Rapid recontamination with MRSA of the environment of an intensive care unit after decontamination with hydrogen peroxide vapour

Meticillin-resistant Staphylococcus aureus (MRSA) persists in the hospital environment and conventional cleaning procedures do not necessarily eliminate contamination. A prospective study was conducted on an intensive care unit to establish the level of environmental contamination with MRSA, assess the effectiveness of hydrogen peroxide vapour (HPV) decontamination and determine the rate of environmental recontamination. MRSA was isolated from 11.2% of environmental sites in the three months preceding the use of HPV and epidemiological typing revealed that the types circulating within the environment were similar to those colonising patients. After patient discharge and terminal cleaning using conventional methods, MRSA was isolated from five sites (17.2%). After HPV decontamination but before the readmission of patients, MRSA was not isolated from the environment. Twenty-four hours after readmitting patients, including two colonized with MRSA, the organism was isolated from five sites. The strains were indistinguishable from a strain with which a patient was colonized but were not all confined to the immediate vicinity of the colonized patient. In the eight weeks after the use of HPV, the environment was sampled on a weekly basis and MRSA was isolated from 16.3% sites. Hydrogen peroxide vapour is effective in eliminating bacteria from the environment but the rapid rate of recontamination suggests that it is not an effective means of maintaining low levels of environmental contamination in an open-plan intensive care unit.     

Tackling contamination of the hospital environment by methicillin-resistant Staphylococcus aureus (MRSA): a comparison between conventional terminal cleaning and hydrogen peroxide vapour decontamination

The hospital environment can sometimes harbour methicillin-resistant Staphylococcus aureus (MRSA) but is not generally regarded as a major source of MRSA infection. We conducted a prospective study in surgical wards of a London teaching hospital affected by MRSA, and compared the effectiveness of standard cleaning with a new method of hydrogen peroxide vapour decontamination. MRSA contamination, measured by surface swabbing was compared before and after terminal cleaning that complied with UK national standards, or hydrogen peroxide vapour decontamination. All isolation rooms, ward bays and bathrooms tested were contaminated with MRSA and several antibiogram types were identified. MRSA was common in sites that might transfer organisms to the hands of staff and was isolated from areas and bed frames used by non-MRSA patients. Seventy-four percent of 359 swabs taken before cleaning yielded MRSA, 70% by direct plating. After cleaning, all areas remained contaminated, with 66% of 124 swabs yielding MRSA, 74% by direct plating. In contrast, after exposing six rooms to hydrogen peroxide vapour, only one of 85 (1.2%) swabs yielded MRSA, by enrichment culture only. The hospital environment can become extensively contaminated with MRSA that is not eliminated by standard cleaning methods. In contrast, hydrogen peroxide vapour decontamination is a highly effective method of eradicating MRSA from rooms, furniture and equipment. Further work is needed to determine the importance of environmental contamination with MRSA and the effect on hospital infection rates of effective decontamination.     

Environmental contamination makes an important contribution to hospital infection

Meticillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) are capable of surviving for days to weeks on environmental surfaces in healthcare facilities. Environmental surfaces frequently touched by healthcare workers are commonly contaminated in the rooms of patients colonized or infected with MRSA or VRE. A number of studies have documented that healthcare workers may contaminate their hands or gloves by touching contaminated environmental surfaces, and that hands or gloves become contaminated with numbers of organisms that are likely to result in transmission to patients. Pathogens may also be transferred directly from contaminated surfaces to susceptible patients. There is an increasing body of evidence that cleaning or disinfection of the environment can reduce transmission of healthcare-associated pathogens. Because routine cleaning of equipment items and other high-touch surfaces does not always remove pathogens from contaminated surfaces, improved methods of disinfecting the hospital environment are needed. Preliminary studies suggest that hydrogen peroxide vapour technology deserves further evaluation as a method for decontamination of the environment in healthcare settings.     

