Methicillin-resistant Staphylococcus aureus: a four-year experience in a spinal cord injury unit in Spain

Bacteriology of pressure ulcers in individuals with spinal cord injury: What we know and what we should know

Individuals with spinal cord injury (SCI) are at increased risk for the development of pressure ulcers. These chronic wounds are debilitating and contribute to prolonged hospitalization and worse medical outcome. However, the species of bacteria and the role that specific species may play in delaying the healing of chronic pressure ulcers in the SCI population has not been well characterized. This study will review the literature regarding what is known currently about the bacteriology of pressure ulcers in individuals with SCI. An electronic literature search of MEDLINE (1966 to February 2014) was performed. Eleven studies detailing bacterial cultures of pressure ulcers in the SCI population met inclusion criteria and were selected for review. Among these studies, bacterial cultures were often polymicrobial with both aerobic and anaerobic bacteria identified with culture techniques that varied significantly. The most common organisms identified in pressure ulcers were Staphylococcus aureus, Proteus mirabilis, Pseudomonas aeruginosa, and Enterococcus faecalis. In general, wounds were poorly characterized with minimal to no physical description and/or location provided. Our present understanding of factors that may alter the microbiome of pressure ulcers in individuals with SCI is quite rudimentary, at best. Well-designed studies are needed to assess appropriate wound culture technique, the impact of bacterial composition on wound healing, development of infection, and the optimum medical and surgical approaches to wound care.

Prevention of methicillin-resistant Staphylococcus aureus infections in spinal cord injury units

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) health care-associated infections (HAIs) are a concern in the 22 acute care Veterans Affairs (VA) spinal cord injury units where patients with unique rehabilitation and medical needs and a high risk of infection are treated.

METHODS

A bundle was implemented in VA spinal cord injury units consisting of nasal surveillance for MRSA on admission/in-hospital transfer/discharge, contact precautions for patients colonized or infected with MRSA, an emphasis on hand hygiene, and an institutional culture change where infection control became everyone's responsibility.

RESULTS

From October 2007, through June 2011, there were 51,627 admissions/transfers/discharges and 816,254 patient-days of care in VA spinal cord injury units. The percentage of patients screened increased to >95.0%. The mean admission MRSA prevalence was 38.6% ± 19.1%. Monthly HAI rates declined 81% from 1.217 per 1,000 patient-days to 0.237 per 1,000 patient-days (P < .001). Bloodstream infections declined by 100% (P = .002), skin and soft-tissue infections by 60% (P = .007), and urinary tract infections by 33% (P = .07).

CONCLUSION

Universal surveillance, contact precautions, hand hygiene, and an institutional culture change was associated with significant declines in MRSA HAIs in a setting with a high prevalence of MRSA colonization and a high risk for infection.

Clinical significance of methicillin-resistantStaphylococcus aureuscolonization in residents in community long-term-care facilities in Spain

Methicillin-resistantStaphylococcus 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.

Natural history of meticillin-resistant Staphylococcus aureus colonisation among residents in community long term care facilities in Spain

The spread of meticillin-resistant Staphylococcus aureus (MRSA) is a major problem for both acute care hospitals and among residents in long term care facilities (LTCFs). We performed a cohort study to assess the natural history of MRSA colonisation in LTCF residents. Two cohorts of residents (231 MRSA carriers and 196 non-carriers) were followed up for an 18 month period, with cultures of nasal and decubitus ulcers performed every six months. In the MRSA carrier cohort, 110 (47.8%) residents had persistent MRSA colonisation for six months or longer, 44 (19.0%) had transient colonisation and nine (3.9%) were intermittently colonised. No risk factors for persistent MRSA colonisation could be determined. The annual incidence of MRSA acquisition was around 20% [95% confidence interval (CI): 14.3-25.5]. Antibiotic treatment was independently associated with MRSA acquisition (odds ratio: 2.27; 95% CI: 1.05-4.88; P=0.03). Just two clones were distinguishable by pulsed-field gel electrophoresis and multilocus sequence typing: CC5-MRSA IV, which is widely disseminated in Spanish hospitals, and ST22-MRSA IV. This study adds to the knowledge of the epidemiology of MRSA in community LTCFs, which are important components of long term care in Spain.

