Risk factors for transmission of carbapenem-resistant Enterobacterales to healthcare personnel gloves and gowns in the USA.

BACKGROUND: Hospitals are sources for acquisition of carbapenem-resistant Entero-bacterales (CRE), and it is believed that the contamination of healthcare personnel (HCP) hands and clothing play a major role in patient-to-patient transmission of antibiotic-resistant bacteria. AIM: The aim of this study was to determine which HCP types, HCP-patient interactions, and patient characteristics are associated with greater transmission of CRE to HCP gloves and gowns in the hospital. METHODS: This was a prospective observational cohort study that enrolled patients with recent surveillance or clinical cultures positive for CRE at five hospitals in four states in the USA. HCP gloves and gown were cultured after patient care. Samples were also obtained from patients' stool, perianal area, and skin of the chest and arm to assess bacterial burden. FINDINGS: Among 313 CRE-colonized patients and 3070 glove and gown cultures obtained after patient care, HCP gloves and gowns were found to be contaminated with CRE 7.9% and 4.3% of the time, respectively. Contamination of either gloves or gowns occurred in 10.0% of interactions. Contamination was highest (15.3%) among respiratory therapists (odds ratio: 3.79; 95% confidence interval: 1.61-8.94) and when any HCP touched the patient (1.52; 1.10-2.12). Associations were also found between CRE transmission to HCP gloves or gown and: being in the intensive care unit, having a positive clinical culture, and increasing bacterial burden on the patient. CONCLUSION: CRE transmission to HCP gloves and gown occurred frequently. These findings may inform evidence-based policies about what situations and for which patients contact precautions are most important.

Admission Laboratory Values Accurately Predict In-hospital Mortality: a Retrospective Cohort Study.

BACKGROUND: The greater the severity of illness of a patient, the more likely the patient will have a poor hospital outcome. However, hospital-wide severity of illness scores that are simple, widely available, and not diagnosis-specific are still needed. Laboratory tests could potentially be used as an alternative to estimate severity of illness. OBJECTIVE: To evaluate the ability of hospital laboratory tests, as measures of severity of illness, to predict in-hospital mortality among hospitalized patients, and therefore, their potential as an alternative method to severity of illness risk adjustment. DESIGNS AND PATIENTS: A retrospective cohort study among 38,367 adult non-trauma patients admitted to the University of Maryland Medical Center between November 2015 and November 2017 was performed. Laboratory tests (hemoglobin, platelet count, white blood cell count, urea nitrogen, creatinine, glucose, sodium, potassium, and total bicarbonate (HCO3)) were included when ordered within 24 h from the time of hospital admission. A multivariable logistic regression model to predict in-hospital mortality was constructed using a section of our cohort (n = 21,003). MAIN MEASURES: Model performance was evaluated using the c-statistic and the Hosmer-Lemeshow (HL) test. In addition, a calibration belt was constructed to determine a confidence interval around the calibration curve with the purpose of identifying ranges of miscalibration. KEY RESULTS: Patient age and all laboratory tests predicted mortality with good discrimination (c = 0.79). Patients with abnormal HCO3 levels or leukocyte counts at admission were twice as likely to die during their hospital stay as patients with normal results. A good model calibration and fit were observed (HL = 13.9, p = 0.18). CONCLUSIONS: Admission laboratory tests are able to predict in-hospital mortality with good accuracy, providing an objective and widely accessible approach to severity of illness risk adjustment.

Deconstructing the relative benefits of a universal glove and gown intervention on MRSA acquisition.

BACKGROUND: The 20-site Benefits of Universal Glove and Gown (BUGG) study found that wearing gloves and gowns for all patient contacts in the intensive care unit (ICU) reduced acquisition rates of meticillin-resistant Staphylococcus aureus (MRSA). The relative importance of gloves and gowns as a barrier, improved hand hygiene, and reduced healthcare worker (HCW)-patient contact rates is unknown. AIM: To determine what proportion of the reduction in acquisition rates observed in the BUGG study was due to improved hand hygiene, reduced contact rates, and universal glove and gown use using agent-based simulation modelling. METHODS: An existing agent-based model to simulate MRSA transmission dynamics in an ICU was modified, and the model was calibrated using site-specific data. Model validation was completed using data collected in the BUGG study. A full 2k factorial design was conducted to quantify the relative benefits of improving each of the aforementioned factors with respect to MRSA acquisition rates. FINDINGS: Across 40 simulated replications for each factorial design point and intervention site, approximately 44% of the decrease in MRSA acquisition rates was due to universal glove and gown use, 38.1% of the decrease was due to improvement in hand hygiene compliance on exiting patient rooms, and 14.5% of the decrease was due to the reduction in HCW-patient contact rates. CONCLUSION: Using mathematical modelling, the decrease in MRSA acquisition in the BUGG study was found to be due primarily to the barrier effects of gowns and gloves, followed by improved hand hygiene and lower HCW-patient contact rates.

