Prevalence of and risk factors for colonization with methicillin-resistant Staphylococcus aureus in an outpatient clinic population.

OBJECTIVES: To determine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) colonization in an outpatient population and to identify risk factors for MRSA colonization. DESIGN: Surveillance cultures were performed during outpatient visits to identify S. aureus colonization. A case-control study was performed to identify risk factors for MRSA colonization. SETTING: Primary care internal medicine clinic. PATIENTS: Adults presenting for non-acute primary care (N = 494). RESULTS: S. aureus was isolated from 122 (24.7%) of the patients for whom cultures were performed. Methicillin-susceptible S. aureus was isolated from 107 (21.7%) of the patients, whereas MRSA was isolated from 15 (3.0%) of the patients. All MRSA isolates were resistant to multiple non-beta-lactam antimicrobial agents. In multivariate analyses, MRSA colonization was independently associated with admission to a nursing home (adjusted odds ratio [OR], 103; 95% confidence interval [CI95], 7 to 999) or hospital in the previous year, although the association with hospital admission was observed only among those without chronic illness (adjusted OR, 7.1; CI95, 1.3 to 38.1). In addition, MRSA colonization was associated with the presence of at least one underlying chronic illness, although this association was observed only among those who had not been hospitalized in the previous year (adjusted OR, 5.1; CI95, 1.2 to 21.9). CONCLUSIONS: We found a low prevalence of MRSA colonization in an adult outpatient population. MRSA carriers most likely acquired the organism through contact with healthcare facilities rather than in the community. These data show that care must be taken when attributing MRSA colonization to the community if detected in outpatients or during the first 24 to 48 hours of hospitalization.     

Prevalence of and risk factors for colonization with methicillin-resistant Staphylococcus aureus at the time of hospital admission.

OBJECTIVES: To determine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) colonization among patients presenting for hospital admission and to identify risk factors for MRSA colonization. DESIGN: Surveillance cultures were performed at the time of hospital admission to identify patients colonized with S. aureus. A case-control study was performed to identify risk factors for MRSA colonization. SETTING: A tertiary-care academic medical center. PATIENTS: Adults presenting for hospital admission (N = 974). RESULTS: S. aureus was isolated from 205 (21%) of the patients for whom cultures were performed. Methicillin-sensitive S. aureus was isolated from 179 (18.4%) of the patients, and MRSA was isolated from 26 (2.7%) of the patients. All 26 MRSA-colonized patients had been admitted to a healthcare facility in the preceding year, had at least one chronic illness, or both. In multivariate analyses comparing MRSA-colonized patients with control-patients, admission to a nursing home (odds ratio [OR], 16.5; 95% confidence interval [CI95], 1.4 to 192.1; P = .025) or a hospitalization of 5 days or longer during the preceding year (OR, 3.91; CI95, 1.1 to 13.9; P = .035) were independent predictors of MRSA colonization. CONCLUSIONS: Patients colonized with MRSA admitted to this hospital likely acquired the organism during previous encounters with healthcare facilities. There was no evidence that MRSA colonization occurs commonly among low-risk individuals in this community. These data suggest that evaluation of recent healthcare exposures is essential if true community acquisition of MRSA is to be confirmed.     

Trends in methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infections: effect of the MRSA "search and isolate" strategy in a hospital in Italy with hyperendemic MRSA.

OBJECTIVE: To evaluate the secular trends in MRSA BSIs after the introduction of a nosocomial MRSA control intervention. DESIGN: Before-after study. SETTING: An 850-bed community hospital with an ICU and vascular surgery, neurosurgery, bone marrow transplantation, and AIDS units. MRSA is endemic at this hospital; the prevalence of methicillin resistance among patients with S. aureus infection is greater than 50%. PATIENTS: Among all inpatients, MRSA BSI was identified, its origin defined, and incidence rates calculated by ward and origin. INTERVENTION: A MRSA control program was implemented based on active surveillance cultures to identify MRSA-colonized patients, followed by isolation using contact precautions. Incidence rates of MRSA BSI during the intervention (i.e., July 1, 1997, to December 31, 2001) and preintervention (i.e., January 1, 1996, to June 30, 1997) periods were compared. RESULTS: Sixty-nine MRSA BSIs were identified. When compared with the preintervention period, the incidence rate of MRSA BSI was reduced from 0.64 to 0.30 per 1000 admissions (RR, 0.46; CI95, 0.25-0.87; P = .02) during the intervention period. The impact was greater in the ICU, with an 89% reduction (RR, 0.11; CI95, 0.01-0.98; P = .03), and for CVC-associated MRSA BSIs, with an 82% decrease (RR, 0.17; CI95, 0.05-0.55; P = .002). Methicillin resistance among S. aureus blood isolates decreased from 46% to 17% (RR, 0.36; CI95, 0.22-0.62; P = .0002). CONCLUSION: A reduction in MRSA bacteremia is achievable through use of the MRSA "search and isolate" intervention even in a hospital with high rates of endemic MRSA.     

