Clostridium difficile contamination of health care workers' hands and its potential contribution to the spread of infection: Review of the literature

BACKGROUND

Clostridium difficile infection (CDI) can be transmitted from patient to patient by the hands of health care workers (HCWs); however, the relative importance of this route in the spread of C difficile in the hospital is currently unknown. Our aim was to review studies examining HCWs' hand carriage and its potential role in CDI transmission.

METHODS

First, English-speaking references addressing HCWs' hand sampling obtained from the PubMed database were reviewed. Second, C difficile outbreaks definitely or probably implicating HCWs were retrieved from the Outbreak Database Web site (www.outbreak-database.com). Finally, cases of C difficile occurring in HCWs after contact with an infected patient were retrieved from PubMed.

RESULTS

A total of 11 studies dealing with HCWs' hand carriage were selected and reviewed. Between 0% and 59% of HCWs' hands were found contaminated with C difficile after caring for a patient with CDI. There were several differences between studies regarding site of hands sampling, timing after contact, and bacteriologic methods. Only 2 C difficile outbreaks implicating HCWs and 6 series of cases of transmission from patients to HCWs have been reported.

CONCLUSIONS

This review shows that HCWs' hands could play an important role in the transmission of C difficile. Hand hygiene and reduction of environmental contamination are essential to control C difficile transmission.

Predicting the Risk of Clostridium difficile Infection upon Admission: A Score to Identify Patients for Antimicrobial Stewardship Efforts

INTRODUCTION

Increasing morbidity and health care costs related to Clostridium difficile infection (CDI) have heightened interest in methods to identify patients who would most benefit from interventions to mitigate the likelihood of CDI.

OBJECTIVE

To develop a risk score that can be calculated upon hospital admission and used by antimicrobial stewards, including pharmacists and clinicians, to identify patients at risk for CDI who would benefit from enhanced antibiotic review and patient education.

METHODS

We assembled a cohort of Kaiser Permanente Northwest patients with a hospital admission from July 1, 2005, through December 30, 2012, and identified CDI in the six months following hospital admission. Using Cox regression, we constructed a score to identify patients at high risk for CDI on the basis of preadmission characteristics. We calculated and plotted the observed six-month CDI risk for each decile of predicted risk.

RESULTS

We identified 721 CDIs following 54,186 hospital admissions-a 6-month incidence of 13.3 CDIs/1000 patient admissions. Patients with the highest predicted risk of CDI had an observed incidence of 53 CDIs/1000 patient admissions. The score differentiated between patients who do and do not develop CDI, with values for the extended C-statistic of 0.75. Predicted risk for CDI agreed closely with observed risk.

CONCLUSION

Our risk score accurately predicted six-month risk for CDI using preadmission characteristics. Accurate predictions among the highest-risk patient subgroups allow for the identification of patients who could be targeted for and who would likely benefit from review of inpatient antibiotic use or enhanced educational efforts at the time of discharge planning.

Receipt of Antibiotics in Hospitalized Patients and Risk for Clostridium difficile Infection in Subsequent Patients Who Occupy the Same Bed

OBJECTIVE

To assess whether receipt of antibiotics by prior hospital bed occupants is associated with increased risk for CDI in subsequent patients who occupy the same bed.

DESIGN, SETTING, AND PARTICIPANTS

This is a retrospective cohort study of adult patients hospitalized in any 1 of 4 facilities between 2010 and 2015. Patients were excluded if they had recent CDI, developed CDI within 48 hours of admission, had inadequate follow-up time, or if their prior bed occupant was in the bed for less than 24 hours.

MAIN OUTCOMES AND MEASURES

The primary exposure was receipt of non-CDI antibiotics by the prior bed occupant and the primary outcome was incident CDI in the subsequent patient to occupy the same bed. Incident CDI was defined as a positive result from a stool polymerase chain reaction for the C difficile toxin B gene followed by treatment for CDI. Demographics, comorbidities, laboratory data, and medication exposures are reported.

RESULTS

Among 100 615 pairs of patients who sequentially occupied a given hospital bed, there were 576 pairs (0.57%) in which subsequent patients developed CDI. Receipt of antibiotics in prior patients was significantly associated with incident CDI in subsequent patients (log-rank P < .01). This relationship remained unchanged after adjusting for factors known to influence risk for CDI including receipt of antibiotics by the subsequent patient (adjusted hazard ratio [aHR], 1.22; 95% CI, 1.02-1.45) and also after excluding 1497 patient pairs among whom the prior patients developed CDI (aHR, 1.20; 95% CI, 1.01-1.43). Aside from antibiotics, no other factors related to the prior bed occupants were associated with increased risk for CDI in subsequent patients.

CONCLUSIONS AND RELEVANCE

Receipt of antibiotics by prior bed occupants was associated with increased risk for CDI in subsequent patients. Antibiotics can directly affect risk for CDI in patients who do not themselves receive antibiotics.

Assessing the Risk of Hospital-Acquired Clostridium Difficile Infection With Proton Pump Inhibitor Use: A Meta-Analysis

BACKGROUND Clostridium difficile is the principal infectious cause of antibiotic-associated diarrhea and accounts for 12% of hospital-acquired infections. Recent literature has shown an increased risk of C. difficile infection (CDI) with proton pump inhibitor (PPI) use. OBJECTIVE To conduct a systematic assessment of the risk of hospital-acquired CDI following exposure to PPI. METHODS We searched multiple databases for studies examining the relationship between PPI and hospital-acquired CDI. Pooled odds ratios were generated and assessment for heterogeneity performed. RESULTS We found 23 observational studies involving 186,033 cases that met eligibility criteria. Across studies, 10,307 cases of hospital-acquired CDI were reported. Significant heterogeneity was present; therefore, a random effects model was used. The pooled odds ratio was 1.81 (95% CI, 1.52-2.14), favoring higher risk of CDI with PPI use. Significant heterogeneity was present, likely due to differences in assessment of exposure, study population, and definition of CDI. DISCUSSION This meta-analysis suggests PPIs significantly increase the risk of hospital-acquired CDI. Given the significant health and economic burden of CDI and the risks of PPI, optimization of PPI use should be included in a multifaceted approach to CDI prevention. Infect Control Hosp Epidemiol 2016;1408-1417.

Epidemiology and outcome of Clostridium difficile infections in patients hospitalized in Internal Medicine: findings from the nationwide FADOI-PRACTICE study

Background

Clostridium difficile (CD) is a leading cause of diarrhoea among hospitalized patients. The objective of this study was to evaluate the rate, the optimal diagnostic work-up, and outcome of CD infections (CDI) in Internal Medicine (IM) wards in Italy.

Methods

PRACTICE is an observational prospective study, involving 40 IM Units and evaluating all consecutive patients hospitalized during a 4-month period. CDI were defined in case of diarrhoea when both enzyme immunoassay for GDH, and test for A/B toxin were positive. Patients with CDI were followed-up for recurrences for 4 weeks after the end of therapy.

Results

Among the 10,780 patients observed, 103 (0.96 %) showed CDI, at admission or during hospitalization. A positive history for CD, antibiotics in the previous 4 weeks, recent hospitalization, female gender and age were significantly associated with CDI (multivariable analysis). In-hospital mortality was 16.5 % in CD group vs 6.7 % in No-CD group (p < 0.001), whereas median length of hospital stay was 16 (IQR = 13) vs 8 (IQR = 8) days (p < 0.001) among patients with or without CDI, respectively. Rate of CD recurrences was 14.6 %. As a post-hoc evaluation, 23 out of 34 GDH+/Tox- samples were toxin positive, when analysed by molecular method (a real-time PCR assay). The overall CD incidence rate was 5.3/10,000 patient-days.

Conclusions

Our results confirm the severity of CDI in medical wards, showing high in-hospital mortality, prolonged hospitalization and frequent short-term recurrences. Further, our survey supports a 2–3 step algorithm for CD diagnosis: EIA for detecting GDH, A and B toxin, followed by a molecular method in case of toxin-negative samples.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1961-9) contains supplementary material, which is available to authorized users.

Proton Pump Inhibitors Do Not Increase Risk for Clostridium difficile Infection in the Intensive Care Unit

OBJECTIVES

Patients in the intensive care unit (ICU) frequently receive proton pump inhibitors (PPIs) and have high rates of Clostridium difficile infection (CDI). PPIs have been associated with CDI in hospitalized patients, but ICU patients differ fundamentally from non-ICU patients and few studies have focused on PPI use exclusively in the critical care setting. We performed a retrospective cohort study to determine the associations between PPIs and health-care facility-onset CDI in the ICU.

