Effect of poly-hexamethylene biguanide hydrochloride (PHMB) treated non-sterile medical gloves upon the transmission of Streptococcus pyogenes, carbapenem-resistant E. coli, MRSA and Klebsiella pneumoniae from contact surfaces.

BACKGROUND: Reduction of accidental contamination of the near-patient environment has potential to reduce acquisition of healthcare-associated infection(s). Although medical gloves should be removed when soiled or touching the environment, compliance is variable. The use of antimicrobial-impregnated medical gloves could reduce the horizontal-transfer of bacterial contamination between surfaces. AIM: Determine the activity of antimicrobial-impregnated gloves against common hospital pathogens: Streptococcus pyogenes, carbapenem-resistant E.coli (CREC), MRSA and ESBL-producing Klebsiella pneumoniae. METHODS: Fingerpads (~1cm2) of PHMB-treated and untreated gloves were inoculated with 10 µL (~104 colony-forming-units [cfu]) of test-bacteria prepared in heavy-soiling (0.5%BSA), blood or distilled-water (no-soiling) and sampled after 0.25, 1, 10 or 15 min contact-time. Donor surfaces (~1cm2 computer-keys) contaminated with wet/dry inoculum were touched with the fingerpad of treated/untreated gloves and subsequently pressed onto recipient (uncontaminated) computer-keys. RESULTS: Approximately 4.50log10cfu of all bacteria persisted after 15 min on untreated gloves regardless of soil-type. In the absence of soiling, PHMB-treated gloves reduced surface-contamination by ~4.5log10cfu (>99.99%) within 10 min of contact-time but only ~2.5log10 (>99.9%) and ~1.0log10 reduction respectively when heavy-soiling or blood was present. Gloves became highly-contaminated (~4.52log10-4.91log10cfu) when handling recently-contaminated computer-keys. Untreated gloves contaminated "recipient" surfaces (~4.5log10cfu) while PHMB-treated gloves transferred fewer bacteria (2.4-3.6log10cfu). When surface contamination was dry, PHMB gloves transferred fewer bacteria (0.3-0.6log10cfu) to "recipient" surfaces than untreated gloves (1.0-1.9log10; P < 0.05). CONCLUSIONS: Antimicrobial-impregnated gloves may be useful in preventing dissemination of organisms in the near-patient environment during routine care. However they are not a substitute for appropriate hand-hygiene procedures.

A feasibility service evaluation of screening and treatment of group A streptococcal pharyngitis in community pharmacies.

OBJECTIVES: The UK 5 year antimicrobial resistance strategy recognizes the role of point-of-care diagnostics to identify where antimicrobials are required, as well as to assess the appropriateness of the diagnosis and treatment. A sore throat test-and-treat service was introduced in 35 community pharmacies across two localities in England during 2014-15. METHODS: Trained pharmacy staff assessed patients presenting with a sore throat using the Centor scoring system and patients meeting three or all four of the criteria were offered a throat swab test for Streptococcus pyogenes, Lancefield group A streptococci. Patients with a positive throat swab test were offered antibiotic treatment. RESULTS: Following screening by pharmacy staff, 149/367 (40.6%) patients were eligible for throat swab testing. Of these, only 36/149 (24.2%) were positive for group A streptococci. Antibiotics were supplied to 9.8% (n = 36/367) of all patients accessing the service. Just under half of patients that were not showing signs of a bacterial infection (60/123, 48.8%) would have gone to their general practitioner if the service had not been available. CONCLUSIONS: This study has shown that it is feasible to deliver a community-pharmacy-based screening and treatment service using point-of-care testing. This type of service has the potential to support the antimicrobial resistance agenda by reducing unnecessary antibiotic use and inappropriate antibiotic consumption.

Recommendations for surveillance priorities for healthcare-associated infections and criteria for their conduct.

