Porous ceramic tablet embedded with silver nanopatches for low-cost point-of-use water purification.

This work describes a novel method to embed silver in ceramic porous media in the form of metallic silver nanopatches. This method has been applied to develop a new POU technology, a silver-infused ceramic tablet that provides long-term water disinfection. The tablet is fabricated using clay, water, sawdust, and silver nitrate. When dropped into a household water storage container, the ceramic tablet releases silver ions at a controlled rate that in turn disinfect microbial pathogens. Characterization of the silver-embedded ceramic media was performed using transmission electron microscopy. Spherical-shaped patches of metallic silver were observed at 1­6 nm diameters and confirmed to be silver with energy dispersive spectroscopy. Disinfection experiments in a 10 L water volume demonstrated a 3 log reduction of Escherichia coli within 8 h while silver levels remained below the World Health Organization drinking water standard (0.1 mg/L). Silver release rate varied with clay mineralogy, sawdust particle size, and initial silver mass. Silver release was repeatable for daily 10 L volumes for 154 days. Results suggest the ceramic tablet can be used to treat a range of water volumes. This technology shows great potential to be a low-cost, simple-to-use water treatment method to provide microbiologically safe drinking water at the household level.

Marketing netcoatings for aquaculture.

Unsustainable harvesting of natural fish stocks is driving an ever growing marine aquaculture industry. Part of the aquaculture support industry is net suppliers who provide producers with nets used in confining fish while they are grown to market size. Biofouling must be addressed in marine environments to ensure maximum product growth by maintaining water flow and waste removal through the nets. Biofouling is managed with copper and organic biocide based net coatings. The aquaculture industry provides a case study for business issues related to entry of improved fouling management technology into the marketplace. Several major hurdles hinder entry of improved novel technologies into the market. The first hurdle is due to the structure of business relationships. Net suppliers can actually cut their business profits dramatically by introducing improved technologies. A second major hurdle is financial costs of registration and demonstration of efficacy and quality product with a new technology. Costs of registration are prohibitive if only the net coatings market is involved. Demonstration of quality product requires collaboration and a team approach between formulators, net suppliers and farmers. An alternative solution is a vertically integrated business model in which the support business and product production business are part of the same company.

A randomised single-blind comparison of the effectiveness of Tristel Fuse (chlorine dioxide) as an office-based fluid soak, with Cidex OPA (ortho-phthaldehyde) using an automated endoscopic reprocessor (AER) as high-level disinfection for flexible cystoscopes.

OBJECTIVE: To compare the effectiveness, safety and cost of Tristel Fuse (chlorine dioxide) with Cidex OPA (ortho-phthaldehyde; 1,2-benzenedicarboxaldehyde) in an automated endoscopic reprocessor (AER) for high-level disinfection of flexible cystoscopes. PATIENTS AND METHODS: A randomised single-blind study comparing the high-level disinfectants Tristel Fuse as a simple office-based soak and Cidex OPA using an AER was performed. Participants were 'blinded' to the agent used for disinfection of the flexible cystoscopes. All patients had negative mid-stream urine at baseline, (MSU) no symptoms suggestive of urinary tract infection (UTI) on the day of investigation, no recent antibiotic use or current indwelling urinary catheter. Patients who underwent cystoscopic biopsy during the procedure were excluded. A urine analysis was done before and 3-5 days after cystoscopy and multiple equipment cultures were performed. The Urogenital Distress Inventory (UDI-6 + two questions from the 'long-form'), symptom and quality-of-life scores were assessed before and after cystoscopy as were ease-of-use assessments and a full cost analysis. RESULTS: In all, 180 of 465 screened participants were randomised 1:1 and the mean age was 72.1 years, 17% were females and 57% of procedures were performed for bladder tumour surveillance. The urine analysis was positive in 5.4% of patients in each group and 29% (Tristel) vs 20% (Cidex) of patients had urinary leukocyturia (p = ns) after cystoscopy. The turnover (minutes per cycle) was 7.5 (Tristel) vs 26.7 (Cidex). The per-procedure costs were $11.67 (American dollars) for Tristel Fuse and $21.82 for Cidex OPA with fixed costs of $4788 for Tristel Fuse and $60,514 for Cidex OPA. CONCLUSIONS: Tristel Fuse appears to be as effective and more cost-effective than Cidex OPA for high-level disinfection of flexible cystoscopes. This has significant cost implications for the office urologist.

Comparative study of disinfectants for use in low-cost gravity driven household water purifiers.

