A large outbreak of Clostridium difficile-associated disease with an unexpected proportion of deaths and colectomies at a teaching hospital following increased fluoroquinolone use

Nosocomial Clostridium difficile-associated diarrhoea in Assiut University Children's Hospital, Egypt

BACKGROUND

There are no large epidemiological studies of Clostridium difficile-associated disease (CDAD) in hospitalised children.

AIM

To describe the frequency, demography, clinical features and outcome of nosocomial CDAD in children admitted to Assiut University Children's Hospital, Egypt.

PATIENTS AND METHODS

In this descriptive cross-sectional study, 72 children developed nosocomial diarrhoea between April 2010 and March 2011. A medical history, clinical assessment and culture for Clostridium difficile and direct toxin detection from stool samples by enzyme immuno-assay were undertaken in all patients.

RESULTS

CDAD was diagnosed in 17 (23·6%) patients. Those aged ≤12 months were the most commonly affected (eight, 47%). The main cause of admission was respiratory disorders (eight, 47% of cases), followed by surgical problems (three, 17·7%). Ten patients (58·8%) had severe symptoms. There were no statistically significant differences between any of the demographic or laboratory data for children with CDAD and children with other causes of nosocomial diarrhoea. None of the patients developed complications. Seven children with CDAD (41·2%) had recurrence.

CONCLUSION

CDAD is an important cause of nosocomial diarrhoea in children in Assiut University Children's Hospital. Established guidelines should be followed in all hospitals to minimise exposure to the pathogen. Physicians can do much to reduce the risk of a severe outcome in children by early identification and rapid management. Further research should be undertaken to identify the risk factors for recurrence.

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.

Novel approaches to treating Clostridium difficile-associated colitis

Clostridium difficile is being recognized as a growing threat to many health-care systems. Epidemiology data shows that infection rates are soaring and the disease burden is increasing. Despite the efficacy of standard treatments, it is becoming evident that novel therapeutics will be required to tackle this disease. These new treatments aim to enhance the intestinal microbial barrier, activate the immune system and neutralize the toxins that mediate this disease. Many of these therapies are still in the beginning stages of investigation, however, in the next few years, more clinical data will become available to help implement many of these exciting new therapeutic approaches.

Infection Prevention and Control Issues After Solid Organ Transplantation

Infections are an important cause of morbidity and mortality in solid organ transplant recipients. Consequently, infection prevention is an essential component of any organ transplant program. Given their frequent and often prolonged contact with the healthcare system, solid organ transplant recipients are at high risk for healthcare-associated infections, including those caused by antibiotic-resistant organisms. In this chapter we review several different healthcare-associated infections of importance to transplant recipients, including those caused by bacterial, viral, and fungal organisms. We also describe infection prevention and control strategies applicable to this patient population. These practices focus on clinical interventions and environmental controls designed to prevent the spread of potentially pathogenic organisms in the healthcare setting. We also describe post-exposure interventions applicable to solid organ transplant recipients exposed to potential pathogens in order to reduce their risk of subsequent infection.

Memory B Cells Encode Neutralizing Antibody Specific for Toxin B from the Clostridium difficile Strains VPI 10463 and NAP1/BI/027 but with Superior Neutralization of VPI 10463 Toxin B

Secreted toxin B (TcdB) substantially contributes to the pathology observed during Clostridium difficile infection. To be successfully incorporated into a vaccine, TcdB-based immunogens must stimulate the production of neutralizing antibody (Ab)-encoding memory B cells (Bmem cells). Despite numerous investigations, a clear analysis of Bmem cellular responses following vaccination against TcdB is lacking. B6 mice were therefore used to test the ability of a nontoxigenic C-terminal domain (CTD) fragment of TcdB to induce Bmem cells that encode TcdB-neutralizing antibody. CTD was produced from the historical VPI 10463 strain (CTD1) and from the hypervirulent strain NAP1/BI/027 (CTD2). It was then demonstrated that CTD1 induced strong recall IgG antibody titers, and this led to the development of functional Bmem cells that could be adoptively transferred to naive recipients. Bmem cell-driven neutralizing Ab responses conferred protection against lethal challenge with TcdB1. Further experiments revealed that an experimental adjuvant (Imject) and a clinical adjuvant (Alhydrogel) were compatible with Bmem cell induction. Reactivity of human Bmem cells to CTD1 was also evident in human peripheral blood mononuclear cells (PBMCs), suggesting that CTD1 could be a good vaccine immunogen. However, CTD2 induced strong Bmem cell-driven antibody titers, and the CTD2 antibody was neutralizing in vitro, but its protection against lethal challenge with TcdB2 was limited to delaying time to death. Therefore, CTD from different C. difficile strains may be a good immunogen for stimulating B cell memory that encodes in vitro neutralizing Ab but may be limited by variable protection against intoxication in vivo.