Active surveillance to determine the impact of methicillin-resistant Staphylococcus aureus colonization on patients in intensive care units of a Veterans Affairs Medical Center.

OBJECTIVE: The impact of methicillin-resistant Staphylococcus aureus (MRSA) colonization on mortality has not been well characterized. We sought to describe the impact of MRSA colonization on patients admitted to intensive care units (ICUs) in the Birmingham Veterans Affairs Medical Center (VAMC). METHODS: We conducted a retrospective cohort study of ICU patients at the Birmingham VAMC during 2005 to evaluate the predictors of MRSA colonization and determine its effect on clinical outcomes. Surveillance cultures for MRSA were performed on admission to the ICU and weekly thereafter. Clinical findings, the incidence of MRSA infection, and mortality within 3 months after ICU admission were recorded. Predictors of mortality and S. aureus colonization were determined using multivariable models. RESULTS: S. aureus colonization was present in 97 (23.3%) of 416 patients screened, of whom 67 (16.1%) were colonized with methicillin-susceptible S. aureus (MSSA) and 30 (7.2%) with MRSA. All-cause mortality at 3 months among MRSA-colonized patients was significantly greater than that among MSSA-colonized patients (46.7% vs 19.4%; P = .009). MRSA colonization was an independent predictor of death (adjusted odds ratio [OR], 3.7 [95% confidence interval [CI], 1.5-8.9]; P = .003) and onset of MRSA infection after hospital discharge (adjusted OR, 7.6 [95% CI, 2.48-23.2]; P < .001). Risk factors for MRSA colonization included recent antibiotic use (adjusted OR, 4.8 [95% CI, 1.9-12.2]; P = .001) and dialysis (adjusted OR, 18.9 [95% CI, 2.1-167.8]; P = .008). CONCLUSIONS: Among ICU patients, MRSA colonization is associated with subsequent MRSA infection and an all-cause mortality that is greater than that for MSSA colonization. Active surveillance for MRSA colonization may identify individuals at risk for these adverse outcomes. Prospective studies of outcomes in MRSA-colonized patients may better define the role of programs for active MRSA surveillance.     

Eradication of methicillin-resistant Staphylococcus aureus from a neonatal intensive care unit by active surveillance and aggressive infection control measures.

OBJECTIVES: To describe an outbreak of hospital-acquired MRSA in a NICU and to identify the risk factors for, outcomes of, and interventions that eliminated it. SETTING: An 18-bed, level III-IV NICU in a community hospital. METHODS: Interventions to control MRSA included active surveillance, aggressive contact isolation, and cohorting and de-colonization of infants and HCWs with MRSA. A case-control study was performed to compare infants with and without MRSA. RESULTS: A cluster of 6 cases of MRSA infection between September and October 2001 represented an increased attack rate of 21.2% compared with 5.3% in the previous months. Active surveillance identified unsuspected MRSA colonization in 6 (21.4%) of 28 patients and 6 (5.5%) of 110 HCWs screened. They were all successfully decolonized. There was an increased risk of MRSA colonization and infection among infants with low birth weight or younger gestational age. Multiple gestation was associated with an increased risk of colonization (OR, 37.5; CI95, 3.9-363.1) and infection (OR, 5.36; CI95, 1.37-20.96). Gavage feeding (OR, 10.33; CI95, 1.28-83.37) and intubation (OR, 5.97; CI95, 1.22-29.31) were associated with increased risk of infection. Infants with MRSA infection had a significantly longer hospital stay than infants without MRSA (51.83 vs 21.46 days; P = .003). Rep-PCR with mec typing and PVL analysis confirmed the presence of a single common strain of hospital-acquired MRSA. CONCLUSION: Active surveillance, aggressive implementation of contact isolation, cohorting, and decolonization effectively eradicated MRSA from the NICU for 2 1/2 years following the outbreak.     

