Difference In Contamination Rates Research Articles

Genomic characterization of carbapenemase-producing Enterobacterales from Dhaka food markets unveils the spread of high-risk antimicrobial-resistant clones and plasmids co-carrying bla NDM and mcr-1.1.

The transmission of carbapenemase-producing Enterobacterales (CPE) in the external environment, especially through food, presents a significant public health risk. To investigate the prevalence and genetic characteristics of CPE in food markets of Dhaka, Bangladesh, using WGS. CPE isolates were obtained from different food and water samples collected from food markets in the southern part of Dhaka, Bangladesh. The isolates subsequently underwent molecular typing, WGS employing both short- and long-read sequencers, and plasmid analysis. This study unveiled an extensive spread of CPE, with no significant difference in contamination rates observed in samples (N = 136), including meat (n = 8), fish (n = 5), vegetables (n = 36) or various food-washed water (n = 65) from markets near hospitals or residential areas. Thirty-eight Enterobacterales from 33 samples carried carbapenemase genes (bla NDM-1, -4, -7, bla KPC-2, bla OXA-181 or bla IMI-1). Among these, the high-risk Escherichia coli ST410 clone was the most prevalent and distributed across various locations. Furthermore, the identification of IncHI2 plasmids co-harbouring resistance genes like bla NDM-5 and mcr-1.1, without discernible epidemiological connections, is a unique finding, suggesting their widespread dissemination. The analysis unveils a dynamic landscape of CPE dissemination in food markets, underscored by the proliferation of novel IncHI2 hybrid plasmids carrying both colistin- and carbapenem-resistance genes. This illuminates the ever-evolving landscape of antimicrobial resistance in Dhaka, urging us to confront its emergent challenges.

Review of Blood Cultures Taken From Arterial Lines in James Cook University Hospital: Contamination Analysis And Comparison With Venous Samples

BACKGROUND: Blood cultures are crucial diagnostic tools for identifying and treating bloodstream infections. Traditionally, venous blood is the preferred source for sample acquisition, but arterial lines offer an alternative. However, concerns regarding contamination and diagnostic accuracy have been raised, questioning the reliability of arterial line blood cultures. This study aimed to evaluate the contamination rates of arterial line blood cultures at James-Cook University Hospital (JCUH), UK and compare them with venous samples to understand their clinical utility better. METHODS: A comprehensive retrospective review analysed 17,643 blood culture samples collected between September 2022 and March 2023 at JCUH. Among these, 109 arterial line blood cultures and 785 venous peripheral adult samples were included for data analysis. Contamination rates were calculated as the number of positive blood cultures with contaminants per total positive samples (arterial or venous). The incidence of contamination was defined as the number of total blood cultures reported with contaminants per total samples (arterial or venous). No discrimination was made based on the number of contaminants found. Clinical information accompanying the blood cultures, such as the specification of arterial lines as 'new' samples, was also considered. RESULTS: The overall contamination rate at JCUH was found to be 4.99%. Specifically, the contamination rate for venous samples was 49.26%, while arterial samples had a higher contamination rate of 56.52%. The incidence of contamination from arterial samples was 11.92%, significantly higher than the incidence rate for venous samples at 3.18%. Most arterial samples were requested from intensive care units (ICUs) and highly dependent wards (HDUs), indicating potential areas for targeted interventions to improve blood culture collection practices. CONCLUSION: Arterial blood cultures demonstrated higher contamination rates compared to venous samples, raising concerns about their reliability. Contamination in arterial samples, particularly when collected from critically ill patients in ICUs and HDUs, can lead to inappropriate use of antibiotics, delayed, or missed diagnosis, and suboptimal patient outcomes. The study recommends targeted interventions to improve arterial blood culture collection practices and further training for healthcare workers involved in arterial line care. Encouraging the use of only 'new' arterial lines and implementing standardized protocols can help reduce contamination rates. Furthermore, the study identified certain limitations, such as potential human errors in data analysis and the need for a larger dataset of arterial line cultures. Extending the analysis to compare different sample sources like CVCs, Hickman lines, and central lines could provide a more comprehensive understanding of contamination rates across various culture collection methods. In conclusion, venous samples showed higher clinical favourability with a lower contamination rate, providing increased dependability for accurate diagnosis and management. Although some studies have not shown clear superiority of arterial samples over venous samples, this analysis highlights considerable differences in contamination rates, suggesting a potential inferiority of arterial blood culture samples. While efforts can be made to optimize the consistency of arterial samples and reduce contamination rates, their use should be approached with caution. Implementing the recommended measures is essential for accurate diagnosis, improved patient outcomes, and effective antibiotic management in clinical practice.