Point-of-use (POU) gravity-driven household water purifiers have been proven to be a simple, low-cost and effective intervention for reducing the impact of waterborne diseases in developing countries. The goal of this study was to compare commonly used water disinfectants for their feasibility of adoption in low-cost POU water purifiers. The potency of each candidate disinfectant was evaluated by conducting a batch disinfection study for estimating the concentration of disinfectant needed to inactivate a given concentration of the bacterial strain Escherichia coli ATCC 11229. Based on the concentration of disinfectant required, the size, weight and cost of a model purifier employing that disinfectant were estimated. Model purifiers based on different disinfectants were compared and disinfectants which resulted in the most safe, compact and inexpensive purifiers were identified. Purifiers based on bromine, tincture iodine, calcium hypochlorite and sodium dichloroisocyanurate were found to be most efficient, cost effective and compact with replacement parts costing US$3.60-6.00 for every 3,000 L of water purified and are thus expected to present the most attractive value proposition to end users.

Evaluation of a hydrogen peroxide-based system for high-level disinfection of vaginal ultrasound probes.

OBJECTIVES: Because of the complex process and the risk of errors associated with the glutaraldehyde-based solutions previously used at our institution for disinfection, our department has implemented a new method for high-level disinfection of vaginal ultrasound probes: the hydrogen peroxide-based Trophon system (Nanosonics, Alexandria, New South Wales, Australia). The aim of this study was to compare the time difference, safety, and sonographers' satisfaction between the glutaraldehyde-based Cidex (CIVCO Medical Solutions, Kalona, IA) and the hydrogen peroxide-based Trophon disinfection systems. METHODS: The Institutional Review Board approved a 14-question survey administered to the 13 sonographers in our department. Survey questions addressed a variety of aspects of the disinfection processes with graded responses over a standardized 5-point scale. A process diagram was developed for each disinfection method with segmental timing analysis, and a cost analysis was performed. RESULTS: Nonvariegated analysis of the survey data with the Wilcoxon signed rank test showed a statistical difference in survey responses in favor of the hydrogen peroxide-based system over the glutaraldehyde-based system regarding efficiency (P = .0013), ease of use (P = .0013), ability to maintain work flow (P = .026), safety (P = .0026), fixing problems (P = .0158), time (P = .0011), and overall satisfaction (P = .0018). The glutaraldehyde-based system took 32 minutes versus 14 minutes for the hydrogen peroxide-based system; the hydrogen peroxide-based system saved on average 7.5 hours per week. The cost of the hydrogen peroxide-based system and weekly maintenance pays for itself if 1.5 more ultrasound examinations are performed each week. CONCLUSIONS: The hydrogen peroxide-based disinfection system was proven to be more efficient and viewed to be easier and safer to use than the glutaraldehyde-based system. The adoption of the hydrogen peroxide-based system led to higher satisfaction among sonographers.

Consumer's demand for Disinfectants and Protective Gear from COVID-19 infection in Al-Hofuf, Saudi.

INTRODUCTION: The paper aims to estimate consumers' demand for personal protecting products (PPP) from COVID-19. Thus, the paper collected primary data on consumers' demand for PPP utilizing the timeframe of the COVID-19 pandemic. METHODOLOGY: The paper uses two sample t-test and Anova test to examine mean differences in the quantity consumed of PPP. Also, the paper uses Almost Ideal Demand System (AIDS) to estimate the responsiveness of quantity demanded of PPP for changes in prices and consumers' income. RESULTS: The results show that there is a significant difference in the mean of quantity demanded of facemasks among men and women. Also, the results show that there is a significant difference in the mean of quantity demand for facemasks, gloves, and hand sanitizer based on respondents' level of education. In addition, the paper analyzed the effect of price and income changes on quantity demanded of PPP. The findings indicate that the quantity demanded of facemask and gloves are sensitive to changes in consumers' income. Also, soap, hand sanitizer, and gloves were recognized as complementary products. Furthermore, facemasks were identified as a complementary product with glove use. Lastly, the own-price elasticities of demand revealed that the demand for PPP is price insensitive. CONCLUSIONS: the paper recommends that the consumer protection unit closely monitor the prices of PPP since the sellers have an opportunity to increase those products prices and maximize their revenue by exploiting the COVID-19 pandemic.

Sporicidal activity of two disinfectants against Clostridium difficile spores.

