methods. Comparison of the surface area measurements between the test groups showed that the average decrease in surface area for all implants was 20%, ranging from a high of 30.9% for a low profile implant to a low of 14.1 % for a high profile implant. The anatomically shaped devices demonstrated nearly uniform degrees of surface area change over three different heights with volume and projection held relatively constant.

CONCLUSIONS

The described bench model provides a useful tool for the study of capsular contracture. Surface area is a descriptive variable that can assess the degree of capsular contracture that is present. A classification system based on surface area is presented.

Health Risk Assessment of Heavy Metals (Pb, Cd, Hg) in Hydroalcoholic Gels of Abidjan, Côte d'Ivoire

Despite the high consumption of hydroalcoholic gels worldwide and particularly in Côte d'Ivoire since the outbreak of the COVID-19 pandemic, very few studies have measured the heavy metal content and human exposure in this product. Thus, 30 samples from supermarkets in Abidjan, Côte d'Ivoire, were collected for the study of risk assessment of exposure to heavy metals contained in hydroalcoholic gels. This study consists of the characterization of the danger by calculating the carcinogenic and non-carcinogenic risk by skin contact. Almost all samples analysed contain trace of lead, cadmium and mercury but at concentrations below the Canadian limit in cosmetic products applied to the skin and below the US FDA limit as an impurity in colour additives used in cosmetic products. The mean values of chronic daily intake via dermal absorption (CDIdermal) for adults were found in the order of mercury > lead > cadmium. The health risk estimation indicated that the mean total hazard quotient for dermal adsorption (HIdermal) obtained is 7.10 × 10^-5 ± 5.52 × 10^-5. This value was below 1, the acceptable limit, representing a non-carcinogenic risk for Abidjan residents through dermal adsorption. Moreover, the incremental lifetime cancer risk (ILCR) evaluation for lead and cadmium was insignificant, and the cancer risk can be neglected, but in case of their overusing, they can cause long-term health problems for consumers.

Systematic review on factors influencing the effectiveness of alcohol-based hand rubbing in healthcare

BACKGROUND

The effectiveness of hand rubbing with alcohol-based handrub (ABHR) is impacted by several factors. To investigate these, World Health Organization (WHO) commissioned a systematic review.

AIM

To evaluate the impact of ABHR volume, application time, rubbing friction and hand size on microbiological load reduction, hand surface coverage or drying time.

METHODS

Medline, CINAHL, Web of Science and ScienceDirect databases were searched for healthcare or laboratory-based primary studies, published in English, (1980- February 2021), investigating the impact of ABHR volume, application time, rubbing friction or hand size on bacterial load reduction, hand coverage or drying time. Two reviewers independently performed data extraction and quality assessment. The results are presented narratively.

FINDINGS

Twenty studies were included in the review. Categories included: ABHR volume, application time and rubbing friction. Sub-categories: bacterial load reduction, hand size, drying time or hand surface coverage. All used experimental or quasi-experimental designs. Findings showed as ABHR volume increased, bacterial load reduced, and drying times increased. Furthermore, one study showed that the application of sprayed ABHR without hand rubbing resulted in significantly lower bacterial load reduction than poured or sprayed ABHR with hand rubbing (- 0.70; 95%CI: - 1.13 to - 0.28). Evidence was heterogeneous in application time, volume, technique, and product. All studies were assessed as high risk of bias.

CONCLUSIONS

There is insufficient evidence to change WHO recommendation of a palmful of ABHR in a cupped hand applied for 20-30 s or manufacturer-recommended volume applied for about 20 s (Centers for Disease Control and Prevention). Future hand hygiene research should standardise volume, application time, and consider hand size.

Evaluation of the Residual Disinfection Effects of Commonly Used Skin Disinfectants against Viruses: An Innovative Contact Transmission Control Method

Lasting disinfection effects, that is, the residual disinfection effects (RDEs), of skin-coated disinfectants have rarely been considered for infection control owing to the challenges involved in the accurate evaluation of RDEs. In this study, we constructed a new skin evaluation model and determined the RDEs of existing disinfectants against viruses. Our results showed that ethanol and isopropanol had no RDE, whereas povidone-iodine, chlorhexidine gluconate, and benzalkonium chloride (BAC) exhibited RDEs, with 10% povidone-iodine and 0.2% BAC showing particularly strong RDEs. The RDE of 0.2% BAC was strong enough to reduce the median survival times of severe acute respiratory syndrome coronavirus-2, human coronavirus-OC43, and influenza virus from 670 to 5.2, 1300 to 12, and 120 to 4.2 min, respectively. Additionally, this strong RDE was maintained even 4 h after coating the skin. Clinical data also showed that the strong RDE of 0.2% BAC was maintained for more than 2 h. Thus, applying disinfectants with strong RDEs on the skin correlates with a reduction in virus survival time and appears to create a skin surface environment that is not conducive to virus survival. A prolonged reduction in virus survival decreases the contact transmission risk, thereby enabling stronger infection control.