Surgical helmet systems in total joint arthroplasty: assessment of hood sterility and donning technique

BackgroundThe incidence of prosthetic joint infection (PJI) is increasing, coincident with the rising volume of joint arthroplasty being performed. With recent controversy regarding the efficacy of surgical helmet systems (SHS) in preventing infection, the focus has turned to the correct donning techniques and usage of surgical hoods. The aim of this study was to compare the bacterial contamination of the operating surgeon’s gloves after two common donning techniques of SHS hoods. We also evaluated the baseline sterility of the SHS hoods at the beginning of the procedure.MethodsThe bacterial contamination rate was quantified using colony-forming units (CFUs), with 50 trials performed per donning technique. Samples were cultured on 5% Columbia blood agar in ambient air at 37 °C for 48 h and all subsequent bacterial growth was identified using a MALDI-TOF mass spectrometer. In Group 1, the operating surgeon donned their colleague’s hood. In Group 2, the operating surgeon had their hood applied by a non-scrubbed colleague. After each trial, the operating surgeon immediately inoculated their gloves onto an agar plate. The immediate sterility of 50 SHS hoods was assessed at two separate zones—the screen (Zone 1) and the neckline (Zone 2).ResultsThere was no significant difference in contamination rates between the two techniques (3% vs. 2%, P = 0.99) or between right and left glove contamination rates. Immediately after donning, 6/50 (12%) of SHS hoods cultured an organism. Contamination rates at both the face shield and neckline zones were equivalent. The majority of bacteria cultured were Bacillus species.DiscussionWe found no significant difference in the operating surgeon’s glove contamination using two common SHS hood-donning techniques when they were performed under laminar airflow with late fan activation. We suggest the SHS hood should not be assumed to be completely sterile and that gloves are changed if it is touched intraoperatively.

Evaluation of Real and Perceived Risk to Health Care Workers Caring for Patients With the Omicron Variant of the SARS-CoV-2 Virus in Surgery and Obstetrics

ObjectivesThe Omicron variant of the SARS-CoV-2 virus is described as more contagious than previous variants. We sought to assess risk to health care workers (HCWs) caring for patients with COVID-19 in surgical/obstetrical settings, and the perception of risk among this group. MethodsFrom January to April 2022, reverse transcription polymerase chain reaction was used to detect the presence of SARS-CoV-2 viral ribonucleic acid in patient, environmental (floor, equipment, passive air) samples, and HCWs’ masks (inside surface) during urgent surgery or obstetrical delivery for patients with SARS-CoV-2 infection. The primary outcome was the proportion of HCWs’ masks testing positive. Results were compared with our previous cross-sectional study involving obstetrical/surgical patients with earlier variants (2020–2021). HCWs completed a risk perception electronic questionnaire. ResultsEleven patients were included: 3 vaginal births and 8 surgeries. In total, 5/108 samples (5%) tested positive (SARS-CoV-2 Omicron) viral ribonucleic acid: 2/5 endotracheal tubes, 1/22 floor samples, 1/4 patient masks, and 1 nasal probe. No samples from the HCWs’ masks (0/35), surgical equipment (0/10), and air (0/11) tested positive. No significant differences were found between the Omicron and 2020/21 patient groups’ positivity rates (Mann-Whitney U test, P = 0.838) or the level of viral load from the nasopharyngeal swabs (P = 0.405). Nurses had a higher risk perception than physicians (P = 0.038). ConclusionNo significant difference in contamination rates was found between SARS-CoV-2 Omicron BA.1 and previous variants in surgical/obstetrical settings. This is reassuring as no HCW mask was positive and no HCW tested positive for COVID-19 post-exposure.

