Prevention of healthcare-associated invasive aspergillosis during hospital construction/renovation works.

The association between healthcare-associated invasive aspergillosis and hospital construction/building works is well recognized. This infection can cause significant morbidity and mortality and imposes a substantial burden on the healthcare system. The population of patients at risk for this opportunistic infection has expanded and multi-triazole drug resistance has emerged globally. Hence the need for a multi-faceted approach to prevent acquisition of invasive aspergillosis in acute care settings. This article is a summary of the Irish National Guidelines for the prevention of healthcare-associated aspergillosis which is based on published reports, international clinical guidelines, official engineering standards, and technical guidelines. We discuss the key recommendations and strategies for the prevention of invasive aspergillosis from the planning/pre-construction, construction, and post-construction phases. The importance of multi-disciplinary team involvement, education, and communication is emphasized.

First outbreak of linezolid-resistant vancomycin-resistant Enterococcus faecium in an Irish hospital, February to September 2014.

An outbreak of linezolid-resistant vancomycin-resistant Enterococcus faecium (LRVREfm) occurred in the hepatology ward of a tertiary referral hospital in Ireland between February and September 2014. LRVREfm was isolated from 15 patients; pulsed-field gel electrophoresis confirmed spread of a single clone. This is the first report of an outbreak of linezolid-resistant vancomycin-resistant enterococcus in Ireland.

The stethoscope and healthcare-associated infection: a snake in the grass or innocent bystander?

There is a concern that stethoscopes may transmit infectious agents which could result in healthcare-associated infection (HCAI). The aim of this review was to evaluate the available literature as to the role of the stethoscope in the development of HCAI. A literature search was conducted across several databases for relevant studies and reports. Stethoscopes were consistently shown to harbour bacteria. The mean rate of stethoscope contamination across 28 studies was 85% (range: 47-100%). The majority of bacteria isolated were deemed to be non-pathogenic. The most frequently isolated organisms were coagulase-negative staphylococci. The mean level of contamination was in excess of the French Normalization standard for cleanliness (which equates to <20 colony-forming units per membrane) in all six studies in which contamination levels were quantified. Potentially pathogenic organisms cultured from stethoscopes included: Staphylococcus aureus, Pseudomonas aeruginosa, vancomycin-resistant enterococci, and Clostridium difficile. There was evidence that bacteria can transfer from the skin of the patient to the stethoscope and from the stethoscope to the skin. However, studies were not designed to detect a correlation between stethoscope contamination and subsequent HCAI. Surveys assessing cleaning practices revealed a suboptimal commitment to stethoscope disinfection among doctors and medical students. The optimum method for stethoscope cleaning has not been defined, although alcohol-based disinfectants are effective in reducing bacterial contamination. In conclusion, a link between contaminated stethoscopes and HCAI has not yet been confirmed, but transfer of bacteria between skin and stethoscope has been shown. The available information would suggest that stethoscopes should be decontaminated between patients.

Investigation of the first outbreak of OXA-48-producing Klebsiella pneumoniae in Ireland.

BACKGROUND: Carbapenemase-producing Enterobacteriaceae (CPE) strains are encountered with increasing frequency in Europe. In November 2010 the European Centre for Disease Control (ECDC) graded Ireland as only having sporadic occurrence of CPE. AIM: To describe the epidemiological and molecular typing analysis of the first outbreak of OXA-48-producing Klebsiella pneumoniae in an Irish tertiary care referral centre. METHODS: Sixteen OXA-48-producing K. pneumoniae isolates were detected, from both clinical and screening specimens, and analysed by pulsed-field gel electrophoresis and by multi-locus sequence typing. FINDINGS: Typing analysis revealed that two outbreak strains were circulating in the hospital, one among surgical patients and one among medical patients. The 'medical strain' ST13 had already been identified as an internationally disseminated clone, whereas the 'surgical strain' ST221 had not previously been reported as an OXA-48-carrying strain. CONCLUSION: Although the outbreak on surgical wards was successfully controlled by implementing strict infection control measures, intermittent detection of individual patients carrying the 'medical strain' of OXA-48 K. pneumoniae has persisted since then. The experience from this outbreak suggests that OXA-48 K. pneumoniae is endemic at low level in the healthcare setting in the Dublin region.

Plastic wound retractors as bacteriological barriers in gastrointestinal surgery: a prospective multi-institutional trial.