Airborne hydrogen peroxide for disinfection of the hospital environment and infection control: a systematic review

We reviewed the effectiveness of airborne hydrogen peroxide as an environmental disinfectant and infection control measure in clinical settings. Systematic review identified ten studies as eligible for inclusion. Hydrogen peroxide was delivered in the form of vapour and dry mist in seven and three studies, respectively. Pathogens evaluated included meticillin-resistant Staphylococcus aureus (MRSA), Clostridium difficile and multiple bacterial types, in five, three, and two studies, respectively. Before the application of any cleaning intervention, 187/480 (39.0%; range: 18.9-81.0%) of all sampled environmental sites were found to be contaminated by the studied pathogens in nine studies that reported specific relevant data. After application of terminal cleaning and airborne hydrogen peroxide, 178/630 (28.3%; range: 11.9-66.1%) of the sampled sites in six studies and 15/682 (2.2%; range: 0-4.0%) of the sampled sites in ten studies, respectively, remained contaminated. Four studies evaluated the use of hydrogen peroxide vapour for infection control. This was associated with control of a nosocomial outbreak in two studies, eradication of persistent environmental contamination with MRSA and decrease in C. difficile infection in each of the remaining two studies.     

The relationship of a clonal outbreak of Enterococcus faecium vanA to methicillin-resistant Staphylococcus aureus incidence in an Australian hospital

Australian isolates of vancomycin-resistant enterococci (VRE) have been widely scattered geographically, predominantly polyclonal and of the VanB phenotype. Forty-nine VRE were isolated from 47 patients in our hospital from October 1996 to December 1999. Forty-four of these VRE were Enterococcus faecium with a vanA glycopeptide resistance genotype. Four isolates were pathogenic. Thirty-five VRE were from an outbreak in the Renal and Infectious Diseases Units over a four-month period. Pulsed-field gel electrophoresis (PFGE) demonstrated that 41 of the 49 VRE were indistinguishable or closely related. Enhanced environmental cleaning, strict contact isolation of colonized patients and reducing inpatient admissions terminated the epidemic. Cohorting of methicillin-resistant Staphylococcus aureus (MRSA)-positive patients was restricted because VRE patients occupied the isolation facilities. This resulted in a statistically significant increase in MRSA infections across the hospital. VRE epidemics have the ability to influence the epidemiology of other nosocomial pathogens when infection control resources are exhausted.     

Intensive care unit environmental cleaning: an evaluation in sixteen hospitals using a novel assessment tool

Despite isolation precautions and enhanced hand hygiene product use, the transmission of healthcare-associated pathogens remains a major problem. Recent studies have confirmed that microbial contamination of the environment in intensive care units (ICUs) can lead to colonisation and infection of patients. Although environmental disinfectants have been used to minimise the spread of microbial pathogens, suboptimal cleaning may limit the effectiveness of such activities. In order to evaluate the thoroughness of cleaning near-patient surfaces, a transparent, easily cleanable and environmentally stable solution was developed that fluoresces when exposed to UV light. The solution was used to mark a standardised group of frequently touched objects in ICU patient rooms following discharge cleaning. These sites were then evaluated after at least two patients had occupied the room and at least two terminal cleanings had been completed. Evaluation of 2320 objects in 197 patient areas disclosed that 57.1% of the standardised sites were cleaned following discharge of the room's occupant in the 16 ICUs studied. Although high rates of cleaning (>80%) were found for toilet seats, sinks and tray tables, consistently low rates of cleaning (<30%) were documented for several objects at high risk of becoming contaminated with nosocomial pathogens, including bedpan cleaners, toilet area handholds, doorknobs and light switches.     

Bed, bath and beyond: pitfalls in prompt eradication of methicillin-resistant Staphylococcus aureus carrier status in healthcare workers

