Outbreak Of Vancomycin-resistant Enterococci Research Articles

Environmental Contamination as an Important Route for the Transmission of the Hospital Pathogen VRE: Modeling and Prediction of Classical Interventions

Background In addition to the close contact between patients and medical staff, the contamination of surfaces plays an important role in the transmission of pathogens such as vancomycin-resistant enterococci (VRE). Mathematical modeling is a very convenient tool for hospital infection control as it allows the quantitative prediction of the effects of special hygiene and control interventions. Methods We present a compartmental model which describes the dynamics of transmission from patient to patient, also taking into account the interaction with medical staff and environmental contamination. Empirical data from a VRE outbreak in the onco-haematological unit at the University Medical Center Freiburg (Germany) were collected with 100 consecutive admissions being followed up for 90 days. Stochastical simulations were used to predict the prevalence of patients colonised with VRE at the time when at least one of the following interventions were introduced: hand hygiene, disinfection of surfaces, cohorting, screening and antibiotic reduction. Results Graphical figures show the temporal dynamics of several simulation scenarios. If no prevention or intervention is present, simulations based on transmission models predict an expected endemic prevalence per ward of 0.83 (95% CI:0.66, 1.00) after the first infected person enters the unit. Interventions may reduce this prevalence, but only the combination of several interventions can control a VRE outbreak. Conclusions The model predicts that only the combination of several interventions can control an VRE outbreak in this setting. The inclusion of environmental contamination improves the compartmental model and allows a prediction of the efficacy of the disinfection of surfaces. These results can be applied to other settings and will therefore help to understand and control the spread of nosocomial pathogens.

Successful control of vancomycin-resistant <i>Enterococcus faecium</i> outbreak in a neurosurgical unit at non-endemic region

Vancomycin-resistant enterococci (VRE) have emerged in many parts of the world, but have only been reported sporadically in Hong Kong. We report an outbreak of vancomycin-resistant Enterococcus faecium (VREfm) in a neurosurgical unit at a tertiary teaching hospital between 3 March and 3 April 2009 in Hong Kong. During the outbreak investigation, clinical samples from 193 (91.5%) of 211 patients who had stayed in the neurosurgical unit and 506 environmental samples were screened for VREfm. Besides the index case, another 3 (1.6%) out of 192 patients were found to be positive for VREfm. Two (0.4%) out of 506 environmental samples were positive for VREfm. All four clinical and two environmental isolates were found to be clonally related by pulse-field gel electrophoresis. The risk factors for nosocomial acquisition of VREfm included advanced age (P=0.047), presence of nasogastric tubing (P=0.002) and tracheostomy (P<0.001), and the use of β-lactam antibiotics (P<0.001) and vancomycin (P=0.001). Contrary to other VRE outbreaks in which the spread was rapid, the neurosurgical patients’ immobilization because of coma and mechanical ventilation dependency, and the vigilant practice of hand hygiene by health-care workers successfully limited the number of secondary cases despite the delayed recognition of the index case. All patients with VREfm were labeled in the hospital network information system so that stringent infection control measures with contact precautions would be carried out once these patients were readmitted to prevent its spread in our locality.

Rapid control of an outbreak of vancomycin-resistant enterococci in a French university hospital

Vancomycin-resistant enterococci (VRE) are emerging in French hospitals. A VRE outbreak occurred in our hospital, prompting efforts to eradicate the organism. The following interventions were implemented simultaneously to control the outbreak: (1) creation of a VRE control committee; (2) cohorting of VRE carriers in a dedicated ward; (3) extensive screening of contact patients; (4) use of a sensitive technique for detecting VRE in rectal samples; (5) intervention of a dedicated team to reduce consumption of selected antibiotics; (6) information for, and education of, all hospital staff; and (7) electronic tracking of in-hospital transfer and readmission of VRE carriers and contact patients. Over a four-week period following admission of the index case, 37 carriers of a single strain of vanA vancomycin-resistant Enterococcus faecium were identified across seven units. A single additional readmitted contact patient was identified later. Of the 39 VRE-positive patients, two had urinary tract infections and 37 were colonised. Of the 32 patients with known VRE stool concentrations, 23 had low and nine high concentrations. One low-concentration patient precipitated transmission in another unit. This aggressive, co-ordinated, multifaceted strategy was successful in halting a widespread VRE outbreak in our hospital.

