Methodology paper: a novel phantom setup for commissioning of scanned ion beam delivery and TPS.

BACKGROUND: Commissioning of treatment planning systems (TPS) and beam delivery for scanned light ion beams is an important quality assurance task. This requires measurement of large sets of high quality dosimetric data in anthropomorphic phantoms to benchmark the TPS and dose delivery under realistic conditions. METHOD: A novel measurement setup is described, which allows for an efficient collection of a large set of accurate dose data in complex phantom geometries. This setup allows dose measurements based on a set of 24 small volume ionization chambers calibrated in dose to water and mounted in a holder, which can be freely positioned in a water phantom with various phantoms mounted in front of the water tank. The phantoms can be scanned in a CT and a CT-based treatment planning can be performed for a direct benchmark of the dose calculation algorithm in various situations. RESULTS: The system has been used for acceptance testing in scanned light ion beam therapy at Heidelberg Ion Beam Therapy Center for scanned proton and carbon ion beams. It demonstrated to be useful to collect large amounts of high quality data for comparison with the TPS calculation using various phantom geometries. CONCLUSION: The setup is an efficient tool for commissioning and verification of treatment planning systems. It is especially suited for dynamic beam delivery, as many data points can be obtained during a single plan delivery, but can be adapted also for other dynamic therapies, like rotational IMRT.

[Disinfecting contact tonometers - a systematic review]. / Desinfektion von Kontakt-Tonometern - ein systematischer Review.

OBJECTIVE: The aim of this study is to provide the best available evidence on how to disinfect contact Goldman tonometers. METHODS: A systematic review of all articles on disinfection of contact tonometers was conducted. Articles published up to July 2008 were identified in Medline, Embase and references from included articles. Two observers participated in the data retrieval and assessment of the studies identified. RESULTS: A total of 89 articles was retrieved, of which 58 could be included. Of those, 18 were clinical studies, 17 experimental microbiological studies, 8 expert assessments or guidelines and 15 reviews, surveys, descriptions of new methods. The clinical studies illustrate the importance of the problem, possible side effects of some disinfection methods but yield inconclusive results regarding efficacy. Experimental studies investigated a variety of bacterial and virological questions as well as material damage by disinfection. Both chlorine-based and hydrogen peroxide-based liquid disinfection were shown to be effective if applied for 5 min. Inconsistent results exist for alcohol wipes and UV disinfection - material damage has been described for both. The US guidelines and most expert recommendations are supported by evidence of the existing data. CONCLUSIONS: Chlorine-based and hydrogen peroxide-based liquid disinfections for 5 minutes are effective and relatively safe for disinfecting contact tonometers.

Comparative review of the test design Tentative Final Monograph (TFM) and EN 12791 for surgical hand disinfectants.

Preoperative antiseptic treatment of the hands of the surgical team is a standard procedure used worldwide in order to reduce the risk of surgical site infection. Two different types of antiseptics are available: alcohol-based hand rubs and antimicrobial liquid detergents ("soaps"). Standards have been developed to determine the antimicrobial efficacy of such preparations: the European norm EN 12971, finally issued in 2005, and the Tentative Final Monograph (TFM) for health care antiseptic products from 1994, which is the corresponding document in the USA. Although both methods use the reduction of resident hand flora as a quantitative parameter for antimicrobial efficacy, there are major differences concerning the test design. Whereas the European method is carried out following a randomized, reference-controlled crossover design, the US method can be characterized as a randomized, blinded parallel arm design. While both standards aim at immediate as well as sustained efficacy of the procedure, according to the EN the test product must not be significantly less effective than the reference procedure, whereas the TFM requires absolute reduction of > or = 1, > or = 2, and > or = 3 log10 per hand on days 1, 2, and 5, respectively. Results from various studies demonstrated that meeting the criteria defined by both standards may happen, but meeting the specifications of one standard does not necessarily mean that the same product will pass the requirements of the other. Missing accordance may be due to a number of considerable differences between both test methods. For a number of reasons the European method seems to be closer to clinical practice and to provide higher patient safety than the US method. However, available study data do neither allow for evaluation of the clinical impact of surgical hand disinfection as such nor of the effect of a particular product on postoperative wound infection rates.

Discrimination between epidemic and non-epidemic glycopeptide-resistant E. faecium in a post-outbreak situation.

