Spread Of Meticillin-resistant Staphylococcus Aureus Research Articles

Joint Healthcare Infection Society (HIS) and Infection Prevention Society (IPS) guidelines for the prevention and control of meticillin-resistant Staphylococcus aureus (MRSA) in healthcare facilities

Joint Healthcare Infection Society (HIS) and Infection Prevention Society (IPS) guidelines for the prevention and control of meticillin-resistant Staphylococcus aureus (MRSA) in healthcare facilities

Frequent MRSA nasal colonization among hospitalized children and their parents in Angola and São Tomé and Príncipe

The prevalence of nosocomial meticillin-resistant Staphylococcus aureus (MRSA) was previously estimated as 23% in a paediatric hospital in Luanda, Angola and 18% in a general hospital in São Tomé and Príncipe. To evaluate the prevalence of S.aureus/MRSA colonization among hospitalized children and their parents at two hospitals in Angola and São Tomé and Príncipe. In 2017, 127 hospitalized children and 129 of their parents had nasal swabs for S.aureus/MRSA carriage in the two countries. The isolates were tested for the presence of the mecA and Panton-Valentine leukocidin (PVL) genes, and characterized by pulsed-field gel electrophoresis (PFGE), spa typing, multi-locus sequence typing and SCCmec typing. Twenty of 127 children (15.7%) and 13 of 129 parents (10.1%) were MRSA nasal carriers. Three lineages comprised 88% of the MRSA isolates: (i) PFGE A-ST5-SCCmec IVa (N=15; 45%), associated with spa type t105, recovered in Angola alone; (ii) PFGE N-ST8-IV/V (N=7; 21%), associated with spa types t008/t121, recovered in São Tomé and Príncipe alone; and (iii) PFGE B-ST88-IVa (N=7; 21%), associated with spa types t325/t786, present in both countries. Fifteen child/guardian pairs were colonized with identical MRSA (N=8) or meticillin-susceptible S.aureus (N=7) strains. PVL was detected in 25% of isolates, including two MRSA (ST30-V and ST8-IVa). Hospitalized children and their parents are important reservoirs of MRSA. Infection control measures should focus on parents in order to minimize the spread of MRSA to the community.

Spa typing and identification of pvl genes of meticillin-resistant Staphylococcus aureus isolated from a Libyan hospital in Tripoli.

The purpose of the study was to investigate the molecular characteristics of meticillin-resistant Staphylococcus aureus (MRSA) isolated from clinical sources in Tripoli, Libya. A total of 95 MRSA strains collected at the Tripoli medical Centre were investigated by spa typing and identification of the Panton-Valentine Leukocidin (pvl) genes. A total of 26 spa types were characterized and distributed among nine clonal complexes; CC5 (n=32), CC80 (n=18), CC8 (n=17) and CC22 (n=12) were the most prevalent clonal complexes. In total, 34% of the isolates were positive for PVL. This study demonstrated the presence of CA-MRSA and pvl positive strains in hospital settings and underlines the importance of using molecular typing to investigate the epidemiology of MRSA. Preventative measures and surveillance systems are needed to control and minimize the spread of MRSA in the Libyan health care system.

Screening and isolation to control meticillin-resistant Staphylococcus aureus: sense, nonsense, and evidence

Screening and isolation to control meticillin-resistant Staphylococcus aureus: sense, nonsense, and evidence

Systematic literature analysis and review of targeted preventive measures to limit healthcare-associated infections by meticillin-resistant Staphylococcus aureus.

Meticillin-resistant Staphylococcus aureus (MRSA) is a major cause of healthcare-associated infections in Europe. Many examples have demonstrated that the spread of MRSA within healthcare settings can be reduced by targeted infection control measures. The aim of this systematic literature analysis and review was to summarise the evidence for the use of bacterial cultures for active surveillance the benefit of rapid screening tests, as well as the use of decolonisation therapies and different types of isolation measures. We included 83 studies published between 2000 and 2012. Although the studies reported good evidence supporting the role of active surveillance followed by decolonisation therapy, the effectiveness of single-room isolation was mostly shown in non-controlled studies, which should inspire further research regarding this issue. Overall, this review highlighted that when planning the implementation of preventive interventions, there is a need to consider the prevalence of MRSA, the incidence of infections, the competing effect of standard control measures (e.g. hand hygiene) and the likelihood of transmission in the respective settings of implementation.

