Evolving epidemiology of carbapenemase-producing Enterobacterales: one hospital's infection prevention and control response over nine years.

BACKGROUND: Preventing carbapenemase-producing Enterobacterales (CPE) transmission is a significant challenge for hospital infection prevention and control teams (IPCTs). Control measures include screening at-risk patients, contact tracing, and the isolation of carriers with contact precautions. AIM: The evolution of infection prevention and control measures was assessed in a tertiary acute care hospital with predominately multi-bedded patient accommodation, from 2011 to 2019 as cases of CPE increased. The implications for, and the response and actions of, the IPCT were also reviewed. METHODS: CPE data collected prospectively from our laboratory, IPCT, and outbreak meeting records were reviewed to assess how the IPCT adapted to the changing epidemiology, from sporadic cases, to outbreaks and to localized endemic CPE. FINDINGS: Of 178 cases, 152 (85%) were healthcare-associated and there was a marked increase in cases from 2017. The number of screening samples tested annually increased from 1190 in 2011 to 16,837 in 2019, and six outbreaks were documented, with larger outbreaks identified in later years. OXA-48 carbapenemase was detected in 88% of isolates and attendance at outbreak meetings alone accounted for 463.5 h of IPCT members, and related staff time. CONCLUSION: Despite considerable efforts and time invested by the IPCT, the number of CPE cases is increasing year-on-year, with more outbreaks being reported in later years, albeit partly in response to increased screening requirements. Infrastructural deficits, the changing epidemiology of CPE, and national policy are major factors in the increasing number of cases.

Sporobolomyces roseus in the cerebrospinal fluid of an immunocompetent patient--to treat or not to treat?

We present the case of an immunocompetent male who presented with symptoms of meningitis. Yeasts were seen in two consecutive cerebrospinal fluid samples, which were identified by PCR as Sporobolomyces roseus. This yeast is rarely encountered in clinical settings, and has only previously been seen to cause infection in immunocompromised patients. This case highlights the challenges presented by the identification of an unusual pathogen in an unexpected clinical setting.

A 12-year review of Staphylococcus aureus bloodstream infections in haemodialysis patients: more work to be done.

Staphylococcus aureus bloodstream infections (BSI) are a significant cause of morbidity and mortality in haemodialysis patients. This study describes a 12-year retrospective review of S. aureus BSI in a large haemodialysis centre in a tertiary referral hospital. The overall rate of S. aureus BSI was 17.9 per 100 patient-years (range 9.7-36.8). The rate of meticillin-resistant S. aureus (MRSA) BSI was 5.6 per 100 patient-years (range 0.9-13.8). Infective complications occurred in 11% of episodes, the most common being infective endocarditis (7.6%). Ten percent of patients died within 30 days of S. aureus being isolated from blood. Most cases of S. aureus BSI (83%) were related to vascular catheters. The provision of lower-risk vascular access, such as arteriovenous fistulae, and reduced use of intravascular catheters should be priorities in all haemodialysis units. Where alternative vascular access cannot be established, interventions to reduce the risk of catheter-related infections should be implemented to reduce morbidity and mortality in this vulnerable patient group.

Surveillance and endemic vancomycin-resistant enterococci: some success in control is possible.

Vancomycin-resistant enterococci (VRE) are prevalent in many Irish hospitals. We analysed surveillance data from 2001 to 2008 in a centre where VRE is endemic. All clinically significant enterococci were tested for susceptibility to vancomycin. All intensive care unit admissions were screened on admission and weekly thereafter. Interventions included isolating/cohorting VRE patients, monthly prevalence surveys of VRE patients, the introduction of an electronic alert system, programmes to improve hand and environmental hygiene, and the appointment of an antibiotic pharmacist. There was a significant increase in the number of positive VRE screening samples from 2001 (1.96 patients with positive VRE screens per 10 000 bed-days) to 2006 (4.98 per 10 000 bed-days) (P < or = 0.001) with a decrease in 2007 (3.18 per 10 000 bed-days) (P < or = 0.01). The number of VRE bloodstream infections (BSI) increased from 0.09 BSI per 10 000 bed-days in 2001 to 0.78 per 10 000 bed-days in 2005 (P < or = 0.001) but decreased subsequently. Linear regression analysis indicated a significant association between new cases of VRE and non-isolated VRE patients, especially between May 2005 and December 2006 [P=0.009; 95% confidence interval (CI): 0.08-0.46] and between May 2005 and December 2008 (P = 0.008; 95% CI: 0.06-0.46). Routine surveillance for VRE together with other measures can control VRE BSI and colonisation, even where VRE is endemic, and where facilities are constrained.

