Staphylococcus aureus carriage in care homes: identification of risk factors, including the role of dementia

Population incidence and associated mortality of urinary tract infection in people living with dementia

OBJECTIVES

Urinary tract infections (UTIs) frequently cause hospitalisation and death in people living with dementia (PLWD). We examine UTI incidence and associated mortality among PLWD relative to matched controls and people with diabetes and investigate whether delayed or withheld treatment further impacts mortality.

METHODS

Data were extracted for n = 2,449,814 people aged ≥ 50 in Wales from 2000-2021, with groups matched by age, sex, and multimorbidity. Poisson regression was used to estimate incidences of UTI and mortality. Cox regression was used to study the effects of treatment timing.

RESULTS

UTIs in dementia (HR=2.18, 95 %CI [1.88-2.53], p < .0) and diabetes (1.21[1.01-1.45], p = .035) were associated with high mortality, with the highest risk in individuals with diabetes and dementia (both) (2.83[2.40-3.34], p < .0) compared to matched individuals with neither dementia nor diabetes. 5.4 % of untreated PLWD died within 60 days of GP diagnosis-increasing to 5.9 % in PLWD with diabetes.

CONCLUSIONS

Incidences of UTI and associated mortality are high in PLWD, especially in those with diabetes and dementia. Delayed treatment for UTI is further associated with high mortality.

Prevalence of indwelling urinary catheters in nursing home residents: Systematic review

BACKGROUND

This systematic review examines the prevalence of indwelling urinary catheters in nursing home residents.

METHODS

MEDLINE via PubMed, CINAHL, and EMBASE were searched from inception to 9 August 2022. Cross-sectional studies and longitudinal studies with cross-sectional analyses reporting catheter prevalence in nursing home residents were identified and summarized descriptively. Study quality was assessed using the Joanna Briggs Institute's tool.

RESULTS

Sixty-seven studies (92.5 % cross-sectional) were included. The reported number of included residents ranged from 73 to 110,656. The median catheter prevalence was 7.3 % (interquartile range 4.3-10.1 %; n = 65 studies). It was higher in Germany (10.2 % [9.7-12.8 %]; n = 15) than in the United States of America (9.3 % [6.3-11.9 %]; n = 9), United Kingdom (6.9 % [4.8-8.5 %]; n = 7), and Sweden (7.3 % [6.4-7.9 %]; n = 6). Furthermore, it was higher among men (17.0 % [16.0-26.0 %]) than among women (5.3 % [4.0-9.5 %]) (n = 9). Only one study investigated differences by age. The prevalence was higher for transurethral (5.7 % [5.6-7.2 %]; n = 12) than for suprapubic (1.2 % [0.6-2.5 %]; n = 13) catheters. Most catheterized residents were long-term catheterized (n = 6) and had their catheter changed within 3 months (n = 2). Symptomatic urinary tract infections were more common among catheterized than among non-catheterized residents (n = 4).

DISCUSSION

Catheter prevalence in nursing home residents varies between studies and countries. Prevalence differences by sex, age, and catheter type as well as duration of catheterization, catheter change intervals, and catheter-associated urinary tract infections are rarely reported because most studies do not primarily focus on catheters. Future studies should focus on the circumstances of urinary catheter use and care in nursing home residents.

REGISTRATION AND FUNDING

PROSPERO (29 August 2022; CRD42022354358); no funding.

The global prevalence of methicillin-resistant Staphylococcus aureus colonization in residents of elderly care centers: a systematic review and meta-analysis

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) is a difficult to treat infection, particularly in residents of elderly care centers (ECCs). Despite the substantial burden of MRSA, an inadequate number of studies have analyzed MRSA prevalence in ECCs.

OBJECTIVES

We conducted a worldwide systematic review and meta-analysis on the prevalence and risk factors of MRSA in ECCs.

METHODS

We searched MEDLINE/PubMed, EMBASE, Web of Science, and Scopus databases and the gray literature sources for all studies published between January 1980 and December 2022 on the prevalence of MRSA in ECCs. A random-effects model was utilized to estimate pooled prevalence rates at 95% confidence intervals (CI). Moreover, the data were analyzed based on World Health Organization-defined regions, income, and human development index levels.

RESULTS

In total, 119 studies, including 164,717 participants from 29 countries, were found eligible for meta-analysis. The pooled global prevalence of MRSA was 14.69% (95% CI 12.39-17.15%; 16,793/164,717). Male gender [prevalence ratio (PR) = 1.55; 95% CI 1.47-1.64], previous MRSA infection (PR = 3.71; 95% CI 3.44-4.01), prior use of antibiotics (PR = 1.97; 95% CI 1.83-2.12), hospitalized within the previous year (PR = 1.32; 95% CI 1.20-1.45), have had any wound (PR = 2.38; 95% CI 2.23-2.55), have used urinary catheter (PR = 2.24; 95% CI 2.06-2.43), have used any medical device (PR = 1.78; 95% CI 1.66-1.91), and those with diabetes (PR = 1.55; CI 1.43-1.67) were more likely to be colonized by MRSA than other patients.

