Jacqui Reilly

Should healthcare workers be screened routinely for meticillin-resistant Staphylococcus aureus? A review of the evidence

Meticillin-resistant Staphylococcus aureus (MRSA) is considered endemic in the UK National Health Service (NHS), and routine MRSA screening of hospital inpatients has recently been introduced in both Scotland and England. The UK National Screening Committee states that public pressure for widening the eligibility criteria of a proposed screening programme should be anticipated and any related decisions scientifically justifiable. A literature review was conducted to examine whether MRSA screening in Scotland should be expanded to include the routine screening of healthcare workers (HCWs). There are no published prevalence studies reporting the overall MRSA carriage rate in HCWs in NHS hospitals. Estimates of HCW carriage from the worldwide literature vary widely depending on the country, hospital specialty and setting (endemic, non-endemic or outbreak). Recent studies conducted in endemic hospital settings report non-outbreak carriage rates of 0-15%. The role of HCW carriage in the transmission of MRSA is not well understood. Persistent carriage could act as a reservoir for infection and HCWs have been implicated as the source in a number of published outbreak reports. There are no published controlled trials examining the impact of routine HCW screening as an intervention in the prevention and control of MRSA infections in the endemic hospital setting. Most of the evidence for HCW screening comes from outbreak reports where the outbreak was brought to an end following the introduction of staff screening as part of a suite of infection control measures. Further research is required before a recommendation could be made to introduce routine MRSA screening of HCWs in the NHS in Scotland.

Nasal Swab Screening for Methicillin-Resistant Staphylococcus aureus—How Well Does It Perform? A Cross-Sectional Study

OBJECTIVE To determine the proportion of methicillin-resistant Staphylococcus aureus (MRSA) detections identified by nasal swabbing using agar culture in comparison with multiple body site testing using agar and nutrient broth culture. DESIGN Cross-sectional study. PATIENTS Adult patients admitted to 36 general specialty wards of 2 large hospitals in Scotland. METHODS Patients were screened for MRSA via multiple body site swabs (nasal, throat, axillary, perineal, and wound/invasive device sites) cultured individually on chromogenic agar and pooled in nutrient broth. Combined results from all sites and cultures provided a gold-standard estimate of true MRSA prevalence. RESULTS This study found that nasal screening performed better than throat, axillary, or perineal screening but at best identified only 66% of true MRSA carriers against the gold standard at an overall prevalence of 2.9%. Axillary screening performed least well. Combining nasal and perineal swabs gave the best 2-site combination (82%). When combined with realistic screening compliance rates of 80%-90%, nasal swabbing alone probably detects just over half of true colonization in practice. Swabbing of clinically relevant sites (wounds, indwelling devices, etc) is important for a small but high-prevalence group. CONCLUSIONS Nasal swabbing is the standard method in many locations for MRSA screening. Its diagnostic efficiency in practice appears to be limited, however, and the resource implications of multiple body site screening have to be balanced against a potential clinical benefit whose magnitude and nature remains unclear.

Costs of healthcare-associated methicillin-resistant Staphylococcus aureus and its control.

Methicillin-resistant Staphylococcus aureus (MRSA) clones have caused a huge worldwide epidemic of hospital-acquired infections over the past 20-30 years and continue to evolve, including the advent of virulent community strains. The burden on healthcare services is highly significant, in particular because MRSA has not replaced susceptible staphylococcal infection but is an additional problem. Treatment strategies for MRSA are suboptimal and compromise the care of patients. MRSA is associated with serious morbidity and mortality, both within and without hospitals. Although the literature on the costs of MRSA and its control is suboptimal, it is clear that the control of MRSA is highly desirable and likely to be cost-effective. Any compromises in control are likely to be false economies.

Universal screening for meticillin-resistant Staphylococcus aureus: interim results from the NHS Scotland pathfinder project

