Development and characterization of a predictive microCT-based non-union model in Fischer F344 rats.

INTRODUCTION: Non-unions remain a clinical problem and are characterised by the failure to heal after a defined period of time. Current preclinical non-union models apply a wide variety of techniques to diminish intrinsic healing potential deviating from the clinical situation. The aim of this study was to develop and characterise a non-union model in rats using internal plate fixation without the need for additional healing insults, whereby bone healing can be longitudinally assessed using microCT. It was hypothesized that healing/non-unions can be accurately predicted at early time points by microCT. MATERIALS AND METHODS: Female, skeletally mature Fischer F344 rats received a 2 mm or 1 mm femoral osteotomy, stabilized with either a 2 mm thick plate or a 1.25 mm thick plate. Healing was monitored by microCT over 14 weeks and histological analysis at euthanasia. The mechanical environment was characterised using finite element (FE) modelling and biomechanical testing. RESULTS: The majority of animals receiving the 2 mm thick plate displayed poor healing responses in both the 2 mm and 1 mm defect size groups. Bone and cartilage formation were markedly improved using the 1.25 mm thick plate. MicroCT could accurately predict bone forming capacity at early time points (3-4 weeks). CONCLUSIONS: The 2 mm thick plating system confers poor healing responses in female Fischer F344 rats, comparable to atrophic non-unions. By reducing plate thickness to increase interfragmentary strain within the defect site healing is improved, leading to borderline healing situations or increased abundance of cartilage tissue present in the defect site with ultimate failure to bridge the defect (hypertrophic non-union). Furthermore, microCT can reliably identify delayed/non-healing animals within 4 weeks, thereby allowing their selective targeting for the testing of novel, clinically relevant treatment strategies in different clinical situations aimed at restoring impaired bone healing.

Helical plating - a novel technique to increase stiffness in defect fractures.

Single-plate fixation bridging bone defects provokes nonunion and risks plate-fatigue failure due to under- dimensioned implants. Adding a helical plate to bridge the fracture increases stiffness and balances load sharing. This study compares the stiffness and plate surface strain of different constructs in a transverse contact and gap femoral shaft fracture model. Eight groups of six synthetic femora each were formed: intact femora; intact femora with lateral locking plate; contact and gap transverse shaft osteotomies each with lateral locking plate, lateral locking plate and helical locking plate, and long proximal femoral nail. Constructs underwent non-destructive quasi-static axial and torsional loading. Plate surface strain evaluation was performed under 200 N axial loading. Constructs with both lateral and helical plates demonstrated similar axial and torsional stiffness- independent of the contact or gap situations - being significantly higher compared to lateral plating (p < 0.01). Torsional stiffness of the constructs, with both lateral and helical plates in the gap situation, was significantly higher compared to this situation stabilised by a nail (p < 0.01). Plate surface strain dropped from 0.3 % in the gap situation with a lateral plate to < 0.1 % in this situation with both a lateral and a helical plate. Additional helical plating increases axial and torsional construct stiffness in synthetic bone and seems to provide well-balanced load sharing. Its use should be considered in very demanding situations for gap or defect fractures, where single-plate osteosynthesis provides inadequate stiffness for fracture healing and induces nonunion.

Re-thinking risk communication: information needs of patients, health professionals and the public regarding MRSA--the communicative behaviour of a public health network in Germany responding to the demand for information.

OBJECTIVES: Multidrug resistant organisms (MDRO), including Meticillin-resistant Staphylococcus aureus (MRSA), and health care associated infections (HCAIs) are pressing issues for health care systems across the world. Information and communication are considered key tools for the prevention and management of infectious diseases. Public Health Authorities (PHA) are in a unique position to communicate with health care professionals, patients and the public regarding the health risks. STUDY DESIGN: We used PHA helpdesk interaction data to first ascertain the information requirements of those getting in contact with the service, and secondly to examine the communicative behaviour of the PHA, with a view to improving the quality of communication strategies. METHODS: Data on helpdesk interactions between 2010 and 2012 were obtained from a MDRO network of nine German PHAs. 501 recordings were coded and descriptive statistics generated for further qualitative thematic analysis. RESULTS: Our analysis revealed a similar pattern of questions among different groups. Key areas of need for information were around eradication, cleaning and isolation measures. Reported problems were a lack of expert knowledge and continuity of treatment. The helpdesk response was mainly a conversation offering scientific advice, but also included other communication services that went beyond the provision of scientific facts, such as follow-up calls, referral suggestions and consultations on behalf of the caller. These social communication activities seem to have an important impact on the acceptability of public health recommendations and use of the helpdesk. CONCLUSIONS: Our findings support a broader discussion about the role of information in the communication process and underline the importance of social elements in the communication process, such as relationship and trust building.