BACKGROUND: Surgical site infection remains a significant problem, and peri-operative strategies to reduce wound exposure to bacteria are needed urgently. Plastic ring wound retractors, used to gain access to the abdominal cavity, may shield the incision site from bacteria. AIM: To evaluate exposure of the surgical incision site to bacteria using a plastic ring wound retractor in gastrointestinal surgery. METHODS: Prospective, observational, multi-centre study. Patients undergoing clean-contaminated gastrointestinal surgery with standard antibiotic prophylaxis were included (N = 250 patients, 500 samples). A plastic wound retractor was used to facilitate access to the abdominal cavity. Samples were taken for bacterial culture from the inside (luminal) and outside (wound) surfaces of the retractor at the end of the operation. FINDINGS: Bacteria were found on 56% (140/250) of samples from the inside surface of the retractor compared with 34% (85/250) of samples from the outside surface of the retractor (P < 0.0001). There was no significant difference in skin-derived organisms from the inside [34/245 (14%)] and outside [27/250 (11%)] surfaces of the retractor (P = 0.108). However, enteric organisms were cultured twice as often from the inside surface of the retractor compared with the outside surface of the retractor (49% vs 26%, respectively; P < 0.0001). CONCLUSION: Plastic wound retractors reduce wound exposure to enteric bacteria in gastrointestinal surgery.

First isolation and outbreak of OXA-48-producing Klebsiella pneumoniae in an Irish hospital, March to June 2011.

Five OXA-48-producing Klebsiella pneumoniae were detected in a tertiary referral hospital in Ireland between March and June 2011. They were found in the clinical isolates of five cases that were inpatients on general surgical wards. None of the cases had received healthcare at a facility outside of Ireland in the previous 12 months. This is the first report of OXA-48-producing K. pneumoniae in Ireland.

An investigation of the subtype diversity of clinical isolates of Irish Clostridium difficile ribotypes 027 and 078 by repetitive-extragenic palindromic PCR.

A repetitive-extragenic palindromic PCR (rep-PCR) subtyping method (DiversiLab) in conjunction with ribotyping, toxinotyping and antimicrobial-susceptibility testing was used to detect subtypes within Clostridium difficile ribotypes 027 and 078. Clinical isolates of ribotypes 027 (toxinotype III) (n = 30) and 078 (toxinotype V) (n = 23) were provided by health-care facilities across the Republic of Ireland over 2 months in 2006 and 1 month in 2009. Ribotype 027 isolates were significantly more related to each other (9 different subtype profiles) when compared to ribotype 078 isolates (14 different profiles) (P = 0.001; cut-off >90 % similarity). Almost half of ribotype 078 isolates (45.5 %) showed no relationship to each other. The clonality of ribotype 027 isolates suggests effective adaptation to the human niche, whereas the considerable genetic diversity within ribotype 078 isolates suggests that they may have originated from a variety of sources. Subtyping correlated well with antimicrobial susceptibility, in particular clindamycin susceptibility for ribotype 027, but diverse antimicrobial-susceptibility profiles were seen in ribotype 078 isolates, even within a single health-care facility. Between 2006 and 2009, a change in the predominant subtype of ribotype 027 was seen, with the recent clone representing half of all ribotype 027 isolates studied. This strain exhibited 89 % similarity to a rep-PCR profile of the North American NAP-1 strain.

Reporting of meticillin-resistant and -susceptible Staphylococcus aureus on death certificates in Irish hospitals.

The documentation of infection with meticillin-resistant Staphylococcus aureus (MRSA) on death certificates has been the subject of considerable public discussion. Using data from five tertiary referral hospitals in Ireland, we compared the documentation of MRSA and meticillin-susceptible S. aureus (MSSA) on death certificates in those patients who died in hospital within 30 days of having MRSA or MSSA isolated from blood cultures. A total of 133 patients had MRSA or MSSA isolated from blood cultures within 30 days of death during the study period. One patient was excluded as the death certificate information was not available; the other 132 patients were eligible for inclusion. MRSA and MSSA were isolated from blood cultures in 59 (44.4%) and 74 (55.6%) cases respectively. One patient was included as a case in both categories as both MRSA and MSSA were isolated from a blood culture. In 15 (25.4%) of the 59 MRSA cases, MRSA was documented on the death certificate. In nine (12.2%) of the 74 patients with MSSA cases, MSSA was documented on the death certificate. MRSA was more likely to be documented on the death certificate than MSSA (odds ratio: 2.46; 95% confidence interval: 1.01-6.01; P < 0.05). These findings indicate that there may be inconsistencies in the way organisms and infections are documented on death certificates in Ireland and that death certification data may underestimate the mortality related to certain organisms. In particular, there appears to be an overemphasis by certifiers on the documentation of MRSA compared with MSSA.