Gut Dysbiosis in Patients with Anorexia Nervosa

Anorexia nervosa (AN) is a psychological illness with devastating physical consequences; however, its pathophysiological mechanism remains unclear. Because numerous reports have indicated the importance of gut microbiota in the regulation of weight gain, it is reasonable to speculate that AN patients might have a microbial imbalance, i.e. dysbiosis, in their gut. In this study, we compared the fecal microbiota of female patients with AN (n = 25), including restrictive (ANR, n = 14) and binge-eating (ANBP, n = 11) subtypes, with those of age-matched healthy female controls (n = 21) using the Yakult Intestinal Flora-SCAN based on 16S or 23S rRNA–targeted RT–quantitative PCR technology. AN patients had significantly lower amounts of total bacteria and obligate anaerobes including those from the Clostridium coccoides group, Clostridium leptum subgroup, and Bacteroides fragilis group than the age-matched healthy women. Lower numbers of Streptococcus were also found in the AN group than in the control group. In the analysis based on AN subtypes, the counts of the Bacteroides fragilis group in the ANR and ANBP groups and the counts of the Clostridium coccoides group in the ANR group were significantly lower than those in the control group. The detection rate of the Lactobacillus plantarum subgroup was significantly lower in the AN group than in the control group. The AN group had significantly lower acetic and propionic acid concentrations in the feces than the control group. Moreover, the subtype analysis showed that the fecal concentrations of acetic acid were lower in the ANR group than in the control group. Principal component analysis confirmed a clear difference in the bacterial components between the AN patients and healthy women. Collectively, these results clearly indicate the existence of dysbiosis in the gut of AN patients.

Spectrum of Clostridium difficile infections: Particular clinical situations

Incidence, pathogenesis, diagnostic techniques and therapeutic management of CDI have prompted abundant and adequate recent literature. However, report on clinical manifestations of CDI is frequently biased by the type of patients selected, the retrospective nature of many papers, the epidemic or endemic characteristics of the population reported. This article seeks to review some less discussed clinical and epidemiological aspects of CDI trying to include the clinical manifestations of this disease in unselected populations and also including discussion of CDI in specific groups of patients such as patients without colon and rectum, pediatric and critical care patients.

Association of Clostridium difficile infection in hospital mortality: A systematic review and meta-analysis

BACKGROUND

The purpose of this study was to evaluate whether Clostridium difficile infection (CDI) contributed to hospital mortality and whether the correlation between intensive care units (ICUs) and surgical wards in hospital CDI risk still remain controversial.

METHODS

By meta-analysis, 12 eligible studies involving 8,509 cases and 247,285 controls were identified via PubMed and Embase.

RESULTS

CDI patients had a higher risk of hospital mortality than non-CDI patients (odds ratio [OR], 1.899; 95% confidence interval [CI], 1.269-2.840), especially in 30-day mortality (OR, 2.521; 95% CI, 1.800-3.531). No correlation was found between hospital CDI and Charlson comorbidity index (OR, 0.830; 95% CI, 0.559-1.231). Patients treated in the ICU have an increased risk of hospital CDI (OR, 1.820; 95% CI, 1.161-2.851). However, the risk of CDI in patients who used to have surgery in surgical wards was not different to patients in the other departments (OR, 1.054; 95% CI, 0.838-1.325). Moreover, CDI patients in studies from the most recent 5 years have a higher risk of hospital mortality (OR, 2.171; 95% CI, 1.426-3.304).

CONCLUSION

Hospital CDI was associated with an increased risk of hospital mortality, especially in 30-day mortality. In addition, when compared with past years, CDI patients have a higher risk of hospital mortality in the most recent 5 years. Given the rapid dissemination of this organism worldwide, there is a need to aggressively develop and evaluate primary preventive strategies targeting CDI among hospitalized patients, especially in ICUs.

The morbidity, mortality, and costs associated with Clostridium difficile infection

Clostridium difficile infection (CDI) is the most common cause of infectious health care-associated diarrhea and is a major burden to patients and the health care system. The incidence and severity of CDI remain at historically high levels. This article reviews the morbidity, mortality, and costs associated with CDI.

Tracing the Spread of Clostridium difficile Ribotype 027 in Germany Based on Bacterial Genome Sequences

We applied whole-genome sequencing to reconstruct the spatial and temporal dynamics underpinning the expansion of Clostridium difficile ribotype 027 in Germany. Based on re-sequencing of genomes from 57 clinical C. difficile isolates, which had been collected from hospitalized patients at 36 locations throughout Germany between 1990 and 2012, we demonstrate that C. difficile genomes have accumulated sequence variation sufficiently fast to document the pathogen's spread at a regional scale. We detected both previously described lineages of fluoroquinolone-resistant C. difficile ribotype 027, FQR1 and FQR2. Using Bayesian phylogeographic analyses, we show that fluoroquinolone-resistant C. difficile 027 was imported into Germany at least four times, that it had been widely disseminated across multiple federal states even before the first outbreak was noted in 2007, and that it has continued to spread since.

Clostridium difficile infection (CDI) in children due to hypervirulent strains PCR-ribotype 027: An emblematic report of two cases

In this report, the first two cases of pediatric Clostridium difficile infection (CDI) due to the hypervirulent PCR-ribotype 027 in Italy are described as emblematic of the role of both the infecting C. difficile strain and patient status in the occurrence and clinical manifestation of CDI in children.

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.

Recurrent Clostridium difficile infection: From colonization to cure

Clostridium difficile infection (CDI) is increasingly prevalent, dangerous and challenging to prevent and manage. Despite intense national and international attention the incidence of primary and of recurrent CDI (PCDI and RCDI, respectively) have risen rapidly throughout the past decade. Of major concern is the increase in cases of RCDI resulting in substantial morbidity, morality and economic burden. RCDI management remains challenging as there is no uniformly effective therapy, no firm consensus on optimal treatment, and reliable data regarding RCDI-specific treatment options is scant. Novel therapeutic strategies are critically needed to rapidly, accurately, and effectively identify and treat patients with, or at-risk for, RCDI. In this review we consider the factors implicated in the epidemiology, pathogenesis and clinical presentation of RCDI, evaluate current management options for RCDI and explore novel and emerging therapies.

