Microbial aetiology of healthcare associated pneumonia in Spain: a prospective, multicentre, case-control study

INTRODUCTION

Healthcare-associated pneumonia (HCAP) is actually considered a subgroup of hospital-acquired pneumonia due to the reported high risk of multidrug-resistant pathogens in the USA. Therefore, current American Thoracic Society/Infectious Diseases Society of America guidelines suggest a nosocomial antibiotic treatment for HCAP. Unfortunately, the scientific evidence supporting this is contradictory.

METHODS

We conducted a prospective multicentre case-control study in Spain, comparing clinical presentation, outcomes and microbial aetiology of HCAP and community-acquired pneumonia (CAP) patients matched by age (±10 years), gender and period of admission (±10 weeks).

RESULTS

476 patients (238 cases, 238 controls) were recruited for 2 years from June 2008. HCAP cases showed significantly more comorbidities (including dysphagia), higher frequency of previous antibiotic use in the preceding month, higher pneumonia severity score and worse clinical status (Charslon and Barthel scores). While microbial aetiology did not differ between the two groups (HCAP and CAP: Streptococcus pneumoniae: 51% vs 55%; viruses: 22% vs 12%; Legionella: 4% vs 9%; Gram-negative bacilli: 5% vs 4%; Pseudomonas aeruginosa: 4% vs 1%), HCAP patients showed worse mortality rates (1-month: HCAP, 12%; CAP 5%; 1-year: HCAP, 24%; CAP, 9%), length of hospital stay (9 vs 7 days), 1-month treatment failure (5.5% vs 1.5%) and readmission rate (18% vs 11%) (p<0.05, each).

CONCLUSIONS

Despite a similar clinical presentation, HCAP was more severe due to patients' conditions (comorbidities) and showed worse clinical outcomes. Microbial aetiology of HCAP did not differ from CAP indicating that it is not related to increased mortality and in Spain most HCAP patients do not need nosocomial antibiotic coverage.

Risk factors of fecal carriage with extended-spectrum β-lactamase-producing Enterobacteriaceae in hospitalized patients

BACKGROUND

Colonization of multidrug-resistant microorganisms is a potential source of cross transmission and subsequent infection. Screening of extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) is not yet a routine practice in most hospitals.

METHODS

The purpose of this study was to investigate the risk factors of fecal carriage of ESBL-E in hospitalized patients. A total of 174 samples (from 97 patients) was collected. Screening test was accomplished using commercial chromogenic medium (ChromID ESBL agar; bioMérieux, Marcy l'Etoile, France). The presence of ESBLs of grown isolates was confirmed by Clinical and Laboratory Standards Institute guidelines. Analysis of the risk factors of ESBL-E carriage was performed by multivariate logistic regression.

RESULTS

Among the risk factors, multivariate analysis demonstrated that prolonged hospitalization (≥90 days) (odds ratio [OR], 6.76; 95% confidence interval [CI]: 1.17-39.23; P = .033), prolonged intensive care unit stay (≥14 days) (OR, 4.78; 95% CI: 1.70-13.42; P = .003), and methicillin-resistant Staphylococcus aureus carriage (OR, 3.29; 95% CI: 1.20-9.01; P = .020) were found to be significantly associated with fecal carriers.

CONCLUSION

This study clarified the characteristics and the risk factors of hospitalized patients carrying ESBL-E. In addition, the cost-benefit of routine screening in addition to methicillin-resistant Staphylococcus aureus and vancomycin-resitant Enterococci needs to be assessed.

Management and prevention of ventilator-associated pneumonia caused by multidrug-resistant pathogens

Ventilator-associated pneumonia (VAP) due to multidrug-resistant (MDR) pathogens is a leading healthcare-associated infection in mechanically ventilated patients. The incidence of VAP due to MDR pathogens has increased significantly in the last decade. Risk factors for VAP due to MDR organisms include advanced age, immunosuppression, broad-spectrum antibiotic exposure, increased severity of illness, previous hospitalization or residence in a chronic care facility and prolonged duration of invasive mechanical ventilation. Methicillin-resistant Staphylococcus aureus and several different species of Gram-negative bacteria can cause MDR VAP. Especially difficult Gram-negative bacteria include Pseudomonas aeruginosa, Acinetobacter baumannii, carbapenemase-producing Enterobacteraciae and extended-spectrum β-lactamase producing bacteria. Proper management includes selecting appropriate antibiotics, optimizing dosing and using timely de-escalation based on antiimicrobial sensitivity data. Evidence-based strategies to prevent VAP that incorporate multidisciplinary staff education and collaboration are essential to reduce the burden of this disease and associated healthcare costs.

Limits of patient isolation measures to control extended-spectrum beta-lactamase-producing Enterobacteriaceae: model-based analysis of clinical data in a pediatric ward

Background

Extended-spectrum beta-lactamase–producing Enterobacteriaceae (ESBL-E) are a growing concern in hospitals and the community. How to control the nosocomial ESBL-E transmission is a matter of debate. Contact isolation of patients has been recommended but evidence supporting it in non-outbreak settings has been inconclusive.

Methods

We used stochastic transmission models to analyze retrospective observational data from a two-phase intervention in a pediatric ward, successively implementing single-room isolation and patient cohorting in an isolation ward, combined with active ESBL-E screening.

