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Biomedical subjects

H Rüden

Publications and source records attributed to H Rüden.

At least 55 records · Page 3Linked to original sources

Comparison of PCR-based methods for typing Escherichia coli.

OBJECTIVE: To establish a library typing system appropriate for studying cross-transmission of Escherichia coli. METHODS: Eighteen epidemiologically unrelated isolates were genotyped by means of pulsed-field gel electrophoresis (PFGE), random amplified polymorphic DNA (RAPD), repetitive (rep) PCR, and fluorescent amplified fragment length polymorphism (AFLP). Fingerprints were analyzed either by Pearson correlation or, in the case of AFLP, by Dice coefficients employing the novel 'uncertain band' software tool from GelCompar II. During a nine-month period, 112 isolates taken from 93 patients hospitalized in five intensive care units were analyzed by use of the two most discriminative PCR typing methods. RESULTS: Genotyping by RAPD and rep-PCR revealed insufficient discrimination. Among 18 epidemiologically unrelated strains with 17 different PFGE patterns, IS3 rep-PCR and AFLP distinguished 10 and 18 types, respectively. Comparison of the different methods for analysis of AFLP fingerprints showed that the Dice coefficients, which ignore 'uncertain bands', offered the best concordance with visual interpretation. Consecutive isolates originating from the same patient differed in less than three fragments. CONCLUSIONS: AFLP analysis showed the highest discriminative capacity for PCR typing of E. coli isolates. Analysis of fingerprints employing the Dice coefficients proved the most efficient method for an automated software-based retrieval of visually indistinguishable genotypes in an AFLP fingerprint database.

Bacterial Typing Techniques↗

Do conventional cleaning and disinfection techniques avoid the risk of endoscopic Helicobacter pylori transmission?

BACKGROUND AND STUDY AIMS: The aim of the present study was to determine whether endoscopes serve as a reservoir for Helicobacter pylori and whether the disinfection technique currently recommended for manual cleaning and disinfection of the instruments completely removes the risk of H. pylori transmission. PATIENTS AND METHODS: A prospective study was carried out in 400 patients who were undergoing upper gastrointestinal endoscopy for routine clinical indications. The patients' H. pylori status of the patients was identified using a urea detection system (HUT) and culture. H. pylori contamination was assayed by culturing rinsing samples from the endoscopes before and after manual cleaning and disinfection. Gastric biopsies were assayed using rapid urease testing (Helicobacter urease test, HUT) of two antral and gastric body biopsies and cultures. RESULTS: A total of 128 of the 400 patients examined were found to be H. pylori-positive using HUT testing. Endoscopes were contaminated in 54 of the 128 rinsing samples from endoscopes used in H. pylori-positive patients (42 %) before cleaning and disinfection. One of the 128 rinsing samples (0.8 %) was found to be contaminated with H. pylori even after routine manual cleaning and disinfection - indicating that these cleaning and disinfection procedures may be insufficient to eradicate H. pylori from endoscopes completely. No seroconversion was observed during serological follow-up in the patient who had previously been examined with an endoscope contaminated with H. pylori. The patient was still found to be seronegative 5 months after inoculation. CONCLUSIONS: Endoscopes are frequently contaminated with H. pylori immediately after gastroduodenal endoscopy in H. pylori-infected patients. Iatrogenic transmission is possible, as H. pylori can survive manual cleaning and disinfection with 2 % glutaraldehyde, particularly when there is ineffective cleaning before disinfection.

Aged↗

[Reliable and unreliable health measures in surgery].

Despite high standards in theatre design, surgical skills and antibiotic prophylaxis, surgical site infections are still a major complication in modern surgery. After urinary tract infections and lower respiratory tract infections they account for 15.8% of all nosocomial infections in Germany [31]. Causes are multiple and only partially exogenous. The single most important (exogenous) risk factor is the technical skill of the surgeon. Not all surgical site infections are therefore preventable by infection control measures alone. Useful and useless infection control measures will be evaluated critically in the following review according to data in the literature.

Air Microbiology↗

[Proven and unproven hygiene measures in orthopedics].

Postoperative wound infections develop in approximately 2-5% of all patients after orthopedic surgery. After urinary tract infection and pneumonia, such wound infections (15%) are the third most frequent type of hospital-acquired infection. In this review we summarize all proven and unproven hygiene measures available in orthopedics, giving special attention to those implemented with the aim of preventing and controlling postoperative wound infections. Routine application only of hygiene procedures of proven efficacy will be an important contribution to economic and ecological quality assurance in hospital.

Cross Infection↗

[Surveillance of postoperative wound infections: reference data of the Hospital Infection Surveillance System (KISS)].