CONCLUSION

Screening programs and preventive measures should target MRSA in ECCs due to the high global prevalence rates.

Prevalence and Risk Factors for Multidrug-Resistant Organisms Colonization in Long-Term Care Facilities Around the World: A Review

Elderly people confined to chronic care facilities face an increased risk of acquiring infections by multidrug-resistant organisms (MDROs). This review presents the current knowledge of the prevalence and risk factors for colonization by MDROs in long-term care facilities (LTCF), thereby providing a useful reference to establish objectives for implementing successful antimicrobial stewardship programs (ASPs). We searched in PubMed and Scopus for studies examining the prevalence of MDROs and/or risk factors for the acquisition of MDROs in LTCF. One hundred and thirty-four studies published from 1987 to 2020 were included. The prevalence of MDROs in LTCF varies between the different continents, where Asia reported the highest prevalence of extended-spectrum ß-lactamase (ESBL) Enterobacterales (71.6%), carbapenem resistant (CR) Enterobacterales (6.9%) and methicillin-resistant Staphylococcus aureus (MRSA) (25.6%) and North America the highest prevalence to MDR Pseudomonas aeruginosa (5.4%), MDR Acinetobacter baumannii (15.0%), vancomycin-resistant Enterococcus spp. (VRE) (4.0%), and Clostridioides difficile (26.1%). Furthermore, MDRO prevalence has experienced changes over time, with increases in MDR P. aeruginosa and extended spectrum ß-lactamase producing Enterobacterales observed starting in 2015 and decreases of CR Enterobacterales, MDR A. baumannii, VRE, MRSA and C. difficile. Several risk factors have been found, such as male sex, chronic wounds, the use of medical devices, and previous antibiotic use. The last of these aspects represents one of the most important modifiable factors for reducing colonization with MDROs through implementing ASPs in LTCF.

Methicillin-susceptible staphylococcus aureus in community-acquired pneumonia: Risk factors and outcomes

OBJECTIVES

We aimed to describe the prevalence, risk factors and outcomes of Methicillin-susceptible S. aureus (MSSA) community-acquired pneumonia (CAP) and compare them with those associated with CAP due to Streptococcus pneumoniae, the most frequent causative microorganism, in a large cohort of patients.

METHODS

This was an observational study of prospectively collected data of consecutive adults with CAP and a definitive etiology enrolled between 2004 and 2018. Patients were divided into MSSA CAP and pneumococcal CAP groups for analysis.

RESULTS

A microbial etiology was established in 1,548 (33%) cases: S. aureus caused 6% of microbiologically-confirmed CAP cases. In the latter, 52 were due to MSSA (60% of S. aureus CAP cases, and 3% of microbiologically-confirmed CAP cases) and 34 were due to MRSA (40% of S. aureus CAP cases, and 2% of microbiologically-confirmed CAP cases). S. pneumoniae was identified in 734 (47%) microbiologically-confirmed CAP cases. The presence of fever was independently associated with a lower risk of MSSA CAP (OR 0.53; 95% CI, 0.28-0.99). Patients with MSSA CAP had higher 30-day mortality than patients with pneumococcal CAP, both before and after adjustment for potential confounders (21% vs 7%, p = 0.002). MSSA was independently associated with 30-day mortality in the overall population.

CONCLUSION

MSSA CAP was associated with worse outcomes than pneumococcal CAP in our cohort. MSSA was an independent factor of mortality.

Asymptomatic carriage of Neisseria meningitidis, Haemophilus influenzae, Streptococcus pneumoniae, Group A Streptococcus and Staphylococcus aureus among adults aged 65 years and older

OBJECTIVE

The aim of this study was to determine the prevalence of Neisseria meningitidis, Haemophilus influenzae, Streptococcus pneumoniae, group A Streptococcus (GAS), and Staphylococcus aureus in asymptomatic elderly people and to unravel risk factors leading to colonization.

METHODS

A multi-centre cross-sectional study was conducted including 677 asymptomatic adults aged 65 years or more, living at home or in nursing homes. Study areas were Greater Aachen (North-Rhine-Westphalia) and Wuerzburg (Bavaria), both regions with medium to high population density. Nasal and oropharyngeal swabs as well as questionnaires were collected from October 2012 to May 2013. Statistical analysis included multiple logistic regression models.