The sporicidal activity of an odour-free peracetic acid-based disinfectant (Wofasteril) and a widely-used dichloroisocyanurate preparation (Chlor-clean) was assessed against spores of the hyper-virulent strain of Clostridium difficile (ribotype 027), in the presence and absence of organic matter. In environmentally clean conditions, dichloroisocyanurate achieved a >3 log10 reduction in 3 minutes, but a minimum contact time of 9 minutes was required to reduce the viable spore load to below detection levels. Peracetic acid achieved a >3 log10 reduction in 30 minutes and was overall significantly less effective (P<0.05). However, in the presence of organic matter - which reflects the true clinical environment - there was no significant difference between the sporicidal activity of dichloroisocyanurate and peracetic acid over a 60-minute period (P=0.188). Given the greater occupational health hazards generally associated with chlorine-releasing agents, odour-free peracetic acid-based disinfectants may offer a suitable alternative for environmental disinfection.

Bringing safe water to remote populations: an evaluation of a portable point-of-use intervention in rural Madagascar.

Rural populations disproportionately lack access to improved water supplies. We evaluated a novel scheme that employed community-based sales agents to disseminate the Safe Water System (SWS)--a household-level water chlorination and safe storage intervention--in rural Madagascar. Respondents from 242 households in 4 villages were interviewed; all used surface water for drinking water. Respondents from 239 households (99%) had heard of Sûr'Eau, the SWS disinfectant; 226 (95%) reported having ever used Sûr'Eau, and 166 (73%) reported current use. Current Sûr'Eau use was confirmed in 54% of households. Community sales agents effectively motivated their neighbors to adopt a new health behavior that prevents diarrhea. Future work should focus on strategies for sustaining SWS use, factors that motivate community-based sales agents to promote SWS, and the feasibility of scaling up this approach.

Cost and financial sustainability of a household-based water treatment and storage intervention in Zambia.

Providing safe water to >1 billion people in need is a major challenge. To address this need, the Safe Water System (SWS) - household water treatment with dilute bleach, safe water storage, and behavior change - has been implemented in >20 countries. To assess the potential sustainability of the SWS, we analyzed costs in Zambia of "Clorin" brand product sold in bottles sufficient for a month of water treatment at a price of $0.09. We analyzed production, marketing, distribution, and overhead costs of Clorin before and after sales reached nationwide scale, and analyzed Clorin sales revenue. The average cost per bottle of Clorin production, marketing and distribution at start-up in 1999 was $1.88 but decreased by 82% to $0.33 in 2003, when >1.7 million bottles were sold. The financial loss per bottle decreased from $1.72 in 1999 to $0.24 in 2003. Net program costs in 2003 were $428,984, or only $0.04 per person-month of protection. A sensitivity analysis showed that if the bottle price increased to $0.18, the project would be self-sustaining at maximum capacity. This analysis demonstrated that efficiencies in the SWS supply chain can be achieved through social marketing. Even with a subsidy, overall program costs per beneficiary are low.

Chlorhexidine spray versus single use sachets for skin preparation before regional nerve blockade for elective caesarean section: an effectiveness, time and cost study.

INTRODUCTION: The importance of skin preparation before regional nerve blockade to prevent infection remains unchallenged. A multi-use spray chlorhexidine may have benefits over single use sachets in terms of convenience and cost, but its efficacy is unknown. We conducted a prospective randomised trial to compare spray and sachet chlorhexidine. METHODS: Elective caesarean section patients were randomised to receive chlorhexidine as a spray (chlorhexidine 0.5% in an alcoholic solution Hydrex DS Derma spray, Adams Healthcare, Leeds, UK) or sachet chlorhexidine (chlorhexidine 0.05% aqueous solution, Unisept, Seton. Leeds, UK) before a standardised combined spinal epidural technique. Skin colonisation was examined before skin preparation and again after epidural catheter removal. RESULTS: Both techniques were effective in reducing skin colonisation (P=0.0001). There was no difference in effectiveness between the groups, with the spray reducing skin colonisation from 88.5% before to 3% after catheter removal, compared with 90% to 12% in the sachet group. Time to achieve skin preparation was significantly reduced in the spray group (2.6 min compared to 4.5 min; P=0.02). The spray cost per patient was 0.01 compared to sachet 0.33. CONCLUSIONS: We suggest a chlorhexidine spray is as effective as single use sachets and is also quicker to apply and less costly.

Effectiveness and microbial contamination of an in-house alcohol-based hand rub.

OBJECTIVES: To evaluate the effectiveness and contamination of an in-house alcohol-based hand rub in a real clinical setting and to compare its effectiveness in bacterial reduction with that of a commercial product. MATERIAL AND METHOD: Effectiveness of the hand rub in bacterial reduction was compared to a commercial product using the modified antiseptic/disinfectant testing method of European Standard (EN 1500) in 12 volunteers. In-house alcohol-based hand rub in 50 clinical wards were serially collected and cultured to determine contamination. RESULTS: The bacterial reduction factor of the hand rub was comparable to that of the commercial product. There was no organisms grown from serial cultures of the in-house alcohol-based hand rub in use for 28 days. CONCLUSION: The in-house alcohol-based hand rub was effective and there was no contamination up to 28 days in use.

