Heinrich K. Geiss

Surgical site infection – a European perspective of incidence and economic burden

This retrospective review of reported surgical site infection (SSI) rates in Europe was undertaken to obtain an estimated scale of the problem and the associated economic burden. Preliminary literature searches revealed incomplete datasets when applying the National Nosocomial Infection Surveillance System criteria. Following an expanded literature search, studies were selected according to the number of parameters reported, from those identified as critical for accurate determination of SSI rates. Forty‐eight studies were analysed. None of the reviewed studies recorded all the data necessary to enable a comparative assessment of the SSI rate to be undertaken. The estimated range from selected studies analysed varied widely from 1·5–20% – a consequence of inconsistencies in data collection methods, surveillance criteria and wide variations in the surgical procedures investigated – often unspecified. SSIs contribute greatly to the economic costs of surgical procedures – estimated range: €1·47–19·1 billion. The analysis suggests that the true rate of SSIs, currently unknown, is likely to have been previously under‐reported. Consequently, the associated economic burden is also likely to be underestimated. A significant improvement in study design, data collection, analysis and reporting will be necessary to ensure that SSI baseline rates are more accurately assessed to enable the evaluation of future cost‐effective measures.

Chlorhexidine and silver-sulfadiazine coated central venous catheters in haematological patients—a double-blind, randomised, prospective, controlled trial

BackgroundCentral venous catheters (CVCs) are essential for the intensive care of patients with haematological illness. Catheter-related infections (CRI) are an important problem in modern medicine, which may lead to life-threatening situations, to prolonged hospitalisation and increased cost. In immunocompromised patients suffering from haemato-oncological diseases, CRI is a significant factor for adverse outcome. Several clinical studies have shown that CVCs coated with antiseptics such as chlorhexidine and silver-sulfadiazine (CHSS) reduce the risk of catheter-related bacteraemia. Most studies, however, were performed on intensive care patients not suffering from chemotherapy-induced immunosuppression.Patients and methodsA prospective double-blind, randomised, controlled trial was performed to investigate the effectiveness of CHSS-coated catheters in haemato-oncological patients. A total number of 184 catheters (median duration of placement, 11 days) were inserted into 184 patients (male 115, female 69), of which 90 were antiseptically coated. After removal, all catheters were investigated for bacterial growth.Main resultsCatheters coated with CHSS were effective in reducing the rate of significant bacterial growth on either the tip or subcutaneous segment (26%) compared to control catheters (49%). The incidence of catheter colonisation was also significantly reduced (12% coated vs 33% uncoated). Data obtained show a significant reduction of catheter colonisation in CHSS catheters. There was no significant difference in the incidence of catheter-related bacteraemia (3% coated vs 7% uncoated). However, due to the overall low rate of CRI, we could not observe a significant reduction in the incidence of catheter-related bacteraemia.ConclusionOur data show that the use of CHSS catheters in patients with haematological malignancy reduces the overall risk of catheter colonisation and CRI, although the incidence of catheter-related bacteremia was similar in both groups.

An Outbreak of Epidemic Keratoconjunctivitis in a Pediatric Unit Due to Adenovirus Type 8

OBJECTIVES To investigate and control an outbreak of epidemic keratoconjunctivitis (EKC) occurring in a neonatal intensive care unit (NICU) and to determine signs specific for EKC in newborns. DESIGN Outbreak investigation and case-control study. SETTING NICU of a 1,600-bed university hospital in Heidelberg, Germany. PATIENTS Case-patients were defined as individuals who had adenoviral antigen detected by ELISA or by PCR from conjunctival swabs or who had clinical signs of conjunctivitis. Twelve newborns from the NICU who had EKC between October and November 1998 were compared with 11 who had bacterial conjunctivitis. INTERVENTION Control measures included cohorting patients in contact isolation, using gloves and gowns for patient care, and using a hand rub and disinfectants with virucidal activity. RESULTS Thirteen patients, 6 healthcare and 11workers, relatives of the patients had EKC, according to our case definition. Case-patients were more likely than control-patients to develop lacrimal swelling (P < .001), eye redness (P = .004), and lacrimation (P = .037) involving both eyes (P = .002). Prior examination by an ophthalmologist was a significant risk factor for EKC (P = .004). For diagnosis or treatment of retinopathy, premature newborns were seen by an ophthalmologist from a nearby eye care center where an EKC outbreak was ongong. No new cases were diagnosed more than 10 days after the implementation of control measures. CONCLUSION In newborns, lacrimal swelling, eye redness, and lacrimation in both eyes should evoke suspicion of EKC. Ophthalmologists who have had contact with known EKC cases should use antiseptics and disinfectants with virucidal activity before contact with newborns or abstain from examining newborns.