RESULTS

The carriage rate was 1.9% ([95%CI: 1.0-3.3%]; 13/677) for H. influenzae, 0.3% ([95%CI: 0-1.1%]; 2/677) for N. meningitidis and 0% ([95% CI: 0-0.5%]; 0/677) for S. pneumoniae and GAS. Staphylococcus aureus was harboured by 28.5% of the individuals ([95% CI: 25.1-32.1%]; 193/677) and 0.7% ([95% CI: 0.2-1.7%]; 5/677) were positive for methicillin-resistant S. aureus. Among elderly community-dwellers colonization with S. aureus was significantly associated with higher educational level (adjusted OR: 1.905 [95% CI: 1.248-2.908]; p = 0.003). Among nursing home residents colonization was associated with being married (adjusted OR: 3.367 [1.502-7.546]; p = 0.003).

CONCLUSION

The prevalence of N. meningitidis, H. influenzae, S. pneumoniae and GAS was low among older people in Germany. The S. aureus rate was expectedly high, while MRSA was found in less than 1% of the individuals.

Naso- and oropharyngeal bacterial carriage in nursing home residents: Impact of multimorbidity and functional impairment

OBJECTIVE

From April 2013 to February 2014 we performed a multicentre prospective cross-sectional study in 541 German nursing home residents. We determined pharyngeal carriage of Streptococcus pneumoniae (primary objective) and other bacteria (secondary objective) in naso- and oropharyngeal swabs by culture-based standard procedures and explored the influence of multimorbidity and functional status on bacterial carriage.

METHODS

Socio-demographic data, vaccination status, multimorbidity, nutrition and functional status defined by Comprehensive Geriatric Assessment were evaluated. We estimated carriage rates with 95% confidence intervals (CI) and explored potential risk factors by logistic regression analysis.

RESULTS

Pneumococcal post-serotyping carriage rate was 0.8% (95%CI 0.2-1.9%; 4/526). Serotyping revealed serotypes 4, 7F, 23B and 23F and S. pseudopneumoniae in two other cases. Odds of carriage were higher in men (Odds ratio OR 5.3 (95%CI 0.9-29.4)), in malnourished residents (OR 4.6 (0.8-25.7)), residents living in shared rooms (OR 3.0 (0.5-16.5)) or having contact with schoolchildren (OR 2.0 (0.2-17.6)). The most frequent pathogen was Staphylococcus aureus (prevalence 29.5% (25.6-33.6%)) with meticillin-resistant Staphylococcus aureus prevalence of 1.1%. Gram-negative bacteria (GNB) were found in 22.5% (19.0-26.3%) with a prevalence of extended-spectrum beta lactamase (ESBL) producing bacteria of 0.8%. Odds of S. aureus carriage were higher for immobility (OR 1.84 (1.15-2.93)) and cognitive impairment (OR 1.54 (0.98-2.40)). Odds of GNB carriage were higher in residents with more severe comorbidity (OR 1.13 (1.00-1.28)) and malnutrition (OR 1.54 (0.81-2.91)).

CONCLUSIONS

Given the observed data, at least long-term carriage of S. pneumoniae in nursing home residents seems to be rare and rather unlikely to cause nursing home acquired pneumonia. The low rate of colonization with multi drug resistant (MDR) bacteria confirms that nursing home residency is not a risk factor for MDR pneumonia in Germany. For individual risk assessment in this susceptible population, immobility and malnutrition should be considered as signs of functional impairment as well as comorbidity.

Epidemiology of patients with MSSA versus MRSA infections of orthopedic implants: Retrospective study of 115 patients

Factors that predict the occurrence of a surgical site infection due to methicillin-resistant Staphylococcus aureus (MRSA) are not well known; however this information could be used to modify the recommended antimicrobial prophylaxis. We carried out a retrospective study of S. aureus infections on orthopedic implants to determine: (1) whether epidemiological factors can be identified that predict a MRSA infection, (2) the impact of these factors as evidenced by the odds ratio (OR).

HYPOTHESIS

Risk factors for a MRSA infection can be identified from a cohort of patients with S. aureus infections.

MATERIALS AND METHODS

We identified 244 patients who experienced a S. aureus surgical site infection (SSI) in 2011-2012 documented by intraoperative sample collection. Of these 244 patients, those who had a previous SSI (n=44), those with a SSI but no orthopedic implant (n=80) or those who had the infection more than 1-year after the initial surgery (n=5) were excluded. This resulted in 115 patients (53 arthroplasty, 62 bone fixation) being analyzed for this study. There were 24 MRSA infections and 91 MSSA infections. The following factors were evaluated in bivariate and multifactorial analysis: age, sex, type of device (prosthesis/bone fixation), predisposition (diabetes, obesity, kidney failure), and environmental factors (hospitalization in intensive care unit within past 5 years, nursing home stay).