Surveillance and feedback of results to clinical teams is central to performance improvement in managing healthcare-acquired infections. A major role of the Advisory Committee on Antimicrobial Resistance and Healthcare-Associated Infections (ARHAI) is to advise on surveillance priorities. A sub-committee was set up to systematically review existing UK surveillance schemes. The following three systems were examined in detail: mandatory reporting of methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia and Clostridium difficile infection to the HPA; surveillance of surgical site infection undertaken by the HPA; and surgical site infection surveillance undertaken at University College London Hospital. Recommendations included the extension of mandatory reporting to include bacteraemia due to Escherichia coli and methicillin-susceptible S. aureus (MSSA), post-discharge surveillance of surgical site infection, the need for validation of surveillance systems and mandatory reporting of Caesarean section wound infections. Mandatory reporting of bacteraemia due to E. coli and MSSA were introduced during 2011 and further extension of surveillance is likely.

Reducing broad-spectrum antibiotic use in intensive care unit between first and second waves of COVID-19 did not adversely affect mortality.

BACKGROUND: The COVID-19 pandemic increased the use of broad-spectrum antibiotics due to diagnostic uncertainty, particularly in critical care. Multi-professional communication became more difficult, weakening stewardship activities. AIM: To determine changes in bacterial co-/secondary infections and antibiotics used in COVID-19 patients in critical care, and mortality rates, between the first and second waves. METHODS: Prospective audit comparing bacterial co-/secondary infections and their treatment during the first two waves of the pandemic in a single-centre teaching hospital intensive care unit. Data on demographics, daily antibiotic use, clinical outcomes, and culture results in patients diagnosed with COVID-19 infection were collected over 11 months. FINDINGS: From March 9th, 2020 to September 2nd, 2020 (Wave 1), there were 156 patients and between September 3rd, 2020 and February 1st, 2021 (Wave 2) there were 235 patients with COVID-19 infection admitted to intensive care. No significant difference was seen in mortality or positive blood culture rates between the two waves. The proportion of patients receiving antimicrobial therapy (93.0% vs 81.7%; P < 0.01) and the duration of meropenem use (median (interquartile range): 5 (2-7) vs 3 (2-5) days; P = 0.01) was lower in Wave 2. However, the number of patients with respiratory isolates of Pseudomonas aeruginosa (4/156 vs 21/235; P < 0.01) and bacteraemia from a respiratory source (3/156 vs 20/235; P < 0.01) increased in Wave 2, associated with an outbreak of infection. There was no significant difference between waves with respect to isolation of other pathogens. CONCLUSION: Reduced broad-spectrum antimicrobial use in the second wave of COVID-19 compared with the first wave was not associated with significant change in mortality.

Surveillance of bloodstream infections in intensive care units in England, May 2016-April 2017: epidemiology and ecology.

BACKGROUND: Bloodstream infections (BSIs) in patients in intensive care units (ICUs) are associated with increased morbidity, mortality and economic costs. Many BSIs are associated with central venous catheters (CVCs). The Infection in Critical Care Quality Improvement Programme (ICCQIP) was established to initiate surveillance of BSIs in English ICUs. METHODS: A web-based data capture system was launched on 1st May 2016 to collect all positive blood cultures (PBCs), patient-days and CVC-days. National Health Service (NHS) trusts in England were invited to participate in the surveillance programme. Data were linked to the antimicrobial resistance dataset maintained by Public Health England and to mortality data. FINDINGS: Between 1st May 2016 and 30th April 2017, 84 ICUs (72 adult ICUs, seven paediatric ICUs and five neonatal ICUs) based in 57 of 147 NHS trusts provided data. In total, 1474 PBCs were reported, with coagulase-negative staphylococci, Escherichia coli, Staphylococcus aureus and Enterococcus faecium being the most commonly reported organisms. The rates of BSI and ICU-associated CVC-BSI were 5.7, 1.5 and 1.3 per 1000 bed-days and 2.3, 1.0 and 1.5 per 1000 ICU-CVC-days in adult, paediatric and neonatal ICUs, respectively. There was wide variation in BSI and CVC-BSI rates within ICU types, particularly in adult ICUs (0-44.0 per 1000 bed-days and 0-18.3 per 1000 ICU-CVC-days). CONCLUSIONS: While the overall rates of ICU-associated CVC-BSIs were lower than 2.5 per 1000 ICU-CVC-days across all age ranges, large differences were observed between ICUs, highlighting the importance of a national standardized surveillance system to identify opportunities for improvement. Data linkage provided clinically important information on resistance patterns and patient outcomes at no extra cost to participating trusts.