Intensified Strategies to Control Vancomycin-Resistant Enterococci in Immunocompromised Patients

Increasing colonization and infection with vancomycin-resistant enterococci (VRE) in immunocompromised patients are associated with increased mortality. Despite contact precautions for VRE control, rapid limitation of its spread is often impossible. We report on a VRE outbreak in a hematologic/oncologic unit including 33 patients. Although 28 of the patients had only VRE colonization, VRE-related infection was probable in 4 patients, and VRE infection of the bloodstream occurred in 1 case. Two patients were identified by VRE screening on admission, 20 were identified by weekly routine VRE screening, and 6 were identified from specimens taken to clarify infections (eg, urine, bronchoalveolar lavage). Five individuals acquired VRE colonization as inpatients (contact patients). Multiple-locus variable-number tandem repeat analysis (MLVA) proved that the outbreak was caused by VanA gene-positive Enterococcus faecium belonging to MLVA genogroup C1(MLVA types 1, 7, 12). The outbreak strains exhibited the potential virulence factor esp(enterococcus surface protein). The outbreak was terminated within 2 months by intensified infection-control measures, including quarantine and the cohorting of patients who tested positive for VRE; however, VRE spread recurred after the measures were discontinued but was again limited by resuming the measures. We conclude that intensive infection-control strategies enable the timely termination of VRE outbreaks, even those involving VRE strains with high epidemic potential on "high-risk wards" (eg, hematologic/oncologic units). Premature discontinuation of infection-control measures may cause recurrence of the VRE spread.

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.

Predictors of Vancomycin-resistant Enterococcus (VRE) Carriage in the First Major VRE Outbreak in Singapore

Until recently, vancomycin-resistant enterococcus (VRE) infection or colonisation was a rare occurrence in Singapore. The first major VRE outbreak involving a 1500-bed tertiary care institution in March 2005 presented major challenges in infection control and came at high costs. This study evaluates the predictors of VRE carriage based on patients' clinical and demographic profiles. Study patients were selected from the hospital inpatient census population during the VRE outbreak (aged 16 years or more). Clinical information from 84 cases and 377 controls were analysed. Significant predictors of VRE carriage included: age>65 years Odds ratio (OR), 1.98; 95% CI (confidence interval), 1.14 to 3.43); female gender (OR, 2.15; 95% CI, 1.27 to 3.65); history of diabetes mellitus (OR, 1.94; 95% CI, 1.14 to 3.30), and staying in a crowded communal ward (OR, 2.75; 95% CI, 1.60 to 4.74). Each additional day of recent hospital stay also posed increased risk (OR, 1.03; 95% CI, 1.01 to 1.04). Elderly diabetic females with prolonged hospitalisation in crowded communal wards formed the profile that significantly predicted VRE carriage in this major hospital-wide outbreak of VRE in Singapore. It is imperative that active VRE surveillance and appropriate infection control measures be maintained in these wards to prevent future VRE outbreaks.

Vancomycin-resistant enterococci outbreak in an intensive care unit: prevention and control

Infection caused by vancomycin-resistant enterococci (VRE) is associated with high morbidity and mortality rates; it poses a serious threat, in particular, to critically ill patients. It generates high costs and challenges infection control programs. An important component of VRE control is the identification of colonized patients. Since December 2001 we have monitored patients in high-risk units, who would be most susceptible for acquiring VRE. Contact precautions are implemented for VRE-colonized or VRE-infected patients.

Entérocoques résistant aux glycopeptides dans un contexte endémo-épidémique: Stratégie d’isolement à l’admission des patients à risque

To evaluate a strategy based on screening and isolation at admission to a department of infectious diseases during an epidemic of vancomycin-resistant Enterococcus (VRE) at the University Hospital of Clermont-Ferrand.Systematic screening for VRE by anal swabs began on November 15, 2004. Patients were isolated on admission if (a) they had been hospitalized more than 24 h in an at-risk department of our hospital or (b) they had received a course of wide-spectrum antimicrobial therapy for longer than 48 h in the three months preceding admission. Patients hospitalized in our department were screened weekly if they were treated with wide-spectrum antibiotics, had a urinary catheter left in place for one week, or were neutropenic.Through May 15, 2005, 12 (3.5%) of 341 swabs were found to be positive for VRE: eight were detected on admission and four during hospitalization. In all, 81 patients were isolated on admission. A case-control study confirmed that the criteria for patient isolation were indeed risk factors for VRE. Isolation was well accepted when it was clearly explained. No new case has been detected since March 2005.An isolation strategy based on known risk factors for VRE with systematic screening on admission appears to be an effective way to control an outbreak of VRE, perhaps in part because it helps to keep the medical staff alert to this problem. Isolation is well tolerated as long as it is explained clearly.