RESULTS

Two factors were correlated with the occurrence of MRSA infections. (1) Nursing home patients had a higher rate of MRSA infections (67% vs. 18%, P=0.017) with an OR of 8.42 (95% CI: 1.06-66.43). (2) Patients who had undergone bone fixation had a lower rate of MRSA infections than patients who had undergone arthroplasty (13% vs. 30%, P=0.023), OR 0.11 (95% CI: 0.02-0.56). Although the sample size was too small to be statistically significant, all of the patients with kidney failure (n=4) had a MRSA infection.

DISCUSSION

Since these MRSA infection risk factors are easy to identify, the antimicrobial prophylaxis could be adapted in these specific patient groups.

MRSA in Croatia: prevalence and management

Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are associated with increased morbidity, mortality and length of hospital stay. MRSA is a major pathogen in hospitals and an important pathogen in community infections with few severe and fatal cases. However, MRSA causes the majority of skin and soft tissue infections in the US. The burden of community MRSA is much smaller in Europe, but there are reports of livestock-associated MRSA (LA-MRSA) isolated from pigs and cattle causing significant infections in the people who are connected to these farms. MRSA has been present in Croatia for more than 45 years, and it exerts a different impact on health-care infections. A remarkable increase in MRSA percentage was noted in primarily sterile samples in 2002 (37%) in comparison to 2001 (31%). This percentage remained quite high until 2008, when the first signs of a reduced trend were observed. The lowest percentage was 22% in 2012.

Impact of hand hygiene on the infectious risk in nursing home residents: A systematic review

BACKGROUND

In nursing homes, the infectious risk is high, making infection control using approaches such as hand hygiene (HH) a major issue. However, the effectiveness of HH in these settings is not well documented, and HH compliance is low.

METHODS

We systematically searched PubMed, Scopus, Web of Science, and Cochrane Clinical Trials for studies in nursing homes that either described a HH-related intervention or assessed HH compliance and included a measured infectious outcome. Two reviewers independently performed the study selection.

RESULTS

Fifty-six studies met the inclusion criteria and were reviewed. Most were outbreak reports (39%), followed by observational studies (23%), controlled trials (23%), and before-after intervention studies (14%). Thirty-five studies (63%) reported results in favor of HH on at least one of their outcome measures; in addition, the infection control success rate was higher when at least one HH-related intervention (eg, staff education on HH, increased availability of handrub solution) was included (70% vs 30% for no intervention). However, only 25% of randomized trials concluded that HH-related interventions led to a reduction in the infectious risk.

CONCLUSION

The results of this systematic review suggest that more evidence on HH effectiveness in nursing homes is needed. Future interventional studies should enhance methodologic rigor using clearly defined outcome measures, standardized reporting of findings, and a relevant HH observation tool.

Prevalence and molecular characteristics of methicillin-resistant Staphylococcus aureus strains isolated in a multicenter study of nursing home residents in Croatia

BACKGROUND

Residents of nursing homes (NHs) are often hospitalized and could present a potential reservoir for methicillin-resistant Staphylococcus aureus (MRSA). The aim of the study was to determine the prevalence for MRSA carriage in residents and staff in Croatian NHs and to characterize MRSA strains using genotyping techniques.

METHODS

A cross-sectional study was performed among 877 residents and staff of 7 NHs representing 3 major Croatian regions. Nasal swabs from residents and staff and other samples from residents with invasive devices were obtained. Identified isolates were submitted to susceptibility testing and genotyping with SCCmec typing, S aureus protein A (spa) locus typing, and pulsed-field gel electrophoresis (PFGE).

RESULTS

The overall prevalence of MRSA colonization was 7.1% (95 confidence interval, 5.4%-8.8%), ranging from 0% to 28.8%. Four MRSA isolates were found in NH staff. All MRSA isolates were negative for Panton-Valentine leukocidin-encoding genes. SCCmec type II was found in 32 MRSA strains; SCCmec IV, in 27 strains; SCCmec I, in 3 strains. The predominant spa type was t008, found in 49 strains; PFGE analysis revealed 2 major clonal groups.

CONCLUSIONS

MRSA strains were found to be colonizing residents and staff of 7 NHs in Croatia. Our study demonstrates the spread of 2 clones within and among Croatian NHs. The data presented here provide an important baseline for future surveillance of MRSA in NH.

