A review of infection control in community healthcare: new challenges but old foes

The demographics of the healthcare population are changing, with an ever-greater proportion of people being treated outside the traditional hospital setting through community healthcare. This shift in the way that healthcare is delivered raises new concerns over community healthcare-associated infections (HCAIs). A literature search between 2000 and December 2013 was conducted in databases including PubMed, SciVerse ScienceDirect and Google Scholar. National and international guideline and policy documents were searched using Google. Many terms were used in the literature searches, including ‘nosocomial’, ‘healthcare infection’, ‘community’ and ‘nursing home’. The rates of HCAI in community healthcare are similar to the rates found in the acute hospital setting, but the types of infection differ, with a greater focus on urinary tract infections (UTIs) in the community and ventilator-associated pneumonias in the hospital setting. Patients who acquire a community HCAI are more likely to exhibit reduced physical condition, have increased levels of morbidity and have higher mortality rates than individuals without infection. Infection control programmes have been developed worldwide to reduce the rates of hospital HCAIs. Such interventions are equally as valid in the community, but how best to implement them and their subsequent impact are much less well understood. The future is clear: HCAIs in the community are going to become an ever-increasing burden and it is critical that our approach to these infections is brought quickly in line with present hospital sector standards.

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.

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.

The neural architecture of discourse compression

Re-telling a story is thought to produce a progressive refinement in the mental representation of the discourse. A neuroanatomical substrate for this compression effect, however, has yet to be identified. We used a discourse re-listening task and functional magnetic resonance imaging (fMRI) to identify brain regions responsive to repeated discourse in twenty healthy volunteers. We found a striking difference in the pattern of activation associated with the first and subsequent presentations of the same story relative to rest. The first presentation was associated with a highly significant increase in blood oxygen level dependent (BOLD) signal in a bilateral perisylvian distribution, including auditory cortex. Listening to the same story on subsequent occasions revealed a wider network with activation extending into frontal, parietal, and subcortical structures. When the first and final presentations of the same story were directly compared, significant increments in activation were found in the middle frontal gyrus bilaterally, and the right inferior parietal lobule, suggesting that the spread of activation with re-listening reflected an active neural process over and above that required for comprehension of the text. Within the right inferior parietal region the change in BOLD signal was highly correlated with a behavioural index of discourse compression based in re-telling, providing converging evidence for the role of the right inferior parietal region in the representation of discourse. Our findings demonstrate, for the first time, the existence of a neural network underlying discourse compression, showing that parts of this network are common to re-telling and re-listening effects.

The place of guidelines in hospital-acquired pneumonia

The recent increase in hospital-acquired infections (HAIs) has meant that hospital-acquired pneumonia (HAP) has come under the spotlight. HAP is the most common HAI contributing to death and affects about 0.5-1% of all patients admitted to hospital. HAP significantly increases health complications and extends the length of time patients stay in hospital by up to 13 days on average, thus impacting significantly on hospital resources. The British Society of Antimicrobial Chemotherapy Hospital-Acquired Pneumonia guidelines were published on the society's website last year and represent one of only two sets of evidence-based HAP guidelines in the world which deal with the trio of prevention, diagnosis and treatment. This paper reviews the evolution and status of HAP guidelines, drawing attention to recent developments, differences in approach and outcomes and further areas of work. There are clear indications that the implementation of evidence-based guidelines will reduce HAP and improve patient outcomes.

Hospital-acquired pneumonia guidelines in Europe: a review of their status and future development

Hospital-acquired pneumonia (HAP) is the most common healthcare-acquired infection contributing to death. Effective management requires accurate diagnosis, administration of a suitable antibiotic regimen early in infection and implementation of prevention strategies. In recent years, there has been a rapid increase in the number of country-specific HAP guidelines in Europe, which vary in their formulation, coverage of different disease aspects and overall recommendations. Development of comprehensive pan-European HAP guidelines would rationalize the conflicting proposals, provide a useful resource and limit guideline proliferation. However, careful consideration needs to be given to the principles of guideline development to ensure that the output is rigorous, broadly applicable and facilitates update as new data becomes available. The use of an evidence-based approach to HAP guideline development is optimal, but is compromised by limitations in the supporting data. The implementation of a formalized evidence grading system is key to introducing consistency into the guideline development process. Pan-European guidelines should provide recommendations on core aspects of HAP common to all treatment settings and locations, and reflect the differing perspectives of the countries involved. Given the different antibiotic susceptibility profiles across Europe, such guidelines should provide general treatment recommendations suitable for local adaptation. The development of such guidelines represents an ideal time to identify priorities for European research, by addressing controversies and identifying previously unconsidered aspects of HAP. Establishing a pan-European consensus on core processes of care should be viewed as an impetus for change to improve clinical practices and should include a suitable implementation strategy.