Evaluation of real and perceived risk to health care workers caring for patients with the Omicron variant of the SARS-CoV-2 virus in surgery and obstetrics

We sought to assess risk to healthcare workers (HCWs) caring for patients with the Omicron variant of the SARS-CoV-2 virus in surgical/obstetrical settings, and the perception of risk amongst this group. From January to April, 2022, reverse transcription polymerase chain reaction was used to detect the presence of SARS-CoV-2 viral RNA in patient, environmental (floor, equipment, passive air) samples, and HCW’s masks (inside surface) during urgent surgery or obstetrical delivery for patients with SARS-CoV-2 infection (at a tertiary care centre). The primary outcome was the proportion of HCWs’ masks testing positive. Results were compared with a previous cross-sectional study involving obstetrical/surgical patients with earlier variants (2020/21) using the Mann-Whitney U and 2-sample z-test. HCWs completed a risk perception electronic questionnaire. 11 patients were included: 3 vaginal births and 8 surgeries. 5/108 samples (5%) tested positive for (SARS-CoV-2 Omicron) viral RNA: 2/5 endotracheal tubes, 1/22 floor samples, 1/4 patient masks and 1 nasal probe. No samples from the HCWs masks (0/35), surgical equipment (0/10) and air samples (0/11) tested positive. No significant differences were found between the Omicron and 2020/21 patient groups’ positivity rates (P = 0.838) or the level of viral load from the nasopharyngeal swabs (P = 0.405). Nurses had a higher risk perception than physicians (P = 0.038). No significant difference in contamination rates were found between SARS-CoV-2 Omicron BA.1 and previous variants in surgical/obstetrical settings. This is reassuring as no HCW mask was positive and no HCW tested positive for COVID-19 post-exposure.

Do Ultraviolet Air Disinfection Units Reduce Contamination by Particulates in Total Knee Replacement Procedures?

Prosthetic joint infections have become the leading cause of joint replacement failure. The primary sources of contamination are skin flora and bacteria from airborne particles. Portable ultraviolet air disinfection units are used in the Operating Room (OR) to prevent contamination from airborne particles; however, their effectiveness is not proven. The purpose of this study was to compare the rate of contamination of sites with and without Ultraviolet (UV) air disinfection units during active surgeries. Sedimentation rates of viable particles were measured during 40 primary TKA procedures. Half of the procedures were performed with ultraviolet air disinfection units. Air-borne particles were collected on nitrocellulose membranes at 5 locations within the OR. After incubation, all microbial colonies were counted and the sedimentation rates were reported in CFUs/m2/hr. 10 additional trials were performed in an empty OR with no staff present. The average contamination rate of all sites was 22 ± 1.1 CFUs/m2/hr in the empty OR vs. 21.3 ± 4.6 CFUs/m2/hr with UV units and 20.3 ± 4.9 CFUs/m2/hr without (P= .03, P= .03, P= .964). Viable contaminates were found in the sterile field in 25% of UV cases vs 45% non-UV. These differences were not statistically significant. There were differences found however, according to the number of staff in the room (6 vs 7 staff: P= .036, 6 vs 8 staff: P= .004). There was no statistical difference in contamination rate with the usage or non-usage of UV units. These 40 cases shows that the largest variables affecting the contamination rate were the number of staff present and size of the OR.

Injury Characteristics, Infection and Resistance Pattern of Open Fracture Tibia in Tertiary Orthopaedic Centre

Background: Open fractures are a frequent occurrence in the in accident and emergency department that requires immediate care. As a pedal bone, the tibia is very prone to accidental injury, easily becomes bare following the trauma and very prone to infection. Updated knowledge about microbial aspects of open tibia fracture infection is essential for proper management. Objective: This study evaluated the injury characteristics and resistance patterns of microorganisms involved in the infection of open fracture tibia in a single-centred study. Methods: This was a cross-sectional study on a total of 384 patients presented at the emergency department with open fractures of the tibia (all Gustilo types) from January 2020 to July 2020 at the National Institute of Traumatology and Orthopedic Rehabilitation (NITOR), Bangladesh. Three successive culture sensitivity tests were carried out-one at the emergency room (surveillance culture), 2nd at the emergency theatre after debridement and third at ward after 1 week (7 to 10 days). Results: Average age of the patients was 36.2± 15.5 years, with motor vehicle accidents being the predominant cause (72.9%). Gustilo III fractures were most prevalent (54.4%). The maximum infection rate was in Gustilo IIIB Fractures (40.4%). There was a significant difference in contamination rate between on admission culture (37.0%) and post debridement culture (26.3%). The infection rate from the ward samples was 44.5 %, where the postdebidement contamination was less only 26.3%. But from the ward sample, it again increased to 44.5%. Among the patient entering the ward after debridement with no contamination (73.7%) became infected in 34.62% cases, which indicates hospital-acquired infection. The bacterial resistance patterns from the ward samples were more virulent with multidrug resistance, predominantly Pseudomonas spp. and Kliebsiella spp. Conclusion: The present study provided insight into the injury characteristics and infection patterns of open fractures of the tibia. Early debridement reduced the contamination, but there was still hospital-acquired infection with more virulent multidrug resistance phenotypes. Bangladesh Med Res Counc Bull 2021; 47(2): 205-211

