Infection control practices among a cohort of Brazilian dentists

Objective: To evaluate infection control practices among dentists in private and public practice. Design: Survey and cross-sectional analysis. Setting: Sertaozinho city, Brazil. Participants: All dentists who were currently working at the study city, and agreed to participate, resulting in a study population of 135 dentists. Methods: Participants were personally interviewed and variables were submitted to X(2) or Fisher`s exact test. Results: Hand washing before and after each patient was reported by 86.7% of dentists, but private practitioners used liquid soap and paper towels more often than their public colleagues (p<0.001). Most of the study population (97.8%) used gloves routinely during clinical sessions, but 8.2% reused them. Dry-heat was the main method employed for sterilisation of heat-stable devices by 80.0% of dentists, but adequate temperature and time of exposure was accomplished by only 32.1% of public and 70.0% of private professionals (p<0.001). Heat-sensitive devices were disinfected with an adequate substance by 60.0% of both affiliation dentists (p=0.908). Conclusions: There is a large gap between infection control recommendations and practices observed among the study population, and the situation is worse in public services. To reverse that situation, infection control issues must be openly debated by professional associations, dental schools and health authorities.

Reprocessing and reuse of single-use medical devices used during hemodynamic procedures in Brazil: A widespread and largely overlooked problem

Background. Several medical devices used during hemodynamic procedures, particularly angiographic diagnostic and therapeutic cardiac catheters, are manufactured for single use only. However, reprocessing and reuse of these devices has been reported, to determine the frequency of reuse and reprocessing of single-use medical devices used during hemodynamic procedures in Brazil and to evaluate how reprocessing is performed. Design. National survey, conducted from December 1999 to July 2001. Methods. Most of the institutions affiliated with the Brazilian Society of Hemodynamic and Interventional Cardiology were surveyed by use of a questionnaire sent in the mail. Results. The questionnaire response rate was 50% (119 of 240 institutions). Of the 119 institutions that responded, 116 (97%) reported reuse of single-use devices used during hemodynamic procedures, and only 26 (22%) reported use of a standardized reprocessing protocol. Cleaning, flushing, rinsing, drying, sterilizing and packaging methods varied greatly and were mostly inadequate. Criteria for discarding reused devices varied widely. Of the 119 institutions that responded, 80 (67%) reported having a surveillance system for adverse events associated with the reuse of medical devices, although most of these institutions did not routinely review the data, and only 38 (32%) described a training program for the personnel who reprocessed single-use devices. Conclusions. The reuse of single-use devices used during hemodynamic procedures was very frequent in hospitals in Brazil. Basic guidance on how to reuse and reprocess single-use medical devices is urgently needed, because, despite the lack of studies to support reusing and reprocessing single-use medical devices, such devices are necessary in limited-resource areas in which these practices are current.

Vancomycin use in a brazilian teaching hospital: comparison with the Hospital Infection Controlpractices Advisory Committee Guidelines (HICPAC)

This study describes vancomycin prescribing patterns in an average complexity hospital and compare the guidelines proposed by the Hospital Infection Control Practices Advisory Committee (HICPAC). The study was conducted in a 256-bed secondary-care hospital. Data were collected of all patients given vancomycin from March 2003 to February 2004, using a standardized chart-extraction form designed. Appropriate and inappropriate use was reviewed according to the Hospital Infection Control Practices Advisory Committee (HICPAC) guidelines on prudent vancomycin use. Out of 118 prescriptions, 95 (80.5%) were considered appropriate. Out of these 95 orders, 77 (81.1%) were administered for empiric treatment of suspected Gram-positive infections, 17 (17.9%) were administered for treatment of proven Gram-positive infections (76.5% identified as Staphyloccocus aureus-like agents) and 1 (1.0%) for beta-lactam allergy. The majority of the patients (96.6%) had recently used an antimicrobial medication (3 months). The mean pre-treatment hospitalization period was 11±10 days. Out of the 118 treatments, 67 (56.8%) were for nosocomial infections. The more frequent indications for vancomycin use were pneumonia (48.3%) and primary sepsis (18.6%), accounting for more than 66% of all treatments. No restriction policy was suggested because vancomycin use was considered adequate in the majority of the treatment cases. The broad empiric use of this antimicrobial was greater than expected in the institution and its use should be revised.