[Multidrug-Resistant Organisms (MDRO) in Rehabilitation Clinics in the Rhine-Main District, Germany, 2014: Risk Analysis and Hygiene Procedures]. / Multiresistente Erreger in Rehabilitationseinrichtungen im Rhein-Main-Gebiet, Deutschland, 2014: II. Ärztliche Risikoanalyse und Hygienemaßnahmen.

BACKGROUND: Many regional German MDRO-networks aim to improve the medical rehabilitation of patients with methicillin-resistant Staphylococcus aureus (MRSA) and other multidrug-resistant pathogens. In 2014, the German Commission for Hospital Hygiene and Infection Control (KRINKO) released revised recommendations for the care of patients with MRSA. In particular, for rehabilitation facilities, these recommendations stipulated a medical risk analysis to establish necessary hygiene measures, and provide specific recommendations. MATERIAL AND METHODS: Based on a large investigation carried out in 21 rehabilitation facilities covering different medical specialties, medical risk analyses according to KRINKO were performed, and the findings evaluated separately for orthopedic, cardiologic, oncologic, neurologic, or geriatric facilities, as well as for all institutions taken together. RESULTS: The overall colonization pressure, i. e. the point prevalence of MRSA and extended spectrum beta-lactamase-producing gram-negative pathogens (ESBL) among hospitalized rehabilitation patients was found to be 0.7% and 7.7%, respectively. Impairment of the intact skin (an established risk factor for persisting MRSA colonization and MRSA infection) was found in 7% of the patients, impaired mobility requiring enhanced level of care in 4.1%, and mental confusion and/or incontinence (potentially impairing the application of hygiene measures) in 11% of patients. Compared to the total study population, there was an increase in all risk factors in geriatric and neurologic rehabilitation patients: skin barrier breaches (in neurologic and in geriatric patients: 18.3 and 19.2%, respectively), impaired mobility (32.7 and 37.0%, respectively), and mental confusion/incontinence (24.5 and 28.0%, respectively). In addition, geriatric patients demonstrated an increased overall prevalence of multidrug-resistant organisms (MRSA: 9.4%; ESBL: 22.7%). DISCUSSION: Risk analysis according to KRINKO showed that in rehabilitation facilities with internal medicine or orthopedics specialties, there was a comparably lower risk for transmission, colonization, and/or infection with multidrug-resistant pathogens, as against institutions with neurologic or geriatric specialty. It appears that in the first type of rehabilitation facilities, consistently carried out basic hygiene measures are sufficient while in neurologic or geriatric rehabilitation hospitals, these measures should be supplemented with additional hygiene measures based on medical risk analysis. Furthermore, for infection control purposes in rehabilitation facilities, patient isolation will be rarely necessary or appropriate. These analyses suggest that in the future, rehabilitation programs for MRSA/ESBL-colonized patients will be more successful.

[Multidrug-Resistant Organisms (MDRO) in Rehabilitation Clinics in the Rhine-Main-District, Germany, 2014: Prevalence and Risk Factors]. / Multiresistente Erreger in Rehabilitationseinrichtungen im Rhein-Main-Gebiet, Deutschland, 2014: I. Prävalenz und Risikofaktoren.

BACKGROUND: While a limited number of studies have investigated the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in medical rehabilitation institutions, almost no data on the colonization of rehabilitation patients with multiresistant gram-negative rods is available. Here we report on a large multicenter study on the prevalence of MRSA and multiresistant pathogens in rehabilitation institutions in the Rhine-Main area in 2014. MATERIALS AND METHODS: Altogether, 21 rehabilitation hospitals participated. For all patients, age, gender, previous history of hospitalizations, surgery, previous colonization with multidrug-resistant organisms, use of a medical device, current antimicrobial therapy, and the current infection status were ascertained. On voluntary basis, nare and throat swabs were taken for analysis of MRSA and rectal swabs were tested for extended spectrum betalactamase-producing gram-negative bacteria (ESBL). RESULTS: 50% of 2 440 patients had a history of hospitalization within the previous 6 months while 39% had undergone surgery during the past 30 days. Approximately a quarter of the patients had been transferred to a rehabilitation hospital directly from an acute care hospital, had been under antimicrobial therapy with the past three months, or had travelled to a foreign country within the previous year. Risk factors such as lesions of the intact skin or presence of medical devices were rarely reported (< 5%) within the exception of patients undergoing geriatric or neurologic acute care rehabilitation. 0.7% (15/2155) of the patients were colonized with MRSA, while 7.7% (110/1434) showed a positive result for ESBL. The highest prevalence rates for multiresistant organisms were encountered among patients with neurologic rehabilitation (MRSA, 1.3%, and ESBL, 10.2%) or with geriatric rehabilitation (MRSA, 9.4%, and ESBL, 22.7%). CONCLUSION: In the rehabilitation patient population, the prevalence rates of MRSA and ESBL were found to be in the range of rates encountered in the general population (reported rates for MRSA, 0.5%, and ESBL, 6.3%). The known risk factors for MRSA such as skin lesions, medical devices and previous history for MRSA were also confirmed among this patient population. Direct transfer from an acute care hospital, antimicrobial treatment during the past 3 months, and wounds proved significant risk factors for ESBL colonization. Patients of neurologic rehabilitation and geriatric patients showed the highest rates of risk factors and the highest prevalence rates of multidrug-resistant organisms. It appears to be of importance for rehabilitation hospitals to be geared to the needs of patients with multidrug-resistant organisms, and prevent the transmission of these pathogens by appropriate hygiene measures.