Clostridium difficile ribotypes in Austria: a multicenter, hospital-based survey

A prospective, noninterventional survey was conducted among Clostridium difficile positive patients identified in the time period of July until October 2012 in 18 hospitals distributed across all nine Austrian provinces. Participating hospitals were asked to send stool samples or isolates from ten successive patients with C.difficile infection to the National Clostridium difficile Reference Laboratory at the Austrian Agency for Health and Food Safety for PCR-ribotyping and in vitro susceptibility testing. A total of 171 eligible patients were identified, including 73 patients with toxin-positive stool specimens and 98 patients from which C. difficile isolates were provided. Of the 159 patients with known age, 127 (74.3 %) were 65 years or older, the median age was 76 years (range: 9–97 years), and the male to female ratio 2.2. Among these patients, 73 % had health care-associated and 20 % community-acquired C. difficile infection (indeterminable 7 %). The all-cause, 30-day mortality was 8.8 % (15/171). Stool samples yielded 46 different PCR-ribotypes, of which ribotypes 027 (20 %), 014 (15.8 %), 053 (10.5 %), 078 (5.3 %), and 002 (4.7 %) were the five most prevalent. Ribotype 027 was found only in the provinces Vienna, Burgenland, and Lower Austria. Severe outcome of C. difficile infection was found to be associated with ribotype 053 (prevalence ratio: 3.04; 95 % CI: 1.24, 7.44), not with the so-called hypervirulent ribotypes 027 and 078. All 027 and 053 isolates exhibited in vitro resistance against moxifloxacin. Fluoroquinolone use in the health care setting must be considered as a factor favoring the spread of these fluoroquinolone resistant C. difficile clones.

Incorrect diagnosis of Clostridium difficile infection in a university hospital in Japan

Physicians often fail to suspect Clostridium difficile infection (CDI) and many microbiology laboratories use suboptimal diagnostic techniques. To estimate the extent of and reasons for incorrect diagnosis of CDI in Japan, we investigated toxigenic C. difficile isolated from all stool culture samples and clinical course. Over a 12-month period in 2010, all stool culture samples (n = 975) submitted from inpatients in a university hospital in Japan were cultured for C. difficile and routine microbiological testing was conducted. In total, 177 C. difficile isolates were recovered, and 127 isolates were toxigenic. Among the toxin-A-positive/toxin-B-positive isolates, 12 were also positive for the binary toxin gene. However, clinically important ribotypes, such as 027 and 078, were not identified. A total of 58 (45.7%) cases with toxigenic C. difficile had unformed stool, and the incidence CDI was 1.6 cases per 10,000 patient-days. Of these 58 cases, 40 were not diagnosed in routine testing due to a lack of clinical suspicion (24.1%, 14/58) or a negative C. difficile toxin assay result (44.8%, 26/58). A stool toxin assay was performed in 54 patients (78.2%, 54/69) who did not have unformed stool. The present study demonstrated that a significant number of CDI cases in Japan might be overlooked or misdiagnosed in clinical practice due to a lack of clinical suspicion and limitations of microbiological testing for CDI in Japan. Providing education to promote awareness of CDI among physicians is important to improve the accuracy of diagnosis in Japan.

Clostridium Difficile Infection from a Surgical Perspective

BACKGROUND

The incidence and the severity of Clostridium difficile infection (CDI) have increased significantly over the last decade, especially in high-risk populations such as patients with inflammatory bowel disease (IBD). Surgeons must be able to both identify and minimize the risk of CDI in their own surgical patients and determine which CDI patients will benefit from surgery.

PURPOSE

We sought to define the risk factors, compare the treatment options, define the surgical indications, and identify factors that affect surgical outcomes for CDI based on the currently available literature.

RESULTS

Antibiotic use, exposure to the C. difficile bacteria, IBD, and higher levels of co-morbidity are all risk factors for CDI. The majority of CDI can be treated with antibiotics. Severe or fulminant colitis, however, has a high potential for poor outcome, but experience and some data suggest a lower mortality rate with colectomy rather than with continued medical treatment. Open total abdominal colectomy with end ileostomy is typically the preferred surgical strategy. It is often difficult to determine which patients will fail medical management as some may not manifest clinical signs of severe infection. Surrogate parameters of failure of medical therapy include respiratory and/or renal insufficiency, age greater than 60 years, peripheral vascular disease, congestive heart failure, and coagulopathy, all of which have been associated with worse surgical outcomes. Evidence suggests that in appropriately selected patients, colectomy performed before the development of shock requiring vasopressors, respiratory failure, renal failure, multi-organ dysfunction, and mental status changes may reduce mortality of the most severe forms of colitis. For less severe or recurrent presentations, creation of a loop ileostomy with intra-operative colonic lavage, fecal microbiota transfer, and C. difficile vaccinations are being discussed but have only been studied in small case-controlled series.

CONCLUSIONS

Prevention, containment, and non-surgical treatment are the cornerstone of management for CDI. However, the most severe forms with toxic colitis benefit from involvement of a surgical team. Swift open total abdominal colectomy with end ileostomy in patients with severe or fulminant C. difficile colitis has the best chance to reduce mortality if it is not delayed until shock, end organ damage, vasopressor requirement, mental status changes develop. Less aggressive approaches may be appropriate for milder and refractory forms but require further study before their applicability can be determined.

