Iris F. Chaberny

Central venous catheter-related infections in hematology and oncology

Catheter-related infections (CRI) cause considerable morbidity in hospitalized patients. The incidence does not seem to be higher in neutropenic patients than in nonneutropenic patients. Gram-positive bacteria (coagulase-negative staphylococci, Staphylococcus aureus) are the pathogens most frequently cultured, followed by Candida species. Positive blood cultures are the cornerstone in the diagnosis of CRIs, while local signs of infection are not necessarily present. Blood cultures should be taken from peripheral blood and from the venous catheter. A shorter time to positivity of catheter blood cultures as compared with peripheral blood cultures supports the diagnosis of a CRI. In many cases, a definite diagnosis requires catheter removal and microbiological analysis. The role plate method with semiquantitative cultures has been established as standard in most laboratories. Antimicrobial treatment of CRI should be directed by the in vitro susceptibility of the isolated pathogen. Primary removal of the catheter is mandatory in S. aureus and Candida infections, as well as in case of tunnel or pocket infections. Future studies will elucidate whether the rate of CRI in neutropenic patients may be reduced by catheters impregnated with antimicrobial agents.

Preventing the Spread of Multidrug- Resistant Gram-Negative Pathogens Recommendations of an Expert Panel of the German Society for Hygiene and Microbiology

BACKGROUNDnInfections with multidrug-resistant gram-negative bacteria are hard to treat and cause high morbidity and mortality. The direct transmission of such pathogens is well documented, and measures to protect other patients would seem indicated. Nonetheless, evidence-based recommendations are not yet available because of insufficient data from clinical trials.nnnMETHODSnAn expert panel was convened by two sections of the German Society for Hygiene and Microbiology (the permanent committee on general and hospital hygiene and the special committee on infection prevention and antibiotic resistance in hospitals) to review existing data on the epidemiology and diagnostic evaluation of multidrug-resistant gram-negative pathogens. The panel carried out a selective review of the relevant literature, with special attention to national guidelines.nnnRESULTS AND CONCLUSIONnIn this paper, the expert panel presents a definition of multidrug-resistant gram-negative pathogens and recommends measures for presenting the spread of infection from colonized and infected patients in non-outbreak situations. These measures depend on the risk profile of the clinical setting. They are mostly to be considered expert opinion, rather than evidence-based.

The prevalence of nosocomial and community acquired infections in a university hospital: an observational study.

BACKGROUNDnNosocomial infections (NI) increase morbidity and mortality. Studies of their prevalence in single institutions can reveal trends over time and help to identify risk factors.nnnMETHODSnIn March and April 2010, data were prospectively recorded from all inpatients at the Hannover Medical School (Germany) except those treated in the pediatric, psychosomatic, and psychiatric services. The data were acquired systematically by chart review and by interviews with the medical staff. Infections were classified according to the definitions of the Centers for Disease Control and Prevention (CDC). Information was obtained on underlying diseases, invasive procedures, the use of antibiotics, devices (the application of specific medical techniques such as drainage, vascular catheters, etc.), and detected pathogens.nnnRESULTSnOf the 1047 patients studied, 117 (11.2%) had a total of 124 nosocomial infections, while 112 (10.7%) had 122 community-acquired infections. The most common NI were surgical site infections (29%), infections of the gastrointestinal tract (26%) and respiratory tract (19%), urinary tract infections (16%), and primary sepsis (4%). The most common pathogens were Escherichia coli, coagulase-negative staphylococci, Candida spp., Enterococcus spp., and Pseudomonas aeruginosa. Multivariable regression analysis revealed the following independent risk factors for NI: antibiotic treatment in the last 6 months (odds ratio [OR] = 2.9), underlying gastrointestinal diseases (OR = 2.3), surgery in the last 12 months (OR = 1.8), and more than two underlying diseases (OR = 1.7). Each additional device that was used gave rise to an OR of 1.4. Further risk factors included age, length of current or previous hospital stay, trauma, stay on an intensive care unit, and artificial ventilation.nnnCONCLUSIONnIn this prevalence study, NI were a common complication. Surgical site infections were the single most common type of NI because of the large number of patients that underwent surgical procedures in our institution. More investigation will be needed to assess the benefit of prevalence studies for optimizing appropriate, effective preventive measures.