Evaluation of biologic occupational risk control practices: Quality indicators development and validation

Background: There is growing demand for the adoption of qualification systems for health care practices. This study is aimed at describing the development and validation of indicators for evaluation of biologic occupational risk control programs. Methods: The study involved 3 stages: (1) setting up a research team, (2) development of indicators, and (3) validation of the indicators by a team of specialists recruited to validate each attribute of the developed indicators. The content validation method was used for the validation, and a psychometric scale was developed for the specialists` assessment. A consensus technique was used, and every attribute that obtained a Content Validity Index of at least 0.75 was approved. Results: Eight indicators were developed for the evaluation of the biologic occupational risk prevention program, with emphasis on accidents caused by sharp instruments and occupational tuberculosis prevention. The indicators included evaluation of the structure, process, and results at the prevention and biologic risk control levels. The majority of indicators achieved a favorable consensus regarding all validated attributes. Conclusion: The developed indicators were considered validated, and the method used for construction and validation proved to be effective.

Development of Control Systems for Safety Instrumented Systems

Safety Instrumented Systems (SIS) are designed to prevent and / or mitigate accidents, avoiding undesirable high potential risk scenarios, assuring protection of people`s health, protecting the environment and saving costs of industrial equipment. The design of these systems require formal methods for ensuring the safety requirements, but according material published in this area, has not identified a consolidated procedure to match the task. This sense, this article introduces a formal method for diagnosis and treatment of critical faults based on Bayesian network (BN) and Petri net (PN). This approach considers diagnosis and treatment for each safety instrumented function (SIF) including hazard and operability (HAZOP) study in the equipment or system under control. It also uses BN and Behavioral Petri net (BPN) for diagnoses and decision-making and the PN for the synthesis, modeling and control to be implemented by Safety Programmable Logic Controller (PLC). An application example considering the diagnosis and treatment of critical faults is presented and illustrates the methodology proposed.

Electro-optically sensitive diamond-like carbon thin films deposited by reactive magnetron sputtering for electronic device applications

The goal of this work is to study and relate electrical and optical properties of diamond-like carbon (DLC) thin films for applications in electronic devices. DLC films were deposited in a reactive RF magnetron sputtering system on p-type silicon and glass substrates. The target was a 99.9999% pure, 6 in. diameter graphite plate and methane was used as processing gas. Eight DLC films were produced for each substrate, varying deposition time, the reactor pressure between 5 mTorr and 10 mTorr while the RF power was applied at 13.56 MHz and varied between 100, 150, 200 and 250W. After deposition, the films were analyzed by I-V and C-V measurements (Cheng et al. (2004) [1]) in order to determine the electric resistivity, photo-current response and dielectric constant, optical transmittance, used to find the optical gap by the Tauc method; and by photoluminescence analysis to determine the photoemission and confirm the optical band gap. These characteristics are compared and the influence of the deposition parameters is discussed. (C) 2011 Published by Elsevier B.V.

Flatness-based control of a single qubit gate

This work considers the open-loop control problem of steering a two-level quantum system from any initial to any final condition. The model of this system evolves on the state space X = SU(2), having two inputs that correspond to the complex amplitude of a resonant laser field. A symmetry preserving flat output is constructed using a fully geometric construction and quaternion computations. Simulation results of this flatness-based open-loop control are provided.

Controlling the clonal spread of Pseudomonas aeruginosa infection

To evaluate nosocomial infections due to imipenem-resistant and imipenem-susceptible Pseudomonas aeruginosa, a case-control study that included genotyping was performed. Hospitalization for more than 15 days was independently associated with infection with an imipenem-resistant organism. Sixty-seven percent of the imipenem-resistant isolates analyzed and 23% of the imipenem-susceptible isolates analyzed belonged to a single clone. Intervention led to a decrease in the number of infections due to imipenem-resistant and imipenem-susceptible P. aeruginosa.

Evaluation of interventions to reduce catheter-associated bloodstream infection: Continuous tailored education versus one basic lecture

Background: This study evaluated the impact of 2 models of educational intervention on rates of central venous catheter-associated bloodstream infections (CVC-BSIs). Methods: This was a prospective observational study conducted between January 2005 and June 2007 in 2 medical intensive care units (designated ICU A and ICU B) in a large teaching hospital. The study was divided into in 3 periods: baseline (only rates were evaluated), preintervention (questionnaire to evaluate knowledge of health care workers [HCWs] and observation of CVC care in both ICUs), and intervention (in ICU A, tailored, continuous intervention; in ICU B, a single lecture). The preintervention and intervention periods for each ICU were compared. Results: During the preintervention period, 940 CVC-days were evaluated in ICUA and 843 CVC-days were evaluated in ICU B. During the intervention period, 2175 CVC-days were evaluated in ICUA and 1694 CVC-days were evaluated in ICU B. Questions regarding CVC insertion, disinfection during catheter manipulation, and use of an alcohol-based product during dressing application were answered correctly by 70%-100% HCWs. Nevertheless, HCWs` adherence to these practices in the preintervention period was low for CVC handling and dressing, hand hygiene (6%-35%), and catheter hub disinfection (45%-68%). During the intervention period, HCWs` adherence to hand hygiene was 48%-98%, and adherence to hub disinfection was 82%-97%. CVC-BSI rates declined in both units. In ICUA, this decrease was progressive and sustained, from 12CVC-BSIs/1000 CVC-days at baseline to 0 after 9 months. In ICU B, the rate initially dropped from 16.2 to 0 CVC-BSIs/1000 CVC-days, but then increased to 13.7 CVC-BSIs/1000 CVC-days. Conclusion: Personal customized, continuous intervention seems to develop a ""culture of prevention"" and is more effective than single intervention, leading to a sustained reduction of infection rates.