Impact of rapid molecular screening for meticillin-resistant Staphylococcus aureus in surgical wards.

BACKGROUND: This study aimed to establish the feasibility and cost-effectiveness of rapid molecular screening for hospital-acquired meticillin-resistant Staphylococcus aureus (MRSA) in surgical patients within a teaching hospital. METHODS: In 2006, nasal swabs were obtained before surgery from all patients undergoing elective and emergency procedures, and screened for MRSA using a rapid molecular technique. MRSA-positive patients were started on suppression therapy of mupirocin nasal ointment (2 per cent) and undiluted chlorhexidine gluconate bodywash. RESULTS: A total of 18,810 samples were processed, of which 850 (4.5 per cent) were MRSA positive. In comparison to the annual mean for the preceding 6 years, MRSA bacteraemia fell by 38.5 per cent (P < 0.001), and MRSA wound isolates fell by 12.7 per cent (P = 0.031). The reduction in MRSA bacteraemia and wound infection was equivalent to a saving of 3.78 beds per year (276,220 pounds sterling), compared with the annual mean for the preceding 6 years. The cost of screening was 302,500 pounds sterling, making a net loss of 26,280 pounds sterling. Compared with 2005, however, there was a net saving of 545,486 pounds sterling. CONCLUSION: Rapid MRSA screening of all surgical admissions resulted in a significant reduction in staphylococcal bacteraemia during the screening period, although a causal link cannot be established.

The efficacy of the inorganic copper-based biocide CuWB50 is compromised by hard water.

AIMS: We sought to explain the unexpected failure of the inorganic copper-based biocide CuWB50 to effectively decontaminate microfibre cleaning cloths that became contaminated with Acinetobacter lwoffii. METHODS AND RESULTS: CuWB50 was diluted using distilled water or tap water obtained from two different ICUs. Microtitre plate assays were used to determine the minimum inhibitory concentration (MIC) for the implicated A. lwoffii. pH and oxidation-reduction potential (ORP) tests were performed and representative water samples were chemically analysed. When diluted in distilled water, the CuWB50 MIC for A. lwoffii was 9 mg l(-1) but in tap water from each ICU it was 37 and 75 mg l(-1) at hardness levels of 246 and 296 mg CaCO(3) l(-1) respectively. CuWB50-distilled water solutions consistently had a lower pH and higher ORP than CuWB50-tap water solutions. CONCLUSIONS: Hard water adversely affects the biocidal efficacy of CuWB50. SIGNIFICANCE AND IMPACT OF THE STUDY: Unintentional environmental contamination is a risk when using wet microfibre cloths. This occurred when cloths were stored in CuWB50 overnight combined with the unintentional but erroneous use of tap water. This study emphasizes the need for clearly documented cleaning protocols embedded within a culture of adequate training and constant supervision of cleaning staff.

Ultraviolet-C decontamination of hand-held tablet devices in the healthcare environment using the Codonics D6000™ disinfection system.

Mobile phones and tablet computers may be contaminated with micro-organisms and become a potential reservoir for cross-transmission of pathogens between healthcare workers and patients. There is no generally accepted guidance on how to reduce contamination on mobile devices in healthcare settings. Our aim was to determine the efficacy of the Codonics D6000™ UV-C disinfection device. Daily disinfection reduced contamination on screens and on protective cases (test) significantly, but not all cases (control) could be decontaminated. The median aerobic colony count on the control and the test cases was 52 cfu/25 cm2 (interquartile range: 33-89) and 22 cfu/25 cm2 (10.5-41), respectively, before disinfection.

Postoperative surveillance, registration and classification of wound infection in cardiac surgery--experiences from Great Britain.

Wound infection in cardiac surgery is a continuing problem despite improvements in surgical technique. The risk factors for, and appearance of, the infected wound differ from operations in other specialties. A robust definition is required for successful surveillance but many are open to different interpretations. At UCLH, comparison between UK and US definitions shows marked differences in patients defined as infected. Surveillance with feedback is effective if conducted over several years, but a high proportion of infected wounds are only identified during post-discharge follow-up. Deteriorating performance of an individual surgeon can be detected and interventions focused on improving faults identified during data collection. Often highlighting the problem is sufficient to reverse the trend, but the process of audit and control is becoming more important as accountability and performance is demanded by primary care providers and patients.