Following recommendations from a Health Technology Assessment (HTA), a prospective cohort study of meticillin-resistant Staphylococcus aureus (MRSA) screening of all admissions (N=29 690) to six acute hospitals in three regions in Scotland indicated that 7.5% of patients were colonised on admission to hospital. Factors associated with colonisation included re-admission, specialty of admission (highest in nephrology, care of the elderly, dermatology and vascular surgery), increasing age, and the source of admission (care home or other hospital). Three percent of all those who were identified as colonised developed hospital-associated MRSA infection, compared with only 0.1% of those not colonised. Specialties with a high rate of colonisation on admission also had higher rates of MRSA infection. Very few patients refused screening (11 patients, 0.03%) or had treatment deferred (14 patients, 0.05%). Several organisational issues were identified, including difficulties in achieving complete uptake of screening (88%) or decolonisation (41%); the latter was largely due to short duration of stay and turnaround time for test results. Patient movement resulted in a decision to decolonise all positive patients rather than just those in high risk specialties as proposed by the HTA. Issues also included a lack of isolation facilities to manage patients with MRSA. The study raises significant concerns about the contribution of decolonisation to reducing risks in hospital due to short duration of stay, and reinforces the central role of infection control precautions. Further study is required before the HTA model can be re-run and conclusions redrawn on the cost and clinical effectiveness of universal MRSA screening.

Results from the Scottish National HAI Prevalence Survey

A national point prevalence survey was undertaken over the period of one calendar year in Scotland from October 2005 to October 2006. The prevalence of healthcare-associated infection (HAI) was 9.5% in acute hospitals and 7.3% in non-acute hospitals. The highest prevalence of HAI in acute hospital inpatients was found in the following specialties: care of the elderly (11.9%), surgery (11.2%), medicine (9.6%) and orthopaedics (9.2%). The lowest prevalence was found in obstetrics (0.9%). The most common types of HAI in acute hospital inpatients were: urinary tract infections (17.9% of all HAI), surgical site infections (15.9%) and gastrointestinal infections (15.4%). In non-acute hospitals one in ten inpatients in two specialties (combined) - medicine (11.4%) and care of the elderly (7.8%) - was found to have HAI, and one in 20 inpatients in psychiatry (5.0%) had HAI. In non-acute hospital patients, urinary tract infections were frequent (28.1% of all HAI) and similarly skin and soft tissue infection (26.8% of all HAI). When combined, these two HAI types affected 4% of all the inpatients in non-acute hospitals. This is the first survey of its kind in Scotland and describes the burden of HAI at a national level.

Core components for effective infection prevention and control programmes: new WHO evidence-based recommendations

Health care-associated infections (HAI) are a major public health problem with a significant impact on morbidity, mortality and quality of life. They represent also an important economic burden to health systems worldwide. However, a large proportion of HAI are preventable through effective infection prevention and control (IPC) measures. Improvements in IPC at the national and facility level are critical for the successful containment of antimicrobial resistance and the prevention of HAI, including outbreaks of highly transmissible diseases through high quality care within the context of universal health coverage. Given the limited availability of IPC evidence-based guidance and standards, the World Health Organization (WHO) decided to prioritize the development of global recommendations on the core components of effective IPC programmes both at the national and acute health care facility level, based on systematic literature reviews and expert consensus. The aim of the guideline development process was to identify the evidence and evaluate its quality, consider patient values and preferences, resource implications, and the feasibility and acceptability of the recommendations. As a result, 11 recommendations and three good practice statements are presented here, including a summary of the supporting evidence, and form the substance of a new WHO IPC guideline.

The Prevalence of Health Care–Associated Infection in Older People in Acute Care Hospitals

OBJECTIVE To determine the prevalence of health care-associated infection (HAI) in older people in acute care hospitals, detailing the specific types of HAI and specialties in which these are most prevalent. DESIGN Secondary analysis of the Scottish National Healthcare Associated Infection Prevalence Survey data set. PATIENTS AND SETTING All inpatients in acute care (n = 11,090) in all acute care hospitals in Scotland (n = 45). RESULTS The study found a linear relationship between prevalence of HAI and increasing age (P<.0001) in hospital inpatients in Scotland. Urinary tract infections and gastrointestinal infections represented the largest burden of HAI in the 75-84- and over-85-year age groups, and surgical-site infections represented the largest burden in inpatients under 75 years of age. The prevalence of urinary catheterization was higher in each of the over-65 age groups (P<.0001). Importantly, this study reveals that a high prevalence of HAI in inpatients over the age of 65 years is found across a range of specialties within acute hospital care. An increased prevalence of HAI was observed in medical, orthopedic, and surgical specialties. CONCLUSIONS HAI is an important outcome indicator of acute inpatient hospital care, and our analysis demonstrates that HAI prevalence increases linearly with increasing age (P<.0001). Focusing interventions on preventing urinary tract infection and gastrointestinal infections would have the biggest public health benefit. To ensure patient safety, the importance of age as a risk factor for HAI cannot be overemphasized to those working in all areas of acute care.