GABA and Glutamate in Children with Primary Complex Motor Stereotypies: An 1H-MRS Study at 7T.

BACKGROUND AND PURPOSE: Complex motor stereotypies are rhythmic, repetitive, fixed, purposeful but purposeless movements that stop with distraction. They can occur in otherwise normal healthy children (primary stereotypies) as well in those with autism spectrum disorders (secondary stereotypies). The underlying neurobiologic basis for these movements is unknown but is thought to involve cortical-striatal-thalamo-cortical pathways. To further clarify potential neurochemical alterations, gamma-aminobutyric acid (GABA), glutamate, glutamine, N-acetylaspartate, and choline levels were measured in 4 frontostriatal regions by using (1)H MRS at 7T. MATERIALS AND METHODS: A total of 18 children with primary complex motor stereotypies and 24 typically developing controls, ages 5-10 years, completed MR spectroscopy at 7T. Single voxel STEAM acquisitions from the anterior cingulate cortex, premotor cortex, dorsolateral prefrontal cortex, and striatum were obtained, and metabolites were quantified with respect to Cr by using LCModel. RESULTS: The 7T scan was well tolerated by all the participants. Compared with the controls, children with complex motor stereotypies had lower levels of GABA in the anterior cingulate cortex (GABA/Cr, P = .049; GABA/Glu, P = .051) and striatum (GABA/Cr, P = .028; GABA/Glu, P = .0037) but not the dorsolateral prefrontal cortex or the premotor cortex. Glutamate, glutamine, NAA, and Cho levels did not differ between groups in any of the aforementioned regions. Within the complex motor stereotypies group, reduced GABA to Cr in the anterior cingulate cortex was significantly associated with greater severity of motor stereotypies (r = -0.59, P = .021). CONCLUSIONS: These results indicate possible GABAergic dysfunction within corticostriatal pathways in children with primary complex motor stereotypies.

Correlation between baseline blood pressure and the brainstem FMRI response to isometric forearm contraction in human volunteers: a pilot study.

It has been shown previously that changes in brainstem neural activity correlate with changes in both mean arterial pressure (MAP) and muscle sympathetic nerve activity (MSNA) during static handgrip (SHG). However, the relationship between baseline MAP and brainstem neural activity is unclear. We investigated changes in blood oxygen level-dependent (BOLD) signal induced by SHG in 12 young adults using BOLD functional magnetic resonance imaging (FMRI). An estimation of the blood pressure response to SHG was obtained in seven subjects during a session outside the MRI scanner and was used to model the blood pressure response to SHG inside the scanner. SHG at 40% of maximum grip increased MAP (mean ± s.d.) at the end of the 180-s squeeze from 85 ± 6 mm Hg to 108 ± 15 mm Hg, P = 0.0001. The brainstem BOLD signal change associated with SHG was localised to the ventrolateral medulla. This regional BOLD signal change negatively correlated with baseline MAP, r = -0.61, P = 0.01. This relationship between baseline MAP and brainstem FMRI responses to forearm contraction is suggestive of a possible role for brainstem activity in the control of MAP and may provide mechanistic insights into neurogenic hypertension.

Methods and recommendations for evaluating and reporting a new diagnostic test.

No standardized guidelines exist for the biostatistical methods appropriate for studies evaluating diagnostic tests. Publication recommendations such as the STARD statement provide guidance for the analysis of data, but biostatistical advice is minimal and application is inconsistent. This article aims to provide a self-contained, accessible resource on the biostatistical aspects of study design and reporting for investigators. For all dichotomous diagnostic tests, estimates of sensitivity and specificity should be reported with confidence intervals. Power calculations are strongly recommended to ensure that investigators achieve desired levels of precision. In the absence of a gold standard reference test, the composite reference standard method is recommended for improving estimates of the sensitivity and specificity of the test under evaluation.