Results

For both periods, model estimates suggested reduced transmission from isolated/cohorted patients. However, most of the incidence originated from sporadic sources (i.e. independent of cross-transmission), unaffected by the isolation measures. When sporadic sources are high, our model predicted that even substantial efforts to prevent transmission from carriers would have limited impact on ESBL-E rates.

Conclusions

Our results provide evidence that, considering the importance of sporadic acquisition, e.g. endogenous selection of resistant strains following antibiotic treatment, contact-isolation measures alone might not suffice to control ESBL-E. They also support the view that estimating cross-transmission extent is key to predicting the relative success of contact-isolation measures. Mathematical models could prove useful for those estimations and guide decisions concerning the most effective control strategy.

Duration of carriage of carbapenem-resistant Enterobacteriaceae following hospital discharge

BACKGROUND

Hospitalized carriers of carbapenem-resistant Enterobacteriaceae (CRE) are cohorted under contact precautions, including in the days between rehospitalization and surveillance culture results. This study investigates duration of CRE carriage to define populations requiring precautions upon readmission.

METHODS

Patients with CRE-positive culture during 2009-2010 were followed up by rectal swab cultures taken retrospectively and prospectively for the study or as part of clinical follow-up.

RESULTS

One hundred thirty-seven patients met the inclusion criteria, with follow-up cultures obtained from 97. Mean time to CRE negativity was 387 days (95% confidence interval: 312-463). Seventy-eight percent of patients (64/82) had positive culture at 3 months, 65% (38/58) at 6 months, and 39% (12/30) at 1 year. Duration of carriage was affected by repeat hospitalization (P = .001) and clinical, as opposed to surveillance, culture (P = .002).

CONCLUSION

CRE carriers from a previous hospitalization have a lower probability of CRE carriage upon readmission if the index specimen was a surveillance culture and 1 year passed without further hospitalization. Multiple hospitalizations and CRE disease extend duration of carriage. This study better defines patients requiring cohorting and isolation, thus limiting spread of CRE and allowing for improved allocation of infection control measures.

Multidrug-resistant gram-negative bacteria colonization of healthy US military personnel in the US and Afghanistan

Background

The US military has seen steady increases in multidrug-resistant (MDR) gram-negative bacteria (GNB) infections in casualties from Iraq and Afghanistan. This study evaluates the prevalence of MDR GNB colonization in US military personnel.

Methods

GNB colonization surveillance of healthy, asymptomatic military personnel (101 in the US and 100 in Afghanistan) was performed by swabbing 7 anatomical sites. US-based personnel had received no antibiotics within 30 days of specimen collection, and Afghanistan-based personnel were receiving doxycycline for malaria chemoprophylaxis at time of specimen collection. Isolates underwent genotypic and phenotypic characterization.

Results

The only colonizing MDR GNB recovered in both populations was Escherichia coli (p=0.01), which was seen in 2% of US-based personnel (all perirectal) and 11% of Afghanistan-based personnel (10 perirectal, 1 foot+groin). Individuals with higher off-base exposures in Afghanistan did not show a difference in overall GNB colonization or MDR E. coli colonization, compared with those with limited off-base exposures.

Conclusion

Healthy US- and Afghanistan-based military personnel have community onset-MDR E. coli colonization, with Afghanistan-based personnel showing a 5.5-fold higher prevalence. The association of doxycycline prophylaxis or other exposures with antimicrobial resistance and increased rates of MDR E. coli colonization needs further evaluation.

Rectal swabs are suitable for quantifying the carriage load of KPC-producing carbapenem-resistant Enterobacteriaceae

It is more convenient and practical to collect rectal swabs than stool specimens to study carriage of colon pathogens. In this study, we examined the ability to use rectal swabs rather than stool specimens to quantify Klebsiella pneumoniae carbapenemase (KPC)-producing carbapenem-resistant Enterobacteriaceae (CRE). We used a quantitative real-time PCR (qPCR) assay to determine the concentration of the bla(KPC) gene relative to the concentration of 16S rRNA genes and a quantitative culture-based method to quantify CRE relative to total aerobic bacteria. Our results demonstrated that rectal swabs are suitable for quantifying the concentration of KPC-producing CRE and that qPCR showed higher correlation between rectal swabs and stool specimens than the culture-based method.

Approaching zero: temporal effects of a restrictive antibiotic policy on hospital-acquired Clostridium difficile, extended-spectrum β-lactamase-producing coliforms and meticillin-resistant Staphylococcus aureus

A restrictive antibiotic policy banning routine use of ceftriaxone and ciprofloxacin was implemented in a 450-bed district general hospital following an educational campaign. Monthly consumption of nine antibiotics was monitored in defined daily doses (DDDs) per 1000 patient-occupied bed-days (1000 pt-bds) 9 months before until 16 months after policy introduction. Hospital-acquired Clostridium difficile, meticillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum β-lactamase (ESBL)-producing coliform cases per month/1000 pt-bds were identified and reviewed throughout the hospital. Between the first and final 6 months of the study, average monthly consumption of ceftriaxone reduced by 95% (from 46.213 to 2.129 DDDs/1000 pt-bds) and that for ciprofloxacin by 72.5% (109.804 to 30.205 DDDs/1000 pt-bds). Over the same periods, hospital-acquisition rates for C. difficile reduced by 77% (2.398 to 0.549 cases/1000 pt-bds), for MRSA by 25% (1.187 to 0.894 cases/1000 pt-bds) and for ESBL-producing coliforms by 17% (1.480 to 1.224 cases/1000 pt-bds). Time-lag modelling confirmed significant associations between ceftriaxone and C. difficile cases at 1 month (correlation 0.83; P<0.005), and between ciprofloxacin and ESBL-producing coliform cases at 2 months (correlation 0.649; P=0.002). An audit performed 3 years after the policy showed sustained reduction in C. difficile rates (0.259 cases/1000 pt-bds), with additional decreases for MRSA (0.409 cases/1000 pt-bds) and ESBL-producing coliforms (0.809 cases/1000 pt-bds). In conclusion, banning two antibiotics resulted in an immediate and profound reduction in hospital-acquired C. difficile, with possible longer-term effects on MRSA and ESBL-producing coliform rates. Antibiotic stewardship is fundamental in the control of major hospital pathogens.