METHODS

We analyzed data from all adult ICU patients at three affiliated hospitals (14 ICUs) between 2010 and 2013. Patients were excluded if they had recent CDI or an ICU stay of <3 days. We parsed electronic medical records for ICU exposures, focusing on PPIs and other potentially modifiable exposures that occurred during ICU stays. Health-care facility-onset CDI in the ICU was defined as a newly positive PCR for the C. difficile toxin B gene from an unformed stool, with subsequent receipt of anti-CDI therapy. We analyzed PPIs and other exposures as time-varying covariates and used Cox proportional hazards models to adjust for demographics, comorbidities, and other clinical factors.

RESULTS

Of 18,134 patients who met the criteria for inclusion, 271 (1.5%) developed health-care facility-onset CDI in the ICU. Receipt of antibiotics was the strongest risk factor for CDI (adjusted HR (aHR) 2.79; 95% confidence interval (CI), 1.50-5.19). There was no significant increase in risk for CDI associated with PPIs in those who did not receive antibiotics (aHR 1.56; 95% CI, 0.72-3.35), and PPIs were actually associated with a decreased risk for CDI in those who received antibiotics (aHR 0.64; 95% CI, 0.48-0.83). There was also no evidence of increased risk for CDI in those who received higher doses of PPIs.

CONCLUSIONS

Exposure to antibiotics was the most important risk factor for health-care facility-onset CDI in the ICU. PPIs did not increase risk for CDI in the ICU regardless of use of antibiotics.

Risk factors associated with interfacility transfers among patients with Clostridium difficile infection

BACKGROUND

Preventing the transmission of Clostridium difficile infection (CDI) over the continuum of care presents an important challenge for infection control.

METHODS

A prospective case-control study was conducted on patients admitted with CDI to a tertiary care hospital in Detroit between August 2012 and September 2013. Patients were then followed for 1 year by telephone interviews and the hospital administrative database. Cases, patients with interfacility transfers (IFTs), were patients admitted to our facility from another health care facility and discharged to long-term care (LTC) facilities. Controls were patients admitted from and discharged to home.

RESULTS

There were 143 patients included in the study. Thirty-six (30%) cases were compared with 84 (70%) controls. Independent risk factors of CDI patients with IFTs (compared with CDI patients without IFTs) included Charlson Comorbidity Index score ≥6 (odds ratio [OR], 5.30; P = .016) and hospital-acquired CDI (OR, 4.92; P = .023). Patients with IFTs were more likely to be readmitted within 90 days of discharge than patients without IFTs (OR, 2.24; P = .046). One-year mortality rate was significantly higher among patients with IFTs than among patients without IFTs (OR, 4.33; P = .01).

CONCLUSIONS

With the growing number of alternate health care centers, it is highly critical to establish better collaboration between acute care and LTC facilities to tackle the increasing burden of CDI across the health care system.

Research Methods in Healthcare Epidemiology and Antimicrobial Stewardship: Use of Administrative and Surveillance Databases

Administrative and surveillance data are used frequently in healthcare epidemiology and antimicrobial stewardship (HE&AS) research because of their wide availability and efficiency. However, data quality issues exist, requiring careful consideration and potential validation of data. This methods paper presents key considerations for using administrative and surveillance data in HE&AS, including types of data available and potential use, data limitations, and the importance of validation. After discussing these issues, we review examples of HE&AS research using administrative data with a focus on scenarios when their use may be advantageous. A checklist is provided to help aid study development in HE&AS using administrative data.

Infect Control Hosp Epidemiol 2016;1–10

Risk factors for Clostridium difficile infection in hemato-oncological patients: A case control study in 144 patients

Evidence on risk factors for Clostridium difficile infection (CDI) in hemato-oncologic patients is conflicting. We studied risk factors for CDI in a large, well-characterized cohort of hemato-oncological patients. 144 hemato-oncological patients were identified in this retrospective, single center study with a microbiologically confirmed CDI-associated diarrhea. Patients were compared with 144 age and sex matched hemato-oncologic patients with CDI negative diarrhea. Risk factors such as prior antimicrobial therapy, type of disease, chemotherapy and survival were evaluated. CDI-positive patients received more frequently any antimicrobial agent and antimicrobial combination therapy than CDI-negative patients (79% vs. 67%; OR = 2.26, p = 0.038 and OR = 2.62, p = 0.003, respectively). CDI positive patients were treated more frequently with antimicrobial agents active against C. difficile than CDI negative ones (25% vs. 13%; OR = 2.2, p = 0.039). The interval between last chemotherapy and onset of diarrhea was significantly shorter in patients without CDI (median, 17 days vs 36 days; p < 0.001). Our study demonstrates that chemotherapy is not a significant risk factor for CDI but for early onset CDI negative diarrhea. The predominant modifiable risk factor for CDI is in hemato-oncological patients antimicrobial treatment. These findings should be taken into account in the daily clinical practice to avoid CDI associated complications and excess health care costs.

Clostridium difficile Infections in Medical Intensive Care Units of a Medical Center in Southern Taiwan: Variable Seasonality and Disease Severity

Critical patients are susceptible to Clostridium difficile infections (CDIs), which cause significant morbidity and mortality in the hospital. In Taiwan, the epidemiology of CDI in intensive care units (ICUs) is not well understood. This study was aimed to describe the incidence and the characteristics of CDI in the ICUs of a medical center in southern Taiwan. Adult patients with diarrhea but without colostomy/colectomy or laxative use were enrolled. Stool samples were collected with or without 5 ml alcohol and were plated on cycloserine-cefoxitin-fructose agar. C. difficile identification was confirmed by polymerase chain reaction. There were 1,551 patients admitted to ICUs, 1,488 screened, and 145 with diarrhea. A total of 75 patients were excluded due either to laxative use, a lack of stool samples, or refusal. Overall, 70 patients were included, and 14 (20%) were diagnosed with CDI, with an incidence of 8.8 cases per 10,000 patient-days. The incidence of CDI was found to be highest in March 2013 and lowest in the last quarter of 2013. The cases were categorized as the following: 5 severe, complicated, 5 severe, and 4 mild or moderate diseases. Among the 14 cases of CDI, the median patient age was 74 (range: 47-94) years, and the median time from admission to diarrhea onset was 16.5 (4-53) days. Eight cases received antimicrobial treatment (primarily metronidazole), and the time to diarrheal resolution was 11.5 days. Though 6 cases were left untreated, no patients died of CDI. The in-hospital mortality of CDI cases was 50%, similar to that of patients without CDI (46.4%; P = 1.0). We concluded that the overall incidence of CDI in our medical ICUs was low and there were variable seasonal incidences and disease severities of CDI.

Antimicrobials: a global alliance for optimizing their rational use in intra-abdominal infections (AGORA)

Intra-abdominal infections (IAI) are an important cause of morbidity and are frequently associated with poor prognosis, particularly in high-risk patients. The cornerstones in the management of complicated IAIs are timely effective source control with appropriate antimicrobial therapy. Empiric antimicrobial therapy is important in the management of intra-abdominal infections and must be broad enough to cover all likely organisms because inappropriate initial antimicrobial therapy is associated with poor patient outcomes and the development of bacterial resistance. The overuse of antimicrobials is widely accepted as a major driver of some emerging infections (such as C. difficile), the selection of resistant pathogens in individual patients, and for the continued development of antimicrobial resistance globally. The growing emergence of multi-drug resistant organisms and the limited development of new agents available to counteract them have caused an impending crisis with alarming implications, especially with regards to Gram-negative bacteria. An international task force from 79 different countries has joined this project by sharing a document on the rational use of antimicrobials for patients with IAIs. The project has been termed AGORA (Antimicrobials: A Global Alliance for Optimizing their Rational Use in Intra-Abdominal Infections). The authors hope that AGORA, involving many of the world's leading experts, can actively raise awareness in health workers and can improve prescribing behavior in treating IAIs.

Intestinal microbiome disruption in patients in a long-term acute care hospital: A case for development of microbiome disruption indices to improve infection prevention

BACKGROUND

Composition and diversity of intestinal microbial communities (microbiota) are generally accepted as a risk factor for poor outcomes; however, we cannot yet use this information to prevent adverse outcomes.

METHODS

Stool was collected from 8 long-term acute care hospital patients experiencing diarrhea and 2 fecal microbiota transplant donors; 16S rDNA V1-V2 hypervariable regions were sequenced. Composition and diversity of each sample were described. Stool was also tested for Clostridium difficile, vancomycin-resistant enterococci (VRE), and carbapenem-resistant Enterobacteriaceae. Associations between microbiota diversity and demographic and clinical characteristics, including antibiotic use, were analyzed.