Vancomycin-resistant enterococci (VRE) have been isolated in increasing numbers. Hospital-adapted VRE exhibit relatively high pathogenicity by expressing factors like enterococcal surface protein (Esp), which facilitates epidemic spread. By contrast, 'community-acquired' VRE show low pathogenicity and non-epidemic features. In 2004 and 2005 an extended outbreak of VRE occurred at a university hospital in Southwestern Germany and an infection control programme was implemented to confine the outbreak. Pulsed-field gel electrophoresis (PFGE), esp PCR, multiple-locus variable number of tandem repeat analysis (MLVA), purK1 typing and multiple-locus sequence typing (MLST) were performed on representative VRE isolates. Twenty-six non-epidemic and two epidemic VRE types (MLST203, MLST280) were identified by PFGE. Seven of the non-outbreak VRE types were esp gene negative, whereas 19 non-outbreak and both epidemic VRE types were esp positive. Eight MLVA types were identified. MLVA type 1 included five PFGE types and MLVA type 159 included 16 PFGE types. Currently there is no efficient method available to identify non-epidemic VRE and avoid unnecessary isolation of patients. More than 50% non-epidemic clones were esp positive; nevertheless, esp PCR appears to be the most promising approach to identify non-epidemic VRE.

Acute musculoskeletal infection: comparison of different methods for intraoperative bacterial identification.

PURPOSE OF THE STUDY: Various techniques are used for detection of pathogens in musculoskeletal infection. These methods differ with respect to reliability and ease of handling. A prospective study was performed to evaluate the efficacy of three intraoperative techniques. MATERIAL AND METHODS: In 20 cases (18 patients) with clinically confirmed acute musculoskeletal infections, intraoperative collected swab samples, tissue samples and fluid samples injected into standard blood culture vials were used for microbiological diagnosis. Identification of bacteria, time necessary for detection and ease of handling during surgery was evaluated. RESULTS: In 19 cases bacterial growth was demonstrated using either intraoperative swabs or blood culture technique (95% sensitivity), whereas 18 tissue biopsies were positive (90% sensitivity. 27 bacterial species were isolated. In 18 instances for the swab technique, 14 instances for the tissue biopsy and 4 operations for the blood culture vials, ease of handling was rated as excellent. DISCUSSION: The study demonstrated differences between the three tested methods with respect to ease of handling. With respect to the number of detected organisms and time for their detection there are no significant differences. These last findings are in contrast to of the results of other authors. The reason for this could be that during operative dissection an accurate and specific collection of specimens from the acute deep infected soft tissues and bones independent from the type of surgical procedure is possible. Therefore, even with the swab method a high amount of microorganisms can be recovered. Especially for intraarticular infections, fluid samples injected into standard blood vials is a practical method for the surgeon. In acute musculoskeletal infections other than joint infections, there is less benefit for the blood culture vials. CONCLUSION: Intraoperative swab technique yields valid results comparable to other techniques and is an accurate technique for detection of pathogens from acute musculoskeletal infections. Key words: implant, infections, bacteriological techniques, comparative study.

Absorbed dose to water determination with ionization chamber dosimetry and calorimetry in restricted neutron, photon, proton and heavy-ion radiation fields.

Absolute dose measurements with a transportable water calorimeter and ionization chambers were performed at a water depth of 20 mm in four different types of radiation fields, for a collimated (60)Co photon beam, for a collimated neutron beam with a fluence-averaged mean energy of 5.25 MeV, for collimated proton beams with mean energies of 36 MeV and 182 MeV at the measuring position, and for a (12)C ion beam in a scanned mode with an energy per atomic mass of 430 MeV u(-1). The ionization chambers actually used were calibrated in units of air kerma in the photon reference field of the PTB and in units of absorbed dose to water for a Farmer-type chamber at GSI. The absorbed dose to water inferred from calorimetry was compared with the dose derived from ionometry by applying the radiation-field-dependent parameters. For neutrons, the quantities of the ICRU Report 45, for protons the quantities of the ICRU Report 59 and for the (12)C ion beam, the recommended values of the International Atomic Energy Agency (IAEA) protocol (TRS 398) were applied. The mean values of the absolute absorbed dose to water obtained with these two independent methods agreed within the standard uncertainty (k = 1) of 1.8% for calorimetry and of 3.0% for ionometry for all types and energies of the radiation beams used in this comparison.