Risk factors for gastrointestinal tract colonization with extended-spectrum β-lactamase (ESBL)-producing Escherichia coli and Klebsiella species in hospitalized patients

We describe the prevalence of and risk factors for colonization with extended-spectrum β-lactamase (ESBL)-producing Escherichia coli and Klebsiella species (ESBL-EK) in hospitalized patients. The prevalence of colonization with ESBL-EK was 2.6%. Colonization was associated with cirrhosis, longer duration of hospital stay prior to surveillance, and prior exposure to clindamycin or meropenem.

[Enterobacteriaceae producing extended spectrum beta-lactamase: epidemiology, risk factors, and prevention]

Multidrug-resistant bacteria are a major worldwide health public concern. It results from the growing increase in antibiotic prescriptions, which are responsible for selection pressure on bacteria. In France like in other countries, enterobacteriaceae producing extended spectrum beta-lactamase (EESBL) are the predominant multidrug-resistant bacteria. EESBL may be responsible for severe infections and require prescription of broad-spectrum antibacterial agents. The current EESBL outbreak is different from methicillin-resistant Staphylococcus aureus outbreak that occurred in the early 1980. Consistently, EESBL are isolated both in hospital and community. Moreover, standard hygiene measures appear ineffective since EESBL prevalence is still increasing. The current inability to contain EESBL outbreak is due to several factors, including the existence of a wide community- and hospital-acquired tank of EESBL, failure to follow strict rules for hygiene, and the current irrational prescription of antibiotics.

Pneumonia in frail older patients: an up to date

Despite advances in diagnosis, antimicrobial therapy and supportive care modalities, community-acquired pneumonia (CAP) remains an important cause of morbidity and mortality, especially in patients who require hospitalization. Elderly patients with poor functional status are characterized by a higher risk of developing severe CAP, due to the frequent presence of underlying respiratory and cardiac diseases, alteration of mental status, and immunosuppression. In recent years, changes in the healthcare system have shifted a considerable part of older patient care from hospitals to the community, and the traditional distinction between community- and hospital-acquired infections has become less clear. Pneumonia occurring among outpatients in contact with the healthcare system has been termed healthcare-associated pneumonia. Older frail patients have a high frequency of aspiration pneumonia and pneumonia due to gram-negative bacilli and other multidrug resistant pathogens. The contemporary presence of renal impairment usually requires specific dose adjustment of antibiotic therapy, which may be toxic in this specific patient population. This review produces a summary of therapeutic recommendations on the basis of the most updated clinical and pharmacological data.

Outbreak of extended spectrum beta-lactamase-producing Klebsiella pneumoniae in an intensive care unit (Brest)

INTRODUCTION

We had for aim to describe control and investigation of an outbreak caused by a strain of Extended spectrum beta-lactamase producing Klebsiella pneumoniae in intensive care units of the Brest teaching hospital.

PATIENTS AND METHOD

The case definition was a patient infected by or carrying the epidemic strain. Control measures and investigations are presented. A case-control study was conducted in the surgical intensive care unit. Each case was matched with two controls based on admission times in the unit. The study focused on diagnostic and therapeutic procedures, and potential contacts with healthcare workers, in this context of cross transmission.

RESULTS

Between February and May 2011, nine cases were reported in the surgical ICU and two in the medical ICU. Eighteen controls were matched with the nine surgical ICU cases. Several factors were found to be statistically associated with infection or colonization by the epidemic strain: the surgical block in which patients had been operated and the ward of first hospitalization; the number of trans-esophageal and trans-thoracic echocardiographies, of central venous catheter insertions, and of surgical operations; intubation. The total number of invasive procedures was also found to be statistically higher among cases.

CONCLUSION

This study identified factors associated with colonization or infection by the epidemic strain. These factors might have been involved in the transmission tree, and be vulnerable elements for the prevention of nosocomial infections and colonisations, and their epidemic spread.

Clinical impact and risk factors for colonization with extended-spectrum β-lactamase-producing bacteria in the intensive care unit

PURPOSE

The changed epidemiology of extended spectrum beta-lactamases (ESBL), the spread to the community and the need for prudent use of carbapenems require updated knowledge of risk factors for colonization with ESBL-producing enterobacteriaceae (ESBL-PE).

METHODS

An 8-month prospective study in the medical ICU of an 850-bed general and university-affiliated hospital.