RESULTS

Antibiotic exposure and Charlson Comorbidity Index were inversely correlated with diversity (Spearman = -0.7). Two patients were positive for VRE; both had microbiomes dominated by Enterococcus faecium, accounting for 67%-84% of their microbiome.

CONCLUSIONS

Antibiotic exposure correlated with diversity; however, other environmental and host factors not easily obtainable in a clinical setting are also known to impact the microbiota. Therefore, direct measurement of microbiome disruption by sequencing, rather than reliance on surrogate markers, might be most predictive of adverse outcomes. If and when microbiome characterization becomes a standard diagnostic test, improving our understanding of microbiome dynamics will allow for interpretation of results to improve patient outcomes.

The Economic Burden of Hospital-Acquired Clostridium difficile Infection: A Population-Based Matched Cohort Study

BACKGROUND High-quality cost estimates for hospital-acquired Clostridium difficile infection (CDI) are vital evidence for healthcare policy and decision-making. OBJECTIVE To evaluate the costs attributable to hospital-acquired CDI from the healthcare payer perspective. METHODS We conducted a population-based propensity-score matched cohort study of incident hospitalized subjects diagnosed with CDI (those with the International Statistical Classification of Diseases and Related Health Problems, 10th Revision, Canada code A04.7) from January 1, 2003, through December 31, 2010, in Ontario, Canada. Infected subjects were matched to uninfected subjects (those without the code A04.7) on age, sex, comorbidities, geography, and other variables, and followed up through December 31, 2011. We stratified results by elective and nonelective admissions. The main study outcomes were up-to-3-year costs, which were evaluated in 2014 Canadian dollars. RESULTS We identified 28,308 infected subjects (mean annual incidence, 27.9 per 100,000 population, 3.3 per 1,000 admissions), with a mean age of 71.5 years (range, 0-107 years), 54.0% female, and 8.0% elective admissions. For elective admission subjects, cumulative mean attributable 1-, 2-, and 3-year costs adjusted for survival (undiscounted) were $32,151 (95% CI, $28,192-$36,005), $34,843 ($29,298-$40,027), and $37,171 ($30,364-$43,415), respectively. For nonelective admission subjects, the corresponding costs were $21,909 ($21,221-$22,609), $26,074 ($25,180-$27,014), and $29,944 ($28,873-$31,086), respectively. CONCLUSIONS Hospital-acquired CDI is associated with substantial healthcare costs. To the best of our knowledge, this study is the first CDI costing study to present longitudinal costs. New strategies may be warranted to mitigate this costly infectious disease. Infect Control Hosp Epidemiol 2016;37:1068-1078.

Clearance of Vancomycin-Resistant Enterococcus Concomitant With Administration of a Microbiota-Based Drug Targeted at Recurrent Clostridium difficile Infection

Background. Vancomycin-resistant Enterococcus (VRE) is a major healthcare-associated pathogen and a well known complication among transplant and immunocompromised patients. We report on stool VRE clearance in a post hoc analysis of the Phase 2 PUNCH CD study assessing a microbiota-based drug for recurrent Clostridium difficile infection (CDI).

Methods. A total of 34 patients enrolled in the PUNCH CD study received 1 or 2 doses of RBX2660 (microbiota suspension). Patients were requested to voluntarily submit stool samples at baseline and at 7, 30, and 60 days and 6 months after the last administration of RBX2660. Stool samples were tested for VRE using bile esculin azide agar with 6 µg/mL vancomycin and Gram staining. Vancomycin resistance was confirmed by Etest.

Results. VRE status (at least 1 test result) was available for 30 patients. All stool samples for 19 patients (63.3%, mean age 61.7 years, 68% female) tested VRE negative. Eleven patients (36.7%, mean age 75.5 years, 64% female) were VRE positive at the first test (baseline or 7-day follow-up). Of these patients, 72.7%, n = 8 converted to negative as of the last available follow-up (30 or 60 days or 6 months). Of the other 3: 1 died (follow-up data not available); 1 patient remained positive at all follow-ups; 1 patient retested positive at 6 months with negative tests during the interim.

Conclusions. Although based on a small sample size, this secondary analysis demonstrated the possibility of successfully converting a high percentage of VRE-positive patients to negative in a recurrent CDI population with RBX2660.

Evaluating the Effectiveness of an Antimicrobial Stewardship Program on Reducing the Incidence Rate of Healthcare-Associated Clostridium difficile Infection: A Non-Randomized, Stepped Wedge, Single-Site, Observational Study

BACKGROUND

The incidence rate of healthcare-associated Clostridium difficile infection (HA-CDI) is estimated at 1 in 100 patients. Antibiotic exposure is the most consistently reported risk factor for HA-CDI. Strategies to reduce the risk of HA-CDI have focused on reducing antibiotic utilization. Prospective audit and feedback is a commonly used antimicrobial stewardship intervention (ASi). The impact of this ASi on risk of HA-CDI is equivocal. This study examines the effectiveness of a prospective audit and feedback ASi on reducing the risk of HA-CDI.

METHODS

Single-site, 339 bed community-hospital in Barrie, Ontario, Canada. Primary outcome is HA-CDI incidence rate. Daily prospective and audit ASi is the exposure variable. ASi implemented across 6 wards in a non-randomized, stepped wedge design. Criteria for ASi; any intravenous antibiotic use for ≥ 48 hrs, any oral fluoroquinolone or oral second generation cephalosporin use for ≥ 48 hrs, or any antimicrobial use for ≥ 5 days. HA-CDI cases and model covariates were aggregated by ward, year and month starting September 2008 and ending February 2016. Multi-level mixed effect negative binomial regression analysis was used to model the primary outcome, with intercept and slope coefficients for ward-level random effects estimated. Other covariates tested for inclusion in the final model were derived from previously published risk factors. Deviance residuals were used to assess the model's goodness-of-fit.

FINDINGS

The dataset included 486 observation periods, of which 350 were control periods and 136 were intervention periods. After accounting for all other model covariates, the estimated overall ASi incidence rate ratio (IRR) was 0.48 (95% 0.30, 0.79). The ASi effect was independent of antimicrobial utilization. The ASi did not seem to reduce the risk of Clostridium difficile infection on the surgery wards (IRR 0.87, 95% CI 0.45, 1.69) compared to the medicine wards (IRR 0.42, 95% CI 0.28, 0.63). The ward-level burden of Clostridium difficile as measured by the ward's previous month's total CDI cases (CDI Lag) and the ward's current month's community-associated CDI cases (CA-CDI) was significantly associated with an increased risk of HA-CDI, with the estimated CDI Lag IRR of 1.21 (95% 1.15, 1.28) and the estimated CA-CDI IRR of 1.10 (95% CI 1.01, 1.20). The ward-level random intercept and slope coefficients were not significant. The final model demonstrated good fit.

CONCLUSIONS

In this study, a daily prospective audit and feedback ASi resulted in a significant reduction in the risk of HA-CDI on the medicine wards, however, this effect was independent of an overall reduction in antibiotic utilization. In addition, the ward-level burden of Clostridium difficile was shown to significantly increase the risk of HA-CDI, reinforcing the importance of the environment as a source of HA-CDI.

The effectiveness and safety of two prophylactic antibiotic regimes in hip-fracture surgery

Antibiotic prophylaxis with cefuroxime can reduce the incidence of deep wound infection (DWI) in hip-fracture surgery, but may increase the risk of C. difficile infection (CDI). An alternative is gentamicin with beta-lactam for which a question exists around clinical effectiveness and safety, given the gentamicin-associated nephrotoxicity particularly in the elderly and narrower sensitivity spectrum. We compared 744 consecutive patients (group I-cefuroxime) with 756 in group II (gentamicin + flucloxacillin) who were well matched. There were 4 cases of CDI in the cefuroxime prophylaxis, whereas none in flucloxacillin plus gentamicin (group II). There was a statistically significant (p = 0.036) increased DWI rate in group II (2.5 %) as compared to group I (1.1 %). However, after controlling for age, gender, ASA grade, surgeon grade, implant type and type of anaesthesia, there was no statistically significant difference between the two groups (p = 0.146). 8.5 % of group I and 16.5 % of group II developed AKI post-operatively (p = 0.023); however, 79 % of group I and 80 % of in group II had complete resolution of AKI prior to their discharge. Further, a significant increase in inpatient deaths (p = 0.057) in group II was observed, but not at 30 days (p = 0.378).