Parasitic Contamination of Soil, Irrigation Water and Rawly Consumed Vegetables in Farmlands of Asmara, Eritrea

Background: About one third of the world population are infected with intestinal parasites. Eating raw vegetables is customary in many parts of the world including Eritrea posing a great risk for transmission of pathogens. Therefore, the aim of this study was to determine the prevalence and risks of parasitic contamination in raw vegetables, soil and irrigation water samples. Methods and materials: A cross-sectional study was carried out on different types of 336 vegetable samples (lettuce, carrot, cabbage and arugula), 60 soil and water samples each using sedimentation technique. Simultaneously, socio demographic and farmer practice data of 60 farmers were collected using structured questionnaire. The obtained data were entered and analysed using SPSS version 20. Result: The magnitude of contamination of vegetable, soil and water samples was 144(42.9%), 21(35%) and 30(50%) respectively. Lettuce was the most contaminated sample (51.2%) and arugula (50.9%), carrot (42.7%) and cabbage (34.1%). The most prevalent parasites detected was S. stercolaris 30.6% followed by A. lumbricoides (11.8%) and hookworm (11.8%). The main findings also include the statistically significant difference in rate of contamination observed among various farmlands, vegetable types, and farmer practices. Also, significant association were observed between vegetable contamination and source of irrigation water (p-value= 0.02) and area of collection (p-value< 0.001). Conclusion: This study conclusively reveals the high burden of vegetable, soil and water contamination and the impact of wastewater irrigation system as major risk factor in transmission of intestinal parasitosis among farmers and communities in Asmara.

A STUDY OF WARMING DEVICES AND PERIOPERATIVE FACTORS POTENTIALLY CONTRIBUTING TO SURGICAL FIELD CONTAMINATION IN SMALL ANIMAL PATIENTS

Bacterial contamination on surgical drapes may increase the risk of surgical site infection (SSI). This preliminary investigation analyzed the relationship between forced-air warming devices and bacterial contamination on surgical drapes in small animal soft tissue surgery settings. The subjects of this study were canine and feline patients enrolled in clean surgical procedures at the National Taiwan University Veterinary Hospital. Bacterial colonies on surgical drapes were sampled on agar plates immediately prior to and 1[Formula: see text]h after skin incision. Cases with bacteria growth on the post-incision sampled agar were considered with surgical field contamination (SFC). Intraoperative warming methods (forced-air warming systems or circulating water blankets) and other factors that potentially contribute to SFC (drape material, patient features, surgical procedure types, surgeons, and number of operating room personnel) were recorded. The study comprised 57 operations, 28 cases belonged to the circulating water blanket group and 29 belonged to the forced-air warming system group. No differences in contamination rate were detected among intraoperative warming methods, drape materials, patient characteristics, surgical procedure types, or number of operating room personnel. However, a significant difference in contamination rate was detected among surgeons.

Contamination rates of different methods of urine culture collection in children: A retrospective cohort study.

Urinary tract infection is a common cause of paediatric morbidity. However, there is no consensus on the default method for urine culture collection in children. This study aimed to examine the contamination rates of different urine collection methods. This was a retrospective cohort study in a paediatric emergency department. Data were collected from electronic health records on all children whose urine culture samples were obtained in the paediatric emergency department between March 2018 and March 2019. Different methods of urine collection included the midstream (MS) method, clean catch (CC), transurethral bladder catheterisation and suprapubic aspiration. Contamination rates and positive urine culture rates were calculated and compared for sex, age, and collection method. Urine culture samples were collected from 1507 children. There were 284 (18.8%) cultures that were positive with significant growth and 52 (3.5%) that were defined as 'contaminated'. The contamination rates for the midstream method in toilet-trained children were 1.6% (10/609), 4.9% (17/348) for CC in pre-continent children, 4.9% (25/515) for transurethral bladder catheterisation and 0% (0/35) (P=0.006) for suprapubic aspiration. There was no significant difference in contamination rates of urine cultures collected by CC and catheterisation in the compared groups. The rates of positive cultures in the subgroup of children with high suspicion for Urinary tract infection were also found to be similar. Our study shows that CC is non-inferior to catheterisation for collecting urine cultures in young children.