Vancomycin administration: the impact of multidisciplinary interventions.

BACKGROUND: The clinical microbiology team observed that patients were not receiving all prescribed doses of vancomycin. Ward staff was confused about ordering and interpreting vancomycin therapeutic drug monitoring (TDM) levels. AIM: To audit the incidence of vancomycin dose omission. To implement a series of interventions to improve vancomycin dose administration, and to repeat the audit process to assess these interventions. METHODS: Three prospective audits were conducted to assess the impact of vancomycin TDM on administration of vancomycin. After the first audit, a number of changes in the TDM process were undertaken. After review of the second audit, a senior pharmacist coordinated ward-based pharmacists in assisting staff to interpret levels, and TDM interpretative charts were designed for drug charts. Following the third audit, feedback to hospital management and a plan for ongoing education were undertaken. RESULTS: There was a significant reduction in the number of vancomycin doses held inappropriately in the third (10% (78/782) of prescribed doses) when compared to the first audit (16% (161/1007) of doses) (p<0.01). Of doses that were held inappropriately, there was a significant decrease in doses held for no apparent reason in audit 3 (16% (27/170) of prescribed doses) when compared to audit 1 (25% (69/282) of doses) (p<0.05). CONCLUSIONS: The interventions resulted in a 37.5% reduction in inappropriately held vancomycin doses over a one-year period; 10% of doses are still being held inappropriately. This study highlights the difficulties in identifying barriers to change and changing healthcare worker behaviour.

Pancreatic abscess due to Aeromonas hydrophila.

Aeromonas hydrophila is an uncommon cause of deep-seated infection in man. We present what we believe to be the first reported case of a pancreatic abscess due to A. hydrophila. The outcome of this case attests to the potentially lethal nature of infection that can occur with this organism.

Third-generation cephalosporin resistance among Gram-negative bacilli causing meningitis in neurosurgical patients: significant challenges in ensuring effective antibiotic therapy.

OBJECTIVES: The treatment of meningitis caused by Gram-negative bacilli in neurosurgical patients is a major challenge because of the complexity of these patients, the emergence of antibiotic resistance in many of the causative organisms and the restricted choice of antibiotics suitable for use, owing to a failure to achieve high enough concentrations in the CSF. We reviewed the incidence, aetiology, treatment and outcome of all patients with Gram-negative bacillary meningitis (GNBM) in our centre over a 7 year period. METHODS: Beaumont Hospital, Dublin is a 720 bed tertiary referral hospital and contains the national neurosurgical centre for the Republic of Ireland. The case notes and microbiological records of all patients with GNBM between 1998 and 2004 inclusive were reviewed retrospectively. Only patients with positive CSF culture and clinical features compatible with meningitis were included. RESULTS: Forty separate episodes of GNBM involving 34 different patients occurred during the study period. The most common causative organisms were Enterobacter spp. (35%), Escherichia coli (22.5%) and Pseudomonas aeruginosa (15%). Twenty-five per cent of isolates were resistant to third-generation cephalosporins. The median duration of treatment was 19.2 days and a combination of intravenous and intraventricular antibiotics was the most common treatment regimen used. Mortality directly related to GNBM was 2.5%. CONCLUSIONS: Although the mortality directly related to GNBM was low, the emergence of strains resistant to third-generation cephalosporins represents a therapeutic challenge. Treatment with combined intravenous and intraventricular antibiotics is recommended for 2-3 weeks, but more studies are required to determine the optimal management of this difficult condition.

Implications of colonization of vancomycin-resistant enterococci (VRE) in renal dialysis patients. Learning to live with it?