[Impact and control of methicillin-resistant Staphylococcus aureus (MRSA) in long-term care facilities]

Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are a growing concern in long-term care facilities (LTCF). Epidemiologic studies performed in our area have shown high rates of MRSA colonization in elderly residents, and very high rates in some centres. However, the clinical impact of nasal MRSA colonization is often slight. Prevention of MRSA transmission in LTCF includes the application of simple preventive measures with proven effectiveness, such as hand washing, adequately covering of infected wounds, and proper use of antibiotics, without limiting the activities of colonized residents or carrying out active surveillance.

Health-care workers: source, vector, or victim of MRSA?

There is ongoing controversy about the role of health-care workers in transmission of meticillin-resistant Staphylococcus aureus (MRSA). We did a search of the literature from January, 1980, to March, 2006, to determine the likelihood of MRSA colonisation and infection in health-care workers and to assess their role in MRSA transmission. In 127 investigations, the average MRSA carriage rate among 33 318 screened health-care workers was 4.6%; 5.1% had clinical infections. Risk factors included chronic skin diseases, poor hygiene practices, and having worked in countries with endemic MRSA. Both transiently and persistently colonised health-care workers were responsible for several MRSA clusters. Transmission from personnel to patients was likely in 63 (93%) of 68 studies that undertook genotyping. MRSA eradication was achieved in 449 (88%) of 510 health-care workers. Subclinical infections and colonisation of extranasal sites were associated with persistent carriage. We discuss advantages and disadvantages of screening and eradication policies for MRSA control and give recommendations for the management of colonised health-care workers in different settings.

Staphylococcus aureus colonization in community-dwelling people with spinal cord dysfunction

OBJECTIVES

To estimate the prevalence of and determine risk factors for Staphylococcus aureus colonization of the perineum.

DESIGN

Cross-sectional study with follow-up of up to 1 year.

SETTING

Multiple outpatient sites.

PARTICIPANTS

Eighty-four community-dwelling adults with spinal cord dysfunction (SCD).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

Colonization of perineum with S. aureus.

RESULTS

Overall, 24% of the study cohort carried S. aureus on their perineal skin at enrollment, with 16% having methicillin-susceptible S. aureus and 10% having methicillin-resistant S. aureus (MRSA). Most perineal carriers were also colonized in the anterior nares. Participants with trauma as the cause of their SCD were more likely to be colonized with S. aureus than participants with SCD caused by multiple sclerosis or other causes (relative risk [RR], 2.8; 95% confidence interval [CI], 1.2-6.6; P=.01). Participants with pelvic decubiti were more likely to be colonized with S. aureus than participants without pelvic decubiti (RR=4.3; 95% CI, 2.4-7.7; P<.001). The recent use of any antibiotic was not associated with an increased risk of colonization with S. aureus (RR=1.5; 95% CI, 0.7-3.3; P=.31); however, recent fluoroquinolone use was significantly associated with perineal colonization (RR=2.8; 95% CI, 1.4-5.8; P=.02). Of the 8 participants with MRSA colonization, only 2 (25%) had a history of MRSA colonization.

CONCLUSIONS

S. aureus colonization of the perineum is common in this outpatient population of people with SCD. The use of fluoroquinolones was associated with S. aureus colonization. Colonization with MRSA without a history of MRSA was common.

Control of an ACC-1-producing Klebsiella pneumoniae outbreak in a physical medicine and rehabilitation unit

This article describes an outbreak of ACC-1-producing Klebsiella pneumoniae involving 40 patients. These were mainly men under 40 years old with a spinal cord injury, in a physical medicine and rehabilitation unit. The main risk factors were prolonged hospital stay, multiple-bed rooms, tracheostomy care and assisted defaecation. The outbreak was only controlled after the introduction of rigorous patient placement (i.e. single rooms or cohorting in the same room), while allowing the patients to have free access to the various technical services (e.g. physiotherapy and occupational therapy) and living spaces necessary for re-education.