Fatal multidrug-resistant Acinetobacter baumannii sepsis in a patient with travel history and recent onset of systemic lupus erythematosus: a case report.

Severe infections are a common cause of death in patients suffering from systemic lupus erythematosus (SLE). We here report on a fatal multidrug-resistant Acinetobacter baumannii sepsis in a patient with newly diagnosed SLE, who had to be treated with immunosuppressants due to lupus nephritis. Detailed analysis of the patient's history revealed that colonisation probably had occurred during a recent hospitalisation of the patient in the Mediterranean region. E-test analysis indicated that resistance to carbapenems was mediated by a plasmid-encoded metallo-beta-lactamase. We conclude that travel history including previously visited health care facilities always should be carefully considered for decisions on anti-infective therapy, as travel activities increasingly facilitate spread of antimicrobial resistances.

Surgical hand disinfection with a propanol-based hand rub: equivalence of shorter application times.

The aim of this study was to determine the efficacy of a propanol-based hand rub at application times shorter than 3 min. The bacterial pre-value was obtained from the finger tips (prEN 12791). Subjects treated their hands with the reference procedure (n-propanol, 60%) for 3 min or the product (crossover design). Sterillium was applied for 3, 2, 1.5 and 1 min. Four other preparations were tested for 1 min. Post-values (immediate effect) were taken from one hand, and the other hand was gloved for 3h. After the gloves were removed, the second post-value was taken (sustained effect). Sterillium was more effective than the reference procedure at 3, 2 and 1.5 min (immediate and sustained effect). The immediate effect after 1 min was significantly lower [mean log(10) reduction factor (RF): 1.91+/-0.90 vs. 2.52+/-0.95; P=0.001], whereas the sustained effect was not (mean RF: 1.81+/-1.06 vs. 2.05+/-1.14; P=0.204). All other preparations failed the efficacy requirement at 1 min for both the immediate and sustained effect. Using 2 x 3 mL Sterillium for a total of 1.5 min for surgical hand disinfection was at least as effective as the 3-min reference disinfection.

Metallo-beta-lactamase expressing multi-resistant Acinetobacter baumannii transmitted in the operation area.

Outbreaks of Acinetobacter baumannii demonstrating multiple antibiotic resistance, including meropenem resistance, have been described as severe therapeutic problems. Here we describe a monoclonal outbreak of infection and colonization with multidrug-resistant A. baumannii over a two-month period. Resistance to meropenem was mediated by expression of a metallo-beta-lactamase enzyme. Four of 14 patients showed clinical signs of infection and two died. Contamination of the environment, water, or instruments were excluded as causes of the outbreak. All patients, except one, underwent surgery in a specific operation theatre where surgery of contamination class IV (infected, dirty) was performed. Although individual surgeon error was eliminated, analyses of the patients' histories suggested that bacterial transmission had occurred during surgery. Five patients showed signs of A. baumannii infection and two of these patients suffered from large abdominal wounds infected with a high density of A. baumannii requiring repeated revisions. Presumably, these revisions favoured the transmission of A. baumannii, which is remarkably resistant to various environmental stresses including soaps, disinfectants and dry conditions. No case of meropenem-resistant A. baumannii had been observed in the hospital before the outbreak. Interestingly, the resistant bacteria appear to have been imported by a patient returning from West Africa. This indicates that, similar to MRSA, multiresistant A. baumannii may be introduced by patients from foreign hospitals. The outbreak was stopped in the following months by reinforcing standard procedures and by taking all necessary precautions such as patient isolation, and finally only one new case was detected.

A calibration procedure for beam monitors in a scanned beam of heavy charged particles.

An international code of practice (CoP) for dosimetry based on standards of absorbed dose to water has recently been published by the IAEA [Technical Report Series No. 398, 2000] (TRS-398). This new CoP includes procedures for proton and heavy ion beams as well as all other beam qualities. In particular it defines reference conditions to which dose measurements should refer to. For proton and ion beams these conditions include dose measurements in the center of all possible modulated Bragg peaks. The recommended reference conditions in general are used also for the calibration of beam monitors. For a dynamic beam delivery system using beam scanning in combination with energy variation, like, e.g., at the German carbon ion radiotherapy facility, this calibration procedure is not appropriate. We have independently developed a different calibration procedure. Similar to the IAEA CoP this procedure is based on the measurement of absorbed dose to water. This is translated in terms of fluence which finally results in an energy-dependent calibration of the beam monitor in units of particle number per monitor unit, which is unique for all treatment fields. In contrast to the IAEA CoP, the reference depth is chosen to be very small. The procedure enables an accurate and reliable determination of calibration factors. In a second step, the calibration is verified by measurements of absorbed dose in various modulated Bragg peaks by comparing measured against calculated doses. The agreement between measured and calculated doses is usually better than 1% for homogeneous fields and the mean deviation for more inhomogeneous treatment fields, as they are used for patient treatments, is within 3%. It is proposed that the CoP in general, and in particular the IAEA TRS-398 should include explicit recommendations for the beam monitor calibration. These recommendations should then distinguish between systems using static and dynamic beams.

