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Chemical disinfection is an indispensable means of preventing infection. This holds true for healthcare settings, but also for all other settings where transmission of pathogens poses a potential health risk to humans and/or animals. Research on how to ensure effectiveness of disinfectants and the process of disinfection, as well as on when, how and where to implement disinfection precautions is an ongoing challenge requiring an interdisciplinary team effort. The valuable resources of active substances used for disinfection must be used wisely and their interaction with the target organisms and the environment should be evaluated and monitored closely, if we are to reliable reap the benefits of disinfection in future generations. In view of the global threat of communicable diseases and emerging and re-emerging pathogens and multidrug-resistant pathogens, the relevance of chemical disinfection is continually increasing. Although this consensus paper pinpoints crucial aspects for strategies of chemical disinfection in terms of the properties of disinfectant agents and disinfection practices in a particularly vulnerable group and setting, i.e., patients in healthcare settings, it takes a comprehensive, holistic approach to do justice to the complexity of the topic of disinfection.

In the past years infections caused by multidrug-resistant Gram-negative bacteria have dramatically increased in all parts of the world. This consensus paper is based on presentations, subsequent discussions and an appraisal of current literature by a panel of international experts invited by the Rudolf Schülke Stiftung, Hamburg. It deals with the epidemiology and the inherent properties of Gram-negative bacteria, elucidating the patterns of the spread of antibiotic resistance, highlighting reservoirs as well as transmission pathways and risk factors for infection, mortality, treatment and prevention options as well as the consequences of their prevalence in livestock. Following a global, One Health approach and based on the evaluation of the existing knowledge about these pathogens, this paper gives recommendations for prevention and infection control measures as well as proposals for various target groups to tackle the threats posed by Gram-negative bacteria and prevent the spread and emergence of new antibiotic resistances.

In developing hygiene strategies, in recent years, the major focus has been on the hands as the key route of infection transmission. However, there is a multitude of lesser-known and underestimated reservoirs for microorganisms which are the triggering sources and vehicles for outbreaks or sporadic cases of infection. Among those are water reservoirs such as sink drains, fixtures, decorative water fountains and waste-water treatment plants, frequently touched textile surfaces such as private curtains in hospitals and laundry, but also transvaginal ultrasound probes, parenteral drug products, and disinfectant wipe dispensers. The review of outbreak reports also reveals Gram-negative and multiple-drug resistant microorganisms to have become an increasingly frequent and severe threat in medical settings. In some instances, the causative organisms are particularly difficult to identify because they are concealed in biofilms or in a state referred to as viable but nonculturable, which eludes conventional culture media-based detection methods. There is an enormous preventative potential in these insights, which has not been fully tapped. New and emerging pathogens, novel pathogen detection methods, and hidden reservoirs of infection should hence be given special consideration when designing the layout of buildings and medical devices, but also when defining the core competencies for medical staff, establishing programmes for patient empowerment and education of the general public, and when implementing protocols for the prevention and control of infections in medical, community and domestic settings.

Background: Nonsterile gloves (NSG) are often overused, while the emphasis should lie in hand hygiene (HH). Furthermore, improper HH leads to contamination of NSG in glove boxes. The aim of this study was to compare microbial loads on hands from health-care workers (HCW) after HH to NSG and to study the influence of position and filling level of glove boxes on contamination rates., Methods: Fingerprints on agar plates were made from randomly chosen HCWs directly after HH. Plates were incubated and colony-forming units counted. NSG taken from glove boxes were also sampled. Filling level and position (horizontal vs vertical) of the glove boxes were recorded., Results: Median colony-forming units count was similar for hands after HH (N = 107, median 1, IQR 5) and NSG (N = 185, median 1, IQR 2, P-value .33). Only few samples in both groups showed growth of pathogenic bacteria. Neither the filling level (P-value .76), nor the position of the glove box (P-value .68) had an influence on NSG contamination., Conclusion: Microbial loads of hands after HH are comparable to NSG. Filling level or position of the glove box did not influence glove contamination. Whether similar microbial counts translate into comparable nosocomial infection rates warrants further research., Competing Interests: Declaration of competing interests The authors have no conflicts of interest to report., (Copyright © 2021 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.)

Sepsis is newly defined as a life-threatening organ dysfunction caused by a dysregulated host response to infection. Organ dysfunction will be determined by an increase in the Sepsis-related Organ Failure Assessment (SOFA) score. The updated definition should facilitate earlier recognition and more timely management of patients with sepsis. Sepsis should be treated as quickly and efficiently as possible as soon as it has been identified. This implies rapid administration of antibiotics and fluids.