A Rule of Thumb for Evaluating Surface Areas of Chronic Wounds

BACKGROUND

Rapid estimation of the area of chronic wounds is clinically important. A simple method using the thumb was investigated for universal physical measurement, particularly of small and multiple wounds; the thumb surface area (TSA) was then compared with the total body surface area (TBSA).

METHODS

A cross-sectional observational study and random sampling were used to obtain the characteristics of 343 participants. Data related to handprint surface area of the thumb and palm were collected using a scanner and laptop and assessed using image software. The TSA as a percentage of TBSA was confirmed based on the traditional rule that regards palmar surface area as 1% of TBSA. Information on factors potentially influencing measurement was gathered with questionnaires to analyze correlations.

RESULTS

The left and right TSAs were on average 4.27% and 4.28%, respectively, of the palmar surface area for all participants. Multiple linear regression analysis found that male and older participants had higher TSA:TBSA proportions (sex, P = .0020; age, P < .0001). The TSA:TBSA proportion increased by age for both males (by age group, 0.0418%, 0.0426%, 0.0432%, and 0.0460%, respectively) and females (0.0400%, 0.0409%, 0.0427%, and 0.0430%, respectively).

CONCLUSIONS

Thumb size is relatively stable in relation to TBSA, lending itself to a universal method for estimating the size of chronic wounds as a percentage of TBSA. It therefore represents a convenient physical measurement for assessing the area of burns and other wounds.

Air Quality Variation in Wuhan, Daegu, and Tokyo during the Explosive Outbreak of COVID-19 and Its Health Effects

This study was designed to assess the variation of the air quality actually measured from the air pollution monitoring stations (AQMS) in three cities (Wuhan, Daegu, and Tokyo), in Asian countries experiencing the explosive outbreak of COVID-19, in a short period of time. In addition, we made a new attempt to calculate the reduced Dose_PM2.5 (μg) at the bronchiolar (Br.) and alveolar-interstitial (AI) regions of the 10-year-old children after the city lockdown/self-reflection of each city. A comparison of the average PM_2.5 of a month before and after the lockdown (Wuhan) and self-reflection (Daegu and Tokyo) clearly shows that the PM_2.5 concentration was decreased by 29.9, 20.9, and 3.6% in Wuhan, Daegu and Tokyo, respectively. Wuhan, Daegu and Tokyo also recorded 53.2, 19.0, and 10.4% falls of NO₂ concentration, respectively. Wuhan, which had the largest decrease of PM_2.5 concentration due to COVID-19, also marked the largest reduced Dose_{PM2.5 10-year-old children} (μg) (3660 μg at Br. and 6222 μg at AI), followed by Daegu (445 μg at Br. and 1287 μg at AI), and Tokyo (18 μg at Br. and 52 μg at AI), over two months after the city lockdown/self-reflection. Our results suggest that the city lockdown/self-reflection had the effect of lowering the concentration of PM_2.5, resulting in an extension of the period it took to the acute allergic airway inflammation (AAI) for the 10-year-old children.

Development of amoxicillin resistance in Escherichia coli after exposure to remnants of a non-related phagemid-containing E. coli: an exploratory study

Objective

To determine the effect of exposure to remnants of a phagemid-containing E. coli, killed by treatment with a propanol-based hand rub, on antimicrobial resistance in E. coli isolates.

Methods

An in vitro model was developed in which a clinical E. coli isolate (EUR1) was exposed to remnants of an E. coli K-12 strain containing a phagemid (pBS-E12) strain treated with Sterillium®. A series of 200 experiments was performed using this in vitro model. As a control, a series of 400 experiments was performed where the EUR1 was exposed either to the remnants of an E. coli K-12 strain (not containing a phagemid) (E12) treated with Sterillium® (n = 200) or to dried Sterillium® only (n = 200). The number of experiments that showed growth of an amoxicillin-resistant EUR1 isolate was evaluated in all three groups. An additional 48 experiments were performed in which a different clinical E. coli isolate (EUR2) was exposed to remnants of the pBS-E12 treated with Sterillium®. Whole-genome sequencing and phenotypic testing for AmpC beta-lactamase production was performed to investigate the mechanism behind this resistance development.