Routine screening for methicillin-resistant Staphylococcus aureus among patients newly admitted to an acute rehabilitation unit.

BACKGROUND: Following an outbreak of methicillin-resistant Staphylococcus aureus (MRSA) infection in our acute rehabilitation unit in 1987, all patients except in-house transfers (because of their low prevalence of MRSA colonization) underwent MRSA screening cultures on admission. OBJECTIVES: To better characterize the current profile of patients with positive MRSA screening cultures at the time of admission to our acute rehabilitation unit, and to determine the relative yield of nares, perianal, and wound screening cultures in this population. METHODS: Prospective chart review with ongoing active surveillance for infections associated with the acute rehabilitation unit RESULTS: The rate of MRSA isolation from one or more body sites increased significantly from 5% (1987-1988) to 12% (1999-2000) (P = .0009) for newly admitted patients and from 0% to 7% (P < .0001) for in-house transfers. A negative nares culture was highly predictive (98%) of a negative perianal culture. Prior history of MRSA infection or colonization and transfer from outside sources were independently associated with positive MRSA screening cultures. CONCLUSION: The rate of MRSA isolation from screening cultures of newly admitted patients, including in-house transfers, has increased significantly during the past decade in our acute rehabilitation unit. When paired with nares cultures, perianal cultures were of limited value in this patient population.     

Epidemiology of methicillin-resistant Staphylococcus aureus colonization in a surgical intensive care unit.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is a cause of healthcare-associated infections among surgical intensive care unit (ICU) patients, though transmission dynamics are unclear. OBJECTIVE: To determine the prevalence of MRSA nasal colonization at ICU admission, to identify associated independent risk factors, to determine the value of these factors in active surveillance, and to determine the incidence of and risk factors associated with MRSA acquisition. DESIGN: Prospective cohort study. SETTING: Surgical ICU at a teaching hospital. PATIENTS: All patients admitted to the surgical ICU. RESULTS: Active surveillance for MRSA by nasal culture was performed at ICU admission during a 15-month period. Patients who stayed in the ICU for more than 48 hours had nasal cultures performed weekly and at discharge from the ICU, and clinical data were collected prospectively. Of 1,469 patients, 122 (8%) were colonized with MRSA at admission; 75 (61%) were identified by surveillance alone. Among 775 patients who stayed in the ICU for more than 48 hours, risk factors for MRSA colonization at admission included the following: hospital admission in the past year (1-2 admissions: adjusted odds ratio [aOR], 2.60 [95% confidence interval {CI}, 1.47-4.60]; more than 2 admissions: aOR, 3.56 [95% CI, 1.72-7.40]), a hospital stay of 5 days or more prior to ICU admission (aOR, 2.54 [95% CI, 1.49-4.32]), chronic obstructive pulmonary disease (aOR, 2.16 [95% CI, 1.17-3.96]), diabetes mellitus (aOR, 1.87 [95% CI, 1.10-3.19]), and isolation of MRSA in the past 6 months (aOR, 8.18 [95% CI, 3.38-19.79]). Sixty-nine (10%) of 670 initially MRSA-negative patients acquired MRSA in the ICU (corresponding to 10.7 cases per 1,000 ICU-days at risk). Risk factors for MRSA acquisition included tracheostomy in the ICU (aOR, 2.18 [95% CI, 1.13-4.20]); decubitus ulcer (aOR, 1.72 [95% CI, 0.97-3.06]), and receipt of enteral nutrition via nasoenteric tube (aOR, 3.73 [95% CI, 1.86-7.51]), percutaneous tube (aOR, 2.35 [95% CI, 0.74-7.49]), or both (aOR, 3.33 [95% CI, 1.13-9.77]). CONCLUSIONS: Active surveillance detected a sizable proportion of MRSA-colonized patients not identified by clinical culture. MRSA colonization on admission was associated with recent healthcare contact and underlying disease. Acquisition was associated with potentially modifiable processes of care.     

