Helga Häfner

Influence of an Infectious Disease Service on Antibiotic Prescription Behavior and Selection of Multiresistant Pathogens

SummaryBackground: A routine infectious disease service was established in January 1998 in order to optimize the antibiotic usage and prescription pattern of a neurologic intensive care unit (NICU). Methods: Treatment guidelines for the most prevalent infections wer implemented and individual antibiotic regimes were discussed at the bedside with infectious disease experts. Results: This interdisciplinary cooperation reduced the total number of antibiotics prescribed by 38.1%, from 7,789 in 1997 to 4,822 in 1998, without comprimising patient outcomes (mortality rate: 22/313 patients in 1997 vs 32/328 patients in 1998). Total patient days (2,254 days vs 2,296 days) and average length of stay in the NICU (7.2 days vs 7.0 days) were comparable. Antimicrobial expenditure decreased by 44.8% (71,680 Euros in 1997 vs 39,567 Euros in 1998). Taking into account the costs for the infectious disease service (approximately 8,000 Euros in 1998), a total saving of 24,113 Euros was made. The dramatic reduction in antibiotic usage (mainly of carbapenems) resulted in a statistically significant decreased isolation of Stenotrophomonas maltophilia (p < 0.05), Enterobacter cloacae (p < 0.05), multiresistant Pseudomonas aeruginosa (p < 0.05) and Candida spp. (p < 0.05), without any change in the infection control guidelines. Conclusion: These data show that an infectious disease service can optimize and reduce antibiotic usage. This results in a decrease in the occurrence of multiresistant gram-negative pathogens and Candida spp. in intensive care units, and, at the same time, saves costs.

Comparison of two sampling methods for the detection of gram-positive and gram-negative bacteria in the environment: moistened swabs versus Rodac plates.

The objective of this study was to evaluate the moistened swab technique vs. Rodac plates for detecting Gram-positive and Gram-negative bacteria in the inanimate environment. Over a period of 22 months, the environment of 190 patients infected or colonized with MRSA, VRE or multiresistant Gram-negative bacteria was sampled in turn. MRSA and VRE could be detected with either method in 33 out of 54 (61.1%) patient rooms in 174 out of 706 (24.6%) environmental samples. However, multiresistant Gram-negative bacteria were found in 42 out of 136 (30.9%) rooms with a very low frequency of 89 out of 1827 (4.9%) environmental samples (p < 0.0001). The sensitivity of the swab technique for Gram-positive cocci was 54% (94/174) vs. 69.5% (121/174) for the Rodac plates, ([CI95%], 47-61% vs. 62-76%, p < 0.05). In contrast, the sensitivity of the swab technique for Gram-negative bacteria was 74.2% (66/89) vs. 42.7% (38/89) for the Rodac plates, ([CI95%], 64-83% vs. 32-54%, p < 0.05). In conclusion, environmental contamination with Gram positive cocci is detected more often than with Gram-negative bacteria. For the detection of Gram-positive cocci, Rodac plates are superior to the swab technique; whereas Gram-negative rods can be detected more often by the swab technique. All these results proved to be statistically significant.

Periodic Surveillance of Nosocomial Infections in a Neurosurgery Intensive Care Unit

Background:We assessed data on the epidemiology of nosocomial infections (NIs) in a 14-bed neurosurgical intensive care unit (NSICU) and used surveillance data for the promotion of quality improvement activities.Patients and Methods:Prospective periodic surveillance was performed over five 3-month periods between July 1998 and October 2002 on all patients admitted with a length of stay > 24 hours.Results:763 patients with a total of 4,512 patient days and a mean length of stay of 5.9 days were enrolled within the 15-month study period. A total of 93 NIs were identified in 82 patients. Urinary tract infections (24.7%), pneumonia (23.6%), and bloodstream infections (17.2%) were the most frequent NIs recorded. Device-associated incidence rates were 6.0 (3.8–9.0, CI95%) for urinary tract infection, 4.4 (2.4–7.4, CI95%) for bloodstream infection, and 10.3 (6.3–15.9, CI95%) for pneumonia per 1,000 days at risk. For improvement of infection control-related processes, evidence-based infection control guidelines were established and an NSICU nurse was designated to be responsible for infection control issues on the ward. In addition, several infection control problems arose during the observation periods and were rapidly responded to by introducing specific intervention strategies.Conclusion:Periodic surveillance is a valuable tool for assessing the epidemiology of NIs in the NSICU setting as well as for promoting the initiation of quality improvement activities.