Characteristics of hospital patients colonized with livestock-associated meticillin-resistant Staphylococcus aureus (MRSA) CC398 versus other MRSA clones

Meticillin-resistant Staphylococcus aureus (MRSA) associated with the clonal complex (CC) 398 has emerged among livestock and humans exposed to these animals. MRSA CC398 has so far contributed relatively little to spread of MRSA and the burden of disease in the healthcare setting. This study aimed to assess whether demographic and clinical differences in patients colonized with MRSA CC398 and those carrying other MRSA clones contribute to the observed differences in transmission and infection rates. Age, sex, length of stay (LOS), diagnoses and medical procedures were assessed in all patients with MRSA admitted to a university hospital in 2008 and 2009. S.aureus protein A gene (spa) typing was performed on the first MRSA isolate from each patient. Patients colonized or infected with MRSA that had spa types indicative of CC398 (MRSA CC398) were compared with patients who had other MRSA clones (MRSA non-CC398). Age (53 vs 59 years), mean LOS (8 vs 13 days) and percentage of patients admitted to an intensive care unit (12% vs 17%) differed significantly between MRSA CC398 and MRSA non-CC398 patients, respectively. The mean numbers and types of diagnoses and medical procedures performed for patients in these two groups also differed significantly. The differences in patient characteristics could explain, at least in part, the relatively low rates of transmission and infection associated with MRSA CC398 in the healthcare setting.

Meticillin-resistant Staphylococcus aureus epidemiology and transmission in a Dutch hospital

The application of the search and destroy (S&D) policy in Scandinavian and Dutch hospitals is associated with low rates of meticillin-resistant Staphylococcus aureus (MRSA). The objective of our study was to describe the MRSA epidemiology and transmission in a Dutch hospital. This descriptive study was performed in a teaching hospital with approximately 40,000 admissions per year. In this hospital the MRSA S&D policy has been applied for several decades. MRSA epidemiology was studied during the years 2001 to 2006. The transmission rate in this hospital was determined using (1) patient's history, (2) relation in time and place to other patients or healthcare workers (HCWs), and (3) molecular typing (pulsed-field gel electrophoresis and Spa). Ninety-five persons were identified as MRSA carriers, namely 82 patients and 13 HCWs. The annual MRSA incidence increased more than three-fold during the study period, which was entirely caused by animal-related MRSA. Twenty-three percent of the patients acquired MRSA in a foreign hospital, 26% via animals, 16% by nosocomial transmission, 4% in another Dutch healthcare institution, 10% in the community via a known MRSA-positive person, and in 22% the source was unknown. For HCWs, 69% of MRSA was due to nosocomial transmission, 15% was related to working in a foreign hospital and in 15% HCWs became colonised via an MRSA-positive partner or relative. The transmission rate of 0.30 (22 secondary cases from 73 index cases) indicates that the spread of MRSA was under control during the study period, and so the S&D policy should be continued.

MRSA in small animal practice: an update

MOST cases of meticillin‐resistant Staphylococcus aureus (MRSA) infection in dogs and cats can be treated successfully as long as the underlying disease is identified and addressed concurrently. However, zoonotic implications,...

Comparison of the effect of ciprofloxacin and Tazocin ® on the incidence of meticillin-resistant Staphylococcus aureus (MRSA) in an Intensive Care Unit

Meticillin-resistant Staphylococcus aureus (MRSA) is a very significant agent of recalcitrant healthcare-associated infections. A major risk of acquiring such infections is thought to be modulated by the use of particular antimicrobial therapies. The aim of this research was to evaluate prospectively the impact of using either ciprofloxacin or Tazocin ® (piperacillin + tazobactam) on the incidence of MRSA in an Intensive Care Unit (ICU). The 1-year (2× 6 months) cross-over study was carried out in a medium-sized (426 beds) teaching hospital. During the first 6-month period, ciprofloxacin was used as the first-line broad-spectrum antibiotic therapy of choice. During the second 6-month period, Tazocin ® was used as first-line therapy. The incidence of hospital-acquired MRSA (i.e. colonised and/or infected) and rates of compliance of the ICU healthcare workers to optimal hand hygiene practices were recorded throughout the study. The study observed no statistically significant differences ( P = 0.1) between MRSA incidence rates in the ICU during the ciprofloxacin (4.4/1000 bed-days) or Tazocin ® (11.4/1000 bed-days) arms of the study. Interestingly, observing healthcare workers’ hand hygiene practices throughout the entire study showed that healthcare workers adhered to these practices 59.2% of the time during the ciprofloxacin arm and 66.0% during the Tazocin ® arm. The low incidence rates within the unit demonstrated the importance of infection control in limiting the spread of MRSA despite the extensive use of antibiotics in a high-risk setting.