Healthcare workers (HCWs) in close contact with patients colonized with methicillin-resistant Staphylococcus aureus (MRSA) were screened for MRSA acquisition. From 1995 to 2001, MRSA was identified from the nasopharyngeal swabs of 87 HCWs, collected one to two weeks after contact with 592 known MRSA-positive patients. These HCWs were withdrawn from work and treated with topical antibiotics/antiseptics. They were advised to disinfect their bathrooms and personal hygiene articles, and to wash bed linen and pillows. They were screened for successful eradication for up to three months. Seventy-three (84%) HCWs lost their carrier status. The eradication regimen failed in 14 cases. In 11 of these MRSA was detected only in later nasopharyngeal swabs (suspected recolonization). Screening identified nasal colonization of close household contacts in eight of these 11 cases. Environmental sampling detected contamination in seven out of eight screened home environments. When eradication treatment was applied to household contacts and when household surfaces were cleaned and disinfected, the carriage cleared in most cases within a few weeks. However, when home environments are heavily contaminated, despite adequate medical treatment, eradication took upto two years. Due to withdrawal from work, the 14 carriers without prompt and lasting eradication after the first course of treatment accounted for about 70% of all lost working days. These experiences support the hypothesis that control measures should not be restricted to antibiotic or antiseptic treatment of long-term carriers (HCWs as well as patients), but must also include cleaning and disinfection of the household.     

Environmental reservoirs of methicillin-resistant Staphylococcus aureus in isolation rooms: correlation with patient isolates and implications for hospital hygiene

Strategies to control and prevent the spread of methicillin-resistant Staphylococcus aureus (MRSA) include early identification of positive patients through screening, patient isolation, hand hygiene, nasal and skin decontamination, and the adequate cleaning and decontamination of clinical areas. However, many national and other guidelines provide few details on environmental decontamination regimens, partly because the role of the environment in the spread of MRSA is not well documented. We prospectively studied the environment of the isolation rooms of 25 MRSA patients for up to four weeks, sampling horizontal surfaces and the air using settle plates as well as an air sampler, while continuing regular daily cleaning according to the hospital protocol. We then typed 20 patient isolates and the corresponding environmental isolates (N=35) to assess the similarity of strains. A high proportion of samples were positive for MRSA; 269/502 (53.6%) surface samples, 70/250 (28%) air samples and 102/251 (40.6%) settle plates. Over half of the surface samples taken from the beds and the mattresses were positive for MRSA. Identical or closely related isolates were recovered from the patient and their environment in 14 (70%) patients, suggesting possible environmental contamination of the isolation rooms, possibly contributing to endemic MRSA. More effective and rigorous use of current approaches to cleaning and decontamination is required as well as consideration of newer technologies to eradicate MRSA and other hospital-acquired pathogens.     

SHEA guideline for preventing nosocomial transmission of multidrug-resistant strains of Staphylococcus aureus and enterococcus.

BACKGROUND: Infection control programs were created three decades ago to control antibiotic-resistant healthcare-associated infections, but there has been little evidence of control in most facilities. After long, steady increases of MRSA and VRE infections in NNIS System hospitals, the Society for Healthcare Epidemiology of America (SHEA) Board of Directors made reducing antibiotic-resistant infections a strategic SHEA goal in January 2000. After 2 more years without improvement, a SHEA task force was appointed to draft this evidence-based guideline on preventing nosocomial transmission of such pathogens, focusing on the two considered most out of control: MRSA and VRE. METHODS: Medline searches were conducted spanning 1966 to 2002. Pertinent abstracts of unpublished studies providing sufficient data were included. RESULTS: Frequent antibiotic therapy in healthcare settings provides a selective advantage for resistant flora, but patients with MRSA or VRE usually acquire it via spread. The CDC has long-recommended contact precautions for patients colonized or infected with such pathogens. Most facilities have required this as policy, but have not actively identified colonized patients with surveillance cultures, leaving most colonized patients undetected and unisolated. Many studies have shown control of endemic and/or epidemic MRSA and VRE infections using surveillance cultures and contact precautions, demonstrating consistency of evidence, high strength of association, reversibility, a dose gradient, and specificity for control with this approach. Adjunctive control measures are also discussed. CONCLUSION: Active surveillance cultures are essential to identify the reservoir for spread of MRSA and VRE infections and make control possible using the CDC's long-recommended contact precautions.     

Risk of hand or glove contamination after contact with patients colonized with vancomycin-resistant enterococcus or the colonized patients' environment.