Do contact precautions cause depression? A two-year study at a tertiary care medical centre.

Contact precautions, used to reduce the transmission of infectious diseases, include the wearing of gowns and gloves for room entry. Previous small studies have shown an association between contact precautions and increased symptoms of depression and anxiety. A retrospective cohort of all patients admitted to a tertiary care centre over two years was studied to assess the relationship between contact precautions and depression or anxiety. During the two-year period, there were 70,275 admissions including 28,564 unique non-intensive-care-unit (ICU), non-psychiatric admissions. After adjusting for potential confounders, contact precautions were associated with depression [odds ratio (OR) 1.4, 95% confidence interval (CI) 1.2-1.5] but not with anxiety (OR 0.8, 95% CI 0.7-1.1) in the non-ICU population. Depression was 40% more prevalent among general inpatients on contact precautions.

Comparison of culture media for detection of Acinetobacter baumannii in surveillance cultures of critically-ill patients.

The objective of this study was to evaluate the performance of CHROMagar Acinetobacter when compared to sheep blood agar, MacConkey agar and MacConkey agar with 6 µg/ml of imipenem for the detection of A. baumannii in surveillance cultures of hospitalized patients. We utilized peri-anal swabs and sputum samples from patients admitted to the University of Maryland Medical Center ICUs from December 7 through December 21, 2009. Samples were plated onto four media in the following order: (1) 5% sheep blood agar (SBA), (2) MacConkey agar, (3) MacConkey agar with 6 µg/ml of imipenem, and (4) CHROMagar Acinetobacter (CHROMagar). SBA was the gold standard to which all media was compared. There were 165 samples collected during the study period. SBA and CHROMagar detected 18 of 18 (100%) Acinetobacter and 11 of 11 (100%) MDR-A. baumannii. MacConkey agar detected 16 of 18 (89%) Acinetobacter and 10 of 11 (91%) MDR- A. baumannii while MacConkey agar with 6 µg/ml imipenem detected 9 of 11 (82%) MDR-A. baumannii. CHROMagar did not differentiate MDR- A. baumannii from non-MDR-A. baumannii. CHROMagar may be useful for rapid detection of patients with MDR-A. baumannii if improved upon to better select for MDR-A. baumannii.

Systems ambiguity and guideline compliance: a qualitative study of how intensive care units follow evidence-based guidelines to reduce healthcare-associated infections.

BACKGROUND: Consistent compliance with evidence-based guidelines is challenging yet critical to patient safety. We conducted a qualitative study to explore the underlying causes for non-compliance with evidence-based guidelines aimed at preventing four types of healthcare-associated infections in the surgical intensive care unit (SICU) setting. METHODS: Twenty semistructured interviews were conducted with attending physicians (3), residents (2), nurses (6), quality improvement coordinators (3), infection control practitioners (2), respiratory therapists (2) and pharmacists (2) in two SICUs. Using a grounded theory approach, we performed thematic analyses of the interviews. RESULTS: The concept of systems ambiguity to explain non-compliance with evidence-based guidelines emerged from the data. Ambiguities hindering consistent compliance were related to tasks, responsibilities, methods, expectations and exceptions. Strategies reported to reduce ambiguity included clarification of expectations from care providers with respect to guideline compliance through education, use of visual cues to indicate the status of patients with respect to a particular guideline, development of tools that provide an overview of information critical for guideline compliance, use of standardised orders, clarification of roles of care providers and use of decision-support tools. CONCLUSIONS: The concept of systems ambiguity is useful to understand causes of non-compliance with evidence-based guidelines aimed at reducing healthcare-associated infections. Multi-faceted interventions are needed to reduce different ambiguity types, hence to improve guideline compliance.

Patient-to-patient transmission is important in extended-spectrum beta-lactamase-producing Klebsiella pneumoniae acquisition.

We performed a prospective cohort study to quantify the number of cases of patient-to-patient transmission of extended-spectrum beta-lactamase-producing Klebsiella species on perianal surveillance culture. Among 27 patients who acquired Klebsiella pneumoniae infection, 14 had infections (52%) that were due to patient-to-patient transmission, and 6 (22%) had a subsequent positive extended-spectrum beta-lactamase clinical culture results.