Measurement of drug concentration and bacterial contamination after diluting morphine for intrathecal administration: an experimental study

BackgroundLow concentrations of morphine are required for safe dosing for intrathecal injections. Sometimes, manual dilution of morphine is performed to achieve these low concentrations, but risks dilution errors and bacterial contamination. The primary goal was to compare the concentrations of morphine and bupivacaine between four groups of syringes. The secondary goal was to investigate the difference in contamination rate between these groups.MethodsTwenty-five experienced anesthesia providers were asked to prepare a mixture of bupivacaine 2.0 mg/ml and morphine 60 μg/ml using 3 different methods as clean and precise as possible. The fourth method used was the aspiration of ampoules prepared by the pharmacy. The concentrations of morphine and bupivacaine were measured by High-Pressure Liquid Chromatography (HPLC). The medication was cultured for bacterial contamination.ResultsGroup 1 (median 60 μg/ml; 95% CI: 59–110 μg/ml) yielded 3 outliers above 180 μg/ml morphine concentration. Group 2 (76 μg/ml; 95% CI: 72–80 μg/ml) and 3 (69 μg/ml; 95% CI: 66–71 μg/ml) were consistently higher than the target concentration of 60 μg. The group “pharmacy” was precise and accurate (59 μg/ml; 95% CI: 59–59 μg/ml). Group 2 and “pharmacy” had one contaminated sample with a spore-forming aerobic gram-positive rod.ConclusionManually diluted morphine is at risk for deviating concentrations, which could lead to increased side-effects. Medication produced by the hospital pharmacy was highly accurate. Furthermore, even when precautions are undertaken, contamination of the medication is a serious risk and appeared to be unrelated to the dilution process.

Bacterial contamination rates in extracorporeal photopheresis.

Extracorporeal photopheresis (ECP) is an immunosuppressive treatment that involves leukocyte apheresis, psoralen and UV light treatment, and subsequent reinfusion. Patients treated with ECP are usually immunosuppressed. Bacterial contamination therefore poses a much unwanted risk, but incidence data are lacking. We screened all 1922 consecutive ECP procedures scheduled within a roughly 3-year period for eligibility. Those with missing data on ECP method (inline or offline) or type of venous access (peripheral or central) were excluded. ECPs with complete aerobic and anaerobic microbial testing of baseline patient blood samples (n = 1637) and of ECP cell concentrates (n = 1814) were included in the analysis. A test for microbial contamination was positive for 1.82% of the cell concentrates, with central venous access was the most significant risk factor for the contamination (odds ratio = 19). Patient blood samples were positive in 3.85% of cases, but no patients became septic. Staphylococcus spp. were most abundant, and products with bacterial contamination did not cause side effects after reinfusion. There were no significant differences in contamination rates between inline and offline ECP. These findings stress the importance of sterile procedures and the benefits of using peripheral over central venous access for reducing the risk of bacterial contamination in ECP.

An Exploratory Trial to Estimate the Proportion of Patients with Tumor Cell Contaminated, Flow Positive Leukapheresis Products Collected with and without Bortezomib As in-Vivo Purging Prior to Autologous Stem Cell Harvest for Multiple Myeloma