中国6省18~75岁人群微量白蛋白尿检出情况及影响因素

  目的  了解中国6省18~75岁人群微量白蛋白尿(microalbuminuria,MAU)检出状况及其影响因素。  方法  本研究于2018年采用多阶段整群随机抽样的方法,从6个省12个县、区中抽取2 693名18~75岁调查对象进行问卷调查、体格测量和24 h尿液收集。采用单因素、多因素Logistic回归分析模型分析相关影响因素。  结果  最终纳入分析的2 607名研究对象中,共检出234名MAU患者,MAU的检出率为8.98%(95% CI: 7.91%~10.14%)。男性、50岁及以上、吸烟、肥胖、高血压和糖尿病人群的MAU检出率分别为10.48%、11.91%、10.94%、14.82%、16.85%和23.21%,高于相对应人群,组间差异有统计学意义(均有P＜0.05)。多因素Logistic回归分析模型分析结果显示,与无高血压、无糖尿病和体重正常人群相比,高血压患者(OR=2.843, 95% CI: 2.093~3.862)、糖尿病患者(OR=2.453, 95% CI: 1.626~3.702)和肥胖人群(OR=1.941, 95% CI: 1.338~2.815)发生MAU的风险较高(均有P＜0.001)。  结论  高血压、糖尿病和肥胖与MAU的发生有关,应重视这些人群的MAU早期筛查,以预防和延缓肾脏损伤的发生发展。     

Nasal carriage of methicillin-resistant Staphylococcus aureus in an American Indian population.

BACKGROUND AND OBJECTIVE: Although reports of methicillin-resistant Staphylococcus aureus (MRSA) infections without healthcare exposure are increasing, population-based data regarding nasal colonization are lacking. We assessed the prevalence of and risk factors for community-associated MRSA nasal carriage in patients of a rural outpatient clinic. DESIGN: A cross-sectional population survey was conducted through random sample and stratification by community of residence. Recent healthcare exposure (ie, hospitalization, dialysis, or healthcare occupation) and other risk factors for MRSA carriage were assessed. Cultures of the nares were performed. Community-associated MRSA was defined as MRSA carriage without healthcare exposure. SETTING: A predominantly American Indian community in Washington. PATIENTS: Those receiving healthcare from an Indian Health Service clinic. RESULTS: Of 1,311 individuals identified for study, 475 (36%) participated. Unsatisfactory culture specimens resulted in exclusion of 6 participants. In all, 128 (27.3%) of 469 participants had S. aureus. Nine (1.9%) of 469 had MRSA carriage; of these, 5 had community-associated MRSA (5 of 469; overall community-associated MRSA carriage rate, 1.1%). MRSA carriage was associated with antimicrobial use in the previous year (risk ratio [RR], 7.2; P = .04) and residence in a household of more than 7 individuals (RR, 4.5; P = .03). Pulsed-field gel electrophoresis indicated that 5 (55%) of 9 MRSA carriage isolates were closely related, including 3 (60%) of 5 that were community associated. CONCLUSIONS: Prevalence of community-associated MRSA colonization was approximately 1% in this rural, American Indian population. Community-associated MRSA colonization was associated with recent antimicrobial use and larger household.     

A bundle of care to reduce colorectal surgical infections: an Australian experience

Staphylococcus aureus carriage increases the risk of infection. Demographic and microbiological data from adult patients with nasal S. aureus carriage were analysed in order to define effect modifiers of this association. Predictors for growth of S. aureus from clinical cultures were identified in a case-control study using bivariate and multi-variate logistic regression analysis. Between 1 January 2005 and 1 April 2009, 645 patients with nasal S. aureus colonization and documented follow-up of ≥90 days were identified; 159 (25%) patients were found to carry meticillin-resistant S.?aureus (MRSA). The median age of patients was 58 years, and 421 (65%) were male. During the subsequent 90 days, one or more clinical cultures were positive for S. aureus in 131 patients (20%). Multi-variate analysis identified a prior history of any S. aureus positive culture [adjusted odds ratio (aOR) 2.4, 95% confidence interval (CI) 1.5-3.8; P=0.0005) as an independent predictor of subsequent S. aureus infection. MRSA colonization was a predictor of infection in patients aged >40 years (aOR 2.5, 95% CI 1.4-4.1; P=0.0004), and even more so in patients aged ≤40 years (aOR 12.4, 95% CI 3.0-51; P=0.0005). Age >40 years was an additional independent risk?factor for meticillin-susceptible S. aureus carriers (aOR 3.0, 95% CI 1.2-7.8; P=0.02) but not for MRSA carriers. Preferential screening of patients at high risk for MRSA carriage and subsequent infection, as well as the absence of a universal policy for the use of decolonization regimens, may partly explain the relatively high risk of S. aureus infection in the patient population. MRSA carriers and older patients with recurrent S. aureus positive cultures may gain the greatest benefit from routine decolonization measures.     