The burden of clostridium difficile infection: estimates of the incidence of CDI from U.S. Administrative databases

BACKGROUND

Many administrative data sources are available to study the epidemiology of infectious diseases, including Clostridium difficile infection (CDI), but few publications have compared CDI event rates across databases using similar methodology. We used comparable methods with multiple administrative databases to compare the incidence of CDI in older and younger persons in the United States.

METHODS

We performed a retrospective study using three longitudinal data sources (Medicare, OptumInsight LabRx, and Healthcare Cost and Utilization Project State Inpatient Database (SID)), and two hospital encounter-level data sources (Nationwide Inpatient Sample (NIS) and Premier Perspective database) to identify CDI in adults aged 18 and older with calculation of CDI incidence rates/100,000 person-years of observation (pyo) and CDI categorization (onset and association).

RESULTS

The incidence of CDI ranged from 66/100,000 in persons under 65 years (LabRx), 383/100,000 in elderly persons (SID), and 677/100,000 in elderly persons (Medicare). Ninety percent of CDI episodes in the LabRx population were characterized as community-onset compared to 41 % in the Medicare population. The majority of CDI episodes in the Medicare and LabRx databases were identified based on only a CDI diagnosis, whereas almost ¾ of encounters coded for CDI in the Premier hospital data were confirmed with a positive test result plus treatment with metronidazole or oral vancomycin. Using only the Medicare inpatient data to calculate encounter-level CDI events resulted in 553 CDI events/100,000 persons, virtually the same as the encounter proportion calculated using the NIS (544/100,000 persons).

CONCLUSIONS

We found that the incidence of CDI was 35 % higher in the Medicare data and fewer episodes were attributed to hospital acquisition when all medical claims were used to identify CDI, compared to only inpatient data lacking information on diagnosis and treatment in the outpatient setting. The incidence of CDI was 10-fold lower and the proportion of community-onset CDI was much higher in the privately insured younger LabRx population compared to the elderly Medicare population. The methods we developed to identify incident CDI can be used by other investigators to study the incidence of other infectious diseases and adverse events using large generalizable administrative datasets.

Comparison of pediatric and adult antibiotic-associated diarrhea and Clostridium difficile infections

Antibiotic-associated diarrhea (AAD) and Clostridum difficile infections (CDI) have been well studied for adult cases, but not as well in the pediatric population. Whether the disease process or response to treatments differs between pediatric and adult patients is an important clinical concern when following global guidelines based largely on adult patients. A systematic review of the literature using databases PubMed (June 3, 1978-2015) was conducted to compare AAD and CDI in pediatric and adult populations and determine significant differences and similarities that might impact clinical decisions. In general, pediatric AAD and CDI have a more rapid onset of symptoms, a shorter duration of disease and fewer CDI complications (required surgeries and extended hospitalizations) than in adults. Children experience more community-associated CDI and are associated with smaller outbreaks than adult cases of CDI. The ribotype NAP1/027/BI is more common in adults than children. Children and adults share some similar risk factors, but adults have more complex risk factor profiles associated with more co-morbidities, types of disruptive factors and a wider range of exposures to C. difficile in the healthcare environment. The treatment of pediatric and adult AAD is similar (discontinuing or switching the inciting antibiotic), but other treatment strategies for AAD have not been established. Pediatric CDI responds better to metronidazole, while adult CDI responds better to vancomycin. Recurrent CDI is not commonly reported for children. Prevention for both pediatric and adult AAD and CDI relies upon integrated infection control programs, antibiotic stewardship and may include the use of adjunctive probiotics. Clinical presentation of pediatric AAD and CDI are different than adult AAD and CDI symptoms. These differences should be taken into account when rating severity of disease and prescribing antibiotics.

Integrating Time-Varying and Ecological Exposures into Multivariate Analyses of Hospital-Acquired Infection Risk Factors: A Review and Demonstration

OBJECTIVES Hospital-acquired infections (HAIs) develop rapidly after brief and transient exposures, and ecological exposures are central to their etiology. However, many studies of HAIs risk do not correctly account for the timing of outcomes relative to exposures, and they ignore ecological factors. We aimed to describe statistical practice in the most cited HAI literature as it relates to these issues, and to demonstrate how to implement models that can be used to account for them. METHODS We conducted a literature search to identify 8 frequently cited articles having primary outcomes that were incident HAIs, were based on individual-level data, and used multivariate statistical methods. Next, using an inpatient cohort of incident Clostridium difficile infection (CDI), we compared 3 valid strategies for assessing risk factors for incident infection: a cohort study with time-fixed exposures, a cohort study with time-varying exposures, and a case-control study with time-varying exposures. RESULTS Of the 8 studies identified in the literature scan, 3 did not adjust for time-at-risk, 6 did not assess the timing of exposures in a time-window prior to outcome ascertainment, 6 did not include ecological covariates, and 6 did not account for the clustering of outcomes in time and space. Our 3 modeling strategies yielded similar risk-factor estimates for CDI risk. CONCLUSIONS Several common statistical methods can be used to augment standard regression methods to improve the identification of HAI risk factors. Infect.

Factors Favouring the Development of Clostridium Difficile Infection in Critically Ill Patients

Clostridium difficile, an anaerobic, spore-forming, toxin-forming, gram-positive bacillus present in the bacterial flora of the colon is the principal cause of nosocomial diarrhoea in adults.

Aim

Assessment of favouring factors of Clostridium difficile infections as well as the interactions between them, in critically ill hospitalized patients undergoing complex medical and surgical treatments.

Material and Methods

A retrospective case-control study involving eighty patients admitted in the Intensive Care Unit (ICU) of the County Clinical Emergency Hospital Tîrgu-Mureş was conducted between January and October 2014. Patients aged eighteen years and over, who had undergone complex medical and surgical treatment, were divided into two subgroups. Group 1 included patients who developed diarrhoea but were not diagnosed as having a Clostridium difficile infection (CDI). Group 2 included patients who developed diarrhoea due to CDI as indicated by a positive culture and the expression of exotoxin. The assessed parameters were age, length of stay (LOS), antibiotic spectrum, association with proton pump inhibitors (PPI) or H2-receptor antagonists, immunological status, the presence or lack of gastrointestinal tract surgery.

Results

The mean age was 64.6 years with an average LOS of 10 days. Fifty-six percent of patients came to the ICU from internal medicine wards and forty-three percent from surgical wards. 20.5% of them were immunosuppressed. Co-association of ceftriaxone and pantoprazole significantly increased the risk of CDI compared to co-administration of any other antibiotic or pantoprazole (p=0.01). The odds ratio for Pantoprazole together with any antibiotic versus antibiotic therapy alone was significantly higher (p=0.018) with a sevenfold increase in the risk of positive exotoxin increase.

Conclusions

Antibiotic use is associated with "no risk to develop CDI" in the first five days of administration. PPIs associated therapy increased the risk of CDI in first seventy-two hours regardless of the antibiotic type, and contributes to an active expression of CD exotoxin.

Identification of Medicare Recipients at Highest Risk for Clostridium difficile Infection in the US by Population Attributable Risk Analysis

Background

Population attributable risk percent (PAR%) is an epidemiological tool that provides an estimate of the percent reduction in total disease burden if that disease could be entirely eliminated among a subpopulation. As such, PAR% is used to efficiently target prevention interventions. Due to significant limitations in current Clostridium difficile Infection (CDI) prevention practices and the development of new approaches to prevent CDI, such as vaccination, we determined the PAR% for CDI in various subpopulations in the Medicare 5% random sample.

Methods

This was a retrospective cohort study using the 2009 Medicare 5% random sample. Comorbidities, infections, and healthcare exposures during the 12 months prior to CDI were identified. CDI incidence and PAR% were calculated for each condition/exposure. Easy to identify subpopulations that could be targeted from prevention interventions were identified based on PAR%.

Findings

There were 1,465,927 Medicare beneficiaries with 9,401 CDI cases for an incidence of 677/100,000 persons. Subpopulations representing less than 15% of the entire population and with a PAR% ≥ 30% were identified. These included deficiency anemia (PAR% = 37.9%), congestive heart failure (PAR% = 30.2%), fluid and electrolyte disorders (PAR% = 29.6%), urinary tract infections (PAR% = 40.5%), pneumonia (PAR% = 35.2%), emergent hospitalization (PAR% = 48.5%) and invasive procedures (PAR% = 38.9%). Stratification by age and hospital exposures indicates hospital exposures are more strongly associated with CDI than age.

Significance

Small and identifiable subpopulations that account for relatively large proportions of CDI cases in the elderly were identified. These data can be used to target specific subpopulations for CDI prevention interventions.