[Consumption of hand-hygiene products in health establishments in the west of France]. / La consommation de produits d'hygiène des mains dans les établissements de soins dans l'interrégion Ouest.

OBJECTIVES: The study had for aim to investigate hand hygiene product use in French hospitals between 2000 and 2003. DESIGN: A questionnaire was sent in 2002 and 2 more in 2003 and 2004 (for 2000 to 2003) requiring data on type of hospital, number of beds, staff members, admissions and patient-day, litres of mild soap, antiseptic soap and alcohol-based rub used and price per litre. Indices were calculated accordingly. RESULTS: 574 hospitals answered over the 4 year period (average 143 per year) representing an average of 50 000 beds/year, 80 000 full-time staff positions, 1.2 million admissions and 16 millions patient-days. The median consumption of mild soap was 3.8 l per bed, 2.7 l per staff member, 2.4 l per 100 admissions, and 10.6 ml per patient-day. The median consumption of antiseptic soap was 1 l per bed, 0.8 l per staff member, 4.8 l per 100 admissions, and 3.2 ml per patient-day. The median consumption of alcohol-based rub (HAS) was 0.3 l per bed, 0.3 l per staff-member, 1.5 l per admission, and 0.9 l per patient-day. Between 2000 and 2003, HAS use significantly increased from 69 to 88% (a relative increase of 31%) and the median consumption increased from 0.5 ml to 1.5 ml per patient-day. 370 fully completed grids gave a number of 7 opportunities per patient-day with less than 1 for HAS. CONCLUSION: The best indicator for an infection control practitioners is the quantity of alcohol-based solution in ml/patient-day and HAS per patient-day is the reference.

Increase in hospital purchase of hand hygiene products: The importance of focusing on the right product.

Alcohol-based handrub (AHR) consumption is positively correlated with increases in hand hygiene (HH) compliance. In our 2,000-bed hospital in India, multiple awareness drives have been conducted to promote HH. This study aimed to determine the quantitative effect of these campaigns on use of HH products (soap and AHR) in the hospital. Over the last 6 years, bar soap consumption has increased by 389.15%, whereas that of AHR increased by 146.7%. We also evaluated microbial contamination of 99 bar soap and 60 liquid soap samples in our hospital for a year. Of the samples, 61 (61.6%) of the bar soaps and 2 (3.3%) of the liquid soaps were found to be contaminated with various organisms (P < .0002). To conclude, the focus should be to increase the right kind of HH product so that hospitals in developing countries procure liquid soaps instead of bar soaps for handwashing purposes.

Implementing the Use of Chemical-Free Products in a Perinatal Unit.

OBJECTIVE: To develop a process to identify, adopt, and increase individual awareness of the use of chemical-free products in perinatal hospital units and to develop leadership skills of the fellow/mentor pair through the Sigma Theta Tau International Maternal-Child Health Nurse Leadership Academy (STTI MCHNLA). DESIGN: Pretest/posttest quality improvement project. SETTING: Tertiary care 80-bed perinatal unit. PATIENTS: Mothers and newborns on perinatal unit. INTERVENTIONS/MEASUREMENTS: The chemical hazard ratings of products currently in use and new products were examined and compared. Chemical-free products were selected and introduced to the hospital system, and education programs were provided for staff and patients. We implemented leadership tools taught at the STTI MCHNLA to facilitate project success. Pre- and postproject evaluations were used to determine interest in the use of chemical-free products and satisfaction with use of the new products. Cost savings were measured. RESULTS: Products currently in use contained potentially harmful chemicals. New, chemical-free products were identified and adopted into practice. Participants were interested in using chemical-free products. Once new products were available, 71% of participants were positive about using them. The fellow and mentor experienced valuable leadership growth throughout the project. CONCLUSIONS: The change to chemical-free products has positioned the organization and partner hospitals as community leaders that set a health standard to reduce environmental exposure for patients, families, and staff. The fellow and mentor learned new skills to assist in practice changes in a large organization by using the tools shared in the STTI MCHNLA.

Vascular catheter site care: the clinical and economic benefits of chlorhexidine gluconate compared with povidone iodine.