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.

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.

Serum Procalcitonin Measurement and Viral Testing to Guide Antibiotic Use for Respiratory Infections in Hospitalized Adults: A Randomized Controlled Trial

Background. Viral lower respiratory tract illness (LRTI) frequently causes adult hospitalization and is linked to antibiotic overuse. European studies suggest that the serum procalcitonin (PCT) level may be used to guide antibiotic therapy. We conducted a trial assessing the feasibility of using PCT algorithms with viral testing to guide antibiotic use in a US hospital.

Methods. Three hundred patients hospitalized with nonpneumonic LRTI during October 2013–April 2014 were randomly assigned at a ratio of 1:1 to receive standard care or PCT-guided care and viral PCR testing. The primary outcome was antibiotic exposure, and safety was assessed at 1 and 3 months.

Results. Among the 151 patients in the intervention group, viruses were identified in 42% (63), and 83% (126) had PCT values of <0.25 µg/mL. There were no significant differences in antibiotic use or adverse events between intervention patients and those in the nonintervention group. Subgroup analyses revealed fewer subjects with positive results of viral testing and low PCT values who were discharged receiving antibiotics (20% vs 45%; P = .002) and shorter antibiotic durations among algorithm-adherent intervention patients versus nonintervention patients (2.0 vs 4.0 days; P = .004). Compared with historical controls (from 2008–2011), antibiotic duration in nonintervention patients decreased by 2 days (6.0 vs 4.0 days; P < .001), suggesting a study effect.

Conclusions. Although antibiotic use was similar in the 2 arms, subgroup analyses of intervention patients suggest that physicians responded to viral and biomarker data. These data can inform the design of future US studies.

Clinical Trials Registration. NCT01907659.

Factors associated with antibiotic misuse in outpatient treatment for upper respiratory tract infections

The Centers for Disease Control and Prevention has promoted the appropriate use of antibiotics since 1995 when it initiated the National Campaign for Appropriate Antibiotic Use in the Community. This study examined upper respiratory tract infections included in the campaign to determine the degree to which antibiotics were appropriately prescribed and subsequent admission rates in a veteran population. This study was a retrospective chart review conducted among outpatients with a diagnosis of a respiratory tract infection, including bronchitis, pharyngitis, sinusitis, or nonspecific upper respiratory tract infection, between January 2009 and December 2011. The study found that 595 (35.8%) patients were treated appropriately, and 1,067 (64.2%) patients received therapy considered inappropriate based on the Get Smart Campaign criteria. Overall the subsequent readmission rate was 1.5%. The majority (77.5%) of patients were prescribed an antibiotic. The most common antibiotics prescribed were azithromycin (39.0%), amoxicillin-clavulanate (13.2%), and moxifloxacin (7.5%). A multivariate regression analysis demonstrated significant predictors of appropriate treatment, including the presence of tonsillar exudates (odds ratio [OR], 0.6; confidence interval [CI], 0.3 to 0.9), fever (OR, 0.6; CI, 0.4 to 0.9), and lymphadenopathy (OR, 0.4; CI, 0.3 to 0.6), while penicillin allergy (OR, 2.9; CI, 1.7 to 4.7) and cough (OR, 1.6; CI, 1.1 to 2.2) were significant predictors for inappropriate treatment. Poor compliance with the Get Smart Campaign was found in outpatients for respiratory infections. Results from this study demonstrate the overprescribing of antibiotics, while providing a focused view of improper prescribing. This article provides evidence that current efforts are insufficient for curtailing inappropriate antibiotic use.

Regional differences in Clostridium difficile infections in relation to fluoroquinolone and proton pump inhibitor use, Finland, 2008-2011

BACKGROUND

Several antimicrobial agents and proton pump inhibitors (PPIs) have been identified as risk factors for Clostridium difficile infections (CDIs). Nationwide laboratory-based surveillance of CDIs in Finland since 2008 has shown variation in regional CDI rates. We evaluated whether regional differences in CDI rates were associated with antibacterial and PPI use.

METHODS

Data on mean annual incidence rates of CDIs during 2008-2011 in 21 healthcare districts (HDs) were obtained from the National Infectious Disease Register, consumption (median annual use) of antimicrobials and PPIs from the Finnish Medical Agency, availability of molecular diagnostics by a laboratory survey and data on ribotypes from the national reference laboratory. The association over the 4 years was measured by incidence rate ratio (IRR) and we performed both bivariate and multivariate analyses.

RESULTS

During 2008-2011, PPI use increased 27% but fluoroquinolone use was stable. The level of fluoroquinolone use was strongly associated with the mean annual CDI incidence rate in different HDs over the 4-year period, but PPI use had less effect. The molecular diagnostics methodology and PCR ribotype 027 were not independently associated with CDI rate. The final multivariable model only included fluoroquinolone and PPI use; IRR for fluoroquinolones was 2.20 (95% confidence interval (CI), 1.32-3.67; p = 0.003).

CONCLUSIONS

Fluoroquinolone use may play a role in regional differences in CDI rates. Although the use has not recently increased, regionally targeted antimicrobial stewardship campaigns promoting appropriate use of fluoroquinolones should still be encouraged since they may decrease the incidence of CDIs.