Results

In 22 (11.0%) of 200 experiments in which the EUR1 isolate was exposed to remnants of a pBS-E12 an amoxicillin-resistant mutant isolate was obtained, as opposed to only 2 (1.0%) of 200 experiments involving the exposure of the EUR1 to Sterillium® only (risk difference: 10.0%; 95% CI 5.4–14.6%)) and 1 (0.5%) of 200 experiments involving the exposure of the EUR1 isolate to the remnants of the phagemid-free E12 (risk difference: 10.5%; 95% CI 6.1–14.9%). In 1 (2.1%) of the 48 experiments in which the EUR2 isolate was exposed to remnants of a pBS-E12 an amoxicillin-resistant mutant isolate was obtained. The development of resistance in all experiments was due to mutations in the promoter/attenuator region of the chromosomal AmpC beta-lactamase (cAmpC) gene leading to cAmpC hyperproduction.

Conclusion

Exposure of an E. coli isolate to another phagemid-containing E. coli that was treated with propanol-based hand rub increased the development of amoxicillin resistance. Although phagemids are cloning vectors that are not present in clinical isolates, this finding may have implications for hand disinfection practices in healthcare facilities.

Probabilistic model for the estimation of the consumer exposure to methicillin-resistant Staphylococcus aureus due to cross-contamination and recontamination

The presence of multidrug-resistant bacteria like methicillin-resistant Staphylococcus aureus (MRSA) in retail meat is one of the current concerns of the public health authorities. Bacterial cross-contamination and recontamination during household food preparation could play an important role in the dissemination of such bacteria, and therefore could contribute to a serious health problem, more specifically for immunocompromised people. In order to evaluate the importance of such events, a probabilistic model was developed to estimate the likelihood and extent of cross-contamination and recontamination and the burden of MRSA from contaminated raw chicken meat via hands and kitchen utensils in a serving (consisting on a slice of bread and a piece of grilled chicken meat) during a household barbecue in Germany. A modular design was used, taking into account the chronological order of the routines during the barbecue event, and Monte Carlo simulations were applied. Available data on the prevalence and burden of MRSA in chicken meat at retail in Germany were used as starting point and were incorporated in the model as probability distributions. The probabilities and extent of bacterial transfer between food items and kitchen utensils (referred to as "Objects") and the routines performed during food preparation (referred to as "Actions") specified by their probabilities of occurrence were incorporated as the main input parameters. The model was set up in R 3.5.0 and converted to a standardized format (FSKX file). Therefore, the code can be easily accessed, evaluated, modified, and reused for different purposes. The present study contributes to the quantification of consumer exposure to MRSA through food consumption once contaminated food has entered the household kitchen. Even when the MRSA prevalence and bacterial load in retail chicken meat in Germany are low, resistant bacteria can reach the consumer due to cross-contamination and recontamination events. The results show that the probability of one CFU to be transferred from the contaminated raw chicken meat to the final serving and the number of MRSA bacteria transferred due to cross-contamination and recontamination events are in general low, being the contamination of the final serving more likely to occur via bread, rather than via grilled chicken. The results show that the prevalence of MRSA at retail highly influences the probability of the final serving to be contaminated. However, this study also highlights the importance of keeping good hygiene practices during the household food manipulation for reducing the spread of MRSA. The provision of the model in a standardized data format will allow an easy incorporation of the developed model into a complete quantitative microbial risk assessment model that will greatly help to estimate the risk of consumer exposure to MRSA through the consumption of contaminated food.

Nursing preference for alcohol-based hand rub volume

Background:

The effectiveness of alcohol-based hand rub (ABHR) is correlated with drying time, which depends on the volume applied. Evidence suggests that there is considerable variation in the amount of ABHR used by healthcare providers.

Objective:

We sought to identify the volume of ABHR preferred for use by nurses.

Methods:

A prospective observation study was performed in 8 units at a tertiary-care hospital. Nurses were provided pocket-sized ABHR bottles with caps to record each bottle opening. Nurses were instructed to use the volume of ABHR they felt was best. The average ABHR volume used per hand hygiene event was calculated using cap data and changes in bottle mass.