Development of a surveillance system for methicillin-resistant Staphylococcus aureus in German hospitals.

OBJECTIVE: To determine the appropriate method to calculate the rate of methicillin-resistant Staphylococcus aureus (MRSA) infection and colonization (hereafter, MRSA rates) for interhospital comparisons, such that the large number of patients who are already MRSA positive on admission is taken into account. DESIGN: A prospective, multicenter, hospital-based surveillance of MRSA-positive case patients from January through December 2004. SETTING: Data from 31 hospitals participating in the German national nosocomial infections surveillance system (KISS) were recorded during routine surveillance by the infection control team at each hospital. RESULTS: Data for 4,215 MRSA-positive case patients were evaluated. From this data, the following values were calculated. The median incidence density was 0.71 MRSA-positive case patients per 1,000 patient-days, and the median nosocomial incidence density was 0.27 patients with nosocomial MRSA infection or colonization per 1,000 patient-days (95% CI, 0.18-0.34). The median average daily MRSA burden was 1.13 MRSA patient-days per 100 patient-days (95% CI, 0.86-1.51), with the average daily MRSA burden defined as the total number of MRSA patient-days divided by the total number of patient-days times 100. The median MRSA-days-associated nosocomial MRSA infection and colonization rate, which describes the MRSA infection risk for other patients in hospitals housing large numbers of MRSA-positive patients and/or many patients who were MRSA positive on admission, was 23.1 cases of nosocomial MRSA infection and colonization per 1,000 MRSA patient-days (95% CI, 17.4-28.6). The values were also calculated for various MRSA screening levels. CONCLUSIONS: The MRSA-days-associated nosocomial MRSA rate allows investigators to assess the extent of MRSA colonization and infection at each hospital, taking into account cases that have been imported from other hospitals, as well as from the community. This information provides an appropriate incentive for hospitals to introduce further infection control measures.     

Rates of carriage of methicillin-resistant and methicillin-susceptible Staphylococcus aureus in an outpatient population.

OBJECTIVES: To assess the prevalence of and the clinical features associated with asymptomatic Staphylococcus aureus colonization in a healthy outpatient population, and to compare the characteristics of colonizing methicillin-resistant S. aureus (MRSA) strains with those of strains causing infection in our community and hospital. SETTING: Outpatient military clinics. METHODS: Specimens were obtained from the nares, pharynx, and axillae of 404 outpatients, and a questionnaire was administered to obtain demographic and risk factor information. MRSA strains were typed by pulsed-field gel electrophoresis (PFGE) and evaluated for antibiotic susceptibility. Antibiograms of study MRSA strains were compared with those of MRSA strains causing clinical illness during the same time period. RESULTS: Methicillin-susceptible S. aureus (MSSA) colonization was present in 153 (38%) of the 404 asymptomatic outpatients, and MRSA colonization was present in 8 (2%). Detection of colonization was highest from the nares. No clinical risk factor was significantly associated with MRSA colonization; however, a tendency was noted for MRSA to be more common in men and in those who were older or who had been recently hospitalized. All colonizing MRSA strains had unique patterns on PFGE. In contrast to strains responsible for hospital infections, most colonizing isolates of MRSA were susceptible to oral antibiotics. CONCLUSIONS: MRSA and MSSA colonization is common in our outpatient population. Colonization is best detected by nares cultures and most carriers of MRSA are without apparent predisposing risk factors for acquisition. Colonizing isolates of MRSA are heterogeneous and, unlike nosocomial isolates, often retain susceptibility to other non-beta-lactam antibiotics.     