Antibiotic prophylaxis and risk of Clostridium difficile infection after coronary artery bypass graft surgery

OBJECTIVE

Antibiotic use, particularly type and duration, is a crucial modifiable risk factor for Clostridium difficile. Cardiac surgery is of particular interest because prophylactic antibiotics are recommended for 48 hours or less (vs ≤24 hours for noncardiac surgery), with increasing vancomycin use. We aimed to study associations between antibiotic prophylaxis (duration/vancomycin use) and C difficile among patients undergoing coronary artery bypass grafting.

METHODS

We extracted data on coronary artery bypass grafting procedures from the national Premier Perspective claims database (2006-2013, n = 154,200, 233 hospitals). Multilevel multivariable logistic regressions measured associations between (1) duration (<2 days, "standard" vs ≥2 days, "extended") and (2) type of antibiotic used ("cephalosporin," "cephalosporin + vancomycin," "vancomycin") and C difficile as outcome.

RESULTS

Overall C difficile prevalence was 0.21% (n = 329). Most patients (59.7%) received a cephalosporin only; in 33.1% vancomycin was added, whereas 7.2% received vancomycin only. Extended prophylaxis was used in 20.9%. In adjusted analyses, extended prophylaxis (vs standard) was associated with significantly increased C difficile risk (odds ratio, 1.43; confidence interval, 1.07-1.92), whereas no significant associations existed for vancomycin use as adjuvant or primary prophylactic compared with the use of cephalosporins (odds ratio, 1.21; confidence interval, 0.92-1.60, and odds ratio, 1.39; confidence interval, 0.94-2.05, respectively). Substantial inter-hospital variation exists in the percentage of extended antibiotic prophylaxis (interquartile range, 2.5-35.7), use of adjuvant vancomycin (interquartile range, 4.2-61.1), and vancomycin alone (interquartile range, 2.3-10.4).

CONCLUSIONS

Although extended use of antibiotic prophylaxis was associated with increased C difficile risk after coronary artery bypass grafting, vancomycin use was not. The observed hospital variation in antibiotic prophylaxis practices suggests great potential for efforts aimed at standardizing practices that subsequently could reduce C difficile risk.

Clostridium difficile infection in solid organ transplant recipients

PURPOSE OF REVIEW

Clostridium difficile infection (CDI) is one of the most common healthcare-associated infections, and the threat associated with CDI continues to grow in all patient populations. There is increasing evidence that CDI has a substantial impact on the morbidity and mortality in solid organ transplant (SOT) recipients. Furthermore, new diagnostic and treatment options and strategies for CDI have emerged over the last decade. The purpose of this review is to provide a general understanding of CDI and its evidence-based diagnosis and management strategies, with a focus on SOT recipients.

RECENT FINDINGS

The incidence and severity of CDI have significantly increased since the year 2000. Studies have identified novel risk factors for CDI, and a new epidemic strain, the NAP1/BI/027, has emerged. Despite the development of newer testing methods and approaches, including nucleic acid amplification tests and testing algorithms, the optimal method for diagnosing CDI is an area of controversy. New agents for treating CDI are being developed, and the use of fecal microbiota transplantation to treat recurrent CDI in SOT recipients is also evolving.

SUMMARY

CDI is a significant problem for SOT recipients. Further studies on diagnostic and therapeutic strategies with a focus on SOT recipients are needed to further improve patient outcomes.

WSES guidelines for management of Clostridium difficile infection in surgical patients

In the last two decades there have been dramatic changes in the epidemiology of Clostridium difficile infection (CDI), with increases in incidence and severity of disease in many countries worldwide. The incidence of CDI has also increased in surgical patients. Optimization of management of C difficile, has therefore become increasingly urgent. An international multidisciplinary panel of experts prepared evidenced-based World Society of Emergency Surgery (WSES) guidelines for management of CDI in surgical patients.

Clostridium difficile infection in Chilean patients submitted to hematopoietic stem cell transplantation

Introduction

Patients submitted to hematopoietic stem cell transplantation have an increased risk of Clostridium difficile infection and multiple risk factors have been identified. Published reports have indicated an incidence from 9% to 30% of transplant patients however to date there is no information about infection in these patients in Chile.

Methods

A retrospective analysis was performed of patients who developed C. difficile infection after hematopoietic stem cell transplantations from 2000 to 2013. Statistical analysis used the Statistical Package for the Social Sciences software.

Results

Two hundred and fifty patients were studied (mean age: 39 years; range: 17–69), with 147 (59%) receiving allogeneic transplants and 103 (41%) receiving autologous transplants. One hundred and ninety-two (77%) patients had diarrhea, with 25 (10%) cases of C. difficile infection being confirmed. Twenty infected patients had undergone allogeneic transplants, of which ten had acute lymphoblastic leukemia, three had acute myeloid leukemia and seven had other diseases (myelodysplastic syndrome, chronic myeloid leukemia, severe aplastic anemia). In the autologous transplant group, five patients had C. difficile infection; two had multiple myeloma, one had amyloidosis, one had acute myeloid leukemia and one had germinal carcinoma. The overall incidence of C. difficile infection was 4% within the first week, 6.4% in the first month and 10% in one year, with no difference in overall survival between infected and non-infected groups (72.0% vs. 67.6%, respectively; p-value = 0.56). Patients infected after allogeneic transplants had a slower time to neutrophil engraftment compared to non-infected patients (17.5 vs. 14.9 days, respectively; p-value = 0.008). In the autologous transplant group there was no significant difference in the neutrophil engraftment time between infected and non-infected patients (12.5 days vs. 11.8 days, respectively; p-value = 0.71). In the allogeneic transplant group, the median time to acute graft-versus-host disease was similar between the two groups (p-value = 0.08), as was the incidence of grades 1–4 acute graft-versus-host disease (40% vs. 48%; p-value >0.05).

Conclusion

The incidence of C. difficile infection after hematopoietic stem cell transplantation was low, with a significant number of cases occurring shortly after transplantation. Allogeneic transplants had a three-time higher risk of infection compared to autologous transplants, but this was not associated with increased mortality, decreased overall survival or higher risk of acute graft-versus-host disease.

Ceftolozane-tazobactam activity against phylogenetically diverse Clostridium difficile strains

Ceftolozane-tazobactam (C/T) is approved for the treatment of complicated intra-abdominal and urinary tract infections and has varied activity against anaerobic bacteria. Here, we evaluate the activity of C/T against a phylogenetically diverse collection of Clostridium difficile isolates and report uniformly high MICs (≥256 μg/ml) to C/T.

Exposure to Gastric Acid-Suppression Therapy Is Associated With Health Care- and Community-Associated Clostridium difficile Infection in Children

OBJECTIVE

The aim of the study was to determine whether gastric acid-suppression therapy is associated with Clostridium difficile infection (CDI) in both inpatient and outpatient pediatric populations.

METHODS

We conducted a retrospective case-control study at a 200-bed academic pediatric hospital and associated outpatient clinics during 2005-2010. We defined cases as children 1 to 18 years of age with a first positive test for C difficile toxin A/B, and matched each case to 2 controls without C difficile. We conducted chart review to elicit selected comorbidities and exposure to gastric acid-suppression therapy and antibiotics in the preceding 3 months of the infection or encounter date. We used bivariate and multivariable logistic regression to evaluate the association between antacid use and CDI, controlling for potential confounders.

RESULTS

We identified 138 children with health care- or community-associated CDIs and 276 controls. The use of any acid suppression therapy was more common in cases compared with controls (34% vs 20%, P = 0.002). When adjusted for demographic variables and comorbidities, gastric acid-suppression therapy remained significantly associated with CDI (adjusted odds ratio [aOR] 1.8, 95% confidence interval [CI] 1.0-3.1). Antibiotic use (aOR 1.7, 95% CI 1.1-2.7) and immunosuppressed state were also associated with CDI in our adjusted model (aOR 2.5, 95% CI 1.2-5.2).

CONCLUSIONS

Gastric acid-suppression therapy was associated with both health care- and community-associated CDIs in children. Larger pediatric studies are necessary to determine the role of proton pump inhibitors specifically in causing CDI in children.

Effects of fluoroquinolone restriction (from 2007 to 2012) on Clostridium difficile infections: interrupted time-series analysis

BACKGROUND

Antimicrobial stewardship is a key component in the reduction of healthcare-associated infections, particularly Clostridium difficile infection (CDI). We successfully restricted the use of cephalosporins and, subsequently, fluoroquinolones. From an endemically high level of >280 cases per year in 2007-08, the number of CDIs reduced to 72 cases in 2011-12.