Surveillance of nosocomial infections in a neurologic intensive care unit.

OBJECTIVE To assess data on the epidemiology of nosocomial infection (NI) among neurologic intensive care patients. DESIGN Prospective periodic surveillance study. SETTING An 8-bed neurologic intensive care unit (ICU). PATIENTS All those admitted for more than 24 hours during five 3-month periods between January 1999 and March 2003. METHODS Standardized surveillance within the German infection surveillance system. RESULTS Three hundred thirty-eight patients with a total of 2,867 patient-days and a mean length of stay of 8.5 days were enrolled during the 15-month study period. A total of 71 NIs were identified among 52 patients. Urinary tract infections (UTIs) were the most frequent NI (36.6%), followed by pneumonia (29.6%) and bloodstream infections (BSIs) (15.5%). The overall incidence and incidence density of NIs were 21.0 per 100 patients and 24.8 per 1,000 patient-days, respectively. Incidence densities were 9.8 UTIs per 1,000 urinary catheter-days (CI95, 6.4-14.4), 5.6 BSIs per 1,000 central venous catheter-days (CI9s, 2.8-10.0), and 12.8 cases of pneumonia per 1,000 ventilation-days (Cl95, 8.0-19.7). Device-associated UTI and pneumonia rates were in the upper range of national and international reference data for medical ICUs, despite the intensive infection control and prevention program in operation in the hospital. CONCLUSION Neurologic intensive care patients have relatively high rates of device-associated nosocomial pneumonia and UTI. For a valid comparison of surveillance data and implementation of targeted prevention strategies, we would strongly recommend provision of national benchmarks for the neurologic ICU setting.

Evaluation of hydrogen peroxide vapor for the inactivation of nosocomial pathogens on porous and nonporous surfaces

BACKGROUND Clostridium difficile spores and multidrug-resistant (MDR) organisms, such as methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), and MDR Acinetobacter baumannii, are important nosocomial pathogens that are difficult to eliminate from the hospital environment. We evaluated the efficacy of hydrogen peroxide vapor (HPV), a no-touch automated room decontamination system, for the inactivation of a range of pathogens dried onto hard nonporous and porous surfaces in an operating room (OR). METHODS Stainless steel and cotton carriers containing >4 log10 viable MRSA, VRE, or MDR A baumannii were placed at 4 locations in the OR along with 7 pouched 6 log10Geobacillus stearothermophilus spore biologic indicators (BIs). HPV was then used to decontaminate the OR. The experiment was repeated 3 times. RESULTS HPV inactivated all spore BIs (>6 log10 reduction), and no MRSA, VRE, or MDR A baumannii were recovered from the stainless steel and cotton carriers (>4-5 log10 reduction, depending on the starting inoculum). HPV was equally effective at all carrier locations. We did not identify any difference in efficacy for microbes dried onto stainless steel or cotton surfaces, indicating that HPV may have a role in the decontamination of both porous and nonporous surfaces. CONCLUSION HPV is an effective way to decontaminate clinical areas where contamination with bacterial spores and MDR organisms is suspected.

Simultaneous placement of multiple central lines increases central line–associated bloodstream infection rates

BACKGROUND Surveillance for central line (CL)-associated bloodstream infections (CLABSIs) is generally advocated. However, the standard definition of this surveillance does not take into account the number of CLs in place and thus the possibility of increased infection risk with multiple CLs in place simultaneously. In this study, we tested the hypothesis that simultaneous placement of more than 1 CL is associated with an increased CLABSI rate. METHODS The number of CLs, CL-days, and CLABSIs and CLABSI rates with regard to the number of CLs in place simultaneously was documented in 2 intensive care units between 2001 and 2011. Standard CLABSI rates, as well as the rates for 1 CL and multiple CLs in place, were calculated. RESULTS The average CLABSI rate was significantly lower in patients with 1 CL in place compared with those with more than 1 CL in place (3.69 per 1,000 CL-days vs 13.09/1,000 CL-days; incidence rate ratio [IRR], 3.63; 95% confidence interval [CI], 2.61-5.05). Importantly, all differences from the standard rate (5.94/1,000 CL-days) were significant (1 CL vs standard: IRR, 0.61; 95% CI, 0.51-0.74; more than 1 CL vs standard: IRR, 2.23; 95% CI, 1.87-2.65; both P < .0001). CONCLUSIONS Our data show that the number of CLs in place had a strong influence on CLABSI rates. Thus, we advocate stratifying patients by the number of CLs in place to take this increased risk of infection into account during surveillance.