Reprocessing endoscopes: national recommendations with a special emphasis on cleaning--the German perspective.

Transmission of pathogens through endoscopes or endoscopic procedures has been documented frequently, although reliable data on the incidence of endoscope-associated infections do not exist. In order to control such infections as well as to ensure adequate quality management in endoscopy, the German Robert Koch Institute has produced recommendations for hygienic processing of flexible endoscopes and accessory devices. Reprocessing using a washer disinfector is explicitly preferred to manual procedures. Control measures are focused on microbiological sampling and limiting values have been defined for rinsing fluids taken from the channels of the scopes. Although the guideline leaves a number of questions open, e.g. test methods to control the efficacy of the cleaning process. It helps to establish quality management in the field of endoscopy and to improve the level of safety both for patients and staff.

Treatment planning for carbon ion radiotherapy in Germany: review of clinical trials and treatment planning studies.

The GSI carbon ion radiotherapy facility established the first completely active beam shaping system for heavy ions, using energy variation on the synchrotron and pencil beam scanning. The introduction of an active beam shaping system for carbon ions has considerable impact on the design of the treatment planning system (TPS). The TPS has to account for the capability of the beam delivery and the biological modelling, which is needed to calculate the RBE for the resulting varying depth dose modulation. The TPS used in clinical routine with carbon ions is described and its use in treatment planning studies are outlined. A clinical trial with carbon ion therapy as primary therapy for chordoma and chondrosarcoma of the base of skull has been completed in 2001. Currently, carbon ion therapy as a boost treatment together with conventional conformal photon therapy or IMRT is under investigation in clinical trials for adenoid cystic carcinoma, chordoma and chondrosarcoma of the cervical spine and sacrococcygeal chordoma. Treatment planning studies comparing carbon ion therapy with IMRT, using optimization of combination therapy, and optimization of beam-line design have already been completed. Analysis of uncertainties in treatment planning has been started with the investigation of range uncertainties stemming from CT imaging. Uncertainties coming from the beam delivery play only a minor role. An attempt to asses the uncertainties introduced in treatment plans by the biological modelling, was done, using phantom verification of calculated cell survival levels. The clinical trials and planning studies are of special importance for the upcoming new clinical ion facility of the Heidelberg university hospital.

Specific hygiene issues relating to reprocessing and reuse of single-use devices for laparoscopic surgery.

OBJECTIVE: To determine whether reprocessed single-use devices (SUD) would (1) meet regulatory standards for sterility, and (2) meet the same material standards as new devices or if they pose an infection risk to other patients. DESIGN: The study included in the first stage single-use laparoscopic dissection devices and in the second stage a variety of clinically used and reprocessed SUDs. The suitability of these devices for cleaning, disinfection, and sterilization was examined. METHODS: Testing of cleanability was conducted on devices contaminated with radioactively labeled blood. Instruments were cleaned using hospital recommended practices. Gamma counts/second were determined before and after cleaning to localize contaminants, which were additionally visualized using light and scanning electron microscopy (SEM). X-ray photoelectron spectroscopy (XPS) was used to quantify contamination elements on the materials tested. Residual bioburden testing on instruments contaminated with microorganisms suspended in blood prior to reprocessing was carried out to establish the efficacy of disinfection and sterilization. RESULTS: During the first stage of the study all devices remained contaminated after cleaning, but were effectively disinfected. Sterilization could not eliminate the challenge microorganisms completely. The findings during the second stage--examination of clinically used devices--were as follows: 11% of the sterile packages were damaged; 33% of the devices were incomplete and parts were missing; 54% did not meet the criteria for functionality; light microscopy, SEM, and XPS showed contamination on the outside and inside of all devices. Of the tested SUDs, 40% remained unsterile following resterilization. CONCLUSIONS: None of the reprocessed SUDs were effectively cleaned or sterilized. This may provide an opportunity for survival and growth of non-resistant or nosocomial organisms and viruses. The use of such inadequately reprocessed SUDs increases the risk for the patient, and can lead to nosocomial infection and to legal consequences for the health care facility.