Monitoring the occurrence of wound infections after cardiac surgery.

The aim of this study was to demonstrate the use of a graphical method for real-time monitoring of the occurrence of surgical wound infection following cardiac surgery. This included developing and incorporating a risk scoring system so that variations in case-mix could be duly accounted for in the monitoring process. We analysed routinely collected data from a London teaching hospital. These data consisted of records for 2146 patients who had undergone cardiac surgery between April 2000 and March 2004 and whose surgical wounds were followed up as part of the local surveillance programme. The risk model was developed using logistic regression analysis with surgical wound infection diagnosed before hospital discharge as the outcome measure. Factors included in the model were the number of surgical wounds, patient age, operations that combined bypass surgery and valve replacement, renal disease and the number of days between hospital admission and surgery. The model was a good predictor of outcomes recorded within an independent data set (Chi-squared=3.81, P=0.58) and we incorporated it into a graphical tool for monitoring outcomes. The risk model and the associated graphical monitoring method could be valuable tools to assist with infection management. If used in real-time, problems with the care process can be quickly identified allowing timely remedial action to be taken.

ESBL-producing Gram-negative organisms in the healthcare environment as a source of genetic material for resistance in human infections.

BACKGROUND: The increasing prevalence of extended-spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae in the healthcare setting and in the community despite established infection control guidelines indicates that these microorganisms may possess survival strategies that allow them to persist in the environment. AIMS: To determine the extent and variation in endemic ESBL-carrying species in different ward environments, and to investigate the potential for cephalosporin resistance to be transferred from environmental isolates to human pathogens. METHODS: Conventional microbiological methods were used to sample 1436 environmental surfaces for ESBL-producing bacteria. Transconjugation assays (broth mating experiments) were performed using environmental ESBL-producing isolates as donors and streptomycin-resistant Escherichia coli (NCTC 50237) as the recipient. FINDINGS: The prevalence of ESBL-producing bacteria on surfaces in a non-outbreak setting was low (45/1436; 3.1%). The sites most likely to be contaminated were the drains of handwash basins (28/105; 26.7%) and floors (14/160; 8.8%). Fifty-nine ESBL-carrying organisms were isolated. Of these, Klebsiella spp. (33.9%), Enterobacter spp. (20.3%), Pantoea spp. (15.3%) and Citrobacter spp. (13.6%) were the most common isolates. ESBL determinants were transferred successfully from three representative environmental isolates (Pantoea calida, Klebsiella oxytoca, Raoultella ornithinolytica) to the human pathogen E. coli. CONCLUSION: ESBL-producing Gram-negative isolates were recovered from the hospital environment in the absence of any ESBL infection on the wards. The drains of handwash basins should be considered potential long-term reservoirs of multi-drug-resistant bacteria and drug resistance genes. These genes can reside in various genera of hardy environmental organisms and be a potential source of ESBL for more common human pathogens.

Comparison of two whole-room ultraviolet irradiation systems for enhanced disinfection of contaminated hospital patient rooms.

BACKGROUND: Ultraviolet (UV) light decontamination systems are being used increasingly to supplement terminal disinfection of patient rooms. However, efficacy may not be consistent in the presence of soil, especially against Clostridium difficile spores. AIM: To demonstrate in-use efficacy of two whole-room UV decontamination systems against three hospital pathogens with and without soil. METHODS: For each system, six patient rooms were decontaminated with UV irradiation (enhanced disinfection) following manual terminal cleaning. Total aerobic colony counts of surface contamination were determined by spot-sampling 15 environmental sites before and after terminal disinfection and after UV irradiation. Efficacy against biological indicator coupons (stainless-steel discs) was performed for each system using test bacteria (106 cfu EMRSA-15 variant A, carbapenemase-producing Klebsiella pneumoniae) or spores (105 cfu C. difficile 027), incorporating low soiling [0.03% bovine serum albumin (BSA)], heavy soiling (10% BSA) or synthetic faeces (C. difficile only) placed at five locations in the room. FINDINGS: UV disinfection eliminated contamination after terminal cleaning in 8/14 (57%) and 11/14 (79%) sites. Both systems demonstrated 4-5 log10 reductions in meticillin-resistant Staphylococcus aureus and K. pneumoniae at low soiling. Lower and more variable log10 reductions were achieved when heavy soiling was present. Between 0.1 and 4.8 log10 reductions in C. difficile spores were achieved with low but not heavy soil challenge. CONCLUSION: Terminal disinfection should be performed on all surfaces prior to UV decontamination. In-house validation studies should be considered to ensure optimal positioning in each room layout and sufficient cycle duration to eliminate target pathogens.