Background: Bacterial endotoxin is known to act as a potent trigger of disseminated coagulation and septic shock. During clinical antibiotic treatment, endotoxin may be released from Gram-negative bacteria. It is known that antibiotic classes differ in their ability to induce endotoxin release., Aim: It was the aim of this study to test the endotoxin-liberating potential of different antibiotics with activity against Escherichia coli and Bacteroides fragilis., Methods: In vitro test models were used to evaluate the endotoxin-liberating potential of moxifloxacin, a 4th-generation quinolone with antianaerobic activity. Bacteria were exposed to moxifloxacin at 2×, 10× and 50× the minimal inhibitory concentration. Endotoxin release was measured by enzyme-linked immunosorbent and Limulus amoebocyte lysate assays. Comparator drugs were ceftazidime and imipenem, i.e. antibiotics with known high and low endotoxin-liberating potential, respectively. As a parameter for biological responses to endotoxin, the release of proinflammatory cytokines (tumor necrosis factor-α, interleukin-1β) from monocytes/macrophages was quantified with bioassays., Results: In all test systems, release of endotoxin during exposure of bacteria to moxifloxacin was minimal or low and comparable with that of imipenem., Conclusions: Moxifloxacin has a low potential to cause endotoxin-mediated detrimental clinical effects. Concerning its endotoxin-releasing properties, moxifloxacin appears to be a choice equivalent to the carbapenems., (Copyright © 2010 S. Karger AG, Basel.)

Background: Endemic infections because of Pseudomonas aeruginosa were observed on a surgical intensive care unit (ICU) for a period of >24 months. Tap water probing revealed persistent colonization of all ICU water taps with a single P aeruginosa clonotype., Methods: Water outlets of the ICU were equipped with disposable point-of-use water filters, changed in weekly and, later, 2-week intervals. To delineate the effect of the filters, 4 study approaches were followed: (1) a descriptive analysis of the incidence of P aeruginosa colonizations and infections, (2) microbiologic examinations of tap water before and after installation of the filters, (3) a comparative cohort analysis of representative patient samples from the prefilter and postfilter time periods, and (4) an analysis of general ward variables for the 2 periods., Results: (1) The mean monthly rate (+/-SD) of P aeruginosa infection/colonization episodes was 3.9 +/- 2.4 in the prefilter and 0.8 +/- 0.8 in the postfilter period. P aeruginosa colonizations were reduced by 85% (P < .0001) and invasive infections by 56% (P < .0003) in the postfilter period. (2) Microbiologic examinations of tap water revealed growth of P aeruginosa in 113 of 117 (97%) samples collected during the prefilter period, compared with 0 of 52 samples taken from filter-equipped taps. (3) In the comparative cohort analysis, a number of patient-related variables were significantly associated with P aeruginosa colonization/infection. Considering these variables in a multivariate analysis, belonging to the postfilter cohort was the factor most strongly associated with a reduced risk of P aeruginosa positivity (relative risk, 0.04; P = .0002). (4) General ward variables such as bed occupancy, personnel-to-patient ratio, or microbiologic culturing density did not differ significantly between the 2 periods., Conclusion: Taking into account various patient-related and general ward variables, point-of-use water filtration was associated with a significant reduction of chronically endemic P aeruginosa colonizations/infections on a surgical ICU.

Background: Germany has witnessed increasing national methicillin-resistant Staphylococcus aureus (MRSA) rates during the past 2 decades. In our 900-bed tertiary care community hospital, a similar increase was noted during the period from 1994 to 2002, although single-room isolation and decolonization therapy were the standard of care., Methods: An intensified infection control program aimed at the reduction of nosocomial MRSA transmissions was developed in 2002 and translated into clinical practice in 2003. Essential components of the program were a detailed written MRSA standard, acquisition of signal-colored isolation gowns and storage carts facilitating the use of separate supplies for MRSA patients, intensified surveillance and feedback of MRSA data, "flagging" of formerly positive MRSA patients, and a general MRSA screening policy for all newly admitted patients on the surgical intensive care unit (ICU). The effect of the program was monitored by continuous surveillance of MRSA cases on all wards. The transmission index was defined as the ratio between secondary and "imported" MRSA cases., Results: Comparing the preintervention (2002) and postintervention (2005-2006) periods, the total number of MRSA patients, MRSA rates on the ICUs, and invasive MRSA infections on the ICUs were reduced. The MRSA transmission index fell from 2.1 (2002) to 0.8 (2006). The rate of deep incisional and organ/space infections due to MRSA occurring after orthopedic surgery was lowered from 0.74 to 0.15%., Conclusions: Our data indicate that the efficacy of single-room isolation and decolonization therapy can be strongly enhanced by means of a multicomponent, comprehensive MRSA control program. The program was effective despite an increasing "import" of new MRSA cases. Programs of this type may be suited to achieve a downward turn of MRSA figures in Germany.