OBJECTIVE: To estimate the level of hand or glove contamination with vancomycin-resistant enterococci (VRE) among healthcare workers (HCWs) who touch a patient colonized with VRE and/or the colonized patient's environment during routine care. DESIGN: Structured observational study. SETTING: Medical intensive care unit of a 700-bed, tertiary-care teaching hospital. PARTICIPANTS: VRE-colonized patients and their caregivers. METHODS: We obtained samples from sites on the intact skin of 22 patients colonized with VRE and samples from sites in the patients' rooms, before and after routine care, during 27 monitoring episodes. A total of 98 unique HCWs were observed during 131 HCW observations. Observers recorded the sites touched by HCWs. Culture samples were obtained from HCWs' hands and gloves before and after care. RESULTS: VRE were isolated from a mean (+/-SD) of 55% +/- 24% of patient sites (n=256) and 17% +/- 12% of environmental sites (n=1,572). Most HCWs (131 [56%]) touched both the patient and the patient's environment; no HCW touched only the patient. Of 103 HCWs whose hand samples were negative for VRE when they entered the room, 52% contaminated their hands or gloves after touching the environment, and 70% contaminated their hands or gloves after touching the patient and the environment (P=.101). In a univariate logistic regression model, the risk of hand or glove contamination was associated with the number of contacts made (odds ratio, 1.1 [95% confidence interval, 1.01-1.19). In a multivariate model, the effect of the number of contacts could not be distinguished from the effect of type of contact (ie, touching the environment alone or touching both the patient and the environment). Overall, 37% of HCWs who did not wear gloves contaminated their hands, and 5% of HCWs who wore gloves did so (an 86% difference). CONCLUSION: HCWs were nearly as likely to have contaminated their hands or gloves after touching the environment in a room occupied by a patient colonized by VRE as after touching the colonized patient and the patient's environment. Gloves were highly protective with respect to hand contamination.     

Comparison of hospital room surface disinfection using a novel ultraviolet germicidal irradiation (UVGI) generator

The estimated 721,800 hospital acquired infections per year in the United States have necessitated development of novel environmental decontamination technologies such as ultraviolet germicidal irradiation (UVGI). This study evaluated the efficacy of a novel, portable UVGI generator (the TORCH, ChlorDiSys Solutions, Inc., Lebanon, NJ) to disinfect surface coupons composed of plastic from a bedrail, stainless steel, chrome-plated light switch cover, and a porcelain tile that were inoculated with methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus faecalis (VRE). Each surface type was placed at 6 different sites within a hospital room and treated by 10-min ultraviolet-C (UVC) exposures using the TORCH with doses ranging from 0–688 mJ/cm² between sites. Organism reductions were compared with untreated surface coupons as controls. Overall, UVGI significantly reduced MRSA by an average of 4.6 log₁₀ (GSD: 1.7 log₁₀, 77% inactivation, p < 0.0001) and VRE by an average of 3.9 log₁₀ (GSD: 1.7 log₁₀, 65% inactivation, p < 0.0001). MRSA on bedrail was reduced significantly (p < 0.0001) less than on other surfaces, while VRE was reduced significantly less on chrome (p = 0.0004) and stainless steel (p = 0.0012) than porcelain tile. Organisms out of direct line of sight of the UVC generator were reduced significantly less (p < 0.0001) than those directly in line of sight. UVGI was found an effective method to inactivate nosocomial pathogens on surfaces evaluated within the hospital environment in direct line of sight of UVGI treatment with variation between organism and surface types.     

Contamination of gowns, gloves, and stethoscopes with vancomycin-resistant enterococci.

OJECTIVE: To measure directly the rate of contamination, during routine patient examination, of gowns, gloves, and stethoscopes with vancomycin-resistant enterococci (VRE). SETTING: A large, academic, tertiary-care hospital. PATIENTS: Between January 1997 and December 1998, 49 patients colonized or infected with VRE were entered in the study. DESIGN: After routine examination, the examiner's glove fingertips, gown (the umbilical region and the cuffs), and stethoscope diaphragm were pressed onto Columbia colistin-nalidixic acid (CNA) agar plates with 5% sheep blood plus vancomycin 6 pg/mL. The stethoscope diaphragm was sampled again after cleaning with a 70% isopropanol wipe. RESULTS: VRE were isolated from at least 1 examiner site (gloves, gowns, or stethoscope) in 33 (67%) of 49 cases. Gloves were contaminated in 63%, gowns in 37%, and stethoscopes in 31%. All three items were positive for VRE in 24%. One case each had stethoscope and gown contamination without glove contamination. Only 1 (2%) of 49 stethoscopes was positive after wiping with an alcohol swab. Contamination at any site was more likely when the patient had a colostomy or ileostomy. Patients identified by rectal-swab culture alone were as likely to contaminate their examiners as were those identified by clinical specimens. CONCLUSIONS: Our study revealed a high rate of examiner contamination with VRE. The similar risk of contamination identified by surveillance and clinical cases reinforces concerns that patients not known to be colonized with VRE could serve as sources for dissemination. Wiping with alcohol is effective in decontaminating stethoscopes.     