Comparison of Clostridium difficile isolates from individuals with recurrent and single episode of infection

PURPOSE

Recurrent Clostridium difficile infection (CDI) is an increasing problem, yet reasons for this are poorly understood. Attention has been paid to the role of strain, with conflicting association of ribotype 027 and recurrences.

METHODS

Stool samples and medical records data were collected from 60 patients: 27 with recurrent CDI and 33 with single episode CDI. C. difficile was isolated and ribotyped, and minimum inhibitory concentrations of metronidazole and vancomycin were determined by Etest.

RESULTS

Twenty-seven ribotypes were identified, but only four (027, 014 and two internally designated strains) were found in more than one patient. Ribotype 027 predominated and was significantly over-represented in the recurrent CDI group (70%) versus the single episode CDI group (30%) (P = 0.004). Female gender and the presence of ribotype 027 were significantly associated with recurrent CDI in the multivariable model. Metronidazole MICs for recurrent isolates were significantly higher compared to single episode isolates (P ≤ 0.024). A general linear model indicated that the difference in MIC was associated with ribotype 027 (P = 0.0023), not whether the isolate was from recurrent or single episode disease (P = 0.25).

CONCLUSIONS

Ribotype 027 was associated with recurrent disease. While there was no difference in the prevalence of metronidazole resistance, isolates from recurrent CDI patients had significantly higher metronidazole MICs, because of higher MICs in ribotype 027. This study provides further support to the clinical importance of ribotype 027 and raises questions about the potential impact of decreased metronidazole susceptibility on the pathophysiology of recurrent CDI.

Effects of proton pump inhibitors and histamine-2 receptor antagonists on response to fidaxomicin or vancomycin in patients with Clostridium difficile-associated diarrhoea

OBJECTIVE

It has been established that use of proton pump inhibitors (PPIs) is associated with an increased risk of acquiring Clostridium difficile-associated diarrhoea (CDAD). However, it is not known whether the use of PPIs or histamine-2 receptor antagonists (H2RAs) concurrently with CDAD-targeted antibiotic treatment affects clinical response or recurrence rates.

DESIGN

In two phase 3 trials, patients with toxin-positive CDAD were randomised to receive fidaxomicin 200 mg twice daily or vancomycin 125 mg four times daily for 10 days. Only inpatients with CDAD (due to complete medication record availability) were included in this post hoc analysis: 701 patients, of whom 446 (64%) used PPIs or H2RAs during study drug treatment or follow-up. Baseline factors that were statistically significant in univariate analyses were analysed in multivariate analyses of effects on clinical response and recurrence.

RESULTS

Multivariate analysis showed that leukocytosis, elevated creatinine and hypoalbuminemia, but not PPI or H2RA use, were significant factors associated with poor clinical responses. Treatment group was the single significant predictor of recurrence; the probability of recurrence after fidaxomicin therapy was half that following vancomycin therapy.

CONCLUSIONS

Acid-suppressing drugs, used by nearly two-thirds of inpatients with CDAD, did not worsen clinical response or recurrence when used concurrently with fidaxomicin or vancomycin. Therefore, development of CDAD does not require discontinuation of anti-acid treatment in patients who have an indication for continuing PPI or H2RA therapy, such as gastro-oesophageal reflux disease and risk of gastrointestinal bleed.

Association between Clostridium difficile infection and antimicrobial usage in a large group of English hospitals

AIMS

This study aimed to determine the association between the reduction in the number of Clostridium difficile infection (CDI) cases reported by the English National Health Service (NHS) hospitals and concurrent antimicrobial use.

METHODS

A retrospective ecological study for January 2005 to December 2008 was conducted using data from 26 of the 29 NHS trusts (i.e. a trust manages one or more hospitals) located in the North West Strategic Health Authority of England. Antimicrobial use data, for patients of all ages, were provided by IMS Health, and CDI case data for patients aged ≥65 years were provided by the Health Protection Agency. Antimicrobial use was converted into defined daily doses (DDDs). The overall association between antimicrobial use and CDI for the trusts was investigated using multilevel models.

RESULTS

Our study shows a positive significant association between the CDI cases and the use of the following antimicrobials: ‘third-generation cephalosporins’ [11.62 CDI cases per 1000 DDDs; 95% confidence interval (CI), 5.92–17.31]; ‘fluoroquinolones’ (4.79 CDI cases per 1000 DDDs; 95% CI, 2.83–6.74); and ‘second-generation cephalosporins’ (4.25 CDI cases per 1000 DDDs; 95% CI, 1.66–6.83). The strength of this association was not significantly different (95% CI) among the antimicrobial groups.

CONCLUSIONS

This study shows that the reduction in the number of CDI cases reported by the English NHS hospitals is associated with concurrent reductions in antimicrobial use. This means that the number of CDI cases over time decreased in a similar fashion to the usage of various antimicrobials.

Risk factors for recurrent Clostridium difficile infection: a systematic review and meta-analysis

OBJECTIVE

An estimated 20-30% of patients with primary Clostridium difficile infection (CDI) develop recurrent CDI (rCDI) within 2 weeks of completion of therapy. While the actual mechanism of recurrence remains unknown, a variety of risk factors have been suggested and studied. The aim of this systematic review and meta-analysis was to evaluate current evidence on the risk factors for rCDI.

DESIGN

We searched MEDLINE and 5 other databases for subject headings and text related to rCDI. All studies investigating risk factors of rCDI in a multivariate model were eligible. Information on study design, patient population, and assessed risk factors were collected. Data were combined using a random-effects model and pooled relative risk ratios (RRs) were calculated.