Development of a surveillance system for methicillin-resistant Staphylococcus aureus in German hospitals.

OBJECTIVEnTo determine the appropriate method to calculate the rate of methicillin-resistant Staphylococcus aureus (MRSA) infection and colonization (hereafter, MRSA rates) for interhospital comparisons, such that the large number of patients who are already MRSA positive on admission is taken into account.nnnDESIGNnA prospective, multicenter, hospital-based surveillance of MRSA-positive case patients from January through December 2004.nnnSETTINGnData from 31 hospitals participating in the German national nosocomial infections surveillance system (KISS) were recorded during routine surveillance by the infection control team at each hospital.nnnRESULTSnData for 4,215 MRSA-positive case patients were evaluated. From this data, the following values were calculated. The median incidence density was 0.71 MRSA-positive case patients per 1,000 patient-days, and the median nosocomial incidence density was 0.27 patients with nosocomial MRSA infection or colonization per 1,000 patient-days (95% CI, 0.18-0.34). The median average daily MRSA burden was 1.13 MRSA patient-days per 100 patient-days (95% CI, 0.86-1.51), with the average daily MRSA burden defined as the total number of MRSA patient-days divided by the total number of patient-days times 100. The median MRSA-days-associated nosocomial MRSA infection and colonization rate, which describes the MRSA infection risk for other patients in hospitals housing large numbers of MRSA-positive patients and/or many patients who were MRSA positive on admission, was 23.1 cases of nosocomial MRSA infection and colonization per 1,000 MRSA patient-days (95% CI, 17.4-28.6). The values were also calculated for various MRSA screening levels.nnnCONCLUSIONSnThe MRSA-days-associated nosocomial MRSA rate allows investigators to assess the extent of MRSA colonization and infection at each hospital, taking into account cases that have been imported from other hospitals, as well as from the community. This information provides an appropriate incentive for hospitals to introduce further infection control measures.

Surveillance invasiver Fadenpilzmykosen in lungentransplantierten Patienten: Effekt antimykotischer Prophylaxe mit Itraconazol und Voriconazol

Von Jan 2002 bis Dez 2003 wurden alle Lungentransplantierten der Medizinischen Hochschule Hannover prospektiv während des postoperativen Krankenhausaufenthalts hinsichtlich der Entwicklung von invasiven Fadenpilzmykosen beobachtet. Patienten wurden als positiv eingestuft, wenn die EORTC‐Kriterien ‘probable or proven’ erfüllt waren. Retrospektiv wurde ermittelt, welche antimykotische Prophylaxe die Patienten erhielten. Von 157 lungentransplantierten Patienten entwickelten 8 eine invasive Mykose (Inzidenz 5.1% nach 17u2003±u200310 Tagen postoperativ). Sie führten zu einer 14‐fach erhöhten Mortalität (OR 13.8, CI95% 2.5–82, Pu2003=u20030.001). Präoperative Kolonisierung der Atemwege mit Aspergillus stellte einen signifikanten Risikofaktor dar (Pu2003<u20030.001, OR 21.9, CI95% 4.9–97). 101 Patienten erhielten vom ersten postoperativen Tag an Itraconazol als antimykotische Prophylaxe. 6 von ihnen entwickelten eine invasive Aspergillose (4.7%). 38 Patienten erhielten eine erst nach >14 Tagen einsetzende antimykotische Prophylaxe mit Itraconazol. Von diesen entwickelten 2 Patienten (3%) eine invasive Aspergillose. Bei 18 Patienten, von denen 10 präoperativ mit Aspergillus besiedelt waren, wurde seit Ende 2002 eine Prophylaxe mit Voriconazol in den ersten 30 postoperativen Tagen durchgeführt. Darunter kam es zu einer Zygomykose. Invasive Fadenpilzmykosen treten bei Lungentransplantierten trotz einer antimykotischen Prophylaxe mit einer hohen Inzidenz von 5% in der frühen postoperativen Phase auf und führen zu einer hohen Mortalität. Ein Management, bei definierten Hochrisikopatienten eine Voriconazol‐Prophylaxe durchzuführen, scheint einer Itraconazolprophylaxe überlegen zu sein. Zur definitiven Klärung sind jedoch noch kontrollierte Studien an größeren Patientenkollektiven erforderlich.