Current prevalence of multidrug-resistant organisms in long-term care facilities in the Rhine-Main district, Germany, 2013.

Multidrug-resistant organisms (MDRO) and in particular multidrug-resistant Gram-negative organisms (MRGN) are an increasing problem in hospital care. However, data on the current prevalence of MDRO in long-term care facilities (LTCFs) are rare. To assess carriage rates of MDRO in LTCF residents in the German Rhine-Main region, we performed a point prevalence survey in 2013. Swabs from nose, throat and perineum were analysed for meticillin-resistant Staphylococcus aureus (MRSA), perianal swabs were analysed for extended-spectrum beta-lactamase (ESBL)-producing organisms, MRGN and vancomycin-resistant enterococci (VRE). In 26 LTCFs, 690 residents were enrolled for analysis of MRSA colonisation and 455 for analysis of rectal carriage of ESBL/MRGN and VRE. Prevalences for MRSA, ESBL/MRGN and VRE were 6.5%, 17.8%, and 0.4%, respectively. MRSA carriage was significantly associated with MRSA history, the presence of urinary catheters, percutaneous endoscopic gastrostomy tubes and previous antibiotic therapy, whereas ESBL/MRGN carriage was exclusively associated with urinary catheters. In conclusion, this study revealed no increase in MRSA prevalence in LTCFs since 2007. In contrast, the rate of ESBL/MRGN carriage in German LTCFs was remarkably high. In nearly all positive residents, MDRO carriage had not been known before, indicating a lack of screening efforts and/or a lack of information on hospital discharge.

[Network against multidrug-resistant organisms in the Rhine-Main region, Germany. A first evaluation]. / MRE-Netz Rhein-Main - Wie bewerten die Einrichtungen die Angebote des Netzwerks? - Eine erste Zwischenevaluation.

BACKGROUND: Multidrug-resistant organisms (MDROs) are not only a problem in the hospital but also in the community setting. The MRE-Net Rhine-Main was founded in order to decrease the rate of development and spread of MDROs in the region and to counter the stigmatisation of people with MDROs. The network attempts to achieve these goals by offering telephone support, information flyers, internet services, information events and training for health-care practitioners from hospitals (HOSP), residential and nursing homes (RNH), outpatient care services (OCS), emergency services (ES), medical practices (MP) and rehabilitation centers (RC). A first interim evaluation examined the expectations each institution had associated with its participation and how well these objectives were fulfilled. Furthermore the utilisation and acceptance of the services offered by the network were investigated. METHOD: The participating institutions (n=143) received a standardised questionnaire adapted to the type of institution by mail including questions focusing on the above-mentioned issues. RESULTS: 96 questionnaires could be evaluated (response 67.1%). More than 90% of the participants expected to participate in trainings, receive improved information, to gain more confidence in handling patients and to improve hygiene measures - with great differences between HOSP, RNH and OCS. These expectations were largely satisfied. 65.5% of the institutions participated at least once in a training, particularly RNH, OCS, whereby the usefulness of the trainings was rated high by these institutions. 14.4% of the institutions had made use of the telephone service, the gain of information was rated as high by HOSP, RNH and OCS. 81% knew of and used the flyers, but almost half of the institutions did not know the homepage of the network. CONCLUSIONS: Overall the expectations of the network participants were met well to very well and the benefit derived from the trainings and the print and online media was rated as high. Therefore the network will continue and further intensify its work.

[Healthcare associated infections (HAI), antibiotic use and prevalence of multidrug-resistant bacteria (MDRO) in residents of long-term care facilities: the Frankfurt HALT plus MDRO project 2012]. / Nosokomiale Infektionen, systemischer Antibiotikaeinsatz und multiresistente Erreger bei Bewohnern von Altenpflegeheimen : Das Frankfurter HALT plus MRE-Projekt, 2012.