By restricting analysis to single averaged strides considered to be characteristic for the individual under investigation, current methods in gait analysis do not exploit the full dynamics of continuous locomotion. Therefore, a novel approach is presented that is based on long-term measurements of kinematic data during treadmill walking. The method consists of reconstructing the system attractor in the embedding space and then analyzing its geometric structure. Estimating the dimension of movement trajectories correlates well with the notion of controlling multiple degrees of freedom during performance of complex movement tasks such as walking. The influence of walking speed on the complexity of physiologic walking was investigated in 10 healthy subjects walking on a treadmill at seven fixed speeds. The results suggest that human walking becomes more complex at slower speeds. This may be associated with results from EMG studies demonstrating more irregular EMG patterns at very slow walking speeds. This study emphasizes that tools from non-linear dynamics are well suited for providing more insight into motor control in humans.

Recently, locomotion therapy on a treadmill has become part of rehabilitation programs for neurological gait disorders (spinal cord injury, hemiplegia). Instrumental gait analysis is an important tool for quantification of therapy progress in terms of functional changes in a patient's gait patterns. Whereas most of current applications focus on diagnostic assessment of gait, the current paper presents an extension of movement analysis offering enhanced therapeutic options. Specifically, the conceptual basis for application of real-time movement feedback in rehabilitation medicine is outlined and is put into context with recent developments in the field. A first technical realization of these concepts is presented and first results are reported. Furthermore, open questions towards a universal environment for movement feedback in rehabilitation medicine are discussed and future lines of research are identified.

The epidemiology of Pseudomonas aeruginosa infections and colonizations was studied prospectively on a 12-bed medical intensive care unit. Patients were monitored for P. aeruginosa colonization by performing throat swabs or tracheal aspirates on admission and weekly thereafter over a period of 6 months. Cultures of possibly infected sites were taken as clinically indicated. Water samples from all patient care-related tap water outlets were collected in 2-weekly intervals and examined for the presence of P. aeruginosa. Strains isolated from patients and water samples were analysed by serotyping and random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) typing. During the 6-month period, 60 of 143 (42%) water samples contained P. aeruginosa at various levels ranging from 1 to >100 colony-forming units per 100ml sample. Genotypically, water samples contained 8 different clonotypes. Nine patients had infections due to P. aeruginosa and 7 patients were colonized. Isolates from patients showed a similar distribution of genotypes as did tap water isolates, and strains of identical genotype as patient strains had been isolated previously from tap water outlets in 8 out of 16 (50%) infection or colonization episodes. However, patients also harboured strains not previously isolated from tap water. Thus, in addition to tap water, other environmental or unknown reservoirs appeared to play a role for the epidemiology of P. aeruginosa infections on this ward. However, because tap water played a significant role for strain transmissions, we conclude that intensified water site care is justified.

In spite of the significant changes in the spectrum of organisms causing intensive care unit (ICU)-associated infections, Pseudomonas aeruginosa has held a nearly unchanged position in the rank order of pathogens causing ICU-related infections during the last 4 decades. Horizontal transmissions between patients have long been considered the most frequent source of P aeruginosa colonizations/infections. The application of molecular typing methods made it possible, during the last approximately 7 years, to identify ICU tap water as a significant source of exogenous P aeruginosa isolates. A review of prospective studies published between 1998 and 2005 showed that between 9.7% and 68.1% of randomly taken tap water samples on different types of ICUs were positive for P aeruginosa , and between 14.2% and 50% of infection/colonization episodes in patients were due to genotypes found in ICU water. Faucets are easily accessible for preventive measures, and the installation of single-use filters on ICU water outlets appears to be an effective concept to reduce water-to-patient transmissions of this important nosocomial pathogen.