Prevalence of Vancomycin-Resistant Enterococci Among Children with End-Stage Renal Failure

To evaluate the prevalence of colonization with vancomycin-resistant enterococcus (VRE) in end-stage renal failure (ESRF), we screened the intestinal flora from 338 pediatric ESRF patients treated in 13 pediatric nephrology units in mid-Europe. Eighty-one patients were undergoing hemodialysis, 66 were undergoing chronic peritoneal dialysis, and 191 were transplant recipients. A total of 363 enterococcal strains were recovered from 232 patients. Twenty-seven enterococcal strains from 24 patients (7.1%) had reduced susceptibility to vancomycin (minimal inhibitory concentration [MIC], >4 microg/mL). Although two patients (0.6%) carried enterococci with high-level resistance to vancomycin (MIC, >32 microg/mL; i.e., VRE), strains of enterococcus with reduced susceptibility to vancomycin (ERSV) were recovered from the other 22 subjects. Past use of vancomycin (P = .05) and tacrolimus therapy (P = .011) were independent risk factors for ERSV or VRE carriage. Enterococcal infections occurred with a similar frequency among enterococcal carriers and noncarriers; no infections with VRE or ERSV were reported. In conclusion, the prevalence of ERSV carriage and the rate of VRE colonization among mid-European children and adolescents with ESRF currently are moderate and low, respectively.

Landouzy septicemia (sepsis tuberculosa acutissima) due to Mycobacterium microti in an immunocompetent man.

Even in developed countries, tuberculosis still contributes significantly to morbidity and mortality. The most frequent causative agent is Mycobacterium tuberculosis, while infections due to other mycobacterial species are usually associated with immunocompromised patients. In the following, we describe the case of a previously healthy man who underwent laparotomy for suspected adrenal carcinoma. Peritoneal “cancerous nodules” turned out to be tuberculous granulomas. After surgery the patient developed a protracted septic shock and died 6 days after surgery. Isolation and identification of the causative agent yielded Mycobacterium microti, an uncommon species of the M. tuberculosis complex. No other pathogen could be isolated during the clinical course, which finally led to the diagnosis of Landouzy septicemia (sepsis tuberculosa acutissima).

Staphylococcus aureus positive for Panton-Valentine leukocidin genes but susceptible to methicillin in patients with furuncles.

A total of 75 Staphylococcus aureus isolates obtained from patients with either recurrent skin abscesses or furuncles (n=48) or chronic infections from other body sites (n=27) were screened for the presence of the lukS-PV and lukF-PV genes encoding Panton-Valentine leukocidin. Significantly more isolates (70.8% vs. 7.4%, p<0.001) from patients suffering skin abscesses or furuncles were positive for lukS-PV and lukF-PV. These isolates belonged to the accessory gene regulator (agr) group Ia (9/48), group III (13/48), or group IV (19/48). In contrast with results of other investigations, none of the isolates positive for the Panton-Valentine leukocidin genes in this study exhibited methicillin resistance.