Results:

In total, 53 nurses participated and 140 nurse shifts were analyzed. The average ABHR dose was 1.09 mL. This value was greater for non-ICU nurses (1.18 mL) than ICU nurses (0.96 mL), but this difference was not significant. We detected no significant association between hand surface area and preferred average dose volume. The ABHR dose volume was 0.006 mL less per use as the number of applications per shift increased (P = .007).

Conclusions:

The average dose of ABHR used was similar to the dose provided by the hospital’s automated dispensers, which deliver 1.1 mL per dose. The volume of ABHR dose was inversely correlated with the number of applications of ABHR per shift and was not correlated with hand size. Further research to understand differences and drivers of ABHR volume preferences and whether automated ABHR dosing may create a risk for people with larger hands is warranted.

Safely Managed Hygiene: A Risk-Based Assessment of Handwashing Water Quality

Sustainable Development Goal (SDG) Indicator 6.2.1 requires household handwashing facilities to have soap and water, but there are no guidelines for handwashing water quality. In contrast, drinking water quality guidelines are defined: water must be "free from contamination" to be defined as "safely managed" (SDG Indicator 6.1.1). We modeled the hypothesized mechanism of infection due to contaminated handwashing water to inform risk-based guidelines for microbial quality of handwashing water. We defined two scenarios that should not occur: (1) if handwashing caused fecal contamination, indicated using Escherichia coli, on a person's hands to increase rather than decrease and (2) if hand-to-mouth contacts following handwashing caused an infection risk greater than an acceptable threshold. We found water containing <1000 E. coli colony-forming units (CFU) per 100 mL removes E. coli from hands with>99.9% probability. However, for the annual probability of infection to be <1:1000, handwashing water must contain <2 × 10^-6 focus-forming units of rotavirus, <1 × 10^-4 CFU of Vibrio cholerae, and <9 × 10^-6 Cryptosporidium oocysts per 100 mL. Our model suggests that handwashing with nonpotable water will generally reduce fecal contamination on hands but may be unable to lower the annual probability of infection risks from hand-to-mouth contacts below 1:1000.

How long is enough? Identification of product dry-time as a primary driver of alcohol-based hand rub efficacy

Background

The World Health Organization has called for the development of improved methodologies to evaluate alcohol-based handrub (ABHR) efficacy, including evaluation at “short application times and volumes that reflect actual use in healthcare facilities”. The objective of this study was to investigate variables influencing ABHR efficacy, under test conditions reflective of clinical use.

Methods

The test product (60% V/V 2-propanol) was evaluated according to a modified EN 1500 methodology, where application volumes of 1 mL, 2 mL, and 3 mL were rubbed until dry. Statistical analyses were performed to investigate the relative influences of product volume, hand size, and product dry-time on efficacy, and hand size and hand contamination on product dry-time.

Results

Mean log₁₀ reduction factors (SD) were 1.99 (0.66), 2.96 (0.84) and 3.28 (0.96); and mean dry-times (SD) were 24 s (7 s), 50 s (14 s), and 67 s (20 s) at application volumes of 1 mL, 2 mL, and 3 mL, respectively (p ≤ 0.030). When data were examined at the individual volunteer level, there was a statistically significant correlation between dry-time and log reduction factor (p < 0.0001), independent of application volume. There was also a statistically significant correlation between hand surface area and dry-times (p = 0.047), but no correlation between hand surface area and efficacy (p = 0.698).

Conclusions

When keeping other variables such as alcohol type and concentration constant, product dry-time appears to be the primary driver of ABHR efficacy suggesting that dosing should be customized to each individual and focus on achieving a product dry-time delivering adequate efficacy.