BACKGROUND: Surgical site infections (SSI), the third-most-frequent nosocomial infection, are a problem in all fields of surgery. Assessing the level of one's own infection rates is often difficult, since there have been no suitable comparative data available in Germany in the past due to the lack of a uniform method of determining these rates. METHODS: Based on an American model, the Hospital Infection Surveillance System (KISS) has been carrying out a standard recording of SSI since 1997 in meanwhile 132 surgical departments of 89 hospitals. Specially trained hygiene personnel record SSI according to CDC definitions in selected indicator operations. RESULTS: Since January 1997, 1,549 SSI have been recorded in 71,038 operations using 13 different surgical techniques. The risk-ratified SSI rates for each of these surgical techniques are provided and can serve as orientational data for other departments. CONCLUSION: The KISS reference data can help in assessing one's own SSI rates. A prerequisite is surveillance according to the KISS protocol.

Confidence Intervals↗

Occurrence of methicillin-resistant Staphylococcus aureus infections in German intensive care units.

BACKGROUND: This study aims to describe the occurrence of nosocomial methicillin-resistant Staphylococcus aureus (MRSA) infections and the relation between endemic and epidemic nosocomial MRSA infections in intensive care units (ICUs) in Germany. METHODS: The ICU component within the German national nosocomial infections surveillance system (KISS) was established in January 1997. The number of participating ICUs increased from 25 in 1997 to 178 (June 2000). In every case of nosocomial infection (NI), the pathogens identified were referred to the surveillance system. To identify clusters and outbreaks and distinguish them from mere single events, the following simple definitions were applied: a "cluster" was two nosocomial MRSA infections within 3 months; an "outbreak" was three or more nosocomial MRSA infections within 3 months; all other MRSA infections were classed as "single events." RESULTS: A total of 10,261 NIs were identified during the observation period in the 139 ICUs which had been participating for at least 6 months. Among the 1,535 nosocomial S. aureus infections, 219 MRSA infections were identified (14.3%). Only 51 (36.7%) of the 139 KISS ICUs identified nosocomial MRSA infections. In 12 ICUs (8.6%) however, more than 50% of all nosocomial S. aureus infections were caused by MRSA. The mean incidence density was 0.31 nosocomial MRSA infections/1,000 patient days (range 0-3.6). Outbreaks were registered in 13 ICUs, clusters in 12 further ICUs and only single events in the remaining 26. 64.0% of all MRSA infections were registered during outbreaks and 12.8% in cluster situations. Thus, only 23.2% of MRSA infections were single events. CONCLUSION: These definitions of clusters and outbreaks can only provide an estimate of the real number of cases. However, through the targeted identification of ICUs with endemic and epidemic MRSA problems and subsequent strict measures to prevent the spread of MRSA within these ICUs, it may be possible to retain, or even reduce, the present level of MRSA infections in Germany.

Cross Infection↗

The practice of perioperative antibiotic prophylaxis in eight German hospitals.

BACKGROUND: Although there is consensus in the international literature on the benefits of using perioperative antibiotic prophylaxis (PAP), there is still considerable scope for improving its use in many hospitals. MATERIALS AND METHODS: In this study, data on the practice of PAP were recorded in eight German hospitals within the framework of a prospective controlled interventional study for the surveillance and prevention of nosocomial infections. RESULTS: A total of 627 surgical procedures (appendectomies, other colorectal procedures, total prosthetic hip replacement) were assessed; 397 with PAP and 224 without PAP; six procedures could not be evaluated. Of the 397 PAP recorded, only 180 (45.3%) were performed correctly in accordance with international standards as a preoperative single dose (19/59 PAP in appendectomies, 72/188 PAP in other colorectal procedures, 89/150 PAP in total prosthetic hip replacement). CONCLUSION: There is still great uncertainty regarding the point in time at which PAP should be administered and its duration. Additional efforts are necessary to improve PAP in accordance with published evidence-based guidelines.

Anti-Bacterial Agents↗

Comparison of hospital-acquired infection rates in paediatric burn patients.

The objective of the present study was to determine risk factors for development of the most common hospital-acquired infections in paediatric burn patients in order to give recommendations for surveillance. The prospective cohort study in a paediatric burn centre was conducted over a period of two years using uni- and multivariate analysis for risk factor identification. In a group of 41 children with an mean total burn surface area (TBSA) of 18.9% 42 hospital-acquired infections were observed. The overall infection rate was 59.7 nosocomial infections per 1000 patient days, the device-associated nosocomial infection rates per 1000 device days were 55.2 for pneumonia, 8.9 for primary bloodstream infections and 41.7 for urinary tract infections. The incidence density of burn wound infections was 18.5 per 1000 patient days. The percentage of TBSA was a significant risk factor for burn wound infections, but percentage of TBSA was not a risk factor for the device-associated infections. Duration of urinary catheter use and ventilation were identified as risk factors for the corresponding hospital-acquired infection. Surveillance of hospital-acquired infections in burn intensive care units should be performed in the same way as other intensive care unit types, as recommended by the National Nosocomial Infections Surveillance system, without consideration of the percentage of TBSA. In addition, burn wound infections should be recorded using the percentage of TBSA for stratification of burn wound infection rates.

Analysis of Variance↗

[Compliance with hand hygiene in intensive care units].