Reducing hospital-acquired infection by design: the new University College London Hospital.

The planning and building of new University College London Hospital has provided a challenge to the Infection Control Team to ensure all areas are easy to clean, air flows are correct and appropriate and that there is every opportunity for handwashing. The seven year process illustrates the paper by Stockley et al. ['Stockley JM, Constantine CE, Orr KE, The Association of Medical Microbiologists' New Hospital Developments Project Group. Building new hospitals: a UK infection control perspective.

Laundering of hospital staff uniforms at home.

Few hospitals now launder staff uniforms. Staff are expected to use their own domestic machines, most of which run with 40 degrees C cycles. However, there is little information on the effectiveness of home laundering. This study demonstrates that domestic washing machines reduce viable counts of Staphylococcus aureus to below detectable levels from an inoculum of 10(8)-10(12) colony-forming units (>or=10(6)-fold reduction), even using low temperature (40 degrees C) programmes. Environmental organisms, predominantly Gram-negative flora, were introduced from the machine itself but were destroyed by tumble drying or ironing. Domestic laundering of uniforms is an acceptable alternative to hospital laundering if combined with tumble drying or ironing.

Efficacy of two hydrogen peroxide vapour aerial decontamination systems for enhanced disinfection of meticillin-resistant Staphylococcus aureus, Klebsiella pneumoniae and Clostridium difficile in single isolation rooms.

BACKGROUND: Hydrogen peroxide vapour (HPV) disinfection systems are being used to reduce patients' exposure to hospital pathogens in the environment. HPV whole-room aerial disinfection systems may vary in terms of operating concentration and mode of delivery. AIM: To assess the efficacy of two HPV systems (HPS1 and HPS2) for whole-room aerial disinfection of single isolation rooms (SIRs). METHODS: Ten SIRs were selected for manual terminal disinfection after patient discharge. Test coupons seeded with biological indicator (BI) organisms [∼10(6) colony-forming units (cfu) of meticillin-resistant Staphylococcus aureus (MRSA) or Klebsiella pneumoniae, or ∼10(5)cfu Clostridium difficile 027 spores] prepared in a soil challenge were placed at five locations per room. For each cycle, 22 high-frequency-touch surfaces in SIRs were sampled with contact plates (∼25cm(2)) before and after HPV decontamination, and BIs were assayed for the persistence of pathogens. FINDINGS: Approximately 95% of 214 sites were contaminated with bacteria after manual terminal disinfection, with high numbers present on the SIR floor (238.0-352.5cfu), bed control panel (24.0-33.5cfu), and nurse call button (21.5-7.0cfu). Enhanced disinfection using HPV reduced surface contamination to low levels: HPS1 [0.25cfu, interquartile range (IQR) 0-1.13] and HPS2 (0.5cfu, IQR 0-2.0). Both systems demonstrated similar turnaround times (∼2-2.5h), and no differences were observed in the efficacy of the two systems against BIs (C. difficile ∼5.1log10 reduction; MRSA/K. pneumoniae ∼6.3log10 reduction). Despite different operating concentrations of hydrogen peroxide, MRSA persisted on 27% of coupons after HPV decontamination. CONCLUSION: Enhanced disinfection with HPV reduces surface contamination left by manual terminal cleaning, minimizing the risks of cross-contamination. The starting concentration and mode of delivery of hydrogen peroxide may not improve the efficacy of decontamination in practice, and therefore the choice of HPV system may be based upon other considerations such as cost, convenience and logistics.