Routes of transmission of influenza A H1N1, SARS CoV, and norovirus in air cabin: Comparative analyses

Identifying the exact transmission route(s) of infectious diseases in indoor environments is a crucial step in developing effective intervention strategies. In this study, we proposed a comparative analysis approach and built a model to simulate outbreaks of 3 different in-flight infections in a similar cabin environment, that is, influenza A H1N1, severe acute respiratory syndrome (SARS) coronavirus (CoV), and norovirus. The simulation results seemed to suggest that the close contact route was probably the most significant route (contributes 70%, 95% confidence interval [CI]: 67%-72%) in the in-flight transmission of influenza A H1N1 transmission; as a result, passengers within 2 rows of the index case had a significantly higher infection risk than others in the outbreak (relative risk [RR]: 13.4, 95% CI: 1.5-121.2, P = .019). For SARS CoV, the airborne, close contact, and fomite routes contributed 21% (95% CI: 19%-23%), 29% (95% CI: 27%-31%), and 50% (95% CI: 48%-53%), respectively. For norovirus, the simulation results suggested that the fomite route played the dominant role (contributes 85%, 95% CI: 83%-87%) in most cases; as a result, passengers in aisle seats had a significantly higher infection risk than others (RR: 9.5, 95% CI: 1.2-77.4, P = .022). This work highlighted a method for using observed outbreak data to analyze the roles of different infection transmission routes.

Formulae Evaluation for Estimating Body Surface Area of Korean Children

Body surface area (BSA) is an important parameter in the conduct of human exposure studies and in clinical processes in children. The aim of this paper was to compare seven BSA formulas and to find out which of these formulas is appropriate for use with Korean children. Body surface area was calculated according to age, age-group and BMI-group using the height and weight data of Korean children (n = 4899) ages 1 to 18 from Korea National Health and Nutrition Examination Survey (2012-2014). We used the formulas of Banerjee and Bhattacharya (1961), Fujimoto and Watanabe (1969), US EPA (1985), Gehan and George (1970), Boyd (1935), Haycock et al (1978) and Mosteller (1987). The average values of the seven formulas were calculated and used as norm values for comparison. All predictions showed a strong positive correlation with the overall average BSA values. Overestimations were observed on the calculations of Gehan and George (1970), US EPA (1985) and Boyd (1935) formulas. Banerjee and Bhattacharya (1961) and Fujimoto and Watanabe (1969) values showed underestimations and the largest error size of 0.027 m² for all ages. BSA estimates of Mosteller (1987) and Haycock et al (1978) were found to be closer to the overall average BSA values with the least error size of 0.004 m². Mosteller's formula is recommended for use in the conduct of human exposure studies and in clinical practice among Korean children, although Haycock et al formula is appropriate for children from 1 to 2 years old.

Assessment of burn size in obese adults; a literature review

PURPOSE

Obesity causes changes in the total body surface area as well as the distribution of skin surfaces. In burn management, three methods are commonly used to determine the surface area burned: the patient's palm, the rule of nines, and the Lund-Browder chart. These methods rely on the distribution of skin surface, although none of these methods consider differences in body mass. This study investigates the relationship between body surfaces and body mass in the assessment of burn size to determine the validity of the conventional methods when applied to obese individuals.

METHODS

The current literature was reviewed using relevant electronic databases. The initial search yielded 247 results. Relevant articles were then reviewed. A total of seven publications fulfilled the inclusion criteria.

RESULTS

The palmar surface area ranged between 0.59%-1.22%, depending on BMI, gender, and ethnicity, compared to 1% according to conventional methods. The palmar surface area of obese individuals approximated 0.7% of the total body surface area in Caucasians. The surface areas comprised 5%-7.5% of the total body surface area for each arm, 15%-20% for each leg, and 40%-52% for the trunk in obese or morbidly obese individuals, compared to 9%, 18%, and 36%, respectively, for normal-weight adults.

CONCLUSIONS

The commonly used methods for assessment of burns should be used with caution when applied to obese burn patients, and the clinical parameters observed even more systematically.

Assessment of Food Safety Knowledge, Attitude, Self-Reported Practices, and Microbiological Hand Hygiene of Food Handlers

Institutional foodborne illness outbreaks continue to hit the headlines in the country, indicating the failure of food handlers to adhere to safe practices during food preparation. Thus, this study aimed to compare the knowledge, attitude, and self-reported practices (KAP) of food safety assessment and microbiological assessment of food handlers’ hands as an indicator of hygiene practices in food premises. This study involved 85 food handlers working in a university located in Kuala Lumpur, Malaysia. The food safety KAP among food handlers (n = 67) was assessed using a questionnaire; while the hand swabs (n = 85) were tested for the total aerobic count, coliforms, and Escherichia coli, Staphylococcus aureus, Salmonella, Vibrio cholerae and Vibrio parahaemolyticus. The food handlers had moderate levels of food safety knowledge (61.7%) with good attitude (51.9/60) and self-reported practices (53.2/60). It is noteworthy that the good self-reported practices were not reflected in the microbiological assessment of food handlers’ hands, in which 65% of the food handlers examined had a total aerobic count ≥20 CFU/cm² and Salmonella was detected on 48% of the food handlers’ hands. In conclusion, the suggestion of this study was that the food handlers had adequate food safety knowledge, but perceived knowledge failed to be translated into practices at work.