Background: The tested device is a new connecting tool for infusion systems that has been designed to replace conventional single-use stopcocks. Because outbreaks of bloodstream infections have been observed during the use of similar connectors in the United States, we examined the microbiological safety of the connecting device after artificial contamination in the laboratory setting and during routine clinical use., Methods: In the first part of the study, the new device was tested in 3 types of in vitro experiments. In the second part of the study, surgical intensive care patients had their entry ports capped with novel devices (n=27) or with conventional stopcocks (n=32), and samples of infusion fluids and swabs from entry ports were taken after completion of infusion periods., Results: The new device did not perpetuate bacterial contaminations in spite of high artificial inocula in the in vitro experiments. Microbial contamination rates after 96 hours of infusion therapy for the novel connecting tool versus conventional stopcock groups were as follows: swabs from 3-way ports, 6/129 versus 1/111; rest fluid from infusion lines, 0/20 versus 1/22; rest fluid from infusion bottles, 2/196 versus 2/208; rest fluid from perfusor syringes, 7/180 versus 6/142 (all differences not significant)., Conclusion: The novel connecting device was microbiologically safe and did not increase microbial contamination rates of intravenous infusion systems.

Gastric infection with Helicobacter pylori is one of the most common chronic infections in humans, causing substantial morbidity and mortality. The diagnosis of H. pylori infection usually involves upper endoscopy with biopsy since the only noninvasive method of comparable accuracy, the [(13)C]urea breath test, requires technical equipment that is not available in most gastroenterological units. Serological methods for detection of H. pylori infection have reached sufficient accuracy to be used as screening tests before endoscopy or for seroepidemiological surveys. In the present study we evaluated different interpretation criteria for use with immunoglobulin G immunoblotting for the diagnosis of H. pylori infection. We applied five different sets of interpretation criteria, four of which had been published previously, to the Western blot results of 294 patients with different gastrointestinal symptoms. Since it is known that less than 2% of patients who are infected with H. pylori fail to seroconvert, an optimally sensitive Western blotting system should be able to detect approximately 98% of active infections. When the different criteria were applied to our patient population, it became apparent that the abilities of the systems to detect active H. pylori infection were quite varied. The results for the sensitivity and specificity, according to the different applied criteria, ranged from 62.8 to 95.9% and from 85.7 to 100.0%, respectively. Positive predictive values and negative predictive values, according to the published criteria, ranged from 97.2 to 100.0% and from 37.7 to 82.4%, respectively. Recommendations for the optimal use of the different interpretation criteria are discussed.

Infections due to Klebsiella pneumoniae and other Klebsiella spp. are a leading cause of hospital-associated morbidity, especially in the intensive care setting. In this study, the hypothesis that normal human sera contain sufficient concentrations of K-antigen-specific antibodies to promote phagocytic killing of encapsulated, highly virulent Klebsiella organisms was tested. K2-antigen-specific IgG and IgM antibodies were detected in each of 10 normal sera, and such antibodies were functionally active in a phagocytic killing assay. Phagocytosis depended critically on sufficient numbers of neutrophils and was impaired by the presence of soluble Klebsiella capsular polysaccharide (CPS). Thus, insufficient numbers of neutrophils and circulation of soluble CPS but not lack of K-specific antibodies may be detrimental in Klebsiella sepsis. The efficacy of hyperimmune sera might be based not on enhancement of phagocytosis but on the neutralization of these detrimental effects of circulating CPS and LPS.

Objective: To study the association between infection and faucet contamination in a surgical intensive care unit (SICU)., Design: Prospective cohort study., Setting: One SICU and 12 peripheral wards., Patients: From 45 patients colonized or infected with P. aeruginosa, 87 positive isolates were collected., Interventions: P. aeruginosa also was found in 150 of 259 (58%) tap water samples taken from patient rooms., Measurements and Main Results: Clonal relationships between patient and tap water isolates were established by random amplification of polymorphic DNA-polymerase chain reaction. A long-time contamination (144 wks) with a single specific genotype for each of the faucets in our SICU was observed. Additional genotypes found in tap water from these faucets were only isolated over short periods of time. P. aeruginosa was shown to reside in single faucets and did not originate from the supplying mains. In 15 of 45 patients (33%), P. aeruginosa genotypes were identical to those from the faucets in the patient rooms. In six other patients, the same genotype was found in faucets from neighboring rooms. Faucets served as the source of infection for patients in 35% of cases, and on the other hand a retrograde contamination of faucets by patients was observed in 15% of cases., Conclusions: Tap water from faucets contaminated with P. aeruginosa plays an important role in the propagation of this pathogen among patients. A high number of transmissions were shown to occur both from faucet to patient and from patient to faucet. Our SICU served as an epicenter for the spread of P. aeruginosa to peripheral wards. It appears prudent to follow strict hygienic precautions such as wearing gloves and performing thorough alcoholic rub disinfection of hands after patient care and after hand washing at locations known to harbor.