RESULTS

Of 610 patients admitted, 531 (87 %) had a rectal swab obtained at admission, showing a 15 % (82 patients) ESBL-PE carriage rate, mostly of E. coli (n = 51, 62 %); ESBL-PE caused 9 (3 %) infections on admission. By multivariable analysis, transfer from another ICU (OR = 2.56 [1, 22]), hospital admission in another country [OR = 5.28 (1.56-17.8)], surgery within the past year [OR = 2.28 (1.34-3.86)], prior neurologic disease [OR = 2.09 (1.1-4.0)], and prior administration of third generation cephalosporin (within 3-12 months before ICU admission) [OR = 3.05 (1.21-7.68)] were independent predictive factors of colonization by ESBL-PE upon ICU admission. Twenty-eight patients (13 % of those staying for more than 5 days) acquired ESBL carriage in ICU, mostly with E. cloacae (n = 13, 46 %) and K. pneumoniae (n = 10, 36 %). In carriers, ESBL-PE caused 10 and 27 % of first and second episodes of ICU-acquired infections, respectively.

CONCLUSION

We found a high prevalence of ESBLE-PE colonization on admission to our ICU, even in the subgroup admitted from the community, but few first infections. Identifying risk factors for ESBL-PE colonization may help identifying which patients may warrant empiric ESBL-targeted antimicrobial drug therapy as a means to limit carbapenem use.

Does health care associated pneumonia really exist?

The most recent ATS guidelines for nosocomial pneumonia of 2005 describe a new clinical category of patients, Health Care-Associated Pneumonia which includes a number of very heterogeneous conditions possibly associated with a high risk of multi-drug resistant (MDR) infections and of mortality. This paper aims at reviewing the current literature on HCAP and examines the controversial issues of HCAP etiology and outcomes, underlining the need of a profound revision of the HCAP concept in the face of the poor and contrasting scientific evidence supporting its basis.

Pretransplant fecal carriage of extended-spectrum β-lactamase-producing Enterobacteriaceae and infection after liver transplant, France

Extended-spectrum β-lactamase-producing Enterobacteriaceae isolates (ESBLE) are emerging pathogens that confer resistance to antimicrobial drugs. We conducted a 10-year study in France (January 2001-April 2010) to investigate the incidence of and risk factors for ESBLE infections after liver transplant. Of 710 transplant patients screened preoperatively for ESBLE fecal carriage, 5.5% had ESBLE infection develop within 4 months after surgery; patients with pretransplant ESBLE fecal carriage were more likely to have infection develop than were noncarriers. Typing showed extensive genetic diversity, with a large predominance of CTX-M enzymes. Independent predictors of ESBLE infection were pretransplant fecal carriage, Model for End Stage Liver Disease score >25, and return to surgery. Our results indicate that the influx of preoperatively acquired ESBLE isolates into the hospital outweighs cross-transmission in the epidemiology of ESBLE infections after liver transplant. Transplant candidates should be systematically screened for carriage, and posttransplant infection in carriers should be treated with carbapenems.

Variability of intestinal colonization with third-generation cephalosporin-resistant Enterobacteriaceae and antibiotic use in intensive care units

OBJECTIVES

Healthcare-associated infections due to third-generation cephalosporin-resistant Enterobacteriaceae (CRE) have become a major public health threat, especially in intensive care units (ICUs). We assessed and compared β-lactam use, the prevalence of colonization with CRE at admission and the incidence of CRE acquisition across ICUs.

PATIENTS AND METHODS

A cohort study was conducted in 10 ICUs of the Paris (France) metropolitan area between November 2005 and February 2006. Antibiotic use was recorded prospectively in all patients admitted during the study period. Rectal swabs were collected at admission, twice weekly thereafter, before β-lactam prescription and before discharge.

RESULTS

A total of 893 patients provided 3453 rectal swabs; 793 of the patients were newly admitted, mostly for medical reasons (80.7%). On admission, 74 patients (9.6%) were colonized with CRE, including 32 with an extended-spectrum β-lactamase (ESBL)-producing strain. Among the remaining 694 naive patients, 94 acquired CRE during their follow-up, including 31 with an ESBL-producing strain. Incidence rates of colonization ranged from 8.8 to 21.0/1000 patient-days for all CRE, and from 1.4 to 10.9/1000 patient-days for ESBL producers. A majority of patients (68.3%) were prescribed β-lactams during their ICU stay, with defined daily doses ranging from 428 to 985/1000 patient-days. Across ICUs, prescriptions of all antibiotics, β-lactams and carbapenems were significantly correlated to incidence rates of colonization with ESBL-producing CRE.

CONCLUSIONS

The standardized and systematic follow-up of patients in 10 ICUs revealed great heterogeneity in the rates of colonization with ESBL- and non-ESBL-producing CRE, as well as in antimicrobial prescription practices.

Efficacy of infection control interventions in reducing the spread of multidrug-resistant organisms in the hospital setting

Multidrug-resistant organisms (MDRO) continue to spread in hospitals globally, but the population-level impact of recommended preventive strategies and the relative benefit of individual strategies targeting all MDRO in the hospital setting are unclear. To explore the dynamics of MDRO transmission in the hospital, we develop a model extending data from clinical individual-level studies to quantify the impact of hand hygiene, contact precautions, reducing antimicrobial exposure and screening surveillance cultures in decreasing the prevalence of MDRO colonization and infection. The effect of an ongoing increase in the influx of patients colonized with MDRO into the hospital setting is also quantified. We find that most recommended strategies have substantial effect in decreasing the prevalence of MDRO over time. However, screening for asymptomatic MDRO colonization among patients who are not receiving antimicrobials is of minimal value in reducing the spread of MDRO.