Influence of acid-citrate-dextrose anticoagulant on blood quality in retransfusion systems after total knee arthroplasty.

The influence of acid-citrate-dextrose (ACD) anticoagulant on the blood quality was assessed in this prospective, randomized, controlled study. The clinical consequences with regard to retransfusion of drainage blood following total knee arthroplasty were evaluated. After total knee arthroplasty, retransfusion was performed utilizing a "SureTrans" retransfusion system in 81 patients. In 42 of them, blood was collected adding an ACD anticoagulant (group A), while in the remaining 39 patients blood was collected without any additives (group B). Blood losses were retransfused over a 6-h period after attaching the retransfusion system to the patient of either group. Blood samples of the 6-h blood collection were taken and analysed for several blood quality parameters. Significant differences were found in the platelet count (61,200+/-16,700 microl(-1) in group A versus 70,100+/-21,600 microl(-1) in group B, p=0.042), the lactate concentration (4.09+/-0.86 mmol/l vs 4.82+/-0.83 mmol/l, p<0.001), the pH (6.96+/-0.10 vs 7.18+/-0.06, p<0.001), as well as the protein content (5.44+/-0.57 g/dl vs 5.85+/-0.43 g/dl, p<0.001). These observed significant differences were, however, of no clinical relevance to the patients' treatment. Hemoglobin concentration, hematocrit, mean corpuscular volume (MCV), erythrocyte count, leukocyte count, concentration of free hemoglobin in the blood plasma (fHb), potassium concentration, lactate dehydrogenase (LDH), serotonin concentration, triglyceride concentration, free fatty acid concentration, and interleukin-6 concentration did not differ significantly. This study indicates that the blood quality in retransfusion systems is not substantially influenced by adding ACD anticoagulant.

Decontaminated single-use devices: an oxymoron that may be placing patients at risk for cross-contamination.

OBJECTIVE: To determine whether reprocessed single-use devices would meet regulatory standards for sterility and meet the same materials standards as a new device. DESIGN: The study included single-use and reusable biopsy forceps and papillotomes and a reusable stone retrieval basket. The suitability of these devices for cleaning and disinfection or sterilization was examined. METHODS: Testing of cleanability was conducted on devices contaminated with technetium 99-radiolabeled human blood. Instruments were cleaned using hospital recommended practices for manual cleaning. Gamma counts per second were determined before and after cleaning to localize contaminants, which were additionally visualized using light and scanning electron microscopy. X-ray photoelectron spectroscopy was used to quantify contamination elements on the materials tested. Residual bioburden testing on instruments contaminated with microorganisms suspended in coagulable sheep blood was carried out to establish the efficacy of disinfection and sterilization. RESULTS: All devices remained contaminated after cleaning, but single-use devices and the stone basket tended to be more heavily contaminated than reusable forceps and papillotomes. Cleaning procedures facilitated distribution of contaminants further into the lumens of the disposable forceps. Decreased concentrations of silicon and increased concentrations of carbon and nitrogen suggested that layers of silicon lubricant had been removed and contaminants were organic material. Reusable devices were effectively disinfected, but single-use devices were not. Sterilization could not eliminate the challenge microorganisms completely. CONCLUSIONS: None of the reprocessed single-use instruments were effectively cleaned, disinfected, or sterilized. This condition may provide an opportunity for the viability of nonresistant or nosocomial organisms and viruses. Additionally, reprocessing procedures may result in material destruction of fragile devices. Cost-saving initiatives that have inspired reprocessing of single-use devices, despite the absence of data establishing the efficacy of decontamination and the durability of materials throughout reprocessing, should be pushed into the background.

Increased interleukin-6 in collected drainage blood after total knee arthroplasty: an association with febrile reactions during retransfusion.