Severe surgical site infection in community hospitals: epidemiology, key procedures, and the changing prevalence of methicillin-resistant Staphylococcus aureus.

OBJECTIVE: To characterize the epidemiology of severe (ie, nonsuperficial) surgical site infection (SSI) in community hospitals. METHODS: SSI data were collected prospectively at 26 community hospitals in the southeastern United States. Two analyses were performed: (1) a study of the overall prevalence rates of SSI and the prevalence rates of SSI due to specific pathogens in 2005 at all participating hospitals and (2) a prospective study of consecutive surgical procedures at 9 of the 26 community hospitals from 2000 through 2005. RESULTS: In 2005, a total of 1,010 SSIs occurred after 89,302 procedures (prevalence rate, 1.13 infections per 100 procedures). Methicillin-resistant S. aureus (MRSA) was the pathogen most commonly recovered (from 175 SSIs). Trend data from 2000 through 2005 demonstrated that the prevalence rate of MRSA SSI almost doubled during this period, increasing from 0.12 infections per 100 procedures (95% confidence interval [CI], 0.12-0.13) to 0.23 infections per 100 procedures (95% CI, 0.22-0.24) (P<.0001). In adjusted analysis, MRSA SSI was significantly more prevalent at the end of the study period than at the beginning (prevalence rate ratio, 1.48 [95% CI, 1.36-1.61]; P<.0001). CONCLUSIONS: MRSA was the pathogen that most commonly caused SSI in our network of community hospitals during 2005. The prevalence of MRSA SSI has increased significantly over the past 6 years.     

Effect of targeted surveillance for control of methicillin-resistant Staphylococcus aureus in a community hospital system.

OBJECTIVE: To examine the cost associated with targeted surveillance for methicillin-resistant Staphylococcus aureus (MRSA) and the effect of such surveillance on the rate of nosocomial MRSA infection in a community hospital system. DESIGN: A before-and-after study comparing the rate of MRSA infection before (BES) and after (AES) the initiation of expanded surveillance. Cost-effectiveness was calculated as the difference between the cost savings associated with preventing nosocomial MRSA bacteremias and surgical site infections AES and the cost of MRSA cultures and contact isolation for patients colonized with MRSA. SETTING AND PARTICIPANTS: Patients in a 400-bed tertiary-care facility (Roper Hospital) and a 180-bed suburban hospital (St. Francis Hospital), both in Charleston, South Carolina.Interventions. Beginning in September 2001, patients were screened for MRSA colonization upon admission to the intensive care unit and weekly thereafter. In July 2002, surveillance was expanded to include targeted screening of patients admitted to general wards who were at risk of MRSA colonization. Colonized patients were placed in contact isolation. RESULTS: The mean rate of nosocomial MRSA infection decreased at Roper (0.76 cases per 1,000 patient-days BES and 0.45 per 1000 patient-days AES; P = .05) and at St. Francis (0.73 cases per 1,000 patient-days BES and 0.57 cases per 1000 patient-days AES; P=.35). Surveillance was cost-effective, preventing 13 nosocomial MRSA bacteremias and 9 surgical site infections, for a savings of 1,545,762 US dollars. CONCLUSIONS: Targeted surveillance for MRSA colonization was cost-effective and provided substantial benefits by reducing the rate of nosocomial MRSA infections in a community hospital system.     

Methicillin-resistant Staphylococcus aureus (MRSA): a community-based prevalence survey

A prevalence survey of nasal methicillin-resistant Staphylococcus aureus (MRSA) carriage was undertaken on a random sample of adults (aged over 16) resident in the community in Birmingham, UK during 1998. Microbiological samples were taken from the anterior nares at the subjects' general practice or in their home. Information about risk factors for the acquisition of MRSA was obtained via a self-completed questionnaire. A 58% response rate (280/483) was achieved. The prevalence of nasal MRSA colonization was 1.5% [4/274, 95% confidence interval (CI) 0.03-2.9%]. Twenty-three per cent (63/274) of subjects were nasal carriers of S. aureus. Six per cent (4/63) of S. aureus isolates were MRSA and 2 of the 4 MRSA carriers reported previous contact with health facilities. The prevalence of MRSA colonization in the general adult population in Birmingham appears to be low.     