Interventions to improve antibiotic prescribing practices for hospital inpatients.

BACKGROUND: Up to 50% of antibiotic usage in hospitals is inappropriate. In hospitals infections caused by antibiotic-resistant bacteria are associated with higher mortality, morbidity and prolonged hospital stay compared with infections caused by antibiotic-susceptible bacteria. Clostridium difficile associated diarrhoea (CDAD) is a hospital acquired infection that is caused by antibiotic prescribing. OBJECTIVES: To estimate the effectiveness of professional interventions that alone, or in combination, are effective in promoting prudent antibiotic prescribing to hospital inpatients, to evaluate the impact of these interventions on reducing the incidence of antimicrobial resistant pathogens or CDAD and their impact on clinical outcome. SEARCH STRATEGY: We searched the Cochrane Effective Practice and Organisation of Care (EPOC) specialized register, Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE from 1980 to November 2003. Additional studies were obtained from the bibliographies of retrieved articles SELECTION CRITERIA: We included all randomised and controlled clinical trials (RCT/CCT), controlled before and after studies (CBA) and interrupted time series (ITS) studies of antibiotic prescribing to hospital inpatients. Interventions included any professional or structural interventions as defined by EPOC. DATA COLLECTION AND ANALYSIS: Two reviewers extracted data and assessed quality. MAIN RESULTS: Sixty six studies were included and 51 (77%) showed a significant improvement in at least one outcome. Six interventions only aimed to increase treatment, 57 interventions aimed to decrease treatment and three interventions aimed to both increase and decrease treatment. The intervention target was the decision to prescribe antibiotics (one study), timing of first dose (six studies), the regimen (drug, dosing interval etc, 61 studies) or the duration of treatment (10 studies); 12 studies had more than one target. Of the six interventions that aimed to increase treatment, five reported a significant improvement in drug outcomes and one a significant improvement in clinical outcome. Of the 60 interventions that aimed to decrease treatment 47 reported drug outcomes of which 38 (81%) significantly improved, 16 reported microbiological outcomes of which 12 (75%) significantly improved and nine reported clinical outcomes of which two (22%) significantly deteriorated and 3 (33%) significantly improved. Five studies aimed to reduce CDAD. Three showed a significant reduction in CDAD. Due to differences in study design and duration of follow up it was only possible to perform meta-regression on a few studies. AUTHORS' CONCLUSIONS: The results show that interventions to improve antibiotic prescribing to hospital inpatients are successful, and can reduce antimicrobial resistance or hospital acquired infections.

Impact of the European Antimicrobial Resistance Surveillance System on the development of a national programme to monitor resistance in Staphylococcus aureus and Streptococcus pneumoniae in Ireland, 1999-2003.

Presented here is the 5-year impact of a national antimicrobial resistance surveillance system in Ireland, which was introduced in accordance with the European Antimicrobial Resistance Surveillance System (EARSS). Participation in EARSS began in Ireland in 1999. Initially, 12 laboratories serving a mix of general and tertiary hospitals participated, but by 2003, participation had increased to 28 laboratories with a population coverage of 89%. During 1999-2003, 4,146 episodes of Staphylococcus aureus bacteraemia were reported, and methicillin resistance was detected in 1,709 (41.2%) of these isolates. Over the same period, 1,245 invasive (blood or cerebrospinal fluid) episodes of Streptococcus pneumoniae infection were reported, and 160 (12.9%) isolates were found to be non-susceptible to penicillin, with 23 (1.8%) demonstrating high-level penicillin resistance. By 2003, most Irish hospitals were participating in EARSS, which has been a catalyst for the development of a national antimicrobial resistance surveillance programme.

Evaluation of the blood coagulation mechanism and platelet aggregation in individuals with mechanical or biological heart prostheses.

Oral anticoagulants have been widely employed to decrease thrombotic risk by reducing the levels of vitamin K-dependent clotting factors. Paradoxically, the use of oral anticoagulants also decreases the levels of natural anticoagulants (protein C and protein S), which favors the hypercoagulability state. Increased platelet activation has been reported in patients undergoing warfarin treatment. These findings have raised questions about the antagonistic effect of oral anticoagulants and their implications for hemostatic balance. The aim of this study is to determine the relationship between warfarin dosage and prothrombin time [International Normalized Ratio (INR)], platelet aggregation, vitamin K-dependent clotting factors, and protein C and protein S. Blood samples from 27 patients were analyzed, seven with mechanical prostheses and 20 with biological prostheses, and 27 controls. Multiple regression analysis showed that factor II most significantly determines the INR. Results showed that the INR, clotting factors, and protein C and protein S activity did not correlate with warfarin dosage, highlighting the need for accurate laboratory monitoring of those undergoing anticoagulant therapy.