Effective Control of a Nosocomial Outbreak of Vancomycin-Resistant Enterococcus faecium in a Hemato-Oncology Unit in a Korean Tertiary Care Hospital

BACKGROUND/OBJECTIVES: To determine the risk factors and cost for nosocomial vancomycin-resistant enterococci (VRE) bacteremia and to control the outbreak of nosocomial VRE bacteremia in a hemato-oncology unit. METHODS: A total of 7 cases of VRE isolated patients were detected from Nov 13 to Dec 2, 2005 in a 69-bed hemato-oncology unit in a 1250-bed tertiary care hospital in Korea. Thirty patients were selected for control among the patients without VRE infection or colonization, who were admitted to the same unit during the same period. Risk factors for VRE bacteremia were analyzed with Mann-Whitney U test and Fishers exact test. Intensive infection control strategies were implemented to control the VRE outbreak: reinforcing strict isolation and hand hygiene for VRE isolated patients, health care workers (HCWs); surveillance cultures from patients, HCWs and environment; thorough environmental cleaning and disinfection; re-education for HCWs about VRE infection control policies. RESULTS: Among the enrolled 7 patients, 4cases had VRE bacteremia and 3 cases were VRE rectal colonizer. VRE were grown from 5 out of 72 surveillance cultures of environment during the outbreak period. Before the outbreak, patients with VRE bacteremia were only 2 cases in the unit from Jan 1, 2004 to Nov 13, 2005. Risk factors for VRE bacteremia were as follows: indwelling Hickman catheter (p = 0.003), duration of hospitalization (p > 0.001), admission to a multi-bed room (p = 0.016) , <i>C. difficile</i> positivity (p = 0.027), and duration of vancomycin usage (p > 0.001). PFGE for VRE revealed 3 different PFGE patterns. VRE from 4 cases showed the same PFGE pattern as that of environmental culture isolates. Intensive infection control implementation terminated outbreak promptly and no new cases were detected up to now (for more than 1 month) after the outbreak. We spent around $900∼950 for investigation and control of the outbreak, which was cheaper than the cost for an isolation private room fee ($4760∼5460). CONCLUSIONS: Our data suggest that early intervention was very effective to control the outbreak and to save the extra cost of strict isolation for VRE patients.

Vancomycin-Resistant Enterococci: Colonization, Infection, Detection, and Treatment

Vancomycin-resistant enterococci (VRE) are becoming a major concern in medical practice. Their increased prevalence and their ability to transfer vancomycin resistance to other bacteria (including methicillin-resistant Staphylococcus aureus) have made them a subject of close scrutiny and intense investigation. Colonization is usually acquired by susceptible hosts in an environment with a high rate of patient colonization with VRE (eg, intensive care units, oncology units). Vancomycin-resistant enterococci can survive in the environment for prolonged periods (>1 week), can contaminate almost any surface, and can be passed from one patient to another by health care workers. Whether VRE colonization leads to infection depends on the health status of the patient. Whereas immunocompetent patients colonized with VRE are at low risk for infection, weakened hosts (patients with hematologic disorders, transplant recipients, or severely ill patients) have an increased likelihood of developing infection following colonization. Quinupristin-dalfopristin and linezolid are among the anti-infective agents that have recently become available to treat infection caused by VRE. Other antimicrobials are currently under development. Molecular techniques such as polymerase chain reaction and standard culture studies are being used to detect VRE colonization, infection, and outbreaks.

Outbreak of vancomycin-resistant Enterococcus spp. in an Italian general intensive care unit

Following the identification of two clinical isolates of vancomycin-resistant enterococci (VRE) from intensive care unit (ICU) patients, a surveillance programme detected that six of eight ICU patients were colonised by VRE. Standard epidemic control measures were instituted in the ICU. During a 16-month period, 13 (2.5%) of 509 ICU patients had VRE-positive swabs upon admission, and 43 (8.7%) of 496 VRE-negative patients were colonised by VRE in the ICU. Patients who acquired VRE in the ICU had a longer ICU stay (p < 0.0001). No other statistically significant differences were demonstrated. Two patients had documented infection (infection/colonisation index, 3.6%; overall VRE infection frequency, 0.4%), but both recovered and were discharged. VRE colonisation did not increase the mortality rate. Automated ribotyping identified three clusters containing, respectively, the first 52 Enterococcus faecium isolates, two Enterococcus faecalis isolates, and two further isolates of E. faecium. Multilocus sequence typing demonstrated that two E. faecium isolates representative of the two ribotypes belonged to sequence types 78 and 18, and that these two isolates belonged to the epidemic lineage C1, which includes isolates with a wide circulation in northern Italy. The outbreak was controlled by continuous implementation of the infection control programme, and by the opening of a new unit with an improved structural design and hand-washing facilities.