Introduction Autologous stem cell transplant (ASCT) is the standard of care for newly diagnosed, transplant-eligible patients with multiple myeloma (MM). Myeloma cell contamination of the graft may lead to poor disease free survival. While ex-vivo purging of the harvested product has not been shown to improve progression-free survival (PFS), in-vivo purging of autologous stem cell grafts is an unexplored intervention in this population. We assessed if in-vivo purging using bortezomib prior to stem cell harvest affected the graft contamination rate in MM patients by using multiparametric flow cytometry (MPFC) for minimal residual disease (MRD) detection in the stem cell product. Methods 101 patients with MM treated with novel therapy prior to ASCT were randomly assigned to control or treatment arms. The control group underwent standard of care (SOC) stem cell collection with G-CSF on days -4 through -1, stem cell collection on day 0 and plerixafor if needed. The treatment group received bortezomib injections as a means of in-vivo purging on days -11 and -8, followed by SOC stem cell harvest. MPFC was used to measure MRD in the harvested products. International Myeloma Working Group response criteria was used to determine status at ASCT. Results 101 patients with MM were included. There were 51 patients in the control arm and 50 patients in the treatment arm. Among the transplanted patients, 24 (24%) [11 (22%) in the control and 13 (26%) in the treatment arm (p=0.6)] had neoplastic myeloma cells in the harvested products detected by MPFC (MRD+). There were 6 (12%) MRD+ cases in patients with CR+VGPR (n=53) and 18 cases (36%) with PR or worse status (n=48) showing correlation between disease status at transplantation and contamination rate (p=0.002). The mean number of CD34+ stem cells collected and time to engraftment did not significantly differ between the two groups. Conclusion In the era of novel drug therapy, contamination of harvest product did not occur in most patients (76% were MRD- by MPFC) regardless of pretreatment with bortezomib. In-vivo purging with bortezomib did not significantly affect the contamination rates compared to the SOC. There was a significant difference in contamination rates correlating with increased severity of disease status at time of transplant. Alternative therapies like monoclonal antibodies to minimize the presence of MRD in this population may be explored in future trials.

Contamination in Adult Midstream Clean-Catch Urine Cultures in the Emergency Department: A Randomized Controlled Trial

IntroductionA midstream clean-catch urine sample is recommended to obtain a urine culture in symptomatic adults with suspected urinary tract infection. The aim of this randomized controlled trial was to determine whether a novel funnel urine-collection system combined with a silver-colloidal cleaning wipe would decrease mixed flora contamination in midstream clean-catch urine cultures from ambulatory adults in the emergency department. MethodsIn a 2x2 factorial trial, adult participants were randomized to 4 groups: (A) sterile screw-top urine collection container/cup paired with a castile-soap wipe (control group); (B) sterile screw-top urine collection container/cup paired with a colloidal silver-impregnated wipe; (C) sterile urine-collection funnel paired with a castile-soap wipe; (D) sterile urine-collection funnel paired with a colloidal silver-impregnated wipe. ResultsThe trial was stopped after interim analysis, as the contamination rate in the control group (30%) was markedly lower than the historical ED contamination rate (40%) at the study site. From 1,112 urinalysis results, 223 urine culture results were analyzed (190 female patients and 33 male patients). Urine contamination rates were as follows: Group A, n = 67 (29.9% contaminated); Group B, n = 69 (34.8% contaminated); Group C, n = 51 (23.5% contaminated); Group D, n = 36 (22.2% contaminated). The differences in contamination rates were not statistically different among any of the groups. DiscussionThe use of a funnel urine-collection system and silver-impregnated wipe did not reduce urine-culture contamination in adult midstream clean-catch urine cultures in the emergency department.

A RANDOMIZED CONTROLLED TRIAL: SUPRAPUBIC ASPIRATION VERSUS URINARY CATHETERIZATION IN THE NEONATAL INTENSIVE CARE UNIT

Abstract BACKGROUND Urinary tract infection (UTI) is common in infants (10%). Urinary catheterization (UC) and supra-pubic aspiration (SPA) allow for sterile collection of urine. Some studies suggest SPA has a lower contamination rate than UC, however the optimal method of urine collection for culture remains unclear. OBJECTIVES To determine if there is: 1) a lower contamination rate in urine obtained by SPA assisted by bladder ultrasound versus UC in infants admitted to a neonatal intensive care unit (NICU); 2) a difference between procedures in: success rates for obtaining urine, short-term complication rates, and number of attempts required. DESIGN/METHODS A multicentre, unblinded, randomized controlled trial from 04/2013 to 05/2016. All gestational age (GA) infants greater than 72 hours of age investigated for UTI were eligible for randomization. Crossover to the other procedure could occur after 2 hours or 2 failed attempts. Target sample size was 165. Contamination was defined as growth of ≥2 microorganisms (SPA, UC) or growth <104 CFU/ml (UC). Primary analysis was by intention-to-treat. RESULTS Enrolment was stopped for futility. 906 families were approached with 151 providing consent. 50 infants were eligible for randomization with 47 randomized (SPA n=23, UC n=24). Table 1 shows participant demographics. UTI incidence was 13% for SPA, 8% for UC (p=0.67). Crossover rates were high: 56% for SPA; 21% for UC. No urine sample was obtained in 2 participants per group despite attempts. There was no statistically significant difference between the 2 groups in contamination rates (14% SPA, 18% UC, p=1.00). No short-term complications were reported in either group. Prior to crossover, there was no difference in the number of attempts (i.e. up to 2 attempts pre-crossover or to successfully obtain urine) per procedure (p=0.08); however, there was a difference in the success rates per procedure (44% SPA, 75% UC, p=0.04). CONCLUSION This trial found no difference in contamination rates between SPA and UC, while noting the low enrolment and high crossover rate. More procedural training (particularly for SPA) may ensure greater procedural confidence and success. Post-procedural consent could improve enrolment given that equipoise on the optimal urine collection method still exists.