Possible risk for re-colonization with methicillin-resistant Staphylococcus aureus (MRSA) by faecal transmission

An increase in the frequency of methicillin-resistant Staphylococcus aureus (MRSA) as an important causative agent of nosocomial infections is observed worldwide. Unfortunately, in spite of optimal hygienic conditions (barrier isolation, screening, decontamination), patients often remain MRSA positive or are detected as "re-colonized" at readmission. The objective of our study was to clarify if this is due to an undetected colonization of the gastrointestinal tract, which could possibly lead to re-colonization after primary successful decontamination. Therefore, all MRSA strains were collected from 290 in-patients of a university hospital over a period of 2 years. A surprisingly high number (24.1% of all) was isolated from stool samples. Even 13.1% of the total collection could be first observed in this material before detecting MRSA in other materials of these patients. To evaluate the epidemiology of these isolates, pulsed-field gel electrophoresis (PFGE) was used. On the basis of PFGE restriction types one main clone and 11 singular clones could be identified. Additionally, for six individual patients MRSA isolates from stool specimens were indistinguishable from other isolates from different locations. We show here that colonization of the gastrointestinal tract with MRSA apparently could play an important role in spreading MRSA via faecal contamination. Hence, we suggest that stool colonization with MRSA could be the source of a so far unrecognized transmission of MRSA within individual patients and within the population. Therefore, our findings imply a modification in the hygienic strategies for handling decontamination and therapy of MRSA patients.     

Colonization and infection with multiple nosocomial pathogens among patients colonized with vancomycin-resistant Enterococcus.

OBJECTIVE: To test the hypothesis that patients colonized with vancomycin-resistant Enterococcus (VRE) have a higher frequency of colonization or infection with other nosocomial pathogens than do patients who are not colonized with VRE. DESIGN: A rectal swab culture survey was conducted to determine the point-prevalence of stool colonization with ceftazidime-resistant gram-negative bacilli in hospitalized patients with or without VRE stool colonization. For a 6-month period, the frequency of Clostridium difficile diarrhea and isolation of antibiotic-resistant (ie, ceftazidime-, piperacillin/tazobactam-, levofloxacin-, or trimethoprim/sulfamethoxazole-resistant) gram-negative bacilli, methicillin-resistant Staphylococcus aureus (MRSA), and non-albicans Candida species from clinical specimens other than stool was examined. SETTING: A Department of Veterans Affairs medical center. PATIENTS: All patients hospitalized in the acute care facility and one nursing home unit during a 1-week period in February 2001. RESULTS: VRE-colonized patients had a higher point-prevalence of rectal colonization with ceftazidime-resistant gram-negative bacilli than did patients not colonized with VRE (17% vs 4%; P = .026). During a 6-month period,the VRE-colonized patients were more likely to have Clostridium difficile-associated diarrhea (26% vs 2%; P = .001), MRSA infection (17% vs 4%; P = .017), or colonization or infection with gram-negative bacilli resistant to 4 different antibiotics. CONCLUSION: VRE-colonized patients in our institution have a higher frequency of colonization or infection with other nosocomial pathogens than do patients who are not colonized with VRE. This suggests that isolation measures implemented to control VRE could help limit the dissemination of other, coexisting pathogens.     

Outbreak of vancomycin-resistant enterococci in a burn unit.