RESULTS

A total of 33 studies (n=18,530) met the inclusion criteria. The most frequent independent risk factors associated with rCDI were age≥65 years (risk ratio [RR], 1.63; 95% confidence interval [CI], 1.24-2.14; P=.0005), additional antibiotics during follow-up (RR, 1.76; 95% CI, 1.52-2.05; P<.00001), use of proton-pump inhibitors (PPIs) (RR, 1.58; 95% CI, 1.13-2.21; P=.008), and renal insufficiency (RR, 1.59; 95% CI, 1.14-2.23; P=.007). The risk was also greater in patients previously on fluoroquinolones (RR, 1.42; 95% CI, 1.28-1.57; P<.00001).

CONCLUSIONS

Multiple risk factors are associated with the development of rCDI. Identification of modifiable risk factors and judicious use of antibiotics and PPI can play an important role in the prevention of rCDI.

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.

Clinical Practice Guidelines for Clostridium difficile Infection in Adults: 2010 Update by the Society for Healthcare Epidemiology of America (SHEA) and the Infectious Diseases Society of America (IDSA)

Since publication of the Society for Healthcare Epidemiology of America position paper onClostridium difficileinfection in 1995, significant changes have occurred in the epidemiology and treatment of this infection.C. difficileremains the most important cause of healthcare-associated diarrhea and is increasingly important as a community pathogen. A more virulent strain ofC. difficilehas been identified and has been responsible for more-severe cases of disease worldwide. Data reporting the decreased effectiveness of metronidazole in the treatment of severe disease have been published. Despite the increasing quantity of data available, areas of controversy still exist. This guideline updates recommendations regarding epidemiology, diagnosis, treatment, and infection control and environmental management.

Moxifloxacin Therapy as a Risk Factor forClostridium difficile–Associated Disease During an Outbreak: Attempts to Control a New Epidemic Strain

An outbreak ofClostridium difficile-associated disease (CDAD) caused by the epidemic North American pulsed-field gel electrophoresis type 1 (NAP1) strain began after a formulary change from levofloxacin to moxifloxacin. Cases of CDAD were associated with moxifloxacin use, but a formulary change back to levofloxacin failed to reduce rates of disease. Substituting use of one fluoroquinolone with use of another without also controlling the overall use of drugs from this class is unlikely to control outbreaks caused by the NAP1 strain ofC. difficile.

Legislative Mandates for Use of Active Surveillance Cultures to Screen for Methicillin-ResistantStaphylococcus aureusand Vancomycin-Resistant Enterococci: Position Statement From the Joint SHEA and APIC Task Force

Legislation aimed at controlling antimicrobial-resistant pathogens through the use of active surveillance cultures to screen hospitalized patients has been introduced in at least 2 US states. In response to the proposed legislation, the Society for Healthcare Epidemiology of America (SHEA) and the Association of Professionals in Infection Control and Epidemiology (APIC) have developed this joint position statement. Both organizations are dedicated to combating healthcare-associated infections with a wide array of methods, including the use of active surveillance cultures in appropriate circumstances. This position statement reviews the proposed legislation and the rationale for use of active surveillance cultures, examines the scientific evidence supporting the use of this strategy, and discusses a number of unresolved issues surrounding legislation mandating use of active surveillance cultures. The following 5 consensus points are offered. (1) Although reducing the burden of antimicrobial-resistant pathogens, including methicillin-resistantStaphylococcus aureus(MRSA) and vancomycin-resistant enterococci (VRE), is of preeminent importance, APIC and SHEA do not support legislation to mandate use of active surveillance cultures to screen for MRSA, VRE, or other antimicrobial-resistant pathogens. (2) SHEA and APIC support the continued development, validation, and application of efficacious and cost-effective strategies for the prevention of infections caused by MRSA, VRE, and other antimicrobial-resistant and antimicrobial-susceptible pathogens. (3) APIC and SHEA welcome efforts by healthcare consumers, together with private, local, state, and federal policy makers, to focus attention on and formulate solutions for the growing problem of antimicrobial resistance and healthcare-associated infections. (4) SHEA and APIC support ongoing additional research to determine and optimize the appropriateness, utility, feasibility, and cost-effectiveness of using active surveillance cultures to screen both lower-risk and high-risk populations. (5) APIC and SHEA support stronger collaboration between state and local public health authorities and institutional infection prevention and control experts.

Is High Consumption of Antibiotics Associated with Clostridium difficile Polymerase Chain Reaction–Ribotype 027 Infections in France?

We compared antibiotic consumption between hospitals affected by a strain of Clostridium difficile designated as polymerase chain reaction–ribotype 027 (CD-027) and those unaffected during an outbreak in northern France. The mean consumption of several β-lactams, amikacin, and fluoroquinolones was high in affected hospitals (P<.05). However, only levofloxacin and imipenem remained associated with emerging CD-027 in the multivariate analysis, suggesting that those antibiotics should be better targeted by prevention campaigns.

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.

Emergence and Control of Fluoroquinolone-Resistant, Toxin A–Negative, Toxin B–PositiveClostridium difficile

Background.

Clostridium difficileis a major cause of infectious diarrhea in hospitalized patients. Between August 2003 and January 2004, we experienced an increase in the incidence ofC. difficile–associated disease. We describe the investigation into and management of the outbreak in this article.

Methods.