Preliminary survey of local bacteriophages with lytic activity against multi‐drug resistant bacteria

Bacteriophages (phages) represent a potential alternative for combating multi‐drug resistant bacteria. Because of their narrow host range and the ever emergence of novel pathogen variants the continued search for phages is a prerequisite for optimal treatment of bacterial infections. Here we performed an ad hoc survey in the surroundings of a University hospital for the presence of phages with therapeutic potential. To this end, 16 aquatic samples of different origins and locations were tested simultaneously for the presence of phages with lytic activity against five current, but distinct strains each from the ESKAPE‐group (i.e., Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter cloacae). Phages could be isolated for 70% of strains, covering all bacterial species except S. aureus. Apart from samples from two lakes, freshwater samples were largely devoid of phages. By contrast, one liter of hospital effluent collected at a single time point already contained phages active against two‐thirds of tested strains. In conclusion, phages with lytic activity against nosocomial pathogens are unevenly distributed across environments with the prime source being the immediate hospital vicinity.

Healthcare worker-related MRSA cluster in a German neonatology level III ICU: a true European story.

Here we investigated a cluster of eight newly Methicillin-resistant Staphylococcus aureus (MRSA)-colonized neonates at an ICU, and present data on molecular strain characterization as well as the source identification process in which we analyze the impact of MRSA-colonized HCWs. Molecular strain characterization revealed a unique pattern which was identified as spa-type t 127--an extremely rare strain type in Germany. Environmental sampling and screening of parents of colonized neonates proved negative. However, staff screening identified one healthcare worker (HCW; 1/134) belonging to a group of recently employed Romanian HCWs who was colonized with the spa 127 strain. Subsequent screening also detected MRSA in 9/51 Romanian HCWs (18%) and 7/9 (14% of all) isolates showed the same molecular pattern as the index case (spa/PFGE type). All carriers were successfully decolonized, after which no new patient cases occurred. As a result, we have now implemented a universal screening programme of all new employees as part of our infection control management strategy. MRSA-colonized HCWs can act as a source for in hospital transmission. Since HCWs from high endemic countries are particular prone to being colonized, they may pose a risk to patients.

Differential Effect of Newly Isolated Phages Belonging to PB1-Like, phiKZ-Like and LUZ24-Like Viruses against Multi-Drug Resistant Pseudomonas aeruginosa under Varying Growth Conditions

In this study, we characterize three phages (SL1 SL2, and SL4), isolated from hospital sewage with lytic activity against clinical isolates of multi-drug resistant Pseudomonas aeruginosa (MDR-PA). The host spectrum ranged from 41% to 54%, with all three phages together covering 79% of all tested clinical isolates. Genome analysis revealed that SL1 (65,849 bp, 91 open reading frames ORFs) belongs to PB1-like viruses, SL2 (279,696 bp, 354 ORFs) to phiKZ-like viruses and SL4 (44,194 bp, 65 ORFs) to LUZ24-like viruses. Planktonic cells of four of five selected MDR-PA strains were suppressed by at least one phage with multiplicities of infection (MOIs) ranging from 1 to 10−6 for 16 h without apparent regrowth of bacterial populations. While SL2 was most potent in suppressing planktonic cultures the strongest anti-biofilm activity was observed with SL4. Phages were able to rescue bacteria-infected wax moth larvae (Galleria melonella) for 24 h, whereby highest survival rates (90%) were observed with SL1. Except for the biofilm experiments, the effect of a cocktail with all three phages was comparable to the action of the best phage alone; hence, there are no synergistic but also no antagonistic effects among phages. The use of a cocktail with these phages is therefore expedient for increasing host range and minimizing the development of phage resistance.

Influence of signal colored hand disinfectant dispensers on hand hygiene compliance at a medical intensive care unit

To assess the influence of signal colors on hand disinfectant dispenser activities, health care workers (HCWs) at a medical intensive care unit were analyzed for a total of 20 weeks with 8 weeks before and 12 weeks after exchange to signal color. No significant increase in hand rubs (HRs) per patient day (PD) was observed (about 40 HRs/PD); however, HCW-adjusted compliance showed a 6% increase with signal colored devices. Therefore, colored devices may help to improve hand hygiene compliance.