OBJECTIVE: To investigate and control an outbreak of colonization and infection caused by vancomycin-resistant enterococci (VRE) in a burn intensive care unit (BICU). DESIGN: Epidemiological investigation, including multiple point-prevalence culture surveys of patients and environment, cultures from hands of healthcare workers (HCWs), pulsed-field gel electrophoresis (PFGE) typing of patient and environmental isolates, case-control study, and institution and monitoring of control measures. SETTING: BICU in an 800-bed university medical center in Galveston, Texas. RESULTS: Between June 6, 1996, and July 14, 1997, 21 patients were colonized by VRE, and 4 of these patients developed bacteremia. Of 2,844 environmental cultures, 338 (11.9%) were positive, but all hand cultures from HCWs were negative. PFGE typing indicated that the outbreak was clonal, with VRE isolates from patients differing by < or =4 bands from the index case. Thirteen of 14 environmental isolates varied by < or =4 bands from the pattern of the index case. A case-control study analyzed by exact logistic regression identified diarrhea (odds ratio [OR], 43.9; 95% confidence interval [CI95], 5.5-infinity; P=.0001) and administration of an antacid (OR, 24.2; CI95, 2.9-infinity; P=.002) as independent risk factors for acquisition of VRE. During a 5-week period in October and November 1996, all patient and 317 environmental cultures were negative for VRE. The outbreak recurred from a contaminated electrocardiogram lead that had not been identified during the prior 5 weeks. VRE were finally eradicated from the BICU in July 1997, using barrier isolation and a very aggressive environmental decontamination program. CONCLUSIONS: A VRE outbreak in a BICU over 13 months was caused by a single clone. After apparent eradication of VRE from a BICU, recrudescence of the outbreak occurred, evidently from a small inapparent source of environmental contamination. Changes in gastrointestinal (GI) tract function (motility) and administration of medications, other than antibiotics, that have an effect on the GI tract may increase the risk of GI tract colonization by VRE in burn patients. Application of barrier isolation and an aggressive environmental decontamination program can eradicate VRE from a burn population.     

Impact of alcohol-based, waterless hand antiseptic on the incidence of infection and colonization with methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci.

OBJECTIVE: Colonized and infected inpatients are major reservoirs for methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE), and transient carriage of these pathogens on the hands of healthcare workers remains the most common mechanism of patient-to-patient transmission. We hypothesized that use of alcohol-based, waterless hand antiseptic would lower the incidence of colonization and/or infection with MRSA and VRE. METHODS: On June 19, 2001, alcohol hand antiseptic was introduced at the University campus and not the nearby Memorial campus of the University of Massachusetts Medical School (Worcester, MA), allowing us to evaluate the impact of this antiseptic on the incidence of MRSA and VRE colonization and infection. From January 1 through December 31, 2001, the incidence of MRSA colonization or infection was compared between the 2 campuses before and after the hand antiseptic was introduced. Its effect on VRE colonization and infection was only studied in the medical intensive care unit at the University campus. RESULTS: At the University campus, the incidence of MRSA colonization or infection decreased from 1.26 cases/1,000 patient-days before the intervention to 0.75 cases/1,000 patient-days after the intervention, for a 1.46-fold decrease (95% confidence interval, 1.04-2.58; P = .037). At the Memorial campus, the incidence of MRSA colonization or infection remained virtually unchanged, from 0.34 cases/1,000 patient-days to 0.49 cases/1,000 patient-days during the same period. However, a separate analysis of the University campus data that controlled for proximity to prevalent cases did not show a significant improvement in the rates of infection or colonization. The incidence of nosocomial VRE colonization or infection before and after the hand antiseptic decreased from 12.0 cases/1,000 patient-days to 3.0 cases/1,000 patient-days, a 2.25-fold decrease (P = .018). Compliance with rectal surveillance for detection of VRE was 86% before and 84% after implementation of the hand antiseptic intervention. The prevalences of VRE cases during these 2 periods were 25% and 29%, respectively (P = .017). CONCLUSIONS: Alcohol hand antiseptic appears to be effective in controlling the transmission of VRE. However, after controlling for proximity to prevalent cases (ie, for clustering), it does not appear to be more effective than standard methods for controlling MRSA. Further controlled studies are needed to evaluate its effectiveness.     