Development of a novel isolation unit for entomophthoralean fungi.

Entomophthoralean fungi are important natural enemies of pests and highly co-evolved with their hosts. However, successful isolation of entomophthoralean fungi can be difficult due to their fastidious culture requirements; this is an important obstacle to research on Entomophthorales. In this study, we designed an isolation unit and evaluated it against the conventional 'descending conidia' isolation method. There was no difference in contamination rate between the methods (78% and 76% clean isolations) despite the isolation unit not requiring laminar-flow facilities. Furthermore, more conidia were collected in the new isolation unit than using a standard method. The isolation unit is efficient, convenient and is operational in the field.

Methicillin resistant Staphylococcus aureus contamination of phlebotomy tourniquets and faucets

Methicillin resistant Staphylococcus aureus (MRSA) is transmitted through direct contact or fomites. The most important means of nosocomial spread is by hospital personnel. However, fomites are being increasingly recognized as sources of nosocomial infection. Our aim was to describe the MRSA contamination rate of phlebotomy tourniquets and faucets in a tertiary care hospital and to compare the contamination of plastic tourniquets with that of fabric tourniquets. A cross-sectional study was carried out in the general wards of a tertiary care hospital in the Colombo District. Two hundred tourniquets were collected and 100 faucets were swabbed and cultured on CHROMagar™ MRSA medium (CHROMagar Microbiology). Contamination rates of 50 plastic tourniquets and 50 fabric tourniquets were compared. MRSA grew in 26% of tourniquets. Majority were plastic tubes. MRSA contamination of tourniquets did not significantly differ by ward (p>0.4). MRSA was found on 26% of faucets. Contamination rate was highest in the common wards for dermatology, dental, rheumatology, and neurology (55.6%), followed by gynaecology (45.2%), cardiology (33.3%), surgery (18.8%), psychiatry (11.1%), and medicine (5.6%). There was a significant difference in rates of contamination of faucets in the different wards (p<0.01). There was no significant difference in the colony count per surface area of the two types of tourniquets after a single use. MRSA contamination rates of tourniquets and faucets were high. Single-use plastic tourniquets were much less contaminated with MRSA than reused tourniquets.

A randomized trial of single versus double high-level disinfection of duodenoscopes and linear echoendoscopes using standard automated reprocessing