Should Electronic Faucets Be Recommended in Hospitals

Microbiological examinations of electronic faucets newly installed in a hospital kitchen revealed high bacteria counts and Pseudomonas aeruginosa during a 6-month period of observation. Our data suggest that the use of electronic faucets poses a potential risk for nosocomial infection in high-risk areas of hospitals.

[Surveillance of invasive mold infections in lung transplant recipients: effect of antimycotic prophylaxis with itraconazole and voriconazole].

Von Jan 2002 bis Dez 2003 wurden alle Lungentransplantierten der Medizinischen Hochschule Hannover prospektiv während des postoperativen Krankenhausaufenthalts hinsichtlich der Entwicklung von invasiven Fadenpilzmykosen beobachtet. Patienten wurden als positiv eingestuft, wenn die EORTC‐Kriterien ‘probable or proven’ erfüllt waren. Retrospektiv wurde ermittelt, welche antimykotische Prophylaxe die Patienten erhielten. Von 157 lungentransplantierten Patienten entwickelten 8 eine invasive Mykose (Inzidenz 5.1% nach 17u2003±u200310 Tagen postoperativ). Sie führten zu einer 14‐fach erhöhten Mortalität (OR 13.8, CI95% 2.5–82, Pu2003=u20030.001). Präoperative Kolonisierung der Atemwege mit Aspergillus stellte einen signifikanten Risikofaktor dar (Pu2003<u20030.001, OR 21.9, CI95% 4.9–97). 101 Patienten erhielten vom ersten postoperativen Tag an Itraconazol als antimykotische Prophylaxe. 6 von ihnen entwickelten eine invasive Aspergillose (4.7%). 38 Patienten erhielten eine erst nach >14 Tagen einsetzende antimykotische Prophylaxe mit Itraconazol. Von diesen entwickelten 2 Patienten (3%) eine invasive Aspergillose. Bei 18 Patienten, von denen 10 präoperativ mit Aspergillus besiedelt waren, wurde seit Ende 2002 eine Prophylaxe mit Voriconazol in den ersten 30 postoperativen Tagen durchgeführt. Darunter kam es zu einer Zygomykose. Invasive Fadenpilzmykosen treten bei Lungentransplantierten trotz einer antimykotischen Prophylaxe mit einer hohen Inzidenz von 5% in der frühen postoperativen Phase auf und führen zu einer hohen Mortalität. Ein Management, bei definierten Hochrisikopatienten eine Voriconazol‐Prophylaxe durchzuführen, scheint einer Itraconazolprophylaxe überlegen zu sein. Zur definitiven Klärung sind jedoch noch kontrollierte Studien an größeren Patientenkollektiven erforderlich.

An infection with linezolid-resistant S. aureus in a patient with left ventricular assist system

We report an infection with a linezolid-resistant S. aureus in a patient with a left ventricular assist system. Linezolid should be used with caution when invasive devices or foreign materials are in place or therapeutic courses last longer than 14 d. Previous cases of linezolid-resistant S. aureus are summarized.

[Prevention and control of the spread of vancomycin-resistant enterococci: results of a workshop held by the German Society for Hygiene and Microbiology].