Multidrug-resistant bacteria colonization amongst patients newly admitted to a geriatric unit: a prospective cohort study

OBJECTIVES

To determine prevalence, incidence and risk factors of colonization by extended-spectrum β-lactamase-producing Enterobacteriacae (ESBLE), methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-resistant Enterococcus (VRE) in aged subjects admitted to an acute geriatric unit at a teaching hospital.

METHODS

During 12 months, 337 patients were screened by nasal, oropharyngeal, groin, axillary and rectal swabs upon admission and at discharge.

RESULTS

The prevalence of ESBLE, MRSA and VRE carriage upon admission was 11.6%, 7.5% and 0.6%, respectively. The incidence density of ESBLE and MRSA carriage was respectively of 1.77 and 2.40 new cases for 1000 patient-days. No cases of VRE acquisition were found. Risk factors for ESBLE colonization on admission were: multiple contacts with the hospital within the previous year, chronic catheter use and a high level of dependency. For MRSA, risk factors were: chronic wounds, anti-acid use and a high level of dependency.

CONCLUSION

This study shows a high prevalence of asymptomatic colonization of ESBL-producing Escherichia coli in patients admitted to an acute geriatric ward, as high as MRSA carriage. A low functional status is a common risk factor both for ESBLE and for MRSA colonization and it highlights the need to reinforce infection control measures.

Extended-spectrum β-lactamase genes of Escherichia coli in chicken meat and humans, The Netherlands

We determined the prevalence and characteristics of extended-spectrum β-lactamase (ESBL) genes of Enterobacteriaceae in retail chicken meat and humans in the Netherlands. Raw meat samples were obtained, and simultaneous cross-sectional surveys of fecal carriage were performed in 4 hospitals in the same area. Human blood cultures from these hospitals that contained ESBL genes were included. A high prevalence of ESBL genes was found in chicken meat (79.8%). Genetic analysis showed that the predominant ESBL genes in chicken meat and human rectal swab specimens were identical. These genes were also frequently found in human blood culture isolates. Typing results of Escherichia coli strains showed a high degree of similarity with strains from meat and humans. These findings suggest that the abundant presence of ESBL genes in the food chain may have a profound effect on future treatment options for a wide range of infections caused by gram-negative bacteria.

Prevalence of antimicrobial-resistant organisms in residential aged care facilities

OBJECTIVE

To assess the frequency of, and risk factors for, colonisation with vancomycin-resistant enterococci (VRE), Clostridium difficile and extended-spectrum β-lactamase (ESBL)-producing organisms in residential aged care facilities (RACFs).

DESIGN, SETTING AND PARTICIPANTS

We conducted a point prevalence survey in October-November 2010 in three RACFs associated with our health service. A single faecal sample was collected from each participating resident and screened for the presence of VRE, C. difficile and ESBL-producing organisms. Presence of risk factors for antibiotic-resistant organisms was identified using a questionnaire.

MAIN OUTCOME MEASURES

Prevalence of colonisation with VRE, C. difficile and ESBL-producing organisms; molecular typing of ESBL-producing organisms; prevalence of risk factors including presence of a urinary catheter, recent inpatient stay in an acute care setting and recent antibiotic consumption.

RESULTS

Of 164 residents in the three facilities, 119 (73%) were screened. Mean age of screened residents was 79.2 years, and 61% were women; 74% had resided in the RACF for > 12 months, 21% had been given antibiotics within the past month and 12% had been in an acute care centre within the past 3 months. Overall rates of VRE (2%) and C. difficile (1%) colonisation were low, but ESBL-producing Escherichia coli was detected in 14 residents (12%) overall, with half of these residing in one wing of an RACF (27% of wing residents tested). Ten of the 14 ESBL-producing isolates had identical molecular typing patterns and belonged to genotye CTX-M-9. Eight of 13 residents had persistent colonisation on repeat testing 3 months later.

CONCLUSION

We found a high prevalence of multiresistant ESBL-producing E. coli in RACF residents. A clonal relatedness of isolates suggests possible transmission within the facility. RACFs should have programs emphasising processes that will limit spread of these organisms, namely good hand hygiene compliance, enhanced environmental cleaning and dedicated antimicrobial stewardship programs.

Nursing and physician attire as possible source of nosocomial infections

BACKGROUND

Uniforms worn by medical and nursing staff are not usually considered important in the transmission of microorganisms. We investigated the rate of potentially pathogenic bacteria present on uniforms worn by hospital staff, as well as the bacterial load of these microorganisms.

METHODS

Cultures were obtained from uniforms of nurses and physicians by pressing standard blood agar plates at the abdominal zone, sleeve ends, and pockets. Each participant completed a questionnaire.

RESULTS

A total of 238 samples were collected from 135 personnel, including 75 nurses (55%) and 60 physicians (45%). Of these, 79 (58%) claimed to change their uniform every day, and 104 (77%) defined the level of hygiene of their attire as fair to excellent. Potentially pathogenic bacteria were isolated from at least one site of the uniforms of 85 participants (63%) and were isolated from 119 samples (50%); 21 (14%) of the samples from nurses' gowns and 6 (6%) of the samples from physicians' gowns (P = NS) included of antibiotic-resistant bacteria.

CONCLUSION

Up to 60% of hospital staff's uniforms are colonized with potentially pathogenic bacteria, including drug-resistant organisms. It remains to be determined whether these bacteria can be transferred to patients and cause clinically relevant infection.