Prevalence, risk factors, and epidemiology of methicillin-resistant Staphylococcus aureus carried by adults over 60 years of age

The epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) in the community in Portugal is not completely understood. To evaluate S. aureus and MRSA carriage among the elderly, we conducted a large cross-sectional study between April 2010 and December 2012. A total of 3,361 adults over 60 years of age were screened for S. aureus nasopharyngeal and oropharyngeal carriage. MRSA were characterized by staphylococcal cassette chromosome mec (SCCmec) typing, spa typing, multilocus sequence typing (MLST), and tested for the presence of Panton-Valentine leukocidin (PVL). Risk factors for MRSA carriage were identified by multiple logistic regression analysis. The prevalence of S. aureus and MRSA carriage among the elderly was 20.1 % and 1.8 %, respectively. The risk of being an MRSA carrier was higher among the elderly living in retirement homes [odds ratio (OR) = 2.90, 95 % confidence interval (CI): 1.48-5.48] and those that had been hospitalized in the previous year (OR = 2.64, 95 % CI: 1.47-4.58). Among the 62 MRSA isolates, 64.5 % were multidrug-resistant and none carried PVL. Most MRSA (82.3 %) were related to three hospital-associated (HA-MRSA) clones disseminated in Portugal: ST105-II (New York/Japan clone; 43.5 %), ST5-IVc (Pediatric clone; 19.4 %), and ST22-IVh (EMRSA-15 clone; 19.4 %). The New York/Japan and Pediatric clones were significantly associated with carriers living in retirement homes, while the EMRSA-15 clone was associated with carriers that had been hospitalized. We conclude that the elderly population in Portugal is essentially free of MRSA. Given the current European societal challenges for a healthy active aging, these results are of importance to healthcare professionals and public authorities to decide on strategies to promote health in this age group.

The general status of patients and limited physical activity as risk factors of Methicillin-resistant Staphylococcus aureus occurrence in long-term care facilities residents in Krakow, Poland

Background

The aim of this study was to investigate the epidemiology and resistance of methicillin-resistant Staphylococcus aureus (MRSA) isolates from long-term care facilities (LTCF) residents and to analyze the potential risk factors for MRSA occurrence, defined as MRSA colonization and/or infection.

Methods

Point prevalence (PPS) and prospective incidence continuous study (CS) was carried out on a group of 193 residents in 2009-2010.

Results

Overall MRSA occurred (with or without infection) among 17.6% of residents. There was 16 cases of infections with SA aetiology, of which 10 (58.8%) were caused by MRSA. The MRSA prevalence in PPS was 12.9%, in CS infection incidence rate was 5.2%. Factors associated with MRSA occurrence were: general status of patients, limited physical activity, wound infections (odds ratio, OR 4.6), ulcers in PPS (OR 2.1), diabetes (OR 1.6), urinary catheterization (OR 1.6) and stool incontinence (OR 1.2).

Conclusions

Our data indicate a need for screening of MRSA before hospitalization or transfer to rehabilitation centres, especially in a group of residents with limitations in physical activity – i.e. with the highest risk of MRSA. Results also suggest the need for contact precautions in patients with high risk of MRSA occurrence, only. Focus on the high-risk population might be a solution for the cost-effective surveillance.

Prevalence of multidrug-resistant organisms and risk factors for carriage in long-term care facilities: a nested case-control study

BACKGROUND

Long-term care facilities (LTCFs) are a potentially important reservoir of multidrug-resistant (MDR) organisms; however, limited data exist.

METHODS

A point-prevalence study was conducted in four co-located LTCFs in Australia. Nasal and rectal swabs were cultured for methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE) and MDR Gram-negative bacilli (GNB). Molecular typing and resistance detection were performed. Risk factors for colonization with an MDR organism were determined using a nested case-control study.

RESULTS

Consent was obtained from 115 (85%) of 136 eligible participants. Forty-one (36%) residents carried at least one type of MDR organism. The prevalence was 16% MRSA (n = 18), 6% VRE (n = 7) and 21% MDR GNB [n = 24; including extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (n = 12) and Acinetobacter baumannii (n = 6)]. The majority of ESBL-producing E. coli and A. baumannii were clonal. Current wound management [adjusted OR (AOR) 8.81 (95% CI 2.78-27.94), P < 0.001], medical device in situ [AOR 5.58 (95% CI 1.34-23.32), P = 0.018] and pressure ulcer [AOR 3.69 (95% CI 1.06-12.86), P = 0.04] were independent risk factors for MDR organism colonization. Advanced dementia [AOR 3.54 (95% CI 1.23-10.23), P = 0.02] and prolonged antibiotic use [AOR 2.95 (95% CI 1.01-8.60), P = 0.047] were independently associated with MRSA colonization, whilst current wound management [AOR 15.59 (95% CI 4.85-50.10), P < 0.001] and fluoroquinolone use [AOR 4.27 (95% CI 1.20-15.25), P = 0.025] were risk factors for MDR GNB colonization.

CONCLUSIONS

LTCFs are an important reservoir of MDR organisms, with person-to-person transmissions being a potential issue. We have identified several predictors of colonization with MDR organisms, allowing a more targeted management of high-risk residents.