P8.05 Outbreak of Vancomycin Resistant Enterococci Among Immunocompromized Patients in a Region with a Very Low Endemic VRE-Rate in Recent Years

P8.05 Outbreak of Vancomycin Resistant Enterococci Among Immunocompromized Patients in a Region with a Very Low Endemic VRE-Rate in Recent Years

P14.01 A Review of Control Measures in Containing a Large Outbreak of Vancomycin-resistant enterococci (VRE) in a Non-endemic Setting

P14.01 A Review of Control Measures in Containing a Large Outbreak of Vancomycin-resistant enterococci (VRE) in a Non-endemic Setting

Outbreak of Vancomycin-Resistant Enterococci (VRE) in a Hematological Oncology Ward and Hygienic Preventive Measures. A Long-Term Study

Background: We report on two endemic outbreaks ofVRE (vancomycin-resistant enterococci, vanA type Ente-rococcusfaecium) on a hematological oncology ward ina university hospital and a new strategic concept to fightagainst spread of VRE. Patients and Methods: Duringmanagement of the outbreak, a total of 1,124 patientsand 1,700 specimens were investigated from June 1999to December 2001. Protective measures were instituted.Intensive prophylactic infection control was practiceduntil December 2003. Results: Of the 1,124 patients,44 were VRE-positive. From 1,700 environment speci-mens,110 VRE isolates were obtained from the inani-mateenvironment, 5 from the living environment. Mole-cularbiological typing identified 5 different clones whichhad spread on the ward in different locations. Conclu-sion:The study shows the need for prophylactic microbi-ologicalscreening investigations in the risk group ofhematological oncology patients and consistent imple-mentationof protective hygiene measures to prevent thespread of multiresistant infectious pathogens on riskwards. It is also shown that intervention can to controlsuch an endemic outbreak.

Outbreak of vancomycin resistant enterococcus in a hematology/oncology unit in a Korean university hospital, and risk factors related to patients, staff, hospital care and facilities

A vancomycin-resistant Enterococcus (VRE) outbreak occurred at a hematology/oncology (HO) service in a tertiary acute care hospital, 1 January to 30 April 2002. This study was undertaken to identify risk factors, and to establish relations between seasonal factors and this VRE outbreak. Every patient (n = 82) and health care worker (HCW) (n = 31) at the HO unit was screened by rectal swab and stool culture during the VRE outbreak. Environmental surface culture (n = 35) and pulsed-field gel electrophoresis (PFGE) of VRE isolates were preformed. Among a total of 82 patients, 17 had VRE. All VRE isolates were E. faecium, the 6 studied further were Van A with identical PFGE patterns. Cultures of surfaces and HCWs were negative for VRE. Prolonged hospital stay (p = 0.02), male gender (p = 0.02), and care in a 6-bed room (p < 0.01) were risk factors for acquisition of VRE. An association with the VRE outbreak period was found again for long hospital stay, but also for the antibiotic usage pattern, frequent surgery and a high proportion of new inexperienced staff (52% vs 4% before the outbreak (p < 0.01, Fisher's exact test). Sudden personnel turnover in high-risk units should be avoided.

Management of Febrile Neutropenia: Single Agent or Combination Therapy?.