A total of 73 consecutive patients with nosocomialC. difficile–associated diarrhea were identified.C. difficileisolates were characterized using toxin-specific enzyme immunoassays, a tissue-culture fibroblast cytotoxicity assay, polymerase chain reaction (PCR), and antimicrobial susceptibility tests. Rates of recurrence and ofC. difficilecolitis were recorded. Changes in antibiotic use and infection control policies were documented.

Results.

The incidence ofC. difficile–associated diarrhea peaked at 21 cases per 1,000 patient admissions. Of theC. difficileisolates recovered, 85 (95%) were identical toxin A–negative and toxin B-positive strains, corresponding to toxinotype VIII and PCR ribotype 017. All clonal isolates were resistant to multiple antibiotics, including ofloxacin, ciprofloxacin, levofloxacin, moxifloxacin, and gatifloxacin (minimum inhibitory concentrations [MICs] of greater than 32μg/mL) and erythromycin, clarithromycin, and clindamycin (MICs of greater than 256μg/mL). RecurrentC. difficile–associated disease occurred in 26 (36%) of the patients. At least 10 (14%) of the patients developedC. difficilecolitis. Additional infection control measures introduced included the use of ward memos, a hand-hygiene awareness campaign, increased environmental cleaning, attention to prescribing practices for antibiotics, increased awareness of diarrheal illness, and early isolation of affected patients. Total use of fluoroquinolones did not change throughout the study period. Despite persistence of this toxin-variant strain, the incidence ofC. difficile–associated disease in our institution decreased to fewer than 5 cases per 1,000 admissions.

Conclusions.

We report on the emergence of a fluoroquinolone- and clindamycin-resistant, toxin A–negative, and toxin B–positive strain ofC. difficileassociated with an outbreak ofC. difficile–associated disease in our institution during a 6-month period. We found that careful attention to improvement of infection control interventions was the most important means of controlling this nosocomial pathogen.

Automated Surveillance of Clostridium difficile Infections Using BioSense

Objective.

To determine the feasibility of using electronic laboratory and admission-discharge-transfer data from BioSense, a national automated surveillance system, to apply new modified Clostridium difficile infection (CDI) surveillance definitions and calculate overall and facility-specific rates of disease.

Design.

Retrospective, multicenter cohort study.

Setting.

Thirty-four hospitals sending inpatient, emergency department, and /or outpatient data to BioSense.

Methods.

Laboratory codes and text-parsing methods were used to extract C. difficile-positive toxin assay results from laboratory data sent to BioSense during the period from January 1, 2007, through June 30, 2008; these were merged with administrative records to determine whether cases were community associated or healthcare onset, as well as patient-day data for rate calculations. A patient was classified as having hospital-onset CDI if he or she had a C. difficile toxin-positive result on a stool sample collected 3 or more days after admission and community-onset CDI if the specimen was collected less than 3 days after admission or the patient was not hospitalized.

Results.

A total of 4,585 patients from 34 hospitals in 12 states had C. difficile-positive assay results. More than half (53.0%) of the cases were community-onset, and 30.8% of these occurred in patients who were recently hospitalized. The overall rate of healthcare-onset CDI was 7.8 cases per 10,000 patient-days, with a range among facilities of 1.5-27.8 cases per 10,000 patient-days.

Conclusions.

Electronic laboratory data sent to the BioSense surveillance system were successfully used to produce disease rates of CDI comparable to those of other studies, which shows the feasibility of using electronic laboratory data to track a disease of public health importance.

Clostridium difficile-Associated Disease in Patients in a Small Rural Hospital

Objective.

To determine the risk factors for Clostridium difficile–associated disease (CDAD) in a 25-bed rural hospital and to compare antimicrobial use ratios at the study hospital with those at a large academic medical center.

Design.

Case-control study.

Setting.

A 25-bed rural hospital in Iowa during the period from August 2002 through January 2005.

Patients.

A total of 17 case patients with CDAD and 34 control patients matched for age (ie, within 10 years of the case patient's age), sex, and admission date (ie, within 2 weeks of the case patient's admission date).

Methods.

Retrospective medical record review was performed to obtain data on antimicrobial exposures during the 6 weeks before hospital admission for both case and control patients. Exact conditional logistic regression was used for univariable and multivariable analyses. Antimicrobial use ratios were calculated to compare the rates of antimicrobial use for case and control patients at the study hospital with the rates for patients evaluated in a study of CDAD at a nearly 700-bed teaching hospital.

Results.

Case patients had a larger cumulative number of days of antimicrobial use (P = .004), and they received a larger total number of antimicrobial agents during hospitalization (P = .001). Antimicrobial use ratios were higher for both case and control patients at the smaller hospital, compared with the larger hospital.

Conclusions.

CDAD at a small rural hospital was not associated with exposure to the antimicrobial classes that are typically associated with CDAD, but was instead related to the total number of antimicrobials used to treat patients. The rate of antimicrobial use for case and control patients was about 40% higher at the small rural hospital, compared with the corresponding rates at a large academic medical center.

Missed diagnosis of Clostridium difficile infection; a prospective evaluation of unselected stool samples

BACKGROUND

Clostridium difficile infection (CDI) is the leading cause of hospital-acquired diarrhoea in developed countries, however a high proportion of CDI episodes go undiagnosed, either because physicians do not request identification of toxigenic C. difficile or microbiologists do not perform the appropriate tests.

OBJECTIVE

To investigate the clinical characteristics of patients with CDI within a non-selected population and to determine risk factors for clinical underdiagnosis.