Duration of methicillin-resistant Staphylococcus aureus carriage, according to risk factors for acquisition.

OBJECTIVE: To examine the duration of methicillin-resistant Staphylococcus aureus (MRSA) carriage and its determinants and the influence of eradication regimens. DESIGN: Retrospective cohort study. SETTING: A 1,033-bed tertiary care university hospital in Bern, Switzerland, in which the prevalence of methicillin resistance among S. aureus isolates is less than 5%. PATIENTS: A total of 116 patients with first-time MRSA detection identified at University Hospital Bern between January 1, 2000, and December 31, 2003, were followed up for a mean duration of 16.2 months. RESULTS: Sixty-eight patients (58.6%) cleared colonization, with a median time to clearance of 7.4 months. Independent determinants for shorter carriage duration were the absence of any modifiable risk factor (receipt of antibiotics, use of an indwelling device, or presence of a skin lesion) (hazard ratio [HR], 0.20 [95% confidence interval {CI}, 0.09-0.42]), absence of immunosuppressive therapy (HR, 0.49 [95% CI, 0.23-1.02]), and hemodialysis (HR, 0.08 [95% CI, 0.01-0.66]) at the time MRSA was first MRSA detected and the administration of decolonization regimen in the absence of a modifiable risk factor (HR, 2.22 [95% CI, 1.36-3.64]). Failure of decolonization treatment was associated with the presence of risk factors at the time of treatment (P=.01). Intermittent screenings that were negative for MRSA were frequent (26% of patients), occurred early after first detection of MRSA (median, 31.5 days), and were associated with a lower probability of clearing colonization (HR, 0.34 [95% CI, 0.17-0.67]) and an increased risk of MRSA infection during follow-up. CONCLUSIONS: Risk factors for MRSA acquisition should be carefully assessed in all MRSA carriers and should be included in infection control policies, such as the timing of decolonization treatment, the definition of MRSA clearance, and the decision of when to suspend isolation measures.     

Clinical significance of methicillin-resistant Staphylococcus aureus colonization in residents in community long-term-care facilities in Spain

Methicillin-resistant Staphylococcus aureus (MRSA) is highly prevalent in Spanish hospitals and community long-term-care facilities (LTCFs). This longitudinal study was performed in community LTCFs to determine whether MRSA colonization is associated with MRSA infections and overall mortality. Nasal and decubitus ulcer cultures were performed every 6 months for an 18-month period on 178 MRSA-colonized residents (86 490 patient-days) and 196 non-MRSA carriers (97 470 patient-days). Fourteen residents developed MRSA infections and 10 of these were skin and soft tissue infections. Two patients with respiratory infections required hospitalization. The incidence rate of MRSA infection was 0·12/1000 patient-days in MRSA carriers and 0·05/1000 patient-days in non-carriers (P=0·46). No difference in MRSA infection rate was found according to the duration of MRSA colonization (P=0·69). The mortality rate was 20·8% in colonized residents and 16·8% in non-carriers; four residents with MRSA infection died. Overall mortality was statistically similar in both cohorts. Our results suggest that despite a high prevalence of MRSA colonization in LTCFs, MRSA infections are neither frequent nor severe while colonized residents remain at the facility. The epidemiological impact of an MRSA reservoir is more relevant than the clinical impact of this colonization for an individual resident and supports current recommendations to control MRSA spread in community LTCFs.     

Increased mortality among elderly patients with meticillin-resistant Staphylococcus aureus bacteraemia