Prevalence of healthcare-associated infection in Scottish intensive care units.

A national point prevalence survey of healthcare-associated infection (HCAI) in all acute hospitals, including intensive care units (ICUs), was carried out in Scotland from October 2005 to October 2006. The survey measured the prevalence of HCAIs to determine the burden on ICU resources. HCAI prevalence in ICUs was compared with HCAI prevalence in patients outside ICU. The prevalence of HCAI in ICU patients was 27.1%, significantly higher than HCAI prevalence in patients outside ICU, which was 9.3%. The prevalence of specific infections, namely pneumonia and lower respiratory tract, bloodstream and surgical site infections, was also significantly higher in ICU patients compared with non-ICU patients. These results highlight the burden on ICU resources from all HCAIs, regardless of site of infection. High HCAI prevalence in Scottish ICUs has major implications for patient safety and ICU resources and emphasises the need for continuing strong collaboration between intensivists and infection control teams.

A retrospective cohort study into acquisition of MRSA and associated risk factors after implementation of universal screening in Scottish hospitals

OBJECTIVE To estimate the proportion of patients who acquire methicillin-resistant Staphylococcus aureus (MRSA) while in hospital and to identify risk factors associated with acquisition of MRSA. DESIGN Retrospective cohort study. PATIENTS Adult patients discharged from 36 general specialty wards of 2 Scottish hospitals that had implemented universal screening for MRSA on admission. METHODS Patients were screened for MRSA on discharge from hospital by using multisite body swabs that were tested by culture. Discharge screening results were linked to admission screening results. Genotyping was undertaken to identify newly acquired MRSA in MRSA-positive patients on admission. RESULTS Of the 5,155 patients screened for MRSA on discharge, 2.9% (95% confidence interval [CI], 2.43-3.34) were found to be positive. In the subcohort screened on both admission and discharge (n = 2,724), 1.3% of all patients acquired MRSA while in hospital (incidence rate, 2.1/1,000 hospital bed-days in this cohort [95% CI, 1.5-2.9]), while 1.3% remained MRSA positive throughout hospital stay. Three risk factors for acquisition of MRSA were identified: age above 64 years, self-reported renal failure, and self-reported presence of open wounds. On a population level, the prevalence of MRSA colonization did not differ between admission and discharge. CONCLUSIONS Cross-transmission of MRSA takes place in Scottish hospitals that have implemented universal screening for MRSA. This study reinforces the importance of infection prevention and control measures to prevent MRSA cross-transmission in hospitals; universal screening for MRSA on admission will in itself not be sufficient to reduce the number of MRSA colonizations and subsequent MRSA infections.

A pragmatic randomized controlled trial of 6-step vs 3-step hand hygiene technique in acute hospital care in the United Kingdom

OBJECTIVE To evaluate the microbiologic effectiveness of the World Health Organizations 6-step and the Centers for Disease Control and Preventions 3-step hand hygiene techniques using alcohol-based handrub. DESIGN A parallel group randomized controlled trial. SETTING An acute care inner-city teaching hospital (Glasgow). PARTICIPANTS Doctors (n=42) and nurses (n=78) undertaking direct patient care. INTERVENTION Random 1:1 allocation of the 6-step (n=60) or the 3-step (n=60) technique. RESULTS The 6-step technique was microbiologically more effective at reducing the median log10 bacterial count. The 6-step technique reduced the count from 3.28 CFU/mL (95% CI, 3.11-3.38 CFU/mL) to 2.58 CFU/mL (2.08-2.93 CFU/mL), whereas the 3-step reduced it from 3.08 CFU/mL (2.977-3.27 CFU/mL) to 2.88 CFU/mL (-2.58 to 3.15 CFU/mL) (P=.02). However, the 6-step technique did not increase the total hand coverage area (98.8% vs 99.0%, P=.15) and required 15% (95% CI, 6%-24%) more time (42.50 seconds vs 35.0 seconds, P=.002). Total hand coverage was not related to the reduction in bacterial count. CONCLUSIONS Two techniques for hand hygiene using alcohol-based handrub are promoted in international guidance, the 6-step by the World Health Organization and 3-step by the Centers for Disease Control and Prevention. The study provides the first evidence in a randomized controlled trial that the 6-step technique is superior, thus these international guidance documents should consider this evidence, as should healthcare organizations using the 3-step technique in practice. Infect Control Hosp Epidemiol 2016;37:661-666.