Norovirus outbreak management: how much cohorting is necessary?

For the control of norovirus outbreaks, it is widely recommended that exposed but asymptomatic patients should be cohorted separately from unexposed patients and from symptomatic patients. The frequency of subsequent symptomatic norovirus infection in contact patients has not been investigated systematically. We retrospectively investigated the development of typical norovirus symptoms in contact patients during seven norovirus outbreaks affecting 57 patients between November 2014 and May 2015. Only one of 14 contact patients developed typical norovirus symptoms, calling into question current recommendations to isolate contact patients.

Disinfection of transvaginal ultrasound probes in a clinical setting: comparative performance of automated and manual reprocessing methods.

OBJECTIVES: Transvaginal and intracavitary ultrasound probes are a possible source of cross-contamination with microorganisms and thus a risk to patients' health. Therefore appropriate methods for reprocessing are needed. This study was designed to compare the standard disinfection method for transvaginal ultrasound probes in Germany with an automated disinfection method in a clinical setting. METHODS: This was a prospective randomized controlled clinical study of two groups. In each group, 120 microbial samples were collected from ultrasound transducers before and after disinfection with either an automated method (Trophon EPR®) or a manual method (Mikrozid Sensitive® wipes). Samples were then analyzed for microbial growth and isolates were identified to species level. RESULTS: Automated disinfection had a statistically significantly higher success rate of 91.4% (106/116) compared with 78.8% (89/113) for manual disinfection (P = 0.009). The risk of contamination was increased by 2.9-fold when disinfection was performed manually (odds ratio, 2.9 (95% CI, 1.3-6.3)). Before disinfection, bacterial contamination was observed on 98.8% of probes. Microbial analysis revealed 36 different species of bacteria, including skin and environmental bacteria as well as pathogenic bacteria such as Staphylococcus aureus, enterobacteriaceae and Pseudomonas spp. CONCLUSIONS: Considering the high number of contaminated probes and bacterial species found, disinfection of the ultrasound probe's body and handle should be performed after each use to decrease the risk of cross-contamination. This study favored automated disinfection owing to its significantly higher efficacy compared with a manual method. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Influence of protective measures after epidural catheter disconnection on catheter lumen colonization: an in vitro study.

BACKGROUND: Epidural anaesthesia provides excellent pain therapy and reduces postoperative morbidity and mortality. Epidural haematoma and infection are catastrophic complications of this therapy. Following accidental catheter disconnection the choice is between reconnection and premature treatment termination. There is little experimental or clinical data guiding clinical decision-making after epidural catheter disconnection. AIM: Investigation of the in vitro effects of clinically applied safety measures after epidural catheter disconnection. METHODS: The proximal 20mm of epidural catheters were submerged into a suspension of 1 × 10(8)cfu Staphylococcus epidermidis. Catheters were treated by the following potentially preventive measures: (i) cutting 2 cm distal to the level of contamination, (ii) disinfection by spray-wipe, or (iii) employing ropivacaine 0.75% as flushing solution instead of normal saline. All measures were used alone, in a dual combination or all together as a triple intervention (N = 10 catheters in each group). Control catheters were not treated. After 24h of culturing, bacterial growth of the eluates was recorded. FINDINGS: All control catheters showed positive cultures. All 49 eluates of catheters that were cut as a single, dual or triple intervention remained sterile. Disinfection prevented bacterial growth in eluate of only six catheters in single or dual interventions. Ropivacaine did not prevent any bacterial growth. CONCLUSION: Only cutting of epidural catheters 20 mm distal to the level of contamination completely prevented bacterial growth. Disinfection might further reduce risk as an additive measure. This supports the clinical practice of catheter shortening and reconnection. The safe window of time and length of shortening needs to be further investigated.

[Surface disinfection in the context of infection prevention in intensive care units]. / Flächendesinfektion im Kontext von Infektionsprävention auf Intensivstationen.

The highest proportion of nosocomial infections occurs on intensive care units (ICU) and infections with multiresistant pathogens are an ever increasing problem. Preventative measures should consist of a bundle of different measures including measures that address a specific problem and standard hygiene measures that are relevant in all areas. Specific measures in ICUs primarily aim at the prevention of ventilator associated pneumonia, blood vessel catheter associated infections and nosocomial urinary tract infections. Surface disinfection belongs to the standard hygiene measures and plays an inferior role compared to hand hygiene; however, surfaces come into focus in outbreak situations. The Commission on Hospital Hygiene (KRINKO) at the Robert Koch Institute (the German health protection agency) published recommendations regarding the cleaning and disinfection of surfaces. The frequency with which cleaning and/or disinfection is required varies according to defined areas of risk. The frequency and the disinfection agents used are documented in the disinfection plan.

[Hygienic aspects in radiology: what the radiologist should know]. / Hygiene in der Radiologie: Was der Radiologe wissen sollte.