Results of two worldwide surveys into physician awareness and perceptions of extended-spectrum β-lactamases

An omnibus survey of microbiologists (n = 400) and a survey of participants (n = 49) in the Meropenem Yearly Susceptibility Test Information Collection (MYSTIC) programme were conducted to determine the awareness and prevalence of extended-spectrum beta-lactamases (ESBLs), and the regularity and method of screening. Of the omnibus survey participants, 69% screened regularly for ESBLs, compared with 83% of MYSTIC participants. In both surveys, ESBLs were more common in Klebsiella pneumoniae (73% and 79%, respectively) and Escherichia coli (63% and 81%, respectively) than in other bacteria. The surveys demonstrated that awareness of, and testing for, ESBLs is inconsistent.

Appropriate antimicrobial treatment in nosocomial infections—the clinical challenges

Resistance to antimicrobial agents is emerging in a wide variety of pathogens, particularly those that cause nosocomial infections. As a consequence of this increasing resistance, morbidity and mortality in nosocomial infections is also increasing. It is therefore critical to treat nosocomial infections appropriately by starting antimicrobial treatment early in the course of infection, using the correct agent, at the most appropriate dose, and for an adequate duration. Indeed, early 'appropriate' antibiotic prescribing has been shown significantly to reduce mortality, length of intensive care unit and hospital stay and overall costs. Early use of the correct antibiotic at the appropriate dose and for an adequate duration are key to initial appropriate antibiotic prescribing. Choosing the right antibiotic depends mainly on the likely pathogen(s) and the expected local susceptibility patterns. Selection of appropriate antimicrobial therapy requires a thorough understanding of the likely microbial cause of the infection, including local susceptibility patterns, as well as the properties of the antimicrobials available for treating these infections, namely spectrum of activity and potency (including activity versus known resistance mechanisms), pharmacokinetic profile and tolerability and safety. This review, based on a series of presentations at the 5th International Conference of the Hospital Infection Society (Edinburgh, 2002) examines the importance of appropriate antimicrobial therapy in nosocomial infections, and provides guidance on how to achieve this.

Determining the value of antimicrobial surveillance programs

Antimicrobial surveillance programs provide important information on the development of bacterial resistance mechanisms in different geographical regions. Data concerning these mechanisms and patterns of antimicrobial resistance allows the implementation of changes in antimicrobial prescribing practices and infection control interventions. The three most widely known global surveillance programs currently in active operation are: The Meropenem Yearly Susceptibility Test Information Collection (MYSTIC), The SENTRY Antimicrobial Surveillance Program, and The Alexander Project. This presentation reviews these surveillance programs, using a set of key criteria in order to assess the significance of each program in monitoring the spread of antimicrobial resistance. The content of the MYSTIC Program monitors the in vitro performance of meropenem in hospital units in which this drug is actively prescribed. This distinguishes the MYSTIC Program from the other two major surveillance programs as it seeks to correlate antimicrobial resistance data, collected from high carbapenem usage institutions, with antimicrobial prescribing patterns over time. The MYSTIC Program and other assessed networks appear to be both valuable and complementary in their design and function.

Resistance in hospitals: implications for empiric choice of therapy

Although some organisms were resistant to antimicrobial agents before such compounds were introduced into clinical practice, it is only since this occurred that the breadth, depth and complexity of this problem has developed. The early acceleration in the production of antimicrobial substances was uniformly matched by the observation of correspondingly resistant organisms. This article reviews whether the presence of antimicrobial resistance in hospitals should have implications for the empiric choice of such therapy. It is shown that although not an absolute, antimicrobial usage is directly reflected in the presence and nature of resistance with both indirect and direct effects. These resistance patterns have been demonstrated to alter the clinical outcome surrounding sepsis care in hospital patients where the key feature is to actually initiate management with an appropriate agent. It is less clear from the available data whether the control of antimicrobials within hospitals can prospectively influence the sustained susceptibility of organisms to the agents being used. The need for locally determined programmes to respond to the threat of hospital antimicrobial resistance development is highlighted. Attention is drawn to the essential interaction between such schemes and related issues such as infection control and microbiological surveillance.

The cyclical variation in the percentage of ciliated cells in the normal human endometrium

The percentage of ciliated cells in the luminal and glandular epithelia of endometrial samples from sixty-eight normal women has been studied. Although the concentration of ciliated cells found in the luminal epithelium tended to lag behind and below those found in the glandular epithelium, no significant difference was found between the absolute percentages of ciliated cells in each site. The number of ciliated cells increased during the proliferative phase to reach a maximum of around 20%. This was maintained during the ovulatory phase, and then declined. The hormonal basis of this variation is discussed.