INTRODUCTION: Nosocomial infections are an important problem in modern hospitals. The prevalence in German intensive care units is 15.3%. Hand washing or hand disinfection is believed to be the most important means of preventing nosocomial infections. We wished to answer the following questions: 1. How good is the compliance of hand hygiene on intensive care units? 2. Is compliance associated with the patient/nurse-ratio? METHOD: In a study of 8 intensive care units the compliance of hand hygiene was observed on two occasions, once in May 1996 and again in November 1997. The prime necessity for hand disinfection occurred when handling ventilation devices, intravascular catheters, urinary catheters and dressings. In addition the patient/nurse-ratio was calculated. RESULTS: A total of 1,879 infection-relevant handlings were observed. The compliance of hand hygiene ranged from 25.7 to 83.2% (mean 55.2%). The most commonly observed handlings were the manipulation of venous catheters (52.7%), the highest compliance was observed with the manipulation of ventilation equipment (91.8%). With a better patient nurse ratio the compliance did not improve but remained the same or was even reduced. DISCUSSION: The compliance of hand disinfection is similar to other study results, but on some intensive care units there was considerable room for improvement. In this study the compliance of hand hygiene is more of a constant factor in individual intensive care units than associated with the patient/nurse-ratio.

Attitude of Health Personnel↗

Surveillance of nosocomial infections in a neurology intensive care unit.

To identify overall and site-specific nosocomial infection (NI) rates in patients receiving neurological intensive care therapy, a prospective study was started in 1997 in the ten-bed neurological intensive-care unit (NICU) of the University Hospital of Freiburg, Germany. Case records and microbiology reports were reviewed twice a week, and ward staff were consulted. NI were defined according to the Center for Disease Control and Prevention (CDC) criteria and were categorised by specific infection site. Within 30 months, 505 patients with a total of 4,873 patient days were studied (mean length of stay: 9.6 days). 122 NI were identified in 96 patients (74 patients with one, 18 with two and 4 with three infections. An incidence of 24.2/100 patients and incidence density of 25.0/1,000 patient days of NI in the neurological ICU were documented. Site-specific incidence rates and incidence densities were: 1.4 bloodstream infections per 100 patients (1.9 central line-associated BSIs per 1,000 central line-days), 11.7 pneumonias per 100 patients (20.4 ventilator-associated pneumonias per 1,000 ventilator-days), 8.7 urinary tract infections per 100 patients (10.0 urinary catheter-associated urinary track infections (UTIs) per 1,000 urinary catheter-days). Additionally, 0.4 cases of meningitis, 0.8 ventriculitis, and 1.2 other infections (catheter-related local infection, diarrhea) were documented per 1,000 patient days. 15% of nosocomial pathogens were A. baumannii (due to a outbreak of an nosocomial pneumonia with A. baumannii), 13% S. aureus, 10% E. coli, 7% CNS,7% Bacteroides spp., 7% Enterobacter spp., 6,5% Klebsiella spp.,5.9% enterococci, 5.9% streptococci, and 4.7% Pseudomonas spp. In eight cases of NI no pathogen could be isolated. In future, data on NI in NICUs should be assessed in greater detail, both to improve the quality of care and serve as a basis for identification and implementation of the most effective measures by which to prevent these infections in patients receiving intensive neurological care.

Adolescent↗

The organization of infection control in Germany.

The authors outline the organization of infection control in Germany, focusing on official regulations, the training of infection control staff, and functions of the infection control committee and the availability of guidelines.

Cross Infection↗

[Prevention of postoperative wound infections. Evidence-based recommendations].

Among all hospitalized patients, surgical site infections (SSI) are the third most frequently hospital-acquired-infection. SSIs remain a substantial cause of morbidity and mortality among surgical patients. This may be partially explained by the emergence of antimicrobial-resistant pathogens and the increased numbers of patients who are elderly and/or have a wide variety of chronic, debilitating, or immunocompromising underlying diseases. This is why it is essential to implement SSI prevention measures. In April 1999 the Centers for Disease Control and Prevention (CDC) presented the "Guideline for Prevention of Surgical Site Infection". The recommendations represent the consensus of the Hospital Infection Control Practices Advisory Committee (HICPAC) regarding strategies for the prevention of SSIs. Whenever possible, the recommendations are based on data from well-designed scientific studies. This guideline is a major step forward and is also essential to optimize the management of surgical patients in Germany.

Age Factors↗

[Reduction of nosocomial infections by a public health quality management concept in surgical patients. 1: Significant reduction of a high initial rate].

A successful introduction of surveillance of NI and quality circles for prevention of infection was achieved in hospital A. The major requirements therefore are according to our experiences determination of the topics of the quality circles by the participants themselves, interest and engagement for the work of the quality circles and the realization of ideas, support by the hospitals' management, acceptance of this work by the wards, continuous evaluation of the work of the quality circle. Often the most important problem was not identification of weaknesses and creating of possible solutions, but putting the ideas into practice on the wards. This was the case for problems in the field of care as well as in the responsibility of physicians. Altogether a significant 42% reduction of nosocomial infections was achieved.

Cross Infection↗