Animal growth promoters: to ban or not to ban? A risk assessment approach.

The use of antibiotics for animal growth promotion has been controversial because of the potential transfer of antibiotic resistance from animals to humans. Such transfer could have severe public health implications in that treatment failures could result. We have followed a risk assessment approach to evaluate policy options for the streptogramin-class of antibiotics: virginiamycin, an animal growth promoter, and quinupristin/dalfopristin, a antibiotic used in humans. Under the assumption that resistance transfer is possible, models project a wide range of outcomes depending mainly on the basic reproductive number (R(0)) that determines the potential for person-to-person transmission. Counter-intuitively, the benefits of a ban on virginiamycin were highest for intermediate values of R(0), and lower for extremely high or low values of R(0).

Risk factors for postoperative mediastinitis due to methicillin-resistant Staphylococcus aureus.

Risk factors for developing postoperative mediastinitis (POM) due to methicillin-resistant Staphylococcus aureus (MRSA) were analyzed in a case-case control study of patients who underwent median sternotomy during the period from 1994 through 2000. Three patient groups were studied. The first consisted of 64 patients with POM due to MRSA; the second consisted of 79 patients with POM due to methicillin-susceptible S. aureus (MSSA); and the third consisted of 80 uninfected control patients. In multivariable analysis, patients who were diabetic (adjusted OR, 2.86; 95% CI, 1.22-6.70), female (OR, 2.70; 95% CI, 1.25-5.88), and >70 years old (OR, 3.43; 95% CI, 1.53-7.71) were more likely to develop POM due to MRSA. In contrast, the only independent risk factor associated with POM due to MSSA was obesity (OR, 2.49; 95% CI, 1.25-4.96). Antimicrobial prophylaxis consisted primarily of cephalosporin antibiotics (administered to 97% of the patients). Changes in perioperative antimicrobial prophylaxis, in addition to other interventions, should be considered for prevention of POM due to MRSA in targeted, high-risk populations.

Assessing risks for a pre-emergent pathogen: virginiamycin use and the emergence of streptogramin resistance in Enterococcus faecium.

Vancomycin-resistant enterococci (VRE) are an important cause of hospital-acquired infections and an emerging infectious disease. VRE infections were resistant to standard antibiotics until quinupristin/dalfopristin (QD), a streptogramin antibiotic, was approved in 1999 for the treatment of vancomycin-resistant Enterococcus faecium infections in people. After that decision, the practice of using virginiamycin in agriculture for animal growth promotion came under intense scrutiny. Virginiamycin, another streptogramin, threatens the efficacy of QD in medicine because streptogramin resistance in enterococci associated with food animals may be transferred to E faecium in hospitalised patients. Policy makers face an unavoidable conundrum when assessing risks for pre-emergent pathogens; good policies that prevent or delay adverse outcomes may leave little evidence that they had an effect. To provide a sound basis for policy, we have reviewed the epidemiology of E faecium and streptogramin resistance and present qualitative results from mathematical models. These models are based on simple assumptions consistent with evidence, and they establish reasonable expectations about the population-genetic and population-dynamic processes underlying the emergence of streptogramin-resistant E faecium (SREF). Using the model, we have identified critical aspects of SREF emergence. We conclude that the emergence of SREF is likely to be the result of an interaction between QD use in medicine and the long-term use of virginiamycin for animal growth promotion. Virginiamycin use has created a credible threat to the efficacy of QD by increasing the mobility and frequency of high-level resistance genes. The potential effects are greatest for intermediate rates of human-to-human transmission (R0 approximately equal 1).

National and regional assessment of the antibacterial soap market: a step toward determining the impact of prevalent antibacterial soaps.