BACKGROUND: Residents of long-term care facilities (LTCF) are at risk of healthcare associated infections (HAI) and are often treated with antibiotics. In Germany a current HAI prevalence of 1.6 % and antibiotic use in 1.15% have been reported. However, data published on the current prevalence of multidrug-resistant organisms (MRDO) in LTCFs in Germany are scarce. Therefore, the prevalence of HAI, antibiotic use and presence of MDROs were investigated in LTCF residents in Frankfurt am Main, Germany. METHODS: A point prevalence study of HAI and antibiotic use according to the European HALT protocol (health care associated infections in long-term care facilities) was carried out; swabs from the nose, throat and perineum were analyzed for methicillin-resistant Staphylococcus aureus (MRSA), extended spectrum beta-lactamase producing enterobacteria (ESBL) and vancomycin-resistant enterococci (VRE). RESULTS: A total of 880 residents in 8 LTCFs were enrolled in the study in 2012. The study participants were 30% male, 46.7% were more than 85 years old, 70% exhibitied urinary or fecal incontinence, 11.4% had an indwelling urinary catheter and 0.1% a vascular catheter. Prevalence rates of HAI and of antibiotic use were 2.5 % and 1.5%, respectively. The prevalence of MDROs in 184 residents who agreed to being tested for MDROs was 9.2% MRSA, 26.7% ESBL and 2.7% VRE. CONCLUSION: The HAIs and antibiotic use were comparable to the German HALT data from 2010. Compared to other German studies there is a steadily increasing MRSA problem in German LTCFs. High and increasing ESBL rates have been detected in German LTCFs. Further studies are needed to confirm this trend, preferably encompassing molecular methods to study epidemiology.

[MRSA bloodstream infections according to the German obligation for notification - data and experience of the MDRO Network Rhine-Main, Germany, 2011]. / Meldepflicht MRSA in Blutkulturen - Daten und Erfahrungen des MRE-Netz Rhein-Main, 2011.

BACKGROUND: Since July 1st, 2009 in accord with the statuary order based on the German law for infectious diseases (Infektionsschutzgesetz), MRSA in blood and liquor have to be notified to the public health authorities. The aim of this extension of the notification to report is to improve the surveillance of nosocomial infections and the prevention of nosocomial MRSA infections. In this paper data of the notifications in the year 2011 within the MDRO-Net Rhine-Main, an association of 7 public health authorities in the region, are reported in order to investigate whether the aims of the obligation for notification could be achieved. RESULTS: In 2011, 138 MRSA bloodstream infections, including 1 MRSA in liquor culture, were notified to the 7 health protection authorities, resulting in an incidence rate of 5.6/100,000 inhabitants. In urban regions with more hospitals available, the incidence rate was higher than in rural districts with less medical facilities (6.9 vs. 4.4/100,000 inhabitants). Only 46 (35%) of the patients with MRSA cultured in their blood had been detected via anamnesis as patients on risk for MRSA, and 59 (45%) had been screened for MRSA on admission. The incidence rate in the different hospitals was 0.041 ± 0.031/1,000 patient days (range 0-0.145/1,000 patient days). CONCLUSIONS: For the first time, data on notification of MRSA cultures in blood specimen are published from a whole MRE Network in Germany encompassing >2.1 million inhabitants. Incidence rates per 100,000 inhabitants alone do not seem adequate to cope with the aims of the obligation for notification. Instead, reference to patient days in the respective clinic enables an external comparison to other medical institutions in the region and is a better base for discussion with these institutions on improvements of surveillance, screening and hygiene.

Acute tryptophan depletion increases experimental nausea but also induces hunger in healthy female subjects.

BACKGROUND: Acute tryptophan depletion (ATD) is an experimental model to reduce central serotonin levels. METHODS: Thirty-eight healthy female subjects were randomly assigned to two groups (ATD and control) in a randomized, double-blinded parallel-group design. Following a standardized and balanced amino acid diet (including 1.21 g tryptophan) on the first day, they received either a protein drink without tryptophan (but substituted by other amino acids) (ATD condition) or the balanced protein drink with tryptophan (control condition) 24 h later. Four hours after its consumption, they were exposed to a standard rotation procedure. Symptom ratings (SR), ratings of hunger and mood scores were taken prior to rotation, at each break, and 15 and 30 min thereafter, together with saliva cortisol samples. KEY RESULTS: Five subjects could not tolerate the entire rotation procedure and were excluded from analysis. For the remaining n = 33, SR and hunger ratings were higher during ATD than during control conditions, but mood was unaffected. Cortisol levels rose significantly with rotation but were unaffected by ATD. High baseline cortisol levels were associated with lower SR during rotation. The protective effects of morning cortisol were pronounced during the menstrual and follicular phase of the cycle and not present during ovulation and the luteal phase. CONCLUSIONS & INFERENCES: Acute tryptophan depletion is associated with increased symptoms of nausea in healthy female subjects when exposed to body rotation. Acute tryptophan depletion also increases hunger rating. These opposite effects may indicate independent actions of the serotonin on central and peripheral functions.