Description of Nosocomial Infection Prevention Practices by Anesthesiologists in a University Hospital

Kishi D; Videira RLR Description of Nosocomial Infection Prevention Practices by Anesthesiologists in a University Hospital. Background and objectives: Anesthesiologists play an important role in the prevention of nosocomial infections. In anesthetic practice, physiologic barriers are routinely breached, allowing patient contamination with microorganisms and the consequent development of infection. The lack of adhesion to recommended practices can facilitate transmission of microorganisms. It is important to describe prophylactic practices of anesthesia-related nosocomial infections performed by anesthesiologists. Methods: Structured questionnaires were distributed to be answered voluntarily and anonymously by anesthesiologists. Results: Among 112 anesthesiologists, 75% answered the questionnaire. Surgical mask is used by 95.2% of anesthesiologists, 96.3% wear gloves frequently, 98.9% wear sterile gloves for neuraxial block, 91.3% use sterile technique for central venous puncture, 95.1% wash their hands between cases, 91.6% try to maintain the endotracheal tube sterile, 96.3% discard the prefilled propofol syringe at the end of each anesthesia, 30% clean the vials before using it in the neuraxial blocks, and 19.8% clean the vials before intravenous use. Conclusions: Respondents showed good adhesion to practices of nosocomial infection prophylaxis and to improve them educational multidisciplinary campaigns are necessary.

Molecular Characterization of Strains of Respiratory Syncytial Virus Identified in a Hematopoietic Stem Cell Transplant Outpatient Unit Over 2 Years: Community or Nosocomial Infection?

Respiratory syncytial virus (RSV) is recognized as the leading cause of nosocomial respiratory infection among hematopoietic stem cell transplant (HSCT) recipients, causing considerable morbidity and mortality. RSV is easily transmitted by contact with contaminated surfaces, and in HSCT units, more than 50% of RSV infections have been characterized as of nosocomial origin. From April 2001 to October 2002, RSV was identified by direct immunofluorescent assay in 42 symptomatic HSCT recipients. Seven RSV strains from 2001 and 12 RSV strains from 2002 were sequenced. RNA extraction, cDNA synthesis, and seminested polymerase chain reaction (PCR) with primers complementary to RSV genes G and F were pet-formed. PCR products were analyzed by nucleotide sequencing of the C-terminal region of gene G for typing (in group A or B). Of the 7 strains analyzed in 2001, only 2 belonged to group B; the other 5 belonged to group A. Of these 7 strains, 3 were identical and were from recipients receiving outpatient care. In 2002, of the 12 strains analyzed, 3 belonged to group A and the other 9 belonged to group B. Of these 9 strains, 7 were genetically identical and were also from recipients receiving outpatient care. Therefore, multiple strains of RSV cocirculated in the hematopoietic stem cell transplant units (ward and outpatient units) between 2001 and 2002. Nosocomial transmission was more likely to occur at the HSCT outpatient unit than in the HSCT ward. Infection control practices should also be implemented in the outpatient setting.

CpG-ODN combined with Neospora caninum lysate, but not with excreted-secreted antigen, enhances protection against infection in mice