Epidemiological relatedness of methicillin-resistant Staphylococcus aureus from a tertiary hospital and a geriatric institution in Spain

From January 2000 to June 2002, 24 Staphylococcus aureus isolates were recovered from decubitus ulcers of patients in a geriatric institution, of which 17 (70.8%) were methicillin-resistant S. aureus (MRSA). Antibiotic resistance and DNA macrorestriction (pulsed-field gel electrophoresis; PFGE) patterns of the MRSA isolates were compared with a collection of 161 MRSA isolates from patients admitted to the institution's reference hospital. PFGE revealed the presence of five clonal types (found also in hospitalised patients) among the 17 MRSA isolates. The findings suggest nosocomial acquisition of the MRSA strains by five patients, with subsequent dissemination of the strains within the institution. The high rate of MRSA highlights the need for epidemiological analysis to control the dissemination of MRSA in long-term care facilities.

Impact of nosocomial infection on length of stay and functional improvement among patients admitted to an acute rehabilitation unit

OBJECTIVE

To identify factors predictive of length of stay (LOS) and the level of functional improvement achieved among patients admitted to an acute rehabilitation unit for the first time, with special reference to the role of nosocomial infection.

SETTING

A 40-bed acute rehabilitation unit within a 300-bed, tertiary-care, public, university-affiliated hospital.

STUDY POPULATION

All patients admitted to the unit between January 1997 and July 1998.

DESIGN

Prospective cohort study in which demographic and clinical data, including occurrence of nosocomial infection, were collected during the entire unit admission of each patient. Multivariate linear regression analysis was used to identify factors predictive of unit LOS or improvement in functional status as measured by the change in the Functional Independence Measure (FIM) score between admission and discharge (deltaFIM).

RESULTS

There were 423 admissions to the rehabilitation unit during the study period, of which 91 (21.5%) had spinal cord injury (SCI) as a principal diagnosis. One hundred seven nosocomial infections occurred during 84 (19.9%) of the 423 admissions. The most common infections were urinary tract (31.8% of all infections), surgical-site (18.5%), and Clostridium difficile diarrhea (15%). Only one patient died of infection. After controlling for severity of illness on admission, functional status on admission, age, and other clinical factors, the significant positive predictors of unit LOS were as follows: SCI (P<.001), pressure ulcer (.002), and nosocomial infection (<.001). Significant negative predictors of deltaFIM were age (P<.001), FIM score on admission (<.001), prior hospital LOS (.002), and nosocomial infection (.007).

CONCLUSIONS

Several variables were identified as contributing to a longer LOS or to a smaller improvement in functional status among patients admitted for the first time to an acute rehabilitation unit. Of these variables, only nosocomial infection has the potential for modification. Studies of new approaches to prevent infections among patients undergoing acute rehabilitation should be pursued.

Prospective surveillance for antibiotic-resistant organisms in patients with spinal cord injury admitted to an acute rehabilitation unit

BACKGROUND

The objective of this study was to evaluate the epidemiology of antibiotic-resistant organisms among patients with spinal cord injury admitted to an acute rehabilitation unit for the first time.

METHODS

After informed consent, 63 patients with spinal cord injury admitted to an acute rehabilitation unit between January 1997 and July 1998 had surveillance cultures (nares, urine, wounds or ulcers, and perineum) done on admission and every 2 weeks thereafter until discharge or as long as 6 weeks after admission.

RESULTS

Of the 4 surveillance sites, perineal cultures most commonly grew one or more potential pathogens; however, antibiotic-resistant organisms were most often isolated from wounds or ulcers and least often in urine cultures. Staphylococcus aureus (methicillin-sensitive plus methicillin-resistant) and enterococci represented 44% of all organisms isolated in surveillance cultures. Methicillin-resistant S aureus was the most common resistant organism isolated. Less than 30% of the gram-negative bacilli isolated were considered antibiotic-resistant strains. Nosocomial infection as a result of any resistant organism was infrequent. After adjusting for various confounding factors in a logistic regression model, only the presence of a pressure ulcer predicted carriage of any resistant organism on admission to the rehabilitation unit. Acquisition of a resistant organism after admission to the unit at one or more surveillance sites occurred in 8 (22%) of 36 patients not colonized on admission.

CONCLUSIONS

Methicillin-resistant S aureus was the most common resistant organism colonizing patients with spinal cord injury at the time of admission to an acute rehabilitation unit and throughout their stay. However, acquisition of any resistant organism after admission was uncommon on this unit, which used Standard Precautions in the routine care of patients. These findings have implications for the type of isolation procedures on acute rehabilitation units. The low rate of acquisition and infection with MRSA after admission argues against attempts at eradication as a method of control.