In a pilot study, we demonstrated that current guidelines for duodenoscope and linear echoendoscope (DLE) reprocessing using a single cycle of high-level disinfection (HLD) in an automated reprocessor may be inadequate. In August 2015, the U.S. Food and Drug Administration offered double HLD as a possible response to address this concern. As a result, Providence Health and Services adopted double HLD as standard procedure for DLEs, but no rigorous clinical studies supported this practice. We undertook a quality improvement study to compare single HLD versus double HLD at 4 of our 34 hospitals. HLD of DLE was randomized, separately in each facility, to either single HLD or double HLD on weekdays, with standard double HLD on weekends or holidays. There was 99.7% compliance with the randomization scheme. Daily qualitative surveillance cultures of dried, post-HLD DLEs were collected for 6 months (1 swab sample from the elevator mechanism and 1 combined brush sample from the suction and working channels for each encounter), and each sample was incubated for 48 hours. Positivity rates of any microbial growth and growth of high-concern pathogens (potentially pathogenic enteric flora) were compared between the 2 study arms. Altogether, 5850 surveillance culture specimens were obtained during 2925 encounters from the 45 DLEs in clinical use in the participating hospitals. Of these, 3052 (52.2%) were from endoscopes cleaned by double HLD. Double HLD demonstrated no benefit over single HLD because similar positivity rates were observed (all P > .05). The elevator mechanism was more frequently colonized than the biopsy channel (5.2% vs 2.9%, P< .001). Among the 224 encounters with positive growth, 140 (62.5%) recovered microbes from only the elevator mechanism specimens, 73 (32.6%) recovered microbes from only the channel specimens, and 11 (4.9%) recovered microbes from both types of specimens. Double HLD failed to improve contamination rates for either sample site at any of the 4 endoscopy facilities, although there were significant overall differences in contamination rates among the facilities (P< .001), as observed in our previous study. Only 8 high-concern pathogens were recovered from 5 DLEs, all from the elevator mechanism. Persistent growth was observed on 2 duodenoscopes. One grew Enterococcus spp (not vancomycin-resistant enterococci) on 3 occasions, and Escherichia coli was present on 2 of these occasions, 1 of which was a multidrug-resistant organism. The other grew different enteric flora on 2 specimens. Our prospectively randomized study, involving 4 separate endoscopy facilities and standard automated endoscope reprocessing, showed that double HLD did not reduce culture positivity rates compared with single HLD in facilities with an already low positive culture rate. Alternative risk mitigation strategies will be assessed in an ongoing effort to reduce endoscope contamination.

High-Level Disinfection of Otorhinolaryngology Clinical Instruments: An Evaluation of the Efficacy and Cost-effectiveness of Instrument Storage.

Objectives Despite increasing interest in individual instrument storage, risk of bacterial cross-contamination of otorhinolaryngology clinic instruments has not been assessed. This study is the first to determine the clinical efficacy and cost-effectiveness of standard high-level disinfection and clinic instrument storage. Methods To assess for cross-contamination, surveillance cultures of otorhinolaryngology clinic instruments subject to standard high-level disinfection and storage were obtained at the start and end of the outpatient clinical workday. Rate of microorganism recovery was compared with cultures of instruments stored in individual peel packs and control cultures of contaminated instruments. Based on historical clinic data, the direct allocation method of cost accounting was used to determine aggregate raw material cost and additional labor hours required to process and restock peel-packed instruments. Results Among 150 cultures of standard high-level disinfected and co-located clinic instruments, 3 positive bacterial cultures occurred; 100% of control cultures were positive for bacterial species ( P < .001). There was no statistical difference between surveillance cultures obtained before and after the clinic day. While there was also no significant difference in rate of contamination between peel-packed and co-located instruments, peel packing all instruments requires 6250 additional labor hours, and conservative analyses place the cost of individual semicritical instrument storage at $97,852.50 per year. Discussion With in vitro inoculation of >200 otorhinolaryngology clinic instruments, this study demonstrates that standard high-level disinfection and storage are equally efficacious to more time-consuming and expensive individual instrument storage protocols, such as peel packing, with regard to bacterial contamination. Implications for Practice Standard high-level disinfection and storage are equally effective to labor-intensive and costly individual instrument storage protocols.

Use of an anaesthesia workstation barrier device to decrease contamination in a simulated operating room

BackgroundStrategies to achieve reductions in perioperative infections have focused on hand hygiene among anaesthestists but have been of limited efficacy. We performed a study in a simulated operating room to determine whether a barrier covering the anaesthesia workstation during induction and intubation might reduce the risk of contamination of the area and possibly, by extension, the patient. MethodsForty-two attending and resident anaesthetists unaware of the study design were enrolled in individual simulation sessions in which they were asked to induce and intubate a human simulator that had been prepared with fluorescent marker in its oropharynx as a marker of potentially pathogenic bacteria. Twenty-one participants were assigned to a control group, whereas the other 21 performed the simulation with a barrier device covering the anaesthesia workstation. After the simulation, an investigator examined 14 target sites with an ultraviolet light to assess spread of the fluorescent marker of contamination to those sites. ResultsThe difference in rates of contamination between the control group and the barrier group was highly significant, with 44.8% (2.5%) of sites contaminated in the control group vs 19.4% (2.6%) of sites in the barrier group (P<0.001). Several key clinical sites showed significant differences in addition to this overall decrement. ConclusionsThe results of this study suggest that application of a barrier device to the anaesthesia workstation during induction and intubation might reduce contamination of the intraoperative environment.