BACKGROUND: Consumer antibacterial soaps contain triclosan or triclocarban. No scientific data have been published to suggest that the use of antibacterial agents in household products prevents infection, and triclosan resistance mechanisms have recently been identified. Little data are available regarding the prevalence of antibacterial agents contained in consumer soaps. METHODS: In a physician-performed survey of 23 stores in 10 states from December 1999 to April 2000, investigators determined the number of national brand liquid and bar soaps and percent of each containing antibacterial agents sold at national chain, regional grocery, and Internet stores. RESULTS: Antibacterial agents were present in 76% of liquid soaps and 29% of bar soaps available nationally. There were no differences found between national, regional, and Internet stores. CONCLUSION: Overall, 45% of surveyed soaps contain antibacterial agents. With limited documented benefits and experimental laboratory evidence suggesting possible adverse effects on the emergence of antimicrobial resistance, consumer antibacterial use of this magnitude should be questioned.

Parallel analysis of individual and aggregated data on antibiotic exposure and resistance in gram-negative bacilli.

To evaluate the potential bias of analyzing aggregated data, we separately examined antibiotic exposure and resistance data for 35,423 patients admitted to a university hospital in Utah, from both an individual-patient perspective and group-level perspective. From 1994 through 1998, use of defined daily doses (per 1000 patient-days) of fluoroquinolones, third-generation cephalosporins, ampicillin-sulbactam, and imipenem increased by 82%, 38%, and 99%, and decreased by 38%, respectively, whereas group-level resistance rates of Enterobacteriaceae or Pseudomonas species changed only minimally. However, in individual-patient-level analyses performed by multivariable proportional hazards regression, exposure to a fluoroquinolone, third-generation cephalosporin, ampicillin-sulbactam, or imipenem was a strong risk factor for resistance to fluoroquinolones (adjusted hazard ratio [AHR], 4.0; P<.001), third-generation cephalosporins (AHR, 3.5; P<.001), ampicillin-sulbactam (AHR, 2.3; P=.008), or imipenem (AHR, 5.7; P<.001), respectively. Thus, group-level and individual-patient-level analyses of antibiotic-use-versus-susceptibility relations yielded divergent results. Multicenter studies should include individual-patient-level data to elucidate more fully the relation between antibiotic exposure and resistance.

Methodological principles of case-control studies that analyzed risk factors for antibiotic resistance: a systematic review.

Case-control studies that analyze the risk factors for antibiotic-resistant organisms have varied epidemiological methodologies, which may lead to biased estimates of antibiotic risk factors. A systematic review of case-control studies that analyzed risk factors for antibiotic-resistant organisms addressed 3 methodological principles: method of control group selection, adjustment for time at risk, and adjustment for comorbid illness. A total of 406 abstracts were reviewed. Thirty-seven studies met the inclusion and exclusion criteria and were reviewed and evaluated for the 3 methodological principles. Thirteen (35%) of 37 studies chose the preferred control group. Eleven adjusted for time at risk. Twenty-seven adjusted for comorbid illness. Future studies need to consider more closely the optimization of control group selection, adjusting for confounding caused by time at risk, and adjusting for confounding caused by comorbid illness.

Benefits of negative penicillin skin test results persist during subsequent hospital admissions.

For an initial series of 38 patients with negative skin test results, we reviewed retrospectively all subsequent admissions over a 2-year period. For 38 patients with negative initial skin test results, there were 48 subsequent readmissions to our institution, of which 35 required antibiotics. beta-lactams were prescribed for 86% of admissions; a penicillin for 37%, and a cephalosporin for 51%. All infections were cured, and there were no allergic drug reactions during any of the admissions that were reviewed.

A survey on handwashing practices and opinions of healthcare workers.

Studies have consistently demonstrated rates of handwashing compliance are less than 50%. The objective of this study was to gain the following information about handwashing: self-reported compliance; attitudes towards handwashing in different patient settings; and attitudes towards interventions aimed at increasing compliance. A 74-question survey was administered to healthcare workers in two tertiary care hospitals. One hundred and ninety nine healthcare workers completed the survey and 89% reported that handwashing is an important means of preventing infection. Sixty-four percent believed that they washed their hands as often as their peers and 2% believed that they washed less often than their peers. Patients with diarrhoea, AIDS or patients on antibiotics led to increased handwashing. Relative to potential interventions, 76% reported that rewards for handwashing would have no effect, 73% reported that punishment would have no effect and 80% reported that easy access to sinks and availability of washing facilities would lead to increased compliance. This survey suggests that healthcare workers understand the importance of handwashing, but tend to overestimate their own compliance. Healthcare workers are not in favour of interventions involving rewards and punishments, but are more attracted to interventions that make handwashing easier.