Effect of vitamin D3 supplementation on Staphylococcus aureus nasal carriage: a randomized, double-blind, placebo-controlled trial in healthy adults

Observational studies have reported an inverse association between serum 25-hydroxyvitamin D (25OHD) concentrations and Staphylococcus aureus nasal carriage; however, clinical trials of vitamin D supplementation are lacking. To assess the effect of vitamin D3 supplementation on persistent S. aureus nasal carriage we conducted a randomized, double-blind, placebo-controlled trial among 322 healthy adults. Participants were given an oral dose of either 200 000 IU vitamin D3 for each of 2 months, followed by 100 000 IU monthly or placebo in an identical dosing regimen, for a total of 18 months. Nasal swabs for S. aureus culture and serum for 25OHD measurement were obtained at baseline, 6, 12 and 18 months of study. The mean baseline concentration of 25OHD was 72 nM (SD 22 nM). Vitamin D3 supplementation increased 25OHD levels which were maintained at >120 nM throughout the study. Nasal colonization by S. aureus was found in 31% of participants at baseline. Persistent carriage, defined as those that had positive S. aureus nasal cultures for all post-baseline swabs, occurred in 20% of the participants but vitamin D3 supplementation was not associated with a reduction in persistent carriage (OR = 1.39, 95% CI 0.63-3.06). Risk factor analysis showed that only gender was significantly associated with carriage, where women were less likely to be carriers than men (relative risk 0.83, 95% CI 0.54-0.99). Serum 25OHD concentrations were not associated with the risk of carriage. In conclusion, monthly administration of 100 000 IU of vitamin D3 did not reduce persistent S. aureus nasal carriage.

Antibiotic resistance, population structure and spread of Staphylococcus aureus in nursing homes in the Euregion Meuse-Rhine

To determine the spread of Staphylococcus aureus within and between nursing home (NH) residents in the Euregion Meuse-Rhine, a cross-border region of the Netherlands and Germany, we investigated the prevalence of antibiotic resistance, genetic background and population structure of both methicillin-susceptible S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) isolates. A total of 245 S. aureus isolates were collected from NH residents. Susceptibility testing was performed with microbroth dilution. The genetic background was determined using spa typing, SCCmec typing, pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Differences in the prevalence of resistance between the German and Dutch MSSA isolates were observed for the macrolides (15 % vs. 2 %, p = 0.003), clindamycin (15 % vs. 0 %, p = 0.003) and ciprofloxacin (34 % vs. 25 %). The macrolide and ciprofloxacin resistance varied between the NHs, while trimethoprim-sulfamethoxazole resistance was low in all residents. The MRSA prevalence was 3.5 % and <1 % among the German and Dutch NH residents, respectively (p = 0.005). The German MRSAs, isolated in 7 out of 10 NHs, belonged to ST22-MRSA-IV or ST225-MRSA-II. spa clonal complexes (spa-CCs) 015 and 002 were prevalent among the German MSSA isolates and spa-CCs 024 and 1716 were prevalent among the Dutch MSSA isolates. The antibiotic resistance of MSSA and the MRSA prevalence were significantly higher among the German NH residents. The spread of two MRSA clones was observed within and between the German NHs, but not between the Dutch and German NHs. Differences in the prevalence of resistance and the prevalence of MRSA between NHs on both sides of the border warrant the continuation of surveillance at a local level.

A basic dynamic transmission model of Staphylococcus aureus in the US population

We present a basic mathematical model of Staphylococcus aureus transmission in the USA based on natural history of infection and nationally representative data. We employed a Susceptible-Colonized-Infected-Recovered-Susceptible compartmental modelling framework with two different phenotypes of S. aureus: methicillin-susceptible (MSSA) and methicillin-resistant (MRSA). The model is dynamic and accounts for the US population growth. For model calibration/validation, we used published 1999–2005 S. aureus infection data in conjunction with the 2001–2004 National Health and Nutrition Examination Survey colonization data. Baseline model projections illustrated how MRSA might continue to expand and gradually replace MSSA over time, in the absence of intervention, if there is strong competition for colonization. The model-based estimate of the basic reproduction number (R₀) highlights the need for infection control. We illustrate the potential population-level impact of intervention with a hypothetical S. aureus vaccination component.

Transmission of methicillin-resistant Staphylococcus aureus in the long term care facilities in Hong Kong

Background

The relative contribution of long term care facilities (LTCFs) and hospitals in the transmission of methicillin-resistant Staphylococcus aureus (MRSA) is unknown.

Methods

Concurrent MRSA screening and spa type analysis was performed in LTCFs and their network hospitals to estimate the rate of MRSA acquisition among residents during their stay in LTCFs and hospitals, by colonization pressure and MRSA transmission calculations.