Despite the high prevalence of meticillin-resistant Staphylococcus aureus (MRSA) infections among the elderly, outcomes of nosocomial MRSA bloodstream infections (BSI) for this patient population have not been fully examined. We performed a case-control study to compare outcomes of hospital-acquired MRSA BSI among patients >/=65 years of age (cases) with those younger than 65 years of age (controls). In a 430-bed tertiary-care teaching hospital, 100 hospitalized patients >/=18 years of age with S. aureus BSI were included in the study. Measurements obtained were: comorbidities, severity of illness at presentation, antibiotic therapy, haematogenous complications and mortality. Overall mortality was significantly higher among cases than controls [36% vs 12%; odds ratio (OR) 4.1, 95% confidence interval (CI) 1.4-14, P<0.01]. A pulmonary source was identified more frequently among elderly patients compared with younger controls (34% vs 16%; OR 2.7, 95%CI 1.1-8.1, P=0.04). On logistic regression, the following variables were independently associated with MRSA BSI among elderly patients: admission to a medical ward (OR 3.1, 95%CI 1.3-7.6, P=0.02), non-central-venous-catheter-related BSI (OR 3, 95%CI 1.2-7.6, P=0.02) and death (OR 3.7, 95%CI 1.3-11, P=0.02). Among patients who received vancomycin, more cases were treated with a reduced dose of vancomycin due to renal insufficiency compared with controls (64% vs 31%; OR 4, 95%CI 2-9, P=0.01). These data suggest that MRSA BSI is associated with significant mortality among the elderly population. Preventing MRSA acquisition among this patient population is of paramount importance.     

北京市海淀区社区居民胃食管反流病的流行病学调查

目的 了解北京市海淀区胃食管反流病(GERD)及其相关症状的分布情况,探讨可能的危险因素,并分析其与既往疾病的相关关系.方法 2008年6-9月,采用多阶段抽样法,对海淀区18～80岁的2615名常住居民进行问卷调查,内容包括基本信息、伴发疾病及反流性疾病问卷.结果 海淀区人群GERD的患病率为8.4%(220/2615),单纯胃灼热、单纯反流、两个症状均有的现患率分别为1.0%(25/2615),6.2%(163/2615)和1.2%(32/2615).多因素分析发现,GERD的可能危险因素有生活在农村(OR=2.237,95%CI:1.422～3.517)、女性(OR=1.456,95%CI:1.085～1.955)、高学历(OR=1.242,95%CI:1.001～1.542)、工作生活压力大(OR=1.277,95%CI:1.089～1.497)、精神状态差(OR=1.320,95%CI:1.046～1.665)和有胃肠病家族史(OR=1.594,95%CI:1.075～2.365);胃灼热症状的危险因素有居住在农村(OR=2.481,95%CI:1.278～4.818)、女性(OR=1.747,95%CI:0.902～3.386)、饮酒(OR=1.838,95%CI:0.916～3.690)、不运动(OR=2.091,95%CI:1.131～3.867)和精神状态差(OR=1.657,95%CI:1.123～2.446);反流症状的可能危险因素有生活在农村(OR=2.171,95%CI:1.326～3.556)、女性(OR=1.505,95%CI:1.102～2.056)、高学历(OR=1.347,95%CI:1.063～1.706)、工作生活压力大(OR=1.317,95%CI:1.113～1.558)、精神状态差(OR=1.266,95%CI:0.992～1.616)和有胃肠病家族史(OR=1.739,95%CI:1.163～2.600).GERD、胃灼热和反流症状与既往病史如焦虑症、抑郁症、消化性溃疡、胃炎、炎症性肠病、肾病有较强的关联.结论 GERD及其相关症状在该地区有一定程度的流行,它与不健康的生活方式、精神心理问题等相关,需要在社区开展有效的干预措施.     

Spread of methicillin-resistant Staphylococcus aureus (MRSA) among household contacts of individuals with nosocomially acquired MRSA.

OBJECTIVE: To determine the frequency with which methicillin-resistant Staphylococcus aureus (MRSA) is spread from colonized or infected patients to their household and community contacts. DESIGN: Retrospective cohort study. SETTING: University hospital. PARTICIPANTS: Household and community contacts of MRSA-colonized or -infected patients for whom MRSA screening cultures were performed. RESULTS: MRSA was isolated from 25 (14.5%) of 172 individuals. Among the contacts of index patients who had at least one MRSA-colonized contact, those with close contact to the index patient were 7.5 times more likely to be colonized (53% vs 7%; 95% confidence interval, 1.1 to 50.3; P = .002). An analysis of antimicrobial susceptibility and DNA fingerprint patterns suggested person-to-person spread. CONCLUSIONS: MRSA colonization occurs frequently among household and community contacts of patients with nosocomially acquired MRSA, suggesting that transmission of nosocomially acquired MRSA outside of the healthcare setting may be a substantial source of MRSA colonization and infection in the community.