Development of an Interception Glove Sampler for Skin Exposures to Aromatic Isocyanates

OBJECTIVES

Skin is an important exposure route for isocyanate chemicals and contributes to systemic sensitization. Methods for assessing skin exposure are currently limited and generally rely upon removal (e.g. tape-strip) techniques prone to underestimation. The aim of this study is to (i) develop and field test an interception-based hand exposure sampler to monitor potential skin exposure to isocyanates in the workplace, (ii) to develop an analytical method based on ultra-high-performance liquid chromatography-UV absorbance-tandem mass spectrometry (UHPLC-UV-MS/MS) for analyzing glove samples; and (iii) compare it with tape-stripping skin sampling method.

METHODS

Laboratory investigations assessed different glove materials/fabrics, methods for impregnating with 1-(9-anthracenylmethyl)piperazine (MAP) derivatizing agent, methylene diphenyl diisocyanate (MDI) uptake and recovery, and durability. Following use, gloves were dissected into sections corresponding to different spatial regions (finger, palm) and analyzed using a newly developed UHPLC-UV-MS/MS method capable of differentiating and quantitating different MDI isomers with high sensitivity. Performance of the glove sampler was further assessed in a pilot field study using six workers.

RESULTS

A MAP-impregnated thin cotton glove sampler and UHPLC-UV-MS/MS analytical method for detecting MDI were successfully developed in laboratory studies. In subsequent field studies, a total of 384 samples from 14 glove pairs identified full-shift exposures ranged from 0.01 to 306 µg of 4,4'-MDI/worker for each hand. Surface area adjusted MDI values measured with the glove sampler (0.13-572ng MDI cm^-2) were considerably higher (~400-fold) than values obtained with tape stripping.

CONCLUSION

A glove sampler and a novel UHPLC-UV-MS/MS analytical method were developed to quantitatively measure MDI skin exposure. The novel interception technique overcomes inherent limitations of removal techniques for measuring isocyanate skin exposure and may be useful in exposure surveillance and future research on isocyanate's health risks.

Relationships of self-identified cold tolerance and cold-induced vasodilatation in the finger

This study was conducted to investigate relationships of self-identified cold tolerance and cold-induced vasodilatation (CIVD) in the finger. Nine males and 34 females participated in the following 2 tests: a CIVD test and a self-reported survey. The CIVD test was conducted 30-min cold-water immersion (3.8 ± 0.3 °C) of the middle finger at an air temperature of 27.9 ± 0.1 °C. The self-reported questionnaire consisted of 28 questions about whole and local body cold and heat tolerances. By a cluster analysis on the survey results, the participants were divided into two groups: high self-identified cold tolerance (HSCT, n = 25) and low self-identified cold tolerance (LSCT, n = 18). LSCT had lower self-identified cold tolerance (P < 0.001), preferred hot thermal stimulation (P = 0.006), and wore heavier clothing during daily life (P < 0.001) than HSCT. LSCT had significantly lower maximal finger temperatures (T max) (P = 0.040), smaller amplitude (P = 0.029), and delayed onset time of CIVD (P = 0.080) when compared to HSCT. Some questions examining the self-identified cold or heat tolerance had relationships with cold tolerance index, T max, and amplitude (P < 0.1). These results indicate that self-identified cold tolerance classified through a standardized survey could be a good index to predict physiological cold tolerance.

Efficacy of alcohol gel for removal of methicillin-resistant Staphylococcus aureus from hands of colonized patients

Of 82 patients with methicillin-resistant Staphylococcus aureus (MRSA) colonization, 67 (82%) had positive hand cultures for MRSA. A single application of alcohol gel (2 mL) consistently reduced the burden of MRSA on hands. However, incomplete removal of MRSA was common, particularly in those with a high baseline level of recovery.