Colonization of patients and contamination of the patients’ environment by MRSA under conditions of single-room isolation

Meticillin-resistant Staphylococcus aureus (MRSA) are endemic in hospitals worldwide and present a major concern in hospital hygiene. The aim of the present study was to investigate the relationship between patients' MRSA colonization of the body and the frequency of environmental contamination. Twenty-five MRSA-positive hospitalized surgical patients and their environment in isolation rooms were screened on four occasions over a 14-day period. Out of 1099 samples from patients, 330 (30.0%) were MRSA-positive. The median number of MRSA-positive body sites per screening decreased significantly from the 1st (3, range 1-9) to the 14th (2, range 0-9, p=0.011) day of isolation. Contamination was found in 45% of the 100 environmental sampling dates and MRSA was detected in a low proportion of the 1000 environmental surface samples: 105/1000 (10.5%). The number of positive results for each sampling date decreased from the 1st (median 1, range 0-8) to the 14th (median 0, range 0-3, p=0.21) day of isolation. The results show a very strong correlation between the number of MRSA-positive body sites of individual patients and the MRSA contamination of the patient's hospital room (r=0.700, p<0.001). Pulsed-field gel electrophoresis (PFGE) analysis demonstrated a 98% agreement between patient and environmental samples. MRSA colonization of the groin area correlates most strongly with colonization of the body and environment. Seventy-five of 240 (31%) samples taken in rooms of patients with colonization of the groin were MRSA-positive, whereas only 27 of 760 (3.6%) samples taken in rooms of patients without colonization of the groin produced positive results (odds ratio 12.3; 95% confidence interval, 7.7-20). It is concluded that MRSA patients without colonization of the groin have a relatively low risk of environmental spread of MRSA and thus a reduced risk of transmission.

Environmental meticillin-resistant Staphylococcus aureus (MRSA) disinfection using dry-mist-generated hydrogen peroxide

Meticillin-resistant Staphylococcus aureus (MRSA) is a major problem in hospitals worldwide. Hand hygiene is recognised as crucial in limiting the spread of MRSA but less is known about the role of MRSA reservoirs in the inanimate hospital environment. We evaluated the effect of hydrogen peroxide vapour diffused by Sterinis((R)) against MRSA in two experimental hospital settings and in two field trials. Dipslides were used for MRSA detection and quantification before and after using the Sterinis disinfection process. In the first experimental hospital setting, four epidemic MRSA strains were placed at five locations and left for one week. All strains survived the week but not the disinfection process. In field trial one 14 upholstered chairs from a department with many MRSA positive patients were left for one month in a closed room prior to disinfection. MRSA was found on the upholstery of four of the 14 chairs. Three chairs became MRSA negative immediately after the disinfection, the fourth 24h later. The second field trial was in the private home of a MRSA positive family of four individuals. One location was found MRSA positive, remaining so after the Sterinis cycles. We found Sterinis to be effective against MRSA in the experimental hospital setting and upholstered chairs, but not in the private home of heavily colonised MRSA patients.

Temporal relationship between prevalence of meticillin-resistant Staphylococcus aureus (MRSA) in one hospital and prevalence of MRSA in the surrounding community: a time-series analysis

We studied the relationship between meticillin-resistant Staphylococcus aureus (MRSA) prevalence in the Aberdeen Royal Infirmary and in the surrounding community (Grampian region: 500 000 inhabitants). We calculated the monthly %MRSA for both hospital and community from January 1996 to February 2002. A dynamic regression model was adjusted to measure any relationship between both series. The monthly %MRSA in the community was strongly related to the monthly %MRSA observed one month before in the hospital (R(2)=90.8%). We found no relationship with antimicrobial community use, although we have previously reported a strong correlation between prior use of antibiotics and incidence of MRSA in the hospital. By using time-series analysis techniques, we demonstrated that variations in MRSA prevalence in the hospital are quickly followed by similar variations in MRSA prevalence in the surrounding community. These results suggest that the reason for the increase in MRSA prevalence in the community was a hospital MRSA outbreak. Screening at patient discharge should be evaluated as a new measure to control spread of MRSA in the community.