AIM

To describe the implementation and impact of fluoroquinolone restriction on CDI.

METHODS

This was an interrupted time-series analysis pre and post fluoroquinolone restriction for 60 months based on a Poisson distribution model.

FINDINGS

In June 2008, fluoroquinolone consumption halved to about 5 defined daily doses (DDD) per 100 occupied bed-days (OBD). This was followed by a significant fall in CDI number [rate ratio (RR): 0.332; 95% confidence interval (CI): 0.240-0.460] which remained low over the subsequent months. Subsequently, fluoroquinolone consumption was further reduced to about 2 DDD/100 OBD in June 2010 accompanied by further reduction in CDI rate (RR: 0.394; 95% CI: 0.199-0.781). In a univariate Poisson model the CDI rate was associated with fluoroquinolone usage (RR: 1.086; 95% CI: 1.077-1.094).

CONCLUSION

We conclude that in an environment where cephalosporin usage is already low, the reduction in fluoroquinolone usage was associated with an immediate, large, and significant reduction in CDI cases.

Burden of Clostridium difficile infection between 2010 and 2013: Trends and outcomes from an academic center in Eastern Europe

AIM

To analyze the incidence and possible risk factors in hospitalized patients treated with Clostridium difficile infection (CDI).

METHODS

A total of 11751 patients were admitted to our clinic between 1 January 2010 and 1 May 2013. Two hundred and forty-seven inpatients were prospectively diagnosed with CDI. For the risk analysis a 1:3 matching was used. Data of 732 patients matched for age, sex, and inpatient care period and unit were compared to those of the CDI population. Inpatient records were collected from an electronic hospital database and comprehensively reviewed.

RESULTS

Incidence of CDI was 21.0/1000 admissions (2.1% of all-cause hospitalizations and 4.45% of total inpatient days). The incidence of severe CDI was 12.6% (2.63/1000 of all-cause hospitalizations). Distribution of CDI cases was different according to the unit type, with highest incidence rates in hematology, gastroenterology and nephrology units (32.9, 25 and 24.6/1000 admissions, respectively) and lowest rates in 1.4% (33/2312) in endocrinology and general internal medicine (14.2 and 16.9/1000 admissions) units. Recurrence of CDI was 11.3% within 12 wk after discharge. Duration of hospital stay was longer in patients with CDI compared to controls (17.6 ± 10.8 d vs 12.4 ± 7.71 d). CDI accounted for 6.3% of all-inpatient deaths, and 30-d mortality rate was 21.9% (54/247 cases). Risk factors for CDI were antibiotic therapy [including third-generation cephalosporins or fluoroquinolones, odds ratio (OR) = 4.559; P < 0.001], use of proton pump inhibitors (OR = 2.082, P < 0.001), previous hospitalization within 12 mo (OR = 3.167, P < 0.001), previous CDI (OR = 15.32; P < 0.001), while presence of diabetes mellitus was associated with a decreased risk for CDI (OR = 0.484; P < 0.001). Treatment of recurrent cases was significantly different from primary infections with more frequent use of vancomycin alone or in combination (P < 0.001), and antibiotic therapy duration was longer (P < 0.02). Severity, mortality and outcome of primary infections and relapsing cases did not significantly differ.

CONCLUSION

CDI was accounted for significant burden with longer hospitalization and adverse outcomes. Antibiotic, PPI therapy and previous hospitalization or CDI were risk factors for CDI.

Risk Factors for Acquisition and Loss of Clostridium difficile Colonization in Hospitalized Patients

Asymptomatic colonization may contribute to Clostridium difficile transmission. Few data identify which patients are at risk for colonization. We performed a prospective cohort study of C. difficile colonization and risk factors for C. difficile acquisition and loss in hospitalized patients. Patients admitted to medical or surgical wards at a tertiary care hospital were enrolled; interviews and chart review were performed to determine patient demographics, C. difficile infection (CDI) history, medications, and health care exposures. Stool samples/rectal swabs were collected at enrollment and discharge; stool samples from clinical laboratory tests were also included. Samples were cultured for C. difficile, and the isolates were tested for toxins A and B and ribotyped. Chi-square tests and univariate logistic regression were used for the analyses. Two hundred thirty-five patients were enrolled. Of the patients, 21% were colonized with C. difficile (toxigenic and nontoxigenic) at admission and 24% at discharge. Ribotype 027 accounted for 6% of the strains at admission and 12% at discharge. Of the patients colonized at admission, 78% were also colonized at discharge. Cephalosporin use was associated with C. difficile acquisition (47% of patients who acquired C. difficile versus 25% of patients who did not; P = 0.03). β-lactam-β-lactamase inhibitor combinations were associated with a loss of C. difficile colonization (36% of patients who lost C. difficile colonization versus 8% of patients colonized at both admission and discharge; P = 0.04), as was metronidazole (27% versus 3%; P = 0.03). Antibiotic use affects the epidemiology of asymptomatic C. difficile colonization, including acquisition and loss, and it requires additional study.

Identification of patients at high risk for Clostridium difficile infection: development and validation of a risk prediction model in hospitalized patients treated with antibiotics

To develop and validate a prediction model for Clostridium difficile infection (CDI) in hospitalized patients treated with systemic antibiotics, we performed a case-cohort study in a tertiary (derivation) and secondary care hospital (validation). Cases had a positive Clostridium test and were treated with systemic antibiotics before suspicion of CDI. Controls were randomly selected from hospitalized patients treated with systemic antibiotics. Potential predictors were selected from the literature. Logistic regression was used to derive the model. Discrimination and calibration of the model were tested in internal and external validation. A total of 180 cases and 330 controls were included for derivation. Age >65 years, recent hospitalization, CDI history, malignancy, chronic renal failure, use of immunosuppressants, receipt of antibiotics before admission, nonsurgical admission, admission to the intensive care unit, gastric tube feeding, treatment with cephalosporins and presence of an underlying infection were independent predictors of CDI. The area under the receiver operating characteristic curve of the model in the derivation cohort was 0.84 (95% confidence interval 0.80-0.87), and was reduced to 0.81 after internal validation. In external validation, consisting of 97 cases and 417 controls, the model area under the curve was 0.81 (95% confidence interval 0.77-0.85) and model calibration was adequate (Brier score 0.004). A simplified risk score was derived. Using a cutoff of 7 points, the positive predictive value, sensitivity and specificity were 1.0%, 72% and 73%, respectively. In conclusion, a risk prediction model was developed and validated, with good discrimination and calibration, that can be used to target preventive interventions in patients with increased risk of CDI.

Fecal microbiota transplantation (FMT) for Clostridium difficile infection: focus on immunocompromised patients

Clostridium difficile infection (CDI) is an emerging problem worldwide associated with significant morbidity, mortality, recurrence rates and healthcare costs. Immunosuppressed patients, including HIV-seropositive individuals, solid organ transplant recipients, patients with malignancies, hematopoietic stem cell transplant recipients, and patients with inflammatory bowel disease are increasingly recognized as being at higher risk of developing CDI where it may be associated with significant complications, recurrence, and mortality. Fecal microbiota transplantation (FMT) has proven to be an effective and safe procedure for the treatment of recurrent or refractory CDI in immunocompetent patients by restoring the gut microbiota and resistance to further recurrences. During the last two years the first data on FMT in immunocompromised patients began to appear in the medical literature. Herein we summarize the use of FMT for the treatment of CDI with a focus on immunocompromised patients.

Strategies to prevent Clostridium difficile infections in acute care hospitals: 2014 update

Previously published guidelines are available that provide comprehensive recommendations for detecting and preventing healthcare-associated infections (HAIs). The intent of this document is to highlight practical recommendations in a concise format designed to assist acute care hospitals in implementing and prioritizing their Clostridium difficile infection (CDI) prevention efforts. This document updates “Strategies to Prevent Clostridium difficile Infections in Acute Care Hospitals,” published in 2008. This expert guidance document is sponsored by the Society for Healthcare Epidemiology of America (SHEA) and is the product of a collaborative effort led by SHEA, the Infectious Diseases Society of America (IDSA), the American Hospital Association (AHA), the Association for Professionals in Infection Control and Epidemiology (APIC), and The Joint Commission, with major contributions from representatives of a number of organizations and societies with content expertise. The list of endorsing and supporting organizations is presented in the introduction to the 2014 updates.