Antineoplastic drug contamination on the hands of employees working throughout the hospital medication system

We previously reported that antineoplastic drug contamination is found on various work surfaces situated throughout the hospital medication system (process flow of drug within a facility from initial delivery to waste disposal). The presence of drug residual on surfaces suggests that healthcare workers involved in some capacity with the system may be exposed through dermal contact. The purpose of this paper was to determine the dermal contamination levels of healthcare employees working throughout a hospital and to identify factors that may influence dermal contamination. We selected participants from six hospitals and wiped the front and back of workers' hands. Wipe samples were analyzed for cyclophosphamide (CP), a commonly used antineoplastic drug, using high-performance liquid chromatography-tandem mass spectrometry. Participants were asked about their frequency of handling antineoplastic drugs, known contact with CP on their work shift, gender, job title, and safe drug handling training. In addition, participants were surveyed regarding their glove usage and hand washing practices prior to wipe sample collection. We collected a total of 225 wipe samples. Only 20% (N = 44) were above the limit of detection (LOD) of 0.36ng per wipe. The average concentration was 0.36ng per wipe, the geometric mean < LOD, the geometric standard deviation 1.98, and the range < LOD to 22.8ng per wipe. Hospital employees were classified into eight different job categories and all categories had some dermal contamination levels in excess of the LOD. The job category with the highest proportion of samples greater than the LOD were those workers in the drug administration unit who were not responsible for drug administration (volunteer, oncologist, ward aide, dietician). Of note, the highest recorded concentration was from a worker who had no known contact with CP on their work shift. Our results suggest that a broader range of healthcare workers than previously believed, including those that do not directly handle or administer the drugs (e.g. unit clerks, ward aides, dieticians, and shipper/receivers), are at risk of exposure to antineoplastic drugs. A review of control measures to minimize antineoplastic drug exposure that encompasses a wide array of healthcare workers involved with the hospital medication system is recommended.

Development of a standardized testing procedure for assessing the irritation potential of occupational skin cleansers

BACKGROUND

Frequent skin cleaning fulfils the definition of occupational 'wet work'. Standardized methods are required to assess the irritation potential of workplace cleansers.

OBJECTIVES

To develop a standardized procedure for testing the irritation potential of occupational skin cleansers.

METHODS

In this single-blind, single-centre trial in 25 healthy volunteers, the irritation potential of five generic reference cleansers was tested by three-times-daily washing with an automated skin cleaning device for 4 days, and quantification of cumulative skin barrier damage was performed by visual scoring, chromametry, transepidermal water loss TEWL, and corneometry. For two cleansers, reproducibility of the irritancy assessment was assessed. Furthermore, the irritation induced by four commercial workplace skin cleansers was studied.

RESULTS

Whereas no significant changes were observed for any of the tested cleansers by either visual scoring or chromametry, significant increases in TEWL and significant decreases in stratum corneum hydration were found for all cleansers. Cleansers differed significantly in their irritation potential. On retesting of two cleansers, the first results were confirmed. Among the four commercial cleansers, one that was claimed to be mild was found to be disproportionally irritant.

CONCLUSIONS

The presented model for testing cleansing preparations allows a highly controlled, practically relevant and reproducible irritancy assessment of occupational skin cleansers.

Patients' potential role in the transmission of health care-associated infections: prevalence of contamination with bacterial pathogens and patient attitudes toward hand hygiene

BACKGROUND

Transmission of health care-associated infections (HAIs) has been primarily attributed to health care workers, and hand hygiene is considered the most important means to reduce transmission. Whereas hand hygiene research has focused on reducing health care worker hand contamination and improving hand hygiene compliance, contamination of patients' hands and their role in the transmission of HAIs remains unknown.

METHODS

Patients' hands were sampled by a "glove juice" recovery method and enumerated for the presence of common health care-associated pathogens. Patient demographics and other covariates were collected to determine their association with patient hand contamination. Patient attitudes and practices toward hand hygiene were also surveyed and analyzed.

RESULTS

Of the 100 patients in the study, 39% of hands were contaminated with at least 1 pathogenic organism, and 8% were contaminated with 2 or more pathogens 48 hours after admission. Patient admission from or discharge to an outside institution and self-reported functional limitations were the only covariates that were significantly associated with hand contamination.

CONCLUSION

Pathogenic organisms can be frequently detected on hands of acute care patients. Future studies are needed to better understand the relationship between patient hand contamination and the acquisition of HAIs in addition to the role patient hand hygiene can play in reducing HAIs.