Results

In 40 LTCFs, 436 (21.6%) of 2020 residents were identified as ‘MRSA-positive’. The incidence of MRSA transmission per 1000-colonization-days among the residents during their stay in LTCFs and hospitals were 309 and 113 respectively, while the colonization pressure in LTCFs and hospitals were 210 and 185 per 1000-patient-days respectively. MRSA spa type t1081 was the most commonly isolated linage in both LTCF residents (76/121, 62.8%) and hospitalized patients (51/87, 58.6%), while type t4677 was significantly associated with LTCF residents (24/121, 19.8%) compared with hospitalized patients (3/87, 3.4%) (p < 0.001). This suggested continuous transmission of MRSA t4677 among LTCF residents. Also, an inverse linear relationship between MRSA prevalence in LTCFs and the average living area per LTCF resident was observed (Pearson correlation −0.443, p = 0.004), with the odds of patients acquiring MRSA reduced by a factor of 0.90 for each 10 square feet increase in living area.

Conclusions

Our data suggest that MRSA transmission was more serious in LTCFs than in hospitals. Infection control should be focused on LTCFs in order to reduce the burden of MRSA carriers in healthcare settings.

Prevalence, risk factors, and molecular epidemiology of methicillin-resistant Staphylococcus aureus nasal and axillary colonization among psychiatric patients on admission to an academic medical center

BACKGROUND

Infection control data from psychiatric units and clinics are limited.

METHODS

This time series study was designed to determine the prevalence and risk factors for methicillin-resistant Staphylococcus aureus (MRSA) colonization and/or infection among 500 men and women on admission to psychiatric units at The Johns Hopkins Hospital. Discharge surveillance was conducted to measure incidence. Molecular characterization was performed.

RESULTS

Five hundred subjects (52% male) were enrolled. The prevalence of MRSA colonization was 5.2% (26 of 498). Seven of 29 patients (24.1%) admitted with a skin and soft tissue infection (SSTI) was MRSA-positive; 4 of these patients had no other positive site, raising the total admission prevalence to 6.0%. A history of abscess (current or within the past 6 months) on admission (odds ratio [OR], 6.06; 95% confidence interval [CI], 2.40-15.31; P < .001), HIV infection (OR, 4.03; 95% CI, 1.52-10.71; P = .005), previous isolation (OR, 5.03; 95% CI, 1.76-14.35; P = .003), and unknown history of isolation (OR, 4.10; 95% CI, 1.41-11.98; P = .01) were associated with increased odds of MRSA colonization. Seven (2.6%) new MRSA colonizations were identified at discharge. Molecular analysis identified USA300 clonal MRSA isolates.

CONCLUSIONS

The prevalence of MRSA colonization in this study population was greater than reported in the general population. Further studies are needed to identify transmission dynamics in this environment.

Is living in a border region a risk for a high prevalence of resistance?

This study assessed the antimicrobial resistance and population structure of Staphylococcus aureus isolated from general practice (GP) patients and nursing home (NH) residents in the province of Limburg (near the border with Germany and Belgium) in comparison with those obtained in the remaining provinces of the Netherlands. A total of 617 and 418 S. aureus isolates were isolated from 2,691 to 1,351 nasal swabs from GP patients and NH residents, respectively. Quantitative antibiotic susceptibility testing was performed using a microbroth dilution method. Putative methicillin-resistant S. aureus (MRSA) isolates were tested for the presence of the mecA gene and spa typing was performed on all S. aureus isolates. No significant differences in the prevalence of resistance were found between the two groups of GP isolates, but the isolates from the NH residents showed a lower resistance for trimethoprim-sulfamethoxazole (p = 0.003) in Limburg province compared with the remaining provinces in the Netherlands. Among the isolates from NH residents in Limburg province, the prevalence of spa-CC 084 was higher (p = 0.003) and that of spa-CC 002 was lower (p = 0.01) compared with isolates from NHs in the remaining provinces of the Netherlands. We observed no differences in resistance and population structure between S. aureus isolates from GP patients in Limburg and the remaining provinces of the Netherlands, and only a few differences were observed between the NH populations. There was no higher prevalence of resistance among the GP and NH isolates from Limburg compared with the remaining provinces.

Methicillin-resistant Staphylococcus aureus (MRSA) management in palliative care units and hospices in Germany: a nationwide survey on patient isolation policies and quality of life

BACKGROUND

For palliative care settings, little is known about the benefits of specific methicillin-resistant Staphylococcus aureus containment regimens and the burdens patient isolation imposes on affected patients, their families, and professional caregivers.

AIM

To explore the current practice of MRSA management and its impact on inpatients' quality of life as perceived by professional caregivers.

DESIGN

Survey of inpatient palliative care institutions using 23-item questionnaires (infrastructural data: six items, management process: 14, clinical significance: three).