The best strategy for the empirical treatment of fever in profoundly neutropenic patients (pts) remains unclear. We retrospectively compared the efficacy and safety of 2 antibacterial regimens consecutively used in our center for febrile neutropenia (FN) in pts undergoing intensive chemotherapy for acute leukemia or autologous stem cell transplantation. From 1/99 to 6/01, 374 episodes of FN in 179 pts were treated with piperacillin-tazobactam plus amikacin (PTA, 4.5 g q6h and 20 mg/kg q24h respectively), then from 7/01 to 12/03, 428 episodes in 223 pts were treated with cefepime (CEF, 2g q8h). Any modification of the initial regimen was evaluated as a failure. Pts were nursed in HEPA-filtered rooms and received prophylactic aciclovir (and ciprofloxacin until 12/99) with no antifungal primary prophylaxis. There were no significant differences between the PTA and CEF episodes regarding median age of the pts, median days with neutrophils <500/μl or presence of an intravenous central catheter. The proportion of documented bacteremias was similar (33/30%) with a Gram negative predominance in both periods (60/66%), mainly due to E. coli (61/64%) and P. aeruginosa (14/14%). As for Gram positive bacteremias, there was an increase in S. aureus (18% in PTA vs 27% in CEF) and a marked decrease in S. viridans (24/4%). Resistance of Gram negative bacteria to the protocol drugs remained low (7% to PT and 4% to A in the first period, 5% to CEF in the second); resistance of coagulase negative staphylococci to ciprofloxacin dropped from 33 to 15%. Success rates were 35% for PTA and 32% for CEF. The reasons for modification of the initial empirical regimen were similar in the 2 periods, the most frequent being persistent fever (56/59%) followed by progression of infection (20/18%), relapsing fever (19/14%), withdrawal due to toxicity (3/6%) and resistant pathogen (1/3%). The addition of an antifungal was the most usual modification, occuring in 44% of PTA and 39% of CEF episodes. Vancomycin (for which a restriction policy had been introduced in 1995 after an outbreak of vancomycin-resistant enterococci) was added in 17 and 15% of the episodes. Amikacin was added in 38% of the CEF episodes. The occurence of further infections did not differ between the 2 periods (26 and 29%) nor did the mortality due to infection (7.7 and 6%). The proportion of severe adverse events (CTC-NCI grades 3/4) was low in both periods (4 and 1%). Cutaneous allergic reactions were less frequent with PTA than with CEF (5 vs 9%). We conclude that monotherapy with CEF was as effective as the combination of PTA for empirical treatment of FN. Both regimens resulted in a low infectious mortality and a very low emergence of resistance, and both were well tolerated.

Early Cessation of a Vancomycin-Resistant Enterococci (VRE) Outbreak in a Hematology-Oncology Department after Implementation of an Enhanced Infection Control Intervention. A Single Center Experience.

Introduction: Worldwide, the incidence of nosocomial outbreaks of VRE has increased especially in high-risk patients such as hematology-oncology patients. Outbreaks reported so far, required a minimum of three months to be controlled. Such outbreaks have a serious impact on daily care and treatment of the patients and hospital economics.Patients and Methods: We describe the outcome of a VRE-outbreak in a department with 48 beds (fourteen 2-patient rooms, and 20 single-patient rooms) including allogeneic BMT. Epidemiological evaluation was initiated after two patients in the department for the first time had a blood stream infection (BSI) with VRE within one week. Two goals had to be achieved immediately: 1) Assessment of the outbreak and 2) Implementation of enhanced infection control measures. Screening of all inpatients on a weekly basis became mandatory (stool sample or rectal swab). All patients, regardless of their status, received a single-patient room and had their own assigned restroom. Therefore an additional ward had to be opened. The patients and staff were re-trained in hygiene rules and contact precautions. Positive VRE-tested patients were cohorted in one ward. In addition, spot screening was performed in the outpatient clinic. Due to a low number of restroom facilities and patient rooms, the outpatient clinic was closed for new admissions and reopened within 6 weeks at a new site with improved facilities and more patient rooms. Antibiotic usage was reviewed. Utilization of glycopeptides and cephalosporins was decreased. Pulsed-field gel electrophoresis (PFGE) was performed on all isolates. The outbreak was actively discussed in the local newspapers and television to inform the public of the situation.Results: This is the largest VRE-outbreak in a hematology-oncology department reported to date. Four-hundred-seventy-five patients were evaluated and 1246 tests were performed, resulting in a mean test frequency of 2.6 tests per patient. In this patient population, 34 VRE-colonized patients were identified, 18 within the first 4 weeks of screening. From January through April 2004, a total of 31 VRE-colonized patients were detected. Two additional VRE-BSI occurred. All patients with VRE-BSI were treated successfully with linezolid. PFGE demonstrated a dominant clone indicating a nosocomial transmission mode. After the opening of the new outpatient clinic and normalization of admission policies on the inpatient wards [the extra ward was closed and ID control measures stayed in effect] only 3 additional VRE-colonized patients were detected but PFGE demonstrated different clones. Cutting down on new admissions and actively discussing the outbreak in public was rewarded with back-to-baseline admissions after cessation of the outbreak.Conclusion: Though VRE-infections nowadays can easily be treated with linezolid, its detection indicates an infection control problem. Awareness of the development of resistant microbes especially in the immunocompromised setting requires pragmatic and stringent ID control measures to prevent or to cease early an outbreak of this magnitude.