Flow cytometric analysis of Clostridium difficile adherence to human intestinal epithelial cells.

Clostridium difficile is the most common cause of diarrhoea in hospitalised patients. Bacterial adherence to gut epithelial cells is a likely prerequisite to infection and toxin production. A novel flow cytometric method was developed for detecting adherence of C. difficile to human colonic and small intestinal epithelial cells (EC) and human intestinal cell lines. Small intestinal and colonic EC were isolated from biopsy specimens with mucolytic and chelating agents. Adherence of fluorochrome-labelled C. difficile to EC was measured by flow cytometry and was calculated as increase in median fluorescent intensity (deltaMFI). Cells with bacteria attached could be distinguished easily from cells alone or cells with unlabelled bacteria attached. Toxin-positive C. difficile adhered to colonic and small intestinal EC (deltaMFI mean 21.2 SD 16.7, n = 33 and 16.5 SD 20.7, n = 19 respectively). The toxin-negative strain also adhered to both epithelial cell types (deltaMFI 26.1 SD 32.5, n = 17 and 18.3 SD 31.3, n = 16). Adherence of toxin-positive C. difficile to the intestinal cell lines Caco-2 (deltaMFI 9.4 SD 4.4, n = 14) and HT29 (deltaMFI 8.1 SD 3.1, n = 12) was quantifiable, although at a significantly lower level than with primary colonic epithelial cells. Adherence of the toxin-negative strain was slightly lower, deltaMFI 6.5 SD 1.8, n = 9 with Caco-2 cells and deltaMFI 6.0 SD 2.0, n = 10 with HT29 cells. Adherence of C. difficile to epithelial cell lines was blocked with C. difficile antiserum, confirming specificity of adherence. In conclusion, flow cytometry is a useful approach to quantifying adherence of C. difficile to human colonic and small intestinal epithelial cells. Binding of toxin-negative as well as toxin-positive bacteria was detectable by this approach. Analysis of C. difficile adherence to target cells may have important implications for the understanding of the pathogenesis of C. difficile-related disease.

Nosocomial infective endocarditis.

SUMMARY: Nosocomial infective endocarditis (NIE) is a rare complication of nosocomial bacteraemia; however, it is an infection of great importance because of its high mortality and because in many cases it is potentially preventable. Whilst many aspects of NIE are similar to community-acquired infective endocarditis (CIE), there are important differences between the two, most notably the predisposing factors, microbial aetiology and prognosis. The diagnosis of NIE is often difficult as many patients have severe underlying disease and coexistent infection elsewhere. Many of these infections could potentially be prevented by the identification of high risk patients, careful assessment of positive blood cultures and effective treatment of bacteraemia in high risk patients. The use of prophylactic antimicrobials in the prevention of infective endocarditis is unproven, however, it is recommended that prophylaxis be considered for certain invasive hospital-based procedures.

VRE in the Republic of Ireland: clinical significance, characteristics and molecular similarity of isolates.

There have been increasing reports worldwide of vancomycin resistant enterococci (VRE) since they were first noted over ten years ago. This study sought to investigate the clinical significance of VRE in Ireland and to compare the phenotypic, genotypic and molecular characteristics of isolates recovered from patients in different institutions. The relative contribution of inter-hospital transmission of strains to the dissemination of VRE in Ireland was assessed. Hospital surveillance for VRE is not well established in Ireland. The organism has been detected in seven hospitals. Detection has been predominantly in oncology inpatients in large tertiary referral hospitals in the Dublin metropolitan area in whom strains generally represent asymptomatic gastrointestinal tract colonization. The predominant species is E. faecium with the Van A resistance phenotype. Twenty-seven (87) of 31 isolates from one unit were shown to be of the same or closely related strain as were 10 (63%) of 16 from another unit, indicating significant nosocomial transmission within institutions. There was no evidence for inter-hospital transmission of VRE. VRE is established in Ireland and nosocomial transmission readily occurs. Regular surveillance for VRE is indicated in high-risk populations in large institutions, specific risk factors for the acquisition of VRE need to be defined and optimal control and preventative strategies need to he instituted to detect and preempt the spread of this organism.