Comparative evaluation of a commercial system for identification of Gram-Positive cocci

Abstract The performance of a new commercial system for the identification of different groups of gram-positive cocci [BBL Crystal Gram-Positive (GP) Identification System; Becton Dickinson Microbiology Systems, Germany] was evaluated in comparison with two currently used commercial systems, the API Staph and the API Strep (bioMérieux Diagnostic, Germany). A total of 191 strains from seven different gram-positive genera comprising 32 different species were tested. For the BBL Crystal GP system, the correct identification rate without additional tests was 89.5% at the species level and 97.9% at the genus level. The findings suggest that the newly introduced BBL Crystal GP ID system provides an accurate method for the identification of gram-positive cocci, with an overall rate of correct species identification of about 90%, similar to that of the established API systems. Its major advantage is the extended spectrum of taxa included in a single test panel in contrast to the two different API test kits. Furthermore, the simplicity of use and the safe and rapid handling in a closed system conveniently accommodate existing laboratory workflow.

A simple isocratic HPLC assay to determine linezolid concentrations in different biomatrices for in vivo and in vitro studies.

Abstract Background: Linezolid is an important therapeutic option for the treatment of infections caused by multiresistant Gram-positive bacteria such as vancomycin-resistant Enterococci (VRE) and methicillin-resistant Staphylococcus aureus (MRSA). However, the clinical benefit of linezolid is threatened by the emergence of resistant strains of MRSA and VRE reported in North America and Europe. For effective antimicrobial treatment, it is extremely important to have exact knowledge of drug concentrations at the site of action. Methods: A simple HPLC method for the rapid and precise determination of linezolid in different biomatrices (e.g., plasma, soft tissue, bone, dialysis fluid and used microbiological broth) was developed and validated. Proteins were precipitated with acetonitrile and separation was performed on a reversed-phase C8 column with a mobile phase consisting of water/acetonitrile (80:20, v/v). UV detection was performed at 251 nm. Results: This method has a lower limit of quantification of 0.3 μg/mL and a linear calibration range of 0.5–40 μg/mL. The method showed excellent reproducibility, with an inter- and intra-day assay precision of <5% (% relative standard deviation), as well as excellent accuracy, with inter- and intra-day assay accuracy ranging from 100.6% to 103.2%. Stability up to 6 months in water and plasma was proven. Quantitative recovery was possible after up to three freeze thaw cycles. Conclusions: The method is useful in the acquisition of in vivo and in vitro data. It is simple, flexible, specific, precise and reproducible, as well as of adequate sensitivity for clinical use. Clin Chem Lab Med 2007;45:1019–22.

Diagnosis of catheter-related infections

Catheter-related infections (CRI) are a major cause of febrile episodes in hospitalized patients. Additionally, approximately 40% of primary infections in intensive care patients are directly related to central venous catheters. Despite the clinical significance of CRI diagnostic procedures are still under debate. Clinical diagnosis which includes systemic signs of infection and suppuration at the catheter entry site is altogether a rare event. Therefore, most cases are still diagnosed by laboratory methods. Although the semiquantitative roll-plate technique is widely used and frequently regarded as gold standard, the disadvantages of a post-hoc diagnosis are obvious. In-situ techniques which leave the suspected catheter in place include differential blood cultures, skin and hub cultures and a new method of microscopic screening of blood drawn through the inflicted catheter. However, until now the true value of all these methods still lack unanimous acceptance. Further research is necessary to close the gap between clinical expectations and laboratory results.

Evaluation of the BIOMIC video reader system for routine use in the clinical microbiology laboratory

The BIOMIC Video Reader System (Giles Scientific, New York, NY, USA) is a semi-automated AST method that combines disk diffusion testing with automated reading and data interpretation. We evaluated this system with 497 strains comprising a total of 5821 drug organism combinations (DOC) from our routine diagnostic laboratory. Additionally, we compared the time required of the manual and the automated method. The overall agreement of interpretative categories of all DOC was 96.1%. However, comparing complete tests the agreement was only 70.8%. The average time required of the BIOMIC system to complete a test was more than twice as long as that of the manual method. Our data suggest that the tested version of the BIOMIC system cannot be recommended for routine use in diagnostic laboratories.