Rectal carriage of extended-spectrum beta-lactamase-producing gram-negative bacilli in community settings in Madagascar

Background

Extended-spectrum ß-lactamase-producing Enterobacteria (ESBL-PE) emerged at the end of the 1980s, causing nosocomial outbreaks and/or hyperendemic situations in hospitals and long-term care facilities. In recent years, community-acquired infections due to ESBL-PE have spread worldwide, especially across developing countries including Madagascar.

Objectives

This study aimed to determine the prevalence and risk factors of intestinal carriage of ESBL-PE in the community of Antananarivo.

Methods

Non-hospitalized patients were recruited in three health centers in different socio economic settings. Fresh stool collected were immediately plated on Drigalski agar containing 3 mg/liter of ceftriaxone. Gram-negative bacilli species were identified and ESBL production was tested by a double disk diffusion (cefotaxime and ceftazidime +/− clavulanate) assay. Characterization of ESBLs were perfomed by PCR and direct sequencing . Molecular epidemiology was analysed by Rep-PCR and ERIC-PCR.

Results

484 patients were screened (sex ratio  = 1.03, median age 28 years). 53 ESBL-PE were isolated from 49 patients (carrier rate 10.1%). The isolates included Escherichia coli (31), Klebsiella pneumoniae (14), Enterobacter cloacae (3), Citrobacter freundii (3), Kluyvera spp. (1) and Pantoae sp.(1). In multivariate analysis, only the socioeconomic status of the head of household was independently associated with ESBL-PE carriage, poverty being the predominant risk factor.

Conclusions

The prevalence of carriage of ESBL in the community of Antananarivo is one of the highest reported worldwide. This alarming spread of resistance genes should be stopped urgently by improving hygiene and streamlining the distribution and consumption of antibiotics.

Influx of multidrug resistant, Gram-negative bacteria (MDRGNB) in a public hospital among elderly patients from long-term care facilities: a single-center pilot study

Residence at a long-term care facility (LTCF) and older age are both recognized as significant risk factors for harboring MDRGNB. However, well designed prospective observational studies are few on the prevalence and risk factors of MDRGNB influx to hospital due to elderly patients arriving from LTCFs. Between November 1 and December 31, 2009, at a 500-bed, public teaching hospital in Seoul, Republic of Korea, all clinical cultures within 48 h of hospitalization from elderly patients at least 50 years of age arriving from LTCFs were collected prospectively. During these periods, the prevalence of MDRGNB influx among elderly patients from LTCFs was higher than that among other hospitalized patients (14.5% vs. 2.5%, odds ratio [OR] 8.1, 95% confidence interval [CI] 3.5-18.8, P<0.001). Of a total of 55 elderly hospitalized subjects from 6 LTCFs, clinical cultures were performed in 37. MDRGNB were found in 8 patients (6 of whom were infected). There was no difference between patients with and without MDRGNB regarding previously reported clinical characteristics associated with harboring MDRGNB. However, the mortality within one month of hospitalization was higher in patients with MDRGNB than without MDRGNB, regardless of the appropriateness of the antibiotics they received (OR, 15.91; 95% CI, 1.01-251.36; P=0.049). In conclusion, the prevalence of MDRGNB influx among elderly patients from LTCFs is significant in Korean public hospital. They require specific remedies in order to reduce the risk of early mortality.

Healthcare-associated pneumonia: approach to management

Healthcare-associated pneumonia patients have worse outcomes and a different microbiologic profile than those with community-acquired pneumonia, including a greater risk for multidrug-resistant (MDR) organism infection. Risks include hospitalization for 2 or more days within 90 days, presentation from a nursing home or long-term care facility, attending a hospital or hemodialysis clinic, receiving intravenous therapy within 30 days, and immunosuppression. Ability to predict infection with MDR organisms varies, and the relative frequency of MDR organisms varies by geographic region. Initial treatment is broad-spectrum empiric antibiotics.

Extended-spectrum β-lactamase-producing Gram-negative pathogens in community-acquired urinary tract infections: an increasing challenge for antimicrobial therapy

BACKGROUND

Extended-spectrum β-lactamases (ESBLs) are an increasing challenge in the treatment of urinary tract infections (UTIs), and also in the community. We aimed to investigate the characteristics of patients with UTIs due to ESBL-producing Escherichia coli and to assess the risk factors for ESBLs in community-acquired isolates.

METHODS

We performed a retrospective study from January 1, 2007 to December 31, 2009 at a tertiary care teaching hospital in Switzerland, comparing patients with community-acquired versus healthcare-associated UTIs due to ESBL-producing E. coli. Additionally, we investigated the antimicrobial susceptibility of these isolates.

RESULTS

A total of 123 patients were studied, of whom 79 (64%) had community-acquired and 44 (36%) had healthcare-associated UTIs. Community-acquired isolates were associated with acute uncomplicated UTIs (odds ratio [OR] 6.62, 95% confidence interval [CI] 1.83-36.5, P < 0.001). Risk factors were recurrent UTI (OR 3.04, 95% CI 1.14-9.14, P = 0.022) and female sex (OR 2.46, 95% CI 1.01-6.08). Community-acquired ESBL-producing E. coli urinary isolates showed high resistance rates to most of the currently used oral antimicrobial agents, including β-lactam antibiotics (amoxicillin-clavulanic acid, 69.6% resistance), quinolones (ciprofloxacin, 84.8% resistance; norfloxacin, 83.9% resistance), and trimethoprim-sulfamethoxazole (75.9% resistance), except for nitrofurantoin (15% resistance) and fosfomycin (0% resistance).