The use of chlorhexidine gluconate solution for vascular catheter insertion site care reduces the risk of catheter-related bloodstream infection by one-half, compared with povidone iodine. Our objective was to evaluate the cost-effectiveness of chlorhexidine gluconate versus povidone iodine. We used data from randomized, controlled trials, meta-analyses, and epidemiologic studies to construct a decision analysis model. We estimated that use of chlorhexidine, rather than povidone, for central catheter site care resulted in a 1.6% decrease in the incidence of catheter-related bloodstream infection, a 0.23% decrease in the incidence of death, and savings of 113 dollars per catheter used. For peripheral catheter site care, the results were similar, although the differences were smaller. The results were found to be robust on multivariate sensitivity analyses. Use of chlorhexidine gluconate in place of the current standard solution for vascular catheter site care is a simple and cost-effective method of improving patient safety in the hospital setting.

Cost improvements through the establishment of prudent infection control practices in a Brazilian general hospital, 1986-1989.

OBJECTIVES: To review procedures currently practiced in a Brazilian general hospital and to eliminate ineffective and inefficient practices. To measure the resulting cost improvements based on rigid hospital financing control. DESIGN: Implementation of surveillance and control programs and prevalence surveys to detect ineffective and inefficient practices. PARTICIPANTS: The study institution is a 130-bed general care facility affiliated with the Brazilian federal government. There were approximately 4,600 admissions per year during the study period (1986-1989). RESULTS: Instituting infection control measures and eliminating ineffective practices resulted in the following: an overall decrease in wound infection rates from 24.4% in 1987 to 3.45% in 1989; a 71% reduction in the global incidence of infection in the intensive care unit; a 74% reduction in the surgical prophylactic use of antibiotics; and a total savings of approximately $2 million (US dollars). CONCLUSIONS: During the period from 1986 to 1989, the infection control committee was able to decrease the overall wound infection rate from 24.4% in 1987 to 3.45% in 1989. This eliminated special health problems and improved patient care and cost-effectiveness for our hospital.

Surface disinfection: should we do it?

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

Disinfection of wastewater with peracetic acid: a review.

Peracetic acid is a strong disinfectant with a wide spectrum of antimicrobial activity. Due to its bactericidal, virucidal, fungicidal, and sporicidal effectiveness as demonstrated in various industries, the use of peracetic acid as a disinfectant for wastewater effluents has been drawing more attention in recent years. The desirable attributes of peracetic acid for wastewater disinfection are the ease of implementing treatment (without the need for expensive capital investment), broad spectrum of activity even in the presence of heterogeneous organic matter, absence of persistent toxic or mutagenic residuals or by-products, no quenching requirement (i.e., no dechlorination), small dependence on pH, short contact time, and effectiveness for primary and secondary effluents. Major disadvantages associated with peracetic acid disinfection are the increases of organic content in the effluent due to acetic acid (AA) and thus in the potential microbial regrowth (acetic acid is already present in the mixture and is also formed after peracetic acid decomposition). Another drawback to the use of peracetic acid is its high cost, which is partly due to limited production capacity worldwide. However, if the demand for peracetic acid increases, especially from the wastewater industry, the future mass production capacity might also be increased, thus lowering the cost. In such a case, in addition to having environmental advantages, peracetic acid may also become cost-competitive with chlorine.

Ultrasound enhancement of biocide efficiency.

In order to take account of the likely increase in costs of biocides in the light of increasing legislation and concern for the environment, there is a need to maximise the efficiency of biocides for the control of biofouling. The use of ultrasound in conjunction with biocides offers such an opportunity. Tests have been carried out using ultrasound generated at 20 kHz in conjunction with the oxidising biocide ozone, in a laboratory pilot plant, to investigate the effects of mutuality. The preliminary results reported in this paper suggest that the combined effect of ultrasound and the biocide is better than either separately employed. Clearly substantially more work is required in order to maximise effectiveness for minimum cost.

Use of antiseptics and disinfectants in Thailand 1990.

A survey by questionnaire was done in March and April 1990 on the use of antiseptics and disinfectants (A/D). Twenty-seven hospitals with 675 wards were enrolled. Results showed that the cost of A/D was 3.3 to 8.1 per cent of the total expenses for drugs. Essential A/D were available and used in most places. Many low level A/D, which have been excluded from modern hospitals, were still employed. Contamination of A/D was a real threat due to improper preparation, unclean containers and refill practices in many wards. Improper applications of A/D, namely: overuse, underuse, and wrong choices were found in many places. Textbooks and written guidelines were available but it is unlikely that they were referred to in practice. A national policy on the use of A/D and proper education to medical personnel are clearly needed.