A Geometric Morphometric Assessment of Hand Shape and Comparison to the 2D:4D Digit Ratio as a Marker of Sexual Dimorphism

Twin studies are extremely useful for investigating hypotheses of genetic influence on a range of behavioral and physical traits in humans. Studies of physical traits, however, are usually limited to size-related biological characteristics because it is inherently difficult to quantify the morphological counterpart – shape. In recent years, the development of geometry-preserving analytical techniques built upon multivariate statistical methodologies has produced a new discipline in biological shape analysis known as geometric morphometrics. In this study of hand shape analysis, we introduce the reader already familiar with the field of twin research to the potential utility of geometric morphometrics and demonstrate the cross-discipline applicability of methods. We also investigate and compare the efficacy of the 2D:4D ratio, a commonly used marker of sexual dimorphism, to the fully multivariate approach of shape analysis in discriminating between male and female sex. Studies of biological shape variation utilizing geometric morphometric techniques may be completed with software freely available on the Internet and time invested to master the small learning curve in concepts and theory.

50 Years of Computer Simulation of the Human Thermoregulatory System

This paper presents an updated and augmented version of the Wissler human thermoregulation model that has been developed continuously over the past 50 years. The existing Fortran code is translated into C with extensive embedded commentary. A graphical user interface (GUI) has been developed in Python to facilitate convenient user designation of input and output variables and formatting of data presentation. Use of the code with the GUI is described and demonstrated. New physiological elements were added to the model to represent the hands and feet, including the unique vascular structures adapted for heat transfer associated with glabrous skin. The heat transfer function and efficacy of glabrous skin is unique within the entire body based on the capacity for a very high rate of blood perfusion and the novel capability for dynamic regulation of blood flow. The model was applied to quantify the absolute and relative contributions of glabrous skin flow to thermoregulation for varying levels of blood perfusion. The model also was used to demonstrate how the unique features of glabrous skin blood flow may be recruited to implement thermal therapeutic procedures. We have developed proprietary methods to manipulate the control of glabrous skin blood flow in conjunction with therapeutic devices and simulated the effect of these methods with the model.

Palm surface area database and estimation formula in Korean children using the alginate method

Studies of palm surface area (PSA) have been investigated as an important reference area unit in physiology and medicine today. Most previous PSA studies have been limited to adults. The purpose of this study was to archive Korean children's PSA data and to calculate an optimized formula for estimating PSA. A total of 305 people, 186 boys and 119 girls all aged between 7 and 18 years, were recruited for this study and their PSA was directly measured by a useful, accurate, and quick method--the alginate method. Mean PSA for males and females was found and the optimized formula for estimating PSA was computed. It would be meaningful to note that this trial was the first to generate data from Korean children, which could be widely available for utilization in anthropometry, toxicology research, thermal physiology and in skin burn studies for Asian children.

Skin deposition of nickel, cobalt, and chromium in production of gas turbines and space propulsion components

Skin exposure to nickel, cobalt, and chromium may cause sensitization and allergic contact dermatitis and it is known that many alloys and platings may release significant amounts of the metals upon contact with skin. Occupational exposure to these sensitizing metals has been studied in different settings with regards to airborne dust and different biological end points, but little is known about deposition on skin from airborne dust and direct contact with materials containing the metals. In this study, skin deposition was studied in 24 workers in an industry for development and manufacturing of gas turbines and space propulsion components. The workers were employed in three departments, representing different exposure scenarios: tools sharpening of hard metal items, production of space propulsion structures, and thermal application of different metal-containing powders. A novel acid wipe sampling technique was used to sample metals from specific skin surfaces on the hands and the forehead of the workers. Total amounts of nickel, cobalt, and chromium were measured by inductively coupled plasma mass spectrometry. The result showed that nickel, cobalt, and chromium could be detected on all skin surfaces sampled. The highest level of nickel was 15 microg cm(-2) h(-1), the highest for cobalt was 4.5 microg cm(-2) h(-1), and for chromium 0.6 microg cm(-2) h(-1). The three departments had different exposures regarding the metals. The highest levels of nickel on the skin of the workers were found in the thermal applications department, cobalt in the tools sharpening department, and chromium in the space propulsion components department. In conclusion, the workers' exposure to the metals was more likely to come from direct skin contact with items, rather than from airborne dust, based on the fact that the levels of metals were much higher on the fingers than on the back side of the hands and the forehead. The skin exposure levels of nickel and cobalt detected are judged capable to induce sensitization and elicit allergic contact dermatitis.