Substantially increased faecal carriage of vancomycin-resistant enterococci in a tertiary Greek hospital after a 4 year time interval.

In a tertiary Greek hospital with no documented vancomycin-resistant enterococci (VRE) infections, a cross-sectional study was conducted in order to determine the degree of VRE faecal carriage among adult patients hospitalized in high-risk units. Specimens for the surveillance were collected from separate patients in two periods (January-May 1999 and January-May 2003); 258 specimens were submitted during the first period and 149 during the second period. Three patients (1.2%) were colonized with VRE during the first period, whereas 52 (34.9%) were colonized during the second period. Two VRE isolates of the first period were Enterococcus faecalis and one Enterococcus faecium, whereas those of the second period were E. faecium except for three E. faecalis and two Enterococcus gallinarum. All VRE isolates apart from the two E. gallinarum isolates were positive for the vanA gene. The 48 vancomycin-resistant E. faecium were classified into eight clonal types, one of those predominating with 29 isolates; the remaining included one to nine isolates. The five vancomycin-resistant E. faecalis formed four distinct clonal types. The study reports a substantially higher prevalence of VRE carriage when the surveillance was repeated after a 4 year time interval. Urgent infection control measures are needed to prevent emergence of VRE outbreaks in our hospital setting.

Impact of surveillance for vancomycin-resistant enterococci on controlling a bloodstream outbreak among patients with hematologic malignancy.

To determine the impact of stool surveillance cultures of critically ill patients on controlling vancomycin-resistant enterococci (VRE) outbreak bacteremia. Stool surveillance cultures were performed on patients who had hematologic malignancy or were critically ill at the time of hospital admission to identify those colonized with VRE. Hence, contact isolation was initiated. A tertiary-care cancer center with a high prevalence of VRE. All patients with hematologic malignancy who were admitted to the hospital as well as all of those admitted to the intensive care unit were eligible. Active stool surveillance cultures performed between 1997 and 2001 decreased the incidence density of VRE bacteremias eightfold while vancomycin use remained constant. In fiscal year (FY) 1997 and FY 1998, there were five and three VRE outbreak bacteremias, respectively. The outbreak clones were responsible for infection in 69% of those patients with VRE bacteremia. However, the stool surveillance program resulted in the complete control of VRE bacteremia by FY 1999 until the end of the study. Despite the steady use of vancomycin, the active surveillance program among high-risk patients with hematologic malignancy and those who were critically ill resulted in the complete control of VRE outbreak bacteremia at our institution.

Effectiveness and safety of enteral vancomycin to control endemicity of methicillin-resistant Staphylococcus aureus in a medical/surgical intensive care unit

A prospective trial was undertaken to assess the effectiveness and safety of enteral vancomycin in controlling methicillin-resistant Staphylococcus aureus (MRSA) in an endemic setting. Over the 49 month period patients aged >14 years were enrolled, following admission to a medical/surgical intensive care unit (ICU) and expected to require ventilation for three days or more. A total of 799 patients were included in the trial. Period one, 1 July 1996–30 April 1997, ( N=140), was observational. During period two, 1 May 1997–30 September 1998, ( N=258), surveillance samples were obtained. MRSA carriers were isolated and received enteral vancomycin. During period three, 1 October 1998–31 July 2000, ( N=401), all ventilated patients were given selective digestive decontamination (SDD) with polymyxin E, tobramycin, amphotericin B and vancomycin and four days of intravenous cefotaxime. The primary endpoints were: (1) incidence of patients with diagnostic samples positive for MRSA acquired on the ICU; (2) incidence of patients with vancomycin-resistant enterococci (VRE) in surveillance or diagnostic samples; (3) incidence of patients with samples positive for S. aureus with intermediate sensitivity to glycopeptides (GISA). The incidence of patients with MRSA in diagnostic samples were 31%, 14%, and 2% in periods one, two and three, respectively ( P<0.001). There was a VRE outbreak involving 13 patients during period three. VRE disappeared with no change in policy. GISA was not detected. These findings support the effectiveness and safety of enteral vancomycin in the control of MRSA.