Outcomes of Clostridium difficile infection in hospitalized leukemia patients: a nationwide analysis

BACKGROUND The incidence of Clostridium difficile infection (CDI) has increased among hospitalized patients and is a common complication of leukemia. We investigated the risks for and outcomes of CDI in hospitalized leukemia patients. METHODS Adults with a primary diagnosis of leukemia were extracted from the United States Nationwide Inpatient Sample database, 2005-2011. The primary outcomes of interest were CDI incidence, CDI-associated mortality, length of stay (LOS), and charges. In a secondary analysis, we sought to identify independent risk factors for CDI in leukemia patients. Logistic regression was used to derive odds ratios (ORs) adjusted for potential confounders. RESULTS A total of 1,243,107 leukemia hospitalizations were identified. Overall CDI incidence was 3.4% and increased from 3.0% to 3.5% during the 7-year study period. Leukemia patients had 2.6-fold higher risk for CDI than non-leukemia patients, adjusted for LOS. CDI was associated with a 20% increase in mortality of leukemia patients, as well as 2.6 times prolonged LOS and higher hospital charges. Multivariate analysis revealed that age >65 years (OR, 1.13), male gender (OR, 1.14), prolonged LOS, admission to teaching hospital (OR, 1.16), complications of sepsis (OR, 1.83), neutropenia (OR, 1.35), renal failure (OR, 1.18), and bone marrow or stem cell transplantation (OR, 1.27) were significantly associated with CDI occurrence. CONCLUSIONS Hospitalized leukemia patients have greater than twice the risk of CDI than non-leukemia patients. The incidence of CDI in this population increased 16.7% from 2005 to 2011. Development of CDI in leukemia patients was associated with increased mortality, longer LOS, and higher hospital charges.

Clostridium difficile in the Long-Term Care Facility: Prevention and Management

Residents of long-term care facilities are at high risk for Clostridium difficile infection due to frequent antibiotic exposure in a population already rendered vulnerable to infection due to advanced age, multiple comorbid conditions and communal living conditions. Moreover, asymptomatic carriage of toxigenic C. difficile and recurrent infections are prevalent in this population. Here, we discuss epidemiology and management of C. difficile infection among residents of long-term care facilities. Also, recognizing that both the population and culture differs significantly from that of hospitals, we also address prevention strategies specific to LTCFs.

Is Clostridium difficile infection an increasingly common severe disease in adult intensive care units? A 10-year experience

PURPOSE

Despite the high concentration of patients with known risk factors for Clostridium difficile infection (CDI) in intensive care units (ICUs), data on ICU patients are scarce. The aim of this study was describe the incidence, clinical characteristics, and evolution of CDI in critically ill patients.

MATERIALS AND METHODS

From 2003 to 2012, adult patients admitted to an ICU (A-ICU) and positive for CDI were included and classified as follows: pre-ICU, if the positive sample was obtained within ±3 days of ICU admission; in-ICU, if obtained after 3 days of ICU admission and up to 3 days after ICU discharge.

RESULTS

We recorded 4095 CDI episodes, of which 328 were A-ICU (8%). Episodes of A-ICU decreased from 19.4 to 8.7 per 10000 ICU days of stay (P < .0001). Most A-ICU CDIs (66.3%) were mild to moderate. Pre-ICU episodes accounted for 16.2% and were more severe complicated than in-ICU episodes (11% vs 0%; P = .020). Overall mortality was 28.6%, and CDI-attributable mortality was only 3%.

CONCLUSION

The incidence of A-ICU CDI has decreased steadily over the last 10 years. A significant proportion of A-ICU CDI episodes are pre-ICU and are more severe than in-ICU CDI episodes. Most episodes of A-ICU CDI were nonsevere, with low associated mortality.

The association of antibiotic treatment regimen and hospital mortality in patients hospitalized with Legionella pneumonia

BACKGROUND

Guidelines recommend azithromycin or a quinolone antibiotic for treatment of Legionella pneumonia. No clinical study has compared these strategies.

METHODS

We performed a retrospective cohort analysis of adults hospitalized in the United States with a diagnosis of Legionella pneumonia in the Premier Perspectives database (1 July 2008-30 June 2013). Our primary outcome was hospital mortality; we additionally evaluated hospital length of stay, development of Clostridium difficile colitis, and total hospital cost. We used propensity-based matching to compare patients treated with azithromycin vs a quinolone. All analyses were repeated on a subgroup of more severely ill patients, defined as requiring intensive care unit admission or mechanical ventilation or having a predicted probability of hospital mortality in the top quartile for all patients.

RESULTS

Legionella pneumonia was diagnosed in 3152 adults across 437 hospitals. Quinolones alone were used in 28.8%, azithromycin alone was used in 34.0%, and 1.8% received both. Crude hospital mortality was similar: 6.6% (95% confidence interval [CI], 5.0%-8.2%) for quinolones vs 6.4% (95% CI, 5.0%-7.9%) for azithromycin (P = .87); after propensity matching (n = 813 in each group), mortality remained similar (6.3% [95% CI, 4.6%-7.9%] vs 6.5% [95% CI, 4.8%-8.2%], P = .84 for the whole cohort, and 14.9% [95% CI, 10.0%-19.8%] vs 18.3% [95% CI, 13.0%-23.6%], P = .36 for the more severely ill). There was no difference in hospital length of stay, development of C. difficile, or total hospital cost.

CONCLUSIONS

Use of azithromycin alone or a quinolone alone for treatment of Legionella pneumonia was associated with similar hospital mortality. Few patients receive combination therapy.

Potential role of post-transplant hypogammaglobulinemia in the risk of Clostridium difficile infection after kidney transplantation: a case-control study

PURPOSE

To identify reversible risk factors for Clostridium difficile infection (CDI) after kidney transplantation (KT) that could lead to a reduction in its incidence and associated complications.

METHODS

We performed a single-center case-control study in which 41 patients undergoing KT between February 2009 and July 2013 who developed a first episode of post-transplant CDI were included as cases. Patients transplanted at the same calendar day (± 2 weeks) as each case with no evidence of CDI and comparable risk exposure period were chosen as controls (2:1 ratio). Serum immunoglobulin and complement levels were systematically measured at baseline and months 1 and 6 after transplantation.

RESULTS

Multivariate regression analysis identified age-adjusted Charlson comorbidity index (odds ratio [OR] per unitary increment 1.31; P value = 0.043), delayed graft function (OR 2.76; P value = 0.039), prior cytomegalovirus (CMV) disease (OR 6.85; P value = 0.011) and prior acute graft rejection (OR 5.92; P value = 0.008) as risk factors for post-transplant CDI. Cases with their first episode of CDI occurring beyond the first month were more likely to have IgG hypogammaglobulinemia (HGG) at month 1 (P value = 0.002), whereas cases with CDI beyond the sixth month were more likely to have HGG of any class at month 6 (P value = 0.003). Poor outcome (graft loss and/or all-cause mortality) was more common among cases (adjusted hazard ratio 5.69; P value = 0.001).

CONCLUSION

The occurrence of CDI exerts a detrimental effect on graft and patient outcome. Post-transplant HGG was a potentially modifiable risk factor for CDI in KT recipients.

Risk of Clostridium difficile infection in intensive care unit patients with sepsis exposed to metronidazole

BACKGROUND

Antimicrobial agents used to treat Clostridium difficile infection (CDI), such as metronidazole and vancomycin, have been used during antibiotic treatment of other infections to try to prevent the development of CDI. We evaluated the hypothesis that intensive care unit (ICU) patients who receive metronidazole as part of an antibiotic treatment regimen for sepsis have a lower risk of subsequently developing CDI.

METHODS

This was a nested case-control study in a cohort of ICU patients who received antibiotic therapy for sepsis.

RESULTS

A total of 10 012 patients aged ≥ 18 years were admitted to the Cooper University Hospital medical/surgical ICU from 1/1/2003 to 12/31/2008. After applying inclusion criteria including having received antibiotic therapy for sepsis and subsequently having developed CDI, 67 cases were identified. The cases were matched for age, gender, date of ICU admission, and hospital length of stay to 67 controls that also received antibiotic therapy for sepsis but did not subsequently develop CDI. In the multivariate analysis, there was no association between metronidazole exposure and the risk of CDI (odds ratio (OR) = 0.57; p = 0.23). The only significant associations on multivariate analysis were antifungal therapy (OR = 0.30; p = 0.02) and aminoglycoside and/or colistin therapy (OR = 0.17; p = 0.02).

CONCLUSIONS

No association was found between metronidazole use and subsequent CDI in ICU patients who received antibiotic therapy for sepsis.

Epidemiological Patterns and Hospital Characteristics Associated with Increased Incidence ofClostridium difficileInfection in Quebec, Canada, 1998–2006

Objective.