It is generally assumed that the antibiotic prescription policy of a hospital has a significant impact on bacterial resistance rates; however, few studies are available to support this concept with valid statistical data. During a 3-year period from 1997 to 2000, we monitored the consumption of beta-lactam and other antibiotics with known activity against Pseudomonas aeruginosa in a 600-bed community hospital. Monthly isolations of P. aeruginosa were assessed, and resistance rates were recorded. Partial correlation coefficients between consumption and resistance rates were determined, taking into account possible associations with other variables such as seasonal effects and transfers from other hospitals. A total of 30 +/- 7 novel P. aeruginosa strains per month were isolated without epidemic clustering. Prescriptions of imipenem varied significantly during the study period, while prescriptions of other antipseudomonal agents were stable, with the exception of an increase in piperacillin-tazobactam prescriptions. Rates of resistance of P. aeruginosa to the antimicrobial agents used showed a time course similar to figures for imipenem consumption. Monthly rates of resistance to imipenem (partial correlation coefficient [cc], 0.63), piperacillin-tazobactam (cc, 0.57), and ceftazidime (cc, 0.56) were significantly associated with imipenem prescription rates in the same or the preceding month, while consumption of ceftazidime or piperacillin-tazobactam had no apparent association with resistance. Among the variables investigated, imipenem consumption was identified as the major factor associated with both carbapenem and beta-lactam resistance in endemic P. aeruginosa. Periods of extensive imipenem use were associated with significant increases in resistance. Our data support the concept that a written antibiotic policy which balances the use of various antibiotic classes may help to avoid disturbances of a hospital's microbial sensitivity patterns.

This study focuses on the relevance of Candida infection (albicans and non-albicans) in patients with necrotizing pancreatitis. Altogether, 92 patients with infected pancreatic necrosis were reviewed for Candida infection. All patients underwent surgical necrosectomy for infected pancreatic necrosis. Data from patients with Candida growth in intraoperative smears were compared to those obtained from patients without Candida infection. There were 22 patients (24%) with Candida infection. Patients with or without Candida infection were comparable regarding age, gender, etiology, and severity scores at admission. Candida patients suffered a higher mortality (64% vs.19%, p = 0.0001) and experienced more systemic complications (3.2 +/- 1.6 vs. 2.1 +/- 1.4; p= 0.004) than patients without Candida. Preoperative antibiotics were given significantly longer prior to Candida infection (19.0 +/- 13.2 vs. 6.4 +/- 10.3 days; p < 0.0001). With regard to the concomitant spectrum of bacteria, solitary gram-negative infection was rare in Candida patients (5% vs. 43%, p =0.0006). The presence of Candida in patients with infected pancreatic necrosis is associated with increased mortality. Our data provide evidence that application of antibiotics contributes to the development of Candida infection and to changes in the bacterial spectrum of infected necrosis with an increase in the incidence of gram-positive infection.

In a prospective clinical study, we investigated the inflammatory response in 88 neonatal subjects (43 boys and 45 girls) who underwent major abdominal surgery owing to congenital malformation involving the gastrointestinal tract and compared it with the response in 20 infants (8 boys, 12 girls; mean age, 4 mo) who underwent elective surgery for resolution of an existing temporary stoma. In both groups, plasma levels of endotoxin, IL-6, and C-reactive protein as well as leukocyte counts were determined during and after surgery. Endotoxin was measured by the Limulus amebocyte test, IL-6 by ELISA, and C-reactive protein by nephelometry. Statistical analyses were performed using the Wilcoxon signed-rank test. A significant increase in circulating endotoxin and a leukocyte shift was observed in the infant group only. Postoperatively, IL-6 levels peaked between 2 and 6 h and C-reactive protein after 24 h in the infant group. In contrast, no significant increase in the levels of endotoxin, IL-6, and C-reactive protein in plasma were observed during and after surgery in the neonatal subjects, except those with gastroschisis. Newborns with gastroschisis developed an inflammatory response after surgery that was less pronounced than the response of infants older than 4 mo. The finding that endotoxemia in newborns does not follow surgical trauma is most likely because of the absence of bacterial colonization of the gastrointestinal tract.