We determined interleukin-6 (IL-6) concentrations in collected shed drainage blood intended for retransfusion in a prospective study in 81 patients after total knee replacement. We found large increases in IL-6 levels, averaging 6.5 (SD 3.9) ng/mL, in shed blood collected in the first 6 postoperative hours. 3 patients had febrile reactions after collected blood was retransfused. The IL-6 levels in the drainage blood of these patients were very high (9.6-13.4 ng/mL). In the blood collected after 6 hours, IL-6 concentrations increased to 47 (SD 33) ng/mL (p < 0.001). These results suggest a relation between increased interleukin-6 concentrations in shed drainage blood and the occurrence of febrile reactions after retransfusion of such blood.

A method for determining the alignment accuracy of the treatment table axis at an isocentric irradiation facility.

At an isocentric irradiation facility, the rotation axis of the treatment table has to be accurately aligned in vertical orientation to the isocentre, which is usually marked by three perpendicular laser planes. In particular, high precision radiotherapy techniques, such as radiosurgery or intensity modulated radiotherapy, require a higher alignment accuracy of the table axis than routinely specified by the manufacturers. A simple and efficient method is presented to measure the direction and the size of the displacement of the table axis from the isocentre as marked by the lasers. In addition, the inclination of the table axis against the vertical direction can be determined. The measured displacement and inclination provide the required data to correct for possible misalignments of the treatment table axis and to maintain its alignment. Measurements were performed over a period of two years for a treatment table located at the German heavy ion therapy facility. The mean radial distance between the table axis and the isocentre was found to be 0.25 +/- 0.25 mm. The mean inclination of the table axis in the XZ- and YZ-planes was measured to be -0.03 +/- 0.02 degrees and -0.04 +/- 0.01 degrees, respectively. The measurements demonstrate the good alignment of the treatment table over the analysed time period. The described method can be applied to any isocentric irradiation facility, especially including isocentric linear accelerators used for radiosurgery or other high precision irradiation techniques.

Time-related changes of collected shed blood in autologous retransfusion after total knee arthroplasty.

A prospective study was done to determine the changes in blood quality parameters of collected drainage blood in retransfusion systems at 6 and 12 h after surgery to verify whether the blood was still suitable for retransfusion purposes for an additional 6 postoperative hours beyond the so far accepted first 6-h time window after surgery. Eighty-one patients received retransfusion within the first 6 h immediately following total knee arthroplasty. Additionally, drainage blood was collected for another 6 h using the same retransfusion system. Samples for laboratory analysis were taken from both the first and second 6-h blood collection interval. Hemoglobin values increased from 9.6 to 10.4 g dl(-1) (p = 0.021). Platelet counts increased from 65,500 to 80,900 microl(-1) (p < 0.001). Leukocyte counts increased from 5,550 to 8,190 1(-1) (p < 0.001). Lactate dehydrogenase (672 U l(-1) during the first vs 651 U l(-1) during the second collection period) and free hemoglobin (71.7 mg dl(-1) vs 67.0 mg dl(-1)) did not change significantly. The potassium concentration decreased slightly from 4.33 to 4.20 mg dl(-1) (p = 0.002). The lactate concentration increased from 4.44 to 7.21 mg dl(-1) (p < 0.001). The pH decreased from 7.07 to 6.94 (p < 0.001). Interleukin-6 concentration increased from 6,500 to 46,500 ng l(-1) (p < 0.001). In this study, we found no relevant difference in most of the drainage blood quality parameters between the first 6-h collection period and the second 6-h collection with regard to its suitability for autologous retransfusion except higher interleukin-6 levels. Due to the higher interleukin concentration, a possible increase in febrile reactions should be taken into account during retransfusion.

Does hand care ruin hand disinfection?

Hand washing and hand disinfection put considerable stress on the skin thus requiring specific hand care. It is important however that the care products do not impair the effect of hand disinfectants. We therefore investigated the interaction of two hand care products (oil-in-water and water-in-oil emulsions) on the microbicidal efficacy of different alcoholic hand-rubs, using the contamination model described in EN 1500. The mean log10-reduction factors for three hand-rubs varied between 4.03 and 4.22 compared with 3.76 and 4.43 for six possible combinations of hand-rubs and hand care products applied immediately prior to disinfection. Differences between reduction factors achieved with hand-rubs alone and in combination with hand care were not significant. Repeated application of care products with subsequent hand disinfection also did not result in significantly lower reduction factors than achieved with hand disinfection alone. Our data suggest that administration of selected products for hand care does not necessarily impair hand disinfection and is therefore recommended for occupational health as well as for infection control reasons.