SETTING/PARTICIPANTS

All palliative care units (179) and hospices (181) listed in Germany's directory of palliative care services. The χ(2) test was used to test for differences; significance level: p ≤ 0.05.

RESULTS

229 of 360 questionnaires were returned. More than 90% of the responding institutions employed specific MRSA protocols. Lack of resources was a more important issue for palliative care units than for hospices regarding availability of single rooms (p = 0.002) and staffing (p = 0.004). Compared to hospices, palliative care units more frequently isolated MRSA patients (p = 0.000), actively treated colonization (p = 0.026), assessed the efficacy of eradication (p = 0.000), provided information on MRSA management to patients (p = 0.014) and relatives (p = 0.001), more often restricted patients' activities (p = 0.000), and reported a negative impact on quality of life (p = 0.000).

CONCLUSIONS

Rigorously applied MRSA protocols impose significant burdens at the end of life. Research on clinical outcomes including quality of life may identify interventions of questionable benefit. The issue of handling MRSA should be studied as a model for the management of other highly complex conditions and special needs such as patient isolation.

Prevalence, risk factors and molecular epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) colonization in residents of long-term care facilities in Luxembourg, 2010

A prevalence survey of methicillin-resistant Staphylococcus aureus (MRSA) was performed in 2010 in 19 long-term care facilities in Luxembourg. Of the 954 participating residents, 69 (7·2%) were colonized by MRSA. Previous history of MRSA [odds ratio (OR) 7·20, 95% confidence interval (CI) 3·19-16·27], quinolone therapy in the previous year (OR 2·27, 95% CI 1·17-4·41) and ≥24 h care administered per week (OR 4·29, 95% CI 1·18-15·56) were independent risk factors for MRSA colonization. More than 75% of strains were of clonal complex (CC)5, mainly spa-type t003 or sequence type (ST)225 and ST710, which is a rapidly emerging lineage prevalent in central Europe. Five residents were colonized by livestock-associated genotypes belonging to CC398. Previously dominant CC8 strains have recently been replaced by more resistant CC5 strains in Luxembourg.

The longitudinal prevalence of MRSA in care home residents and the effectiveness of improving infection prevention knowledge and practice on colonisation using a stepped wedge study design

Objectives To determine the prevalence and health outcomes of meticillin-resistant Staphylococcus aureus (MRSA) colonisation in elderly care home residents. To measure the effectiveness of improving infection prevention knowledge and practice on MRSA prevalence. Setting Care homes for elderly residents in Leeds, UK. Participants Residents able to give informed consent. Design A controlled intervention study, using a stepped wedge design, comprising 65 homes divided into three groups. Baseline MRSA prevalence was determined by screening the nares of residents (n=2492). An intervention based upon staff education and training on hand hygiene was delivered at three different times according to group number. Scores for three assessment methods, an audit of hand hygiene facilities, staff hand hygiene observations and an educational questionnaire, were collected before and after the intervention. After each group of homes received the intervention, all participants were screened for MRSA nasal colonisation. In total, four surveys took place between November 2006 and February 2009. Results MRSA prevalence was 20%, 19%, 22% and 21% in each survey, respectively. There was a significant improvement in scores for all three assessment methods post-intervention (p≤0.001). The intervention was associated with a small but significant increase in MRSA prevalence (p=0.023). MRSA colonisation was associated with previous and subsequent MRSA infection but was not significantly associated with subsequent hospitalisation or mortality. Conclusions The intervention did not result in a decrease in the prevalence of MRSA colonisation in care home residents. Additional measures will be required to reduce endemic MRSA colonisation in care homes.

Conceptual model for reducing infections and antimicrobial resistance in skilled nursing facilities: focusing on residents with indwelling devices

Infections in skilled nursing facilities (SNFs) are common and result in frequent hospital transfers, functional decline, and death. Colonization with multidrug-resistant organisms (MDROs) - including methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), and multidrug-resistant gram-negative bacilli (R-GNB) - is also increasingly prevalent in SNFs. Antimicrobial resistance among common bacteria can adversely affect clinical outcomes and increase health care costs. Recognizing a need for action, legislators, policy-makers, and consumer groups are advocating for surveillance cultures to identify asymptomatic patients with MDROs, particularly MRSA in hospitals and SNFs. Implementing this policy for all SNF residents may be costly, impractical, and ineffective. Such a policy may result in a large increase in the number of SNF residents placed in isolation precautions with the potential for reduced attention by health care workers, isolation, and functional decline. Detection of colonization and subsequent attempts to eradicate selected MDROs can also lead to more strains with drug resistance. We propose an alternative strategy that uses a focused multicomponent bundle approach that targets residents at a higher risk of colonization and infection with MDROs, specifically those who have an indwelling device. If this strategy is effective, similar strategies can be studied and implemented for other high-risk groups.