ZusammenfassungDie Inzidenz von Erkrankungen durch Vancomycin-resistente Enterokokken (VRE), insbesondere E.xa0faecium, steigt in verschiedenen deutschen Krankenhäusern, und eine Reihe von Ausbrüchen ist dokumentiert. Auch auf den Intensivstationen des Krankenhaus-Infektions-Surveillance-Systems (KISS) wurden in den Jahren von 2003–2005 ein erheblicher Anstieg der VRE-Inzidenz von 0,5 auf 11,0/10.000xa0Patienten und ein Anstieg der VRE-assoziierten Letalität beobachtet. Die Gründe für diese Entwicklung sind nicht abschließend geklärt. Da VRE aber schwere Infektionen verursachen können, muss ihre Übertragung durch geeignete Maßnahmen verhindert werden. Der vorliegende Beitrag fasst die in einem Workshop erarbeiteten Empfehlungen der Deutschen Gesellschaft für Hygiene und Mikrobiologie zur Prävention von VRE-Transmissionen bei endemischem und epidemischem Auftreten zusammen. Diskutiert werden die Indikationen zum VRE-Screening, mikrobiologische Diagnostik und allgemeine (Isolierung und Schutzkleidung) sowie zusätzliche Hygienemaßnahmen während nosokomialer Ausbrüche durch VRE.AbstractThe incidence of vancomycin-resistant enterococci (VRE), especially E.xa0faecium, is increasing in several German hospitals and some facilities have experienced VRE outbreaks. The German National Nosocomial Infection Surveillance System has also noticed a sharp increase in the incidence of nosocomial VRE infections per 10,000 patients from 0.5 in 2003 to 11.0 in 2005 accompanied by a rise in VRE-associated mortality. However, the reasons of this increase remain unknown. As VRE may cause severe nosocomial infections, transmission must be restricted. This article provides the guidelines as defined by the workshop of the German Society for Hygiene and Microbiology for the prevention of VRE transmission in both, endemic and epidemic, settings. The following topics are discussed: indication for VRE screening, microbiological diagnostics, general infection control measures (isolation precautions and use of protective clothing) and additional hygiene measures in the nosocomial VRE outbreak setting.

Antibiotics: MRSA Prevention Measures in German Hospitals Results of a Survey Among Hospitals, Performed as Part of the MRSA-KISS Module

BACKGROUNDnIn this study, we investigated the measures currently being taken in German hospitals to prevent infection with methicillin-resistant strains of Staphylococcus aureus (MRSA). To this end, we circulated a questionnaire among hospitals participating in the MRSA-KISS module. KISS in the name of this project stands for hospital infection surveillance system (in German, Krankenhaus-Infektions-Surveillance-System).nnnMETHODSnThe questionnaire was sent to all MRSA-KISS participants. A study doctor visited a representative sample of hospitals to validate the responses. The study doctor checked the questionnaire responses with a systematic on-site interview of the contact person in each hospital, then evaluated the information contained in them by recording all of the MRSA patients who were present in the hospital on the day of the visit in a point-prevalence study (PPS).nnnRESULTSnAll 134 participants filled out the questionnaire. The screening of patients at risk on admission is an established part of the clinical routine in all of the surveyed hospitals, as are MRSA decolonization procedures. These preventive measures have been recommended for routine use in Germany by the Robert Koch Institute (RKI, the German counterpart of the Centers for Disease Control and Prevention). The surveyed hospitals also used further preventive strategies, including, for example, an alerting system for the identification, upon hospital admission, of patients with a known history of MRSA positivity (72%); pre-admission screening of all patients (13%); universal screening on admission in some hospital wards (19%); and the prophylactic isolation of patients suspected of having MRSA with pending microbiological test results (21%). 35 hospitals were visited for validation. Most of the responses in each hospital were internally consistent and adequately reflected the real situation on site. Less consistency was seen in responses regarding the detection of MRSA by clinical testing and the measures that were taken after MRSA was detected.nnnCONCLUSIONnThe surveyed hospitals are, in fact, implementing many of the RKIs recommendations, as well as other preventive measures against MRSA.