Hospital hygiene is of pivotal importance in radiology departments, where patient throughput is high and staff come into direct contact with both inpatients and outpatients. Every member of the medical and technical team should be aware of all the general and specific hygiene requirements and ensure that they are considered during the daily routine. Failure to do so on the part of just one individual can result in bacterial contamination in the department, exposing both patients and staff to the risk of infection. For the purposes of performing examinations and interventions in infectious patients, the hospital hygienist and medical hygiene officer should introduce appropriate organisational structures to ensure that an appropriate level of hygiene is guaranteed and can be adapted to each patient. This will ensure a minimal degree of disruption to work flow in the radiology department. It is of particular importance that medical and technical staff receive regular hygiene training and instruction. Such training ensures that members of staff are fully aware of the hygiene requirements, are responsibly engaged and that they each possess the expertise and confidence to deal with general and specific hygiene issues in any particular case.

Cross-border comparison of the admission prevalence and clonal structure of meticillin-resistant Staphylococcus aureus.

Since patient exchange between hospitals sharing a common catchment area might favour regional spread of meticillin-resistant Staphylococcus aureus (MRSA), the reliable detection of patients colonised at admission is crucial. Thus, hospitals in the Dutch-German border area EUREGIO MRSA-net aim at synchronising their local MRSA standards in order to prevent unidentified inter-hospital as well as cross-border spread. This assumes enhanced knowledge of MRSA prevalence and risk factors associated with MRSA carriage at admission. We conducted nasal MRSA screening of all inpatients admitted to 39 German hospitals (in the period 1 November to 30 November 2006) and to one Dutch hospital (in the period 1 July to 30 September 2007) in the EUREGIO MRSA-net. A total of 390 MRSA cases were detected among 25,540 patients screened. The admission prevalence was 1.6 MRSA/100 patients (6.5% of all S. aureus) in the German and 0.5 MRSA/100 patients (1.4% of all S. aureus) in the Dutch part of the border region. Overall, the predominating S. aureus protein A gene (spa) sequence types were t003, t032 and t011. One isolate (t044) carried Panton-Valentine leukocidin (PVL) encoding genes. Altogether, 79% and 67% of all MRSA patients in the German and Dutch regions respectively, were identifiable by the classical nosocomial risk factors assessed. In patients lacking all risk factors assessed, spa types t011 and t034 were predominant (P<0.001).

[The importance of MRSA in patient care. Epidemiology, prevention and therapy]. / Bedeutung von MRSA in der Patientenversorgung. Epidemiologie, Prophylaxe und Therapie.

Methicillin-resistant Staphylococcus aureus (MRSA) has for several years been increasingly spreading at inpatient and outpatient health care facilities. This constitutes a great epidemiological problem. Measures are needed for MRSA management, including screening, hygiene, containment, and sanitation as well as for a stricter control of antibiotic use. In order to be able to monitor and assess the MRSA problem in the future, there are surveillance systems which can provide approaches for continuously improving MRSA management and thus offer a long-term solution. In this context, regional networks for implementing MRSA prevention strategies are of particular importance. Their goal is reducing MRSA-caused infections in an area and stop circulation of MRSA between the various health care facilities. For the management of MRSA infections, interdisciplinary cooperation between the attending orthopedic specialist and the clinical microbiologist is very important for planning an effective treatment regimen to ensure a successful outcome, particularly in view of the growing shortage of resources in the healthcare system.

[Significance of microbial colonisation in materials for orthopaedic technology. New insights]. / Bedeutung der mikrobiellen Besiedlung orthopädietechnischer Materialien. Neue Erkenntnisse.

A great problem in the treatment of diabetes are infections of diabetic feet. A likely reservoir of microorganisms are contaminated orthopaedic materials. Insoles from 70 patients were examined for potential microbial colonisation. Commonly employed materials were contaminated in vitro under standardised conditions using known microorganisms. After treating with an alcoholic skin disinfectant, the organisms were counted semiquantitatively. In addition to pathogens, the surfaces showed mainly microorganisms present in the normal skin flora. In all materials tested, disinfection reduced the number of organisms by 4-5 log orders. It could be shown that simple disinfection (wiping) reduces the microorganisms present on orthopaedic materials to an acceptable number. Further studies are needed to determine whether this also reduces the incidence of diabetic skin and soft tissue infection.

[Evidence-based infection control methods using spa genotyping for MRSA spread in hospitals]. / Evidenzbasierte Hygienemassnahmen mittels spa-Typisierung bei MRSA-Häufungen im Krankenhaus.

BACKGROUND AND OBJECTIVE: Isolation of methicillin resistant Staphylococcus aureus (MRSA) often implies rigorous infection control measures. The use of rapid and accurate typing is required to monitor their spread. Prompt identification of epidemic MRSA is crucial to control an outbreak, in order to avoid unnecessary interventions in patients and staff. In this study we evaluated protein A ( spa) gene repeat sequence analysis for MRSA typing in a hospital. METHODS: In 2003, all non-replicate MRSA-strains from staff and patients admitted to the University Hospital Münster (1480 beds), Germany, were spa typed. The spa types were assigned using the Ridom StaphType software. Typing results were correlated with the epidemiological findings of each MRSA isolate. RESULTS: Assignment of spa types was possible for all 175 MRSA isolates and provided rapid (mean, 2 days) typing results. spa typing method yielded 34 spa types. Synchronizing the sequencing results with a central database (http://www.spaServer.ridom.de) created a reproducible and uniform nomenclature for easy intra- and inter-hospital comparisons. CONCLUSION: spa typing makes continuous and fast MRSA typing possible for hospital isolates. The differentiation between outbreaks and accidental accumulations due to imported MRSA was easily possible and allowed implementation of focused and evidence-based infection control measures.