Isolation of patients in single rooms or cohorts to reduce spread of MRSA in intensive-care units: prospective two centre study

Background Hospital-acquired infection due to meticillin-resistant Staphylococcus aureus (MRSA) is common within intensive-care units. Single room or cohort isolation of infected or colonised patients is used to reduce spread, but its benefit over and above other contact precautions is not known. We aimed to assess the effectiveness of moving versus not moving infected or colonised patients in intensive-care units to prevent transmission of MRSA. Methods We undertook a prospective 1-year study in the intensive-care units of two teaching hospitals. Admission and weekly screens were used to ascertain the incidence of MRSA colonisation. In the middle 6 months, MRSA positive patients were not moved to a single room or cohort nursed unless they were carrying other multiresistant or notifiable pathogens. Standard precautions were practised throughout. Hand hygiene was encouraged and compliance audited. Findings Patients' characteristics and MRSA acquisition rates were similar in the periods when patients were moved and not moved. The crude (unadjusted) Cox proportional-hazards model showed no evidence of increased transmission during the non-move phase (0·73 [95% CI 0·49–1·10], p=0·94 one-sided). There were no changes in transmission of any particular strain of MRSA nor in handwashing frequency between management phases. Interpretation Moving MRSA-positive patients into single rooms or cohorted bays does not reduce crossinfection. Because transfer and isolation of critically ill patients in single rooms carries potential risks, our findings suggest that re-evaluation of isolation policies is required in intensive-care units where MRSA is endemic, and that more effective means of preventing spread of MRSA in such settings need to be found. Published online January 7, 2005 http://image.thelancet.com/extras/04art9304web.pdf Hospital-acquired infection due to meticillin-resistant Staphylococcus aureus (MRSA) is common within intensive-care units. Single room or cohort isolation of infected or colonised patients is used to reduce spread, but its benefit over and above other contact precautions is not known. We aimed to assess the effectiveness of moving versus not moving infected or colonised patients in intensive-care units to prevent transmission of MRSA. We undertook a prospective 1-year study in the intensive-care units of two teaching hospitals. Admission and weekly screens were used to ascertain the incidence of MRSA colonisation. In the middle 6 months, MRSA positive patients were not moved to a single room or cohort nursed unless they were carrying other multiresistant or notifiable pathogens. Standard precautions were practised throughout. Hand hygiene was encouraged and compliance audited. Patients' characteristics and MRSA acquisition rates were similar in the periods when patients were moved and not moved. The crude (unadjusted) Cox proportional-hazards model showed no evidence of increased transmission during the non-move phase (0·73 [95% CI 0·49–1·10], p=0·94 one-sided). There were no changes in transmission of any particular strain of MRSA nor in handwashing frequency between management phases. Moving MRSA-positive patients into single rooms or cohorted bays does not reduce crossinfection. Because transfer and isolation of critically ill patients in single rooms carries potential risks, our findings suggest that re-evaluation of isolation policies is required in intensive-care units where MRSA is endemic, and that more effective means of preventing spread of MRSA in such settings need to be found. Published online January 7, 2005 http://image.thelancet.com/extras/04art9304web.pdf Controlling meticillin-resistant Staphylococcus aureus, aka “Superbug”Published online January 7, 2005. http://image.thelancet.com/extras/04cmt422web.pdf Full-Text PDF

Isolation of patients in single rooms or cohorts to reduce spread of MRSA in intensive-care units: prospective two centre study

Hospital-acquired infection due to meticillin-resistant Staphylococcus aureus (MRSA) is common within intensive-care units. Single room or cohort isolation of infected or colonised patients is used to reduce spread, but its benefit over and above other contact precautions is not known. We aimed to assess the effectiveness of moving versus not moving infected or colonised patients in intensive-care units to prevent transmission of MRSA. We undertook a prospective 1-year study in the intensive-care units of two teaching hospitals. Admission and weekly screens were used to ascertain the incidence of MRSA colonisation. In the middle 6 months, MRSA-positive patients were not moved to a single room or cohort nursed unless they were carrying other multiresistant or notifiable pathogens. Standard precautions were practised throughout. Hand hygiene was encouraged and compliance audited. Patients' characteristics and MRSA acquisition rates were similar in the periods when patients were moved and not moved. The crude (unadjusted) Cox proportional-hazards model showed no evidence of increased transmission during the non-move phase (0.73 [95% CI 0.49-1.10], p=0.94 one-sided). There were no changes in transmission of any particular strain of MRSA nor in handwashing frequency between management phases. Moving MRSA-positive patients into single rooms or cohorted bays does not reduce crossinfection. Because transfer and isolation of critically ill patients in single rooms carries potential risks, our findings suggest that re-evaluation of isolation policies is required in intensive-care units where MRSA is endemic, and that more effective means of preventing spread of MRSA in such settings need to be found.