CONCLUSION

UTI due to ESBL-producing E. coli are emerging, and also in a country with low antibiotic use. Because of increasing antibiotic resistance rates of E. coli to current standard therapy and because of the resistance patterns of ESBL-producing E. coli, guidelines for the management of UTIs must be revised. Fosfomycin or nitrofurantoin are recommended for the first-line empirical oral treatment of community-acquired uncomplicated UTIs.

Clinical predictive values of extended-spectrum beta-lactamase carriage in patients admitted to medical wards

We aimed to reassess, through clinical items, populations at risk for extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) carriage at admission to hospital and to assess the risk of further positive clinical culture of ESBL-E among carriers. We performed a 5-month cohort study in a medicine ward of a 500-bed university teaching hospital in the Parisian area of France. All admitted patients were prospectively enrolled for rectal swabbing and clinical data collection, including bacterial infection at admission and during stay. Variables associated with ESBL-E carriage were identified by univariate and multivariate analysis. Five hundred patients were included. The prevalence of ESBL-E was 6.6% (33/500) upon admission. Only previous carriage of multidrug-resistant bacteria (MDRB) was associated with carriage (odds ratio [OR]: 17.7, 95% confidence interval (CI) 5.8-54.2, p < 0.001), yet, the positive predictive value (PPV) was not higher than 50%. When prior MDRB carriage was not considered in the multivariate analysis, only prior antibiotic consumption was found to be associated with carriage at admission (OR: 2.2 [1.1-4.5], p = 0.02). Two patients had ESBL-E infection at admission, yet, no patient became infected with ESBL-E during their stay. The clinical prediction of ESBL carriage at admission in our wards was found to be poorly efficient for assessing the at-risk population.

Healthcare-associated pneumonia: diagnostic criteria and distinction from community-acquired pneumonia

BACKGROUND

Traditionally, pneumonia developing in patients who receive healthcare services in the outpatient environment has been classified as community-acquired pneumonia (CAP). However, recent investigations suggest that this type of infection, known as healthcare-associated pneumonia (HCAP), is distinct from CAP in terms of its epidemiology, etiology, and risk for infection with multidrug-resistant (MDR) pathogens.

METHODS

A Medline literature review of available clinical studies using the term HCAP was conducted to determine outcomes compared to CAP and effective empiric treatment strategies.

RESULTS

Analysis of multi-institutional clinical data showed that mortality in hospitalized patients with HCAP is greater than that in CAP, and patients with HCAP received inappropriate initial empiric antibiotic treatment more frequently than CAP patients. The bacterial pathogens associated with HCAP also differed from CAP with potentially MDR Gram-positive and Gram-negative bacteria being more common in HCAP.

CONCLUSIONS

All patients hospitalized with suspected HCAP should be evaluated for their underlying risk of infection with MDR pathogens. Because HCAP is similar to hospital-acquired pneumonia (HAP), both clinically and etiologically, it should be treated as HAP until culture data become available.

Identifying patients harboring extended-spectrum-beta-lactamase-producing Enterobacteriaceae on hospital admission: derivation and validation of a scoring system

Increases in community-acquired infections caused by extended-spectrum-β-lactamase (ESBL)-producing Enterobacteriaceae have important implications for hospital infection control and empirical antibiotic therapy protocols. We developed and validated a tool for identifying patients harboring these organisms at hospital admission. We retrospectively analyzed chart data for 849 adult inpatients. The derivation cohort included 339 patients admitted to a large hospital in Rome during 2008, with (n = 113) or without (n = 226) culture positivity for ESBL-producing Escherichia coli, Klebsiella spp., or Proteus mirabilis within 48 h after admission. Logistic-regression-based prediction scores were calculated based on variables independently associated with the outcome. The model was validated in a second cohort (n = 510) selected with identical criteria in hospitals in Genoa and Turin during 2009. Prediction scores were based on the following six variables (reported with odds ratio for study outcome and the 95% confidence intervals in brackets): recent (≤ 12 months before admission) hospitalization (5.69 [2.94 to 10.99]), transfer from another health care facility (5.61 [1.65 to 19.08]), Charlson comorbidity score ≥ 4 (3.80 [1.90 to 7.59]), recent (≤ 3 months before admission) β-lactam and/or fluoroquinolone treatment (3.68 [1.96 to 6.91]), recent urinary catheterization (3.52 [1.96 to 6.91]), and age ≥ 70 years (3.20 [1.79 to 5.70]). The model displayed good calibration and good-to-excellent discrimination in the derivation and validation sets (Hosmer-Lemshow χ(2) = 15.28 and 14.07; P = 0.17 and 0.23; areas under the receiver-operating characteristic curve, 0.83 and 0.92). It reliably identified patients likely to be harboring ESBL-producing Enterobacteriaceae at hospital admission who may need special infection control measures. Further study is needed to confirm this model's potential as a guide for prescribing empirical antibiotic therapy.

Modelling the impact of antibiotic use on antibiotic-resistant Escherichia coli using population-based data from a large hospital and its surrounding community

OBJECTIVES

To determine the temporal relationship between antibiotic use and incidence of antibiotic-resistant Escherichia coli in both the inpatient and outpatient setting of a large urban area.