Vancomycin-resistant enterococci (VRE) commonly colonize, but less frequently infect, debilitated patients, such as those on chronic renal dialysis. The emergence of VRE amongst our cohort of renal replacement therapy patients posed considerable challenges in our attempts to prevent spread. Although 60 of 451 (13%) patients became colonized, only two patients required systemic antibiotics for confirmed or suspected invasive infection. Mortality and inpatient stay was greater in VRE-positive compared with VRE-negative patients (50% versus 10%) and patients who were screened on three or more occasions were likely to remain positive (e.g. 56% of patients screened on six occasions were positive). The application of recommended guidelines for the control of VRE, however, severely disrupted our renal dialysis programme and therefore had to be abandoned. As patients on renal dialysis are more likely to acquire VRE, remain colonized, require antibiotics and require regular inpatient or outpatient care more frequently than other patients, control measures should be adapted to minimize spread but not disrupt important and essential medical services.

Antimicrobial susceptibility of invasive isolates of Streptococcus pneumoniae in Ireland.

Between January 1999 and June 2002, 646 invasive isolates of Streptococcus pneumoniae were collected in Ireland. MICs of penicillin, ciprofloxacin, cefotaxime, moxifloxacin and linezolid were determined by Etest methodology. Eighty-seven (13.5%) isolates showed intermediate resistance to penicillin, while seven (1.1%) showed high-level resistance. Eighty-seven (13.5%) isolates were resistant to erythromycin, but all isolates were susceptible to cefotaxime, moxifloxacin and linezolid. The prevalence of pneumococcal isolates non-susceptible to penicillin in Ireland is worryingly high, but currently there are alternative agents available to treat invasive infection.

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.

The impact of laboratory reporting practice on antibiotic utilisation.

Microbiology reports are often misinterpreted by clinicians, which may lead to inappropriate antibiotic prescribing. Restricted release of susceptibilities combined with interpretative comments, can have a positive impact on the level of appropriate antibiotic use. Such a system requires two-way communication between the laboratory and the clinician and the laboratory's reporting practices should encourage such communication. The production and transmission of clinically relevant microbiology reports should be an integral part of infectious disease management programmes in hospitals.

Clostridium difficile colitis associated with chronic renal failure.

BACKGROUND: Clostridium difficile-associated diarrhoea (CDAD) is a potentially life-threatening illness which has been shown to be more common and more severe in patients with chronic renal failure (CRF) than in other groups. A review of CDAD in our nephrology unit was carried out. METHODS: A review of microbiology and histology records identified 32 cases of CDAD in the nephrology unit over a 24-month period. Patient notes were reviewed to identify risk factors, clinical features and outcome. Available isolates of C. difficile underwent 16S ribosomal RNA typing. RESULTS: The incidence of CDAD in the nephrology unit was 10.7 per 1000 admissions, compared to 2.7 per 1000 in other areas of the hospital (P<0.0001). CDAD was considered the sole or principal cause of death in six (19%) and was considered a contributing factor in a further seven (22%). Mortality was significantly higher among patients with established CRF (P=0.04). Seven cases occurred as a cluster, over a 1-month period. Isolates from this cluster, along with comparative strains from other areas of the hospital, were found to be PCR type 1. Diarrhoea occurred in 28 (89%) of cases, pyrexia in 17 (53%) and ileus or abdominal pain in 14 (44%). Six patients responded to discontinuation of antibiotics alone and 22 required metronidazole and/or vancomycin. Three patients had colectomy and one caecostomy because of toxic megacolon. Four patients died before specific therapy could be given and in two of these cases the diagnosis was made at autopsy. Twenty-six patients had a record of recent antibiotic therapy. Of these, 15 had at least one agent considered to be inappropriate (excessively broad spectrum agent in 11, excessive duration of therapy in four). Nine patients had only received antibiotics prior to admission. CONCLUSIONS: CDAD carries a high mortality in nephrology patients, especially those with established CRF. The diagnosis may be missed if a careful antibiotic history is not taken, including agents received prior to admission. Rational antibiotic prescribing and adherence to infection control measures are vital to reduce the incidence of this serious condition.