To explore epidemiological patterns of the incidence ofClostridium difficileinfection (CDI) and hospital characteristics associated with increased incidence during nonepidemic and epidemic years.

Design.

Retrospective and prospective ecological study.

Setting.

Eighty-three acute care hospitals participating in CDI surveillance in the province of Quebec, Canada.

Methods.

A Serfling-type regression model applied to data obtained from an administrative database (1998-2006) and prospective Quebec CDI surveillance (2004-2006) was used to calculate expected CDI baseline incidence and to detect incidence exceeding the defined epidemic threshold at the provincial and hospital level. Multivariable Poisson regression was used to determine hospital characteristics associated with increased incidence during nonepidemic (1998-2001) and epidemic (2003-2005) periods.

Results.

During the study period (1998-2006), 4,525,847 discharges, including 45,508 with a CDI in any diagnosis field, were reported by 83 hospitals. During 1998-2001, the average Quebec incidence of CDI was 10,304 cases in 1,775,822 discharges (5.8 cases per 1,000 discharges) and presented a pattern of seasonality, with similar patterns at the hospital level for some hospitals. The Quebec epidemic started in October-November 2002 and peaked in March 2004 at 845 cases in 40,852 discharges (20.7 cases per 1,000 discharges). In multivariable analysis, higher incidence was associated with location in Montreal and surrounding regions, greater hospital size, larger proportion of hospitalized elderly patients, longer length of stay, and greater proportion of comorbidities in patients, whereas teaching profile was associated with decreased incidence during both nonepidemic and epidemic periods. The effect of geographical location on incidence was greater during the epidemic.

Conclusion.

Baseline incidence from nonepidemic years and hospital characteristics associated with CDI incidence should be taken into account when estimating the efficacy of interventions.

Infections After High-Dose Chemotherapy and Autologous Hematopoietic Stem Cell Transplantation

Infection represents an important cause of morbidity after autologous hematopoietic stem cell transplantation (HSCT). Immunodeficiency is the key risk factor and results from interplay between the underlying disease and its therapy. Various defects in the immune system coexist in HSCT recipients. In the early post-transplant period, neutropenia, oral and gastrointestinal mucositis, and the presence of central venous catheters are the main risk factors. Bacterial infections predominate, and the agents and antibiotic susceptibility profiles vary widely in different regions. Invasive candidiasis is infrequent with fluconazole use, but the incidence of invasive aspergillosis is on the rise, mainly in patients receiving purine analogues or intensive chemotherapy before transplant. In the post-engraftment period, infections are less frequent, but may contribute to significant non-relapse mortality. The dynamics of immune reconstitution drives the risk for infection in this period. The most frequent infections are varicella-zoster virus disease and respiratory tract infections. Assessment of the risk of infection in each period and the identification of patients at higher risk of specific infections are critical to the appropriate management of infectious complications after autologous hematopoietic stem cell transplantation.

Predicting the risk of Clostridium difficile infection following an outpatient visit: development and external validation of a pragmatic, prognostic risk score

Increasing morbidity related to Clostridium difficile infection (CDI) has heightened interest in the identification of patients who would most benefit from recognition of risk and intervention. We sought to develop and validate a prognostic risk score to predict CDI risk for individual patients following an outpatient healthcare visit. We assembled a cohort of Kaiser Permanente Northwest (KPNW) patients with an index outpatient visit between 2005 and 2008, and identified CDI in the year following that visit. Applying Cox regression, we synthesized a priori predictors into a CDI risk score, which we validated among a Kaiser Permanente Colorado (KPCO) cohort. We calculated and plotted the observed 1-year CDI risk for each decile of predicted risk for both cohorts. Among 356 920 KPNW patients, 608 experienced CDI, giving a 1-year incidence of 2.2 CDIs per 1000 patients. The Cox model differentiated between patients who do and do not develop CDI: there was a C-statistic of 0.83 for KPNW. The simpler points-based risk score, derived from the Cox model, was validated successfully among 296 550 KPCO patients, with no decline in the area under the receiver operating characteristic curve: 0.785 (KPNW) vs. 0.790 (KPCO). The predicted risk for CDI agreed closely with the observed risk. Our CDI risk score utilized data collected during usual care to successfully identify patients who developed CDI, discriminating them from patients at the lowest risk for CDI. Our prognostic CDI risk score provides a decision-making tool for clinicians in the outpatient setting.

Infection control in the intensive care unit

It is critical for health care personnel to recognize and appreciate the detrimental impact of intensive care unit (ICU)-acquired infections. The economic, clinical, and social expenses to patients and hospitals are overwhelming. To limit the incidence of ICU-acquired infections, aggressive infection control measures must be implemented and enforced. Researchers and national committees have developed and continue to develop evidence-based guidelines to control ICU infections. A multifaceted approach, including infection prevention committees, antimicrobial stewardship programs, daily reassessments-intervention bundles, identifying and minimizing risk factors, and continuing staff education programs, is essential. Infection control in the ICU is an evolving area of critical care research.

Phenotypic and genotypic analysis of Clostridium difficile isolates: a single-center study

Clostridium difficile infections (CDI) are a growing concern in North America, because of their increasing incidence and severity. Using integrated approaches, we correlated pathogen genotypes and host clinical characteristics for 46 C. difficile infections in a tertiary care medical center during a 6-month interval from January to June 2010. Multilocus sequence typing (MLST) demonstrated 21 known and 2 novel sequence types (STs), suggesting that the institution's C. difficile strains are genetically diverse. ST-1 (which corresponds to pulsed-field gel electrophoresis strain type NAP1/ribotype 027) was the most prevalent (32.6%); 43.5% of the isolates were binary toxin gene positive, of which 75% were ST-1. All strains were ciprofloxacin resistant and metronidazole susceptible, and 8.3% and 13.0% of the isolates were resistant to clindamycin and tetracycline, respectively. The corresponding resistance loci, including potential novel mutations, were identified from the whole-genome sequencing (WGS) of the resistant strains. Core genome single nucleotide polymorphisms (SNPs) determining the phylogenetic relatedness of the 46 strains recapitulated MLST types and provided greater interstrain differentiation. The disease severity was greatest in patients infected with ST-1 and/or binary gene-positive strains, but genome-wide SNP analysis failed to provide additional associations with CDI severity within the same STs. We conclude that MLST and core genome SNP typing result in the same phylogenetic grouping of the 46 C. difficile strains collected in a single hospital. WGS also has the capacity to differentiate those strains within STs and allows the comparison of strains at the individual gene level and at the whole-genome level.

Hospital roommates and development of health care-onset Clostridium difficile infection

There is potential for person-to-person transmission in Clostridium difficile outbreak settings. A limited number of studies have examined the role of hospital roommates in the development of nosocomial infections. This retrospective cohort study evaluated room cooccupancy and duration of exposure to roommates as predictors of health care-onset C difficile infection (CDI). Among roommates of patients with CDI, duration of room cooccupancy was significantly longer in those developing CDI.

Recombination drives evolution of the Clostridium difficile 16S-23S rRNA intergenic spacer region

PCR-ribotyping, a typing method based on size variation in 16S-23S rRNA intergenic spacer region (ISR), has been used widely for molecular epidemiological investigations of C. difficile infections. In the present study, we describe the sequence diversity of ISRs from 43 C. difficile strains, representing different PCR-ribotypes and suggest homologous recombination as a possible mechanism driving the evolution of 16S-23S rRNA ISRs. ISRs of 45 different lengths (ranging from 185 bp to 564 bp) were found among 458 ISRs. All ISRs could be described with one of the 22 different structural groups defined by the presence or absence of different sequence modules; tRNAAla genes and different combinations of spacers of different lengths (33 bp, 53 bp or 20 bp) and 9 bp direct repeats separating the spacers. The ISR structural group, in most cases, coincided with the sequence length. ISRs that were of the same lengths had also very similar nucleotide sequence, suggesting that ISRs were not suitable for discriminating between different strains based only on the ISR sequence. Despite large variations in the length, the alignment of ISR sequences, based on the primary sequence and secondary structure information, revealed many conserved regions which were mainly involved in maturation of pre-rRNA. Phylogenetic analysis of the ISR alignment yielded strong evidence for intra- and inter-homologous recombination which could be one of the mechanisms driving the evolution of C. difficile 16S-23S ISRs. The modular structure of the ISR, the high sequence similarities of ISRs of the same sizes and the presence of homologous recombination also suggest that different copies of C. difficile 16S-23S rRNA ISR are evolving in concert.