Comorbidity risk-adjustment measures were developed and validated for studies of antibiotic-resistant infections

OBJECTIVES: Comorbidities are often included in risk-factor models for nosocomial antibiotic-resistant bacterial infections, and aggregate comorbidity measures are valuable because they allow one variable to represent many. This study aimed to develop new aggregate comorbidity measures based upon the Chronic Disease Score (CDS) for assessing the comorbidity-attributable risk of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) nosocomial infections. STUDY DESIGN AND SETTING: For each outcome, two retrospective cohort studies of hospitalized patients were conducted. Outcomes were a first MRSA or VRE positive clinical culture obtained 48 hours or more postadmission. Each cohort was divided into development (July 1998-2001) and validation (August 2001-2003) samples. New comorbidity measures were created for MRSA (CDS-MRSA), VRE (CDS-VRE), or any nosocomial infection outcome (CDS-ID) using logistic regression and subsequently validated. Model discrimination was measured using the c-statistic. RESULTS: Discrimination of the CDS-MRSA (c=0.60), CDS-VRE (c=0.65), and CDS-ID (MRSA: c=0.57; VRE: c=0.64) was greater than that of the original CDS (MRSA: c=0.52; VRE: c=0.57). CONCLUSION: The CDS-MRSA, CDS-VRE, and CDS-ID are new infectious disease specific comorbidity risk-adjustment measures that will be useful for the quality of future epidemiologic studies of MRSA, VRE, and other infectious diseases.     

Favorable impact of a multidisciplinary antibiotic management program conducted during 7 years.

OBJECTIVE: To evaluate the impact of an interventional multidisciplinary antibiotic management program on expenditures for antibiotics and on the incidence of nosocomial infections caused by Clostridium difficile and antibiotic-resistant pathogens during 7 years. DESIGN: Prospective study with comparison with preintervention trends. SETTING: University-affiliated teaching hospital. PATIENTS: All adult inpatients. INTERVENTION: A multidisciplinary antibiotic management program to minimize the inappropriate use of third-generation cephalosporins was implemented in 1991. Its impact was evaluated prospectively. The incidence of nosocomial C. difficile and resistant Enterobacteriaceae infections as well as the rate of vancomycin-resistant enterococci (VRE) and methicillin-resistant Staphylococcus aureus (MRSA) were compared with those of National Nosocomial Infections Surveillance System hospitals of similar size. RESULTS: Following implementation of the program, there was a 22% decrease in the use of parenteral broad-spectrum antibiotics (P < .0001) despite a 15% increase in acuity of patient care during the following 7 years. Concomitantly, there was a significant (P = .002) decrease in nosocomial infections caused by C. difficile and a significant (P = .02) decrease in nosocomial infections caused by resistant Enterobacteriaceae. The program also appeared to have a favorable impact on VRE rates without a sustained impact on MRSA rates. CONCLUSION: These results suggest that an ongoing multidisciplinary antibiotic management program may have a sustained beneficial impact on both expenditures for antibiotics and the incidence of nosocomial infection by C. difficile and resistant bacterial pathogens.     

医务人员工作服病原菌调查

目的 了解医务人员工作服的病原菌污染情况,提出医务人员工作服的管理措施,加强医务人员医院感染预防控制意识.方法 采集医院7个科室医师及护士工作服共182件,在袖口部进行病原菌污染检测.结果 被检工作服均受病原菌污染,以微球菌属所占比例最高,其次是凝固酶阴性葡萄球菌,未检出金黄色葡萄球菌,科室以急诊科污染最严重,其次是呼吸内科,以ICU最轻微;工作服穿着3d后,袖端平均含菌量为3.6 CFU/cm2,有7.7％的工作服含菌量超标,穿着7d平均含菌量为6.2 CFU/cm2,有19.2％超标,穿着14 d平均含菌量＞13.0CFU/cm2,有60.0％超标.结论 工作服袖口污染严重,医务人员要加强工作服换洗意识;医院总体上可以实行一周换洗1次的制度,但重点科室及个别污染严重的科室需要缩短周期;各个科室要做好消毒隔离等措施,要保持通风;医院需要加强医务人员工作服的清洁及消毒的管理,杜绝医院感染的发生.