CpG oligodeoxynucleotides (ODN) have shown to be potent immunoadjuvants for several pathogens, but there is limited information concerning their use in immunization protocols against neosporosis. This study aimed to evaluate the potential of CpG-ODN combined with Neosporar lysate antigen (NLA) or excreted-secreted antigen (NcESA) to induce protective immune response against Neospora caninum infection in mice. C57BL/6 mice were vaccinated subcutaneously three times at 2-week intervals with NLA, NLA+CpG, NcESA, NcESA+CpG, CpG (adjuvant control) or PBS (infection control). Serological assays showed an increased specific IgG2a response in animals immunized with either antigen plus adjuvant and elevated levels of the IgG1 isotype in those vaccinated with antigens alone. Splenocyte proliferative responses upon antigen stimulation were higher in groups immunized with NLA OF NcESA combined with CpG, showing increased IL-12 levels. Also, mice vaccinated with NcESA or NcESA+CpG demonstrated higher IFN-gamma levels and IFN-gamma/IL-10 ratio. After lethal challenge, mice immunized with NLA+CpG or NLA had lower Morbidity score and body weight changes in comparison to other groups, and animals did not succumb during acute infection. In contrast, NcESA+CpG or NcESA groups exhibited the highest morbidity scores, body weight impairment and mortality rates, associated with greatest brain parasite burden and inflammation. In conclusion, CpG-ODN was able to induce a Th1-type humoral immune response with predominant IgG2a levels for either NLA or NcESA, but resulting in an effective Th1-driven cellular immune response and total Protection only when combined with NLA. Vaccination with NcESA alone or combined with CpG resulted in a strong cellular immune response associated with high levels of IFN-gamma and inflammation, rendering mice more susceptible to parasite challenge. (C) 2009 Elsevier Ltd. All rights reserved.

Probing the functionalization of gold surfaces and protein adsorption by PM-IRRAS

The control of morphology and coating of metal surfaces is essential for a number of organic electronic devices including photovoltaic cells and sensors. In this study, we monitor the functionalization of gold surfaces with 11-mercaptoundecanoic acid (MUA, HS(CH(2))(10)CO(2)H) and cysteamine, aiming at passivating the surfaces for application in surface plasmon resonance (SPR) biosensors. Using polarization-modulated infrared reflection-absorption spectroscopy (PM-IRRAS), cyclic voltammetry, atomic force microscopy and quartz crystal microbalance, we observed a time-dependent organization process of the adsorbed MUA monolayer with alkyl chains perpendicular to the gold surface. Such optimized condition for surface passivation was obtained with a systematic search for experimental parameters leading to the lowest electrochemical signal of the functionalized gold electrode. The ability to build supramolecular architectures was also confirmed by detecting with PM-IRRAS the adsorption of streptavidin on the MUA-functionalized gold. As the approaches used for surface functionalization and its verification with PM-IRRAS are generic, one may now envisage monitoring the fabrication of tailored electrodes for a variety of applications.

Antimicrobial efficacy of chemical disinfectants on contaminated full metal crowns

Prosthetic restorations that have been tried in the patient's mouth are potential sources of infection. In order to avoid cross-infection, protocols for infection control should be established in dental office and laboratory. This study evaluated the antimicrobial efficacy of disinfectants on full metal crowns contaminated with microorganisms. Full crowns cast in a Ni-Cr alloy were assigned to one control group (n=6) and 5 experimental groups (n=18). The crowns were placed in flat-bottom glass balloons and were autoclaved. A microbial suspension of each type of strain - S. aureus, P. aeruginosa, S. mutans, E. faecalis and C. albicans- was aseptically added to each experimental group, the crowns being allowed for contamination during 30 min. The contaminated specimens were placed into recipients with the chemical disinfectants (1% and 2% sodium hypochlorite and 2% glutaraldehyde) for 5, 10 and 15 min. Thereafter, the crowns were placed into tubes containing different broths and incubated at 35ºC. The control specimens were contaminated, immersed in distilled water for 20 min and cultured in Thioglycollate broth at 35ºC. Microbial growth assay was performed by qualitative visual examination after 48 h, 7 and 12 days. Microbial growth was noticed only in the control group. In the experimental groups, turbidity of the broths was not observed, regardless of the strains and immersion intervals, thus indicating absence of microbial growth. In conclusion, all chemical disinfectants were effective in preventing microbial growth onto full metal crowns.

Microwave dielectric permittivity and photoluminescence of Eu(2)O(3) doped laser heated pedestal growth Ta(2)O(5) fibers

We report the microwave dielectric properties and photoluminescence of undoped and europium oxide doped Ta(2)O(5) fibers, grown by laser heated pedestal growth technique. The effects of Eu(2)O(3) doping (1-3 mol %) on the structural, optical, and dielectric properties were investigated. At a frequency of 5 GHz, the undoped material exhibits a dielectric permittivity of 21 and for Eu(2)O(3) doped Ta(2)O(5) samples it increases, reaching up to 36 for the highest doping concentration. Nevertheless, the dielectric losses maintain a very low value. For this wide band gap oxide, Eu(3+) optical activation was achieved and the emission is observed up to room temperature. Thus, the transparency and high permittivity make this material promising for electronic devices and microwave applications. (c) 2008 American Institute of Physics.