[Candida- and Aspergillus-antibody-Elisa--expected positive antibody results in sera of the clinical-mycological routine diagnostics]. / Candida- und Aspergillus-Antikorper-ELISA--Erwartungswerte positiver Antikorpernachweise aus Seren der klinisch-mykologischen Routinediagnostik.

Based on the ELISA results of more than 15000 serum samples of clinical mycological routine diagnostics, the expected frequency of positive antibody ELISA results within the immunoglobulin classes IgM, IgG and IgA was determined, to optimize the diagnostic assessment of first or single result of Candida or Aspergillus antibody ELISA. In general diagnostics the expected frequency of positive antibody ELISA results of the first sample within the immunoglobulin classes were as follows: Candida antibody IgM 6.1%; IgG 6.0%; IgA 2.1% and Aspergillus antibody IgM 11.4%; IgG 22.1% and IgA 5.1%, respectively. Using the Candida antibody ELISA as confirmation test only, percentages of positive antibody results in the first sample were 2.5 to 3 times higher than in general diagnostics. In follow-up examinations the Candida antibodies showed different kinetics within the immunoglobulin classes compared to those of the Aspergillus antibodies.

Salmonella enteritidis causing brain abscess and coxitis following intracranial surgery.

We report the case of a 46-year-old woman who underwent surgery for an adamantinous craniopharyngeoma (WHO grade I). The postoperative course, during which the patient received 16 mg/day of dexamethasone, was initially uneventful. After a fortnight the patient developed infectious signs and an intracranial abscess at the operation site with simultaneous purulent coxitis. Both the intracranial abscess and the coxitis were evacuated and drained. In tissue samples and pus obtained during re-craniotomy and during surgery on the hip, Salmonella enteritidis was detected by cultivation. Salmonella enteritidis was also isolated from several stool specimens. There was no known salmonellosis in the patient's medical history. She recovered as a result of antibiotic treatment with ciprofloxacin and chloramphenicol. The intracranial abscess healed without leaving any neurological deficit. Unfortunately the left hip subsequently required further surgery, culminating in removal of the entire femoral head. Prosthetic replacement could not yet be performed due to the recurrent septic course of the hip. Our case illustrates a serious complication with presumed haematogenous spread of the infection from a pre-existing asymptomatic and unknown colon infection. The immunosuppressive effect of corticosteroids in the treatment of the brain neoplasm might have been a contributing factor to the sudden exacerbation of the latent infection.

Detection of Staphylococcus aureus by 16S rRNA directed in situ hybridisation in a patient with a brain abscess caused by small colony variants.

A 45 year old man was admitted to hospital with a right sided facial paralysis and three month history of seizures. Computed tomography showed a left temporal mass including both intracerebral and extracerebral structures. Ten years earlier the patient had undergone a neurosurgical intervention in the same anatomical region to treat a subarachnoid haemorrhage. In tissue samples and pus obtained during neurosurgery, Staphylococcus aureus was detected by a 16S rRNA-directed in situ hybridisation technique. Following long term cultivation, small colony variants (SCV) of methicillin resistant S aureus were identified. The patient was treated successfully with a combination of vancomycin and rifampin followed by prolonged treatment with teicoplanin, with no sign of infection on follow up nine months after discharge. This is the first report in which S aureus SCV have been identified as causative organisms in a patient with brain abscess and in which in situ hybridisation has been used to detect S aureus in a clinical specimen containing SCV. Antimicrobial agents such as rifampin which have intracellular activity should be included in treatment of infections caused by S aureus SCV.

[Incidence and detection of nosocomial infections in technical orthopedics]. / Häufigkeit und Erfassung nosokomialer Infektionen in der Technischen Orthopädie.

The significance of nosocomial infections is increasing. The reasons for this are a higher concentration of problematic patients in hospitals due to the increasing number of outpatient surgeries, the increase of invasive therapeutic and diagnostic procedures, the growing share of immunodeficient patients as well as the increase in antibiotic-resistant and multiresistant pathogenic organisms. Basic changes in the medical system call for a systematic discussion about directed quality management. Surveillance, i.e., the systematic registration and evaluation of occurred diseases as well as the feedback to the personnel in charge is very important in this context, particularly when complemented by comprehensive hygienic measures. The growing significance of hospital infections increasingly triggered by multiresistant pathogenic organisms emphasizes the importance of general prevention. Each hospital has to determine which surveillance methods for the registration of nosocomial infections and multiresistant pathogenic organisms are the most appropriate under their respective conditions. To get a first idea of possible problem areas, prevalence studies are very suitable for the start before moving on to well-directed incidence studies in certain wards and for certain kinds of infection.