METHODS

A retrospective observational time-series analysis was performed to evaluate the incidence of non-duplicate clinical isolates of E. coli resistant to ciprofloxacin, trimethoprim/sulfamethoxazole and cefepime from January 2000 through December 2007, combined with a transfer function model of aggregated data on antibiotic use in both settings obtained from the hospital's pharmacy and outpatient billing offices.

RESULTS

Ciprofloxacin resistance increased from 6.0% (2000) to 15.4% (2007; P<0.0001) and cefepime resistance from 0.9% (2002) to 3.2% (2007; P=0.01). Trimethoprim/sulfamethoxazole resistance remained stable (23.7%-25.8%). Total antibiotic use increased in both settings, while fluoroquinolone use increased significantly only among outpatients. A temporal effect between fluoroquinolone resistance in community E. coli isolates and outpatient use of ciprofloxacin (immediate effect and time lag 1 month) and moxifloxacin (time lag 4 months) was observed, explaining 51% of the variance over time. The incidence of cefepime resistance in E. coli was correlated with ciprofloxacin use in the inpatient (lag 1 month) and outpatient (lag 4 months) settings and with the use of ceftriaxone (lag 0 month), piperacillin/tazobactam (3 months) and cefepime (3 months) in the hospital (R2=51%).

CONCLUSIONS

These results support efforts to reduce prescribing of fluoroquinolones for control of resistant E. coli including extended-spectrum β-lactamase producers and show the added value of time-series analysis to better understand the interaction between community and hospital antibiotic prescribing and its spill-over effect on antibiotic resistance.

Clinical profiles of patients colonized or infected with extended-spectrum beta-lactamase producing Enterobacteriaceae isolates: a 20 month retrospective study at a Belgian University Hospital

Background

Description of the clinical pictures of patients colonized or infected by ESBL-producing Enterobacteriaceae isolates and admitted to hospital are rather scarce in Europe. However, a better delineation of the clinical patterns associated with the carriage of ESBL-producing isolates may allow healthcare providers to identify more rapidly at risk patients. This matter is of particular concern because of the growing proportion of ESBL-producing Enterobacteriaceae species isolates worldwide.

Methods

We undertook a descriptive analysis of 114 consecutive patients in whom ESBL-producing Enterobacteriaceae isolates were collected from clinical specimens over a 20-month period. Clinical data were obtained through retrospective analysis of medical record charts. Microbiological cultures were carried out by standard laboratory methods.

Results

The proportion of ESBL-producing Enterobacteriaceae strains after exclusion of duplicate isolates was 4.5% and the incidence rate was 4.3 cases/1000 patients admitted. Healthcare-associated acquisition was important (n = 104) while community-acquisition was less frequently found (n = 10). Among the former group, two-thirds of the patients were aged over 65 years and 24% of these were living in nursing homes. Sixty-eight (65%) of the patients with healthcare-associated ESBL, were considered clinically infected. In this group, the number and severity of co-morbidities was high, particularly including diabetes mellitus and chronic renal insufficiency. Other known risk factors for ESBL colonization or infection such as prior antibiotic exposure, urinary catheter or previous hospitalisation were also often found. The four main diagnostic categories were: urinary tract infections, lower respiratory tract infections, septicaemia and intra-abdominal infections. For hospitalized patients, the median hospital length of stay was 23 days and the average mortality rate during hospitalization was 13% (Confidence Interval 95%: 7-19). Escherichia coli, by far, accounted as the most common ESBL-producing Enterobacteriaceae species (77/114; [68%]) while CTX-M-1 group was by far the most prevalent ESBL enzyme (n = 56).

Conclusion

In this retrospective study, the clinical profiles of patients carrying healthcare-associated ESBL-producing Enterobacteriacae is characterized by a high prevalence rate of several major co-morbidities and potential known risk factors. Both, the length of hospital stay and overall hospital mortality rates were particularly high. A prospective case-control matched study should be designed and performed in order to control for possible inclusion bias.

Extended spectrum beta-lactamase-producing bacteria and Clostridium difficile in patients with pouchitis

BACKGROUND

Treatment with fluoroquinolones is associated with the development of Clostridium difficile and extended spectrum beta-lactamase-producing bacteria (ESBL). Clostridium difficile and ESBL are resistant to many antibiotics and each may cause pouchitis after restorative proctocolectomy (RPC) refractory to empirical antibiotic therapy.

AIM

To assess the prevalence and establish risk factors for the development of ESBL and Clostridium difficile toxins (CDT) in RPC patients with recurrent or refractory pouchitis under follow-up at our institution over a 1-year period.

METHOD

An enzyme-linked immunosorbent assay was used to detect CDT and a culture technique was used to identity ESBL in faecal samples. All patients had previously received fluoroquinolone treatment.

RESULTS

Forty-eight patients (35 (74%) men; median age 42 years) underwent testing at a median interval from RPC of 8 (range 1-25) years. No patient had a positive CDT result, but ESBL bacteria were identified in 16 (33%) samples. ESBL positivity was significantly related to prepouch ileitis (P = 0.035) and maintenance antibiotic therapy (P = 0.039).

CONCLUSIONS

Extended spectrum beta-lactamase, but not CDT, is a common finding in faecal samples from patients with recurrent or refractory pouchitis. Treatment with maintenance antibiotics and prepouch ileitis are risk factors for developing ESBL-producing bacteria.