METHODS

We conducted a prospective study in which systematic testing for toxigenic C. difficile on all diarrhoeic stool samples was performed regardless of the clinician's request. Patients aged >2 years positive for toxigenic C. difficile and diarrhoea were enrolled (Jan-June 2013) and monitored at least 2 months after their last episode.

RESULTS

We identified 204 cases of CDI, of which three-quarters were healthcare-associated. Most cases were mild to moderate (83.8%), the recurrence rate was 16.2%, and CDI-related mortality was low (2.5%). A significant proportion (12.7%) of CDI cases would have been missed owing to lack of clinical suspicion. Community-acquired cases and young age were risk factors for clinical underdiagnosis.

CONCLUSION

Our data support the introduction of a systematic search for toxigenic C. difficile in all diarrhoeic stools from inpatients and outpatients older than 2 years.

Experience with fecal microbiota transplantation in the treatment ofClostridium difficileinfection

Introduction: During the past years a dramatic change has been observed in the epidemiology of Clostridium difficile infections. Aim: The aim of the authors was to investigate the possibility of the fecal microbiota transplantation and study differences, if any, in the success rate of the two different upper gastrointestinal tract method. Method: 100 ml of fecal microbiota solution was instilled via a nasoduodenal tube in 15 cases and a nasogastric tube in 15 cases. The authors defined the primary cure rate as the percentage of cases in which the symptoms disappeared without recurrence within 6 weeks after the first fecal microbiota transplantation, while secondary cure rate was calculated as the percentage of cases in which the symptoms resolved after the second fecal microbiota transplantation. Results: It was found that fecal microbiota transplantation applied via the nasoduodenal tube resulted in a 100% primary cure rate. With the use of the nasogastric tube, the primary and secondary cure rate were 80% and 93.3%, respectively. Fecal microbiota transplantation via the upper gastrointestinal tract was found to have an overall primary cure rate of 90.0% and a secondary cure rate of 96.7%. Conclusions: Fecal microbiota transplantation proved to be very effective, particularly in recurrent infections and cases where conventional treatment failed. Orv. Hetil., 2014, 155(44), 1758–1762.

Anti-infective prophylaxis in pediatric patients with acute myeloid leukemia

Pediatric patients undergoing treatment for acute myeloid leukemia (AML) are at high risk for infectious complications, predominantly due to Gram-negative bacteria, viridans group streptococci and fungal pathogens. In order to prevent infections in these patients, most institutions have implemented a number of non-pharmacological approaches to supportive care. In addition, antibiotic prophylaxis reduces bacterial infection, but may increase the emergence of resistance. Antifungal prophylaxis is generally recommended for children with AML. Whereas the use of hematopoietic growth factors has not resulted in improved survival, the efficacy of prophylactic granulocyte transfusions has to be determined.

The evaluation of Clostridium difficile infection (CDI) in a community hospital

INTRODUCTION

Clostridium difficile is a serious reemerging pathogen in Europe and North America. C. difficile infection (CDI) has been of concern over the last decade in view of its significant morbidity and mortality, as well as the high health care costs involved with each case. Although multiple risk factors are known to be associated with CDI, a number of patients develop severe infection even in the absence of known risk factors. CDI is diagnosed by the detection of the toxin A/B in stools by enzyme immunoassay (EIA) or by polymerase chain reaction (PCR). There is conflicting literature regarding whether any particular group of antibiotics is associated with higher risk for CDI. There is also a tendency to perform repeated stool tests for toxin A/B if the first test is negative. We evaluated 100 consecutive hospitalized patients who tested positive for C. difficile over a one-year period.

METHODS

We performed a retrospective analysis of 100 consecutive patients with CDI admitted to our hospital between July 2008 and June 2009. Patient records were reviewed for risk factors, treatment, and clinical outcomes. We also evaluated the number of stool tests performed for the detection of C. difficile and fecal leukocyte testing in each patient.

RESULTS

The majority of the patients were more than 60 years of age (87%). Forty-four percent of patients presented from a nursing facility. More than 50% were on Proton Pump Inhibitors (PPIs) at the time of admission. Co-morbidities in our patients included malignancy in 28%, diabetes mellitus in 25%, and chronic renal disease in 23%. Most of the patients had multiple co-morbidities. Patients who had taken antibiotics in the previous six months constituted 74% of the total study population. A beta-lactam alone or in combination with other antibiotics was prescribed in 48%, quinolones in 13% and clindamycin in 4% of patients. Stool samples were tested only once in 53% of patients and twice or more in 43%. Metronidazole was the initial therapy in 86% of patients. Intensive care unit stay was required in 33% of patients. Seventeen percent died during their hospitalization.

CONCLUSIONS

Elderly patients are especially vulnerable to CDI when exposed to antibiotics, and higher mortality and morbidity is observed in this age group. PPI use was common in our patients. Metronidazole was used as the first line agent in the majority of patients. We also determined a tendency to test for the C. difficile toxin in more than one stool sample. All of these practices need to be modified based on the current guidelines.

Investigation to identify a resource-efficient case-control methodology for determining antibiotics associated with Clostridium difficile infection

BACKGROUND

Antimicrobial exposure remains an important risk factor for developing Clostridium difficile infection (CDI). Efficient method to identify antibiotics associated with CDI is important for formulating strategies to curtail their use. As a prelude to a more extensive Agency for Healthcare Research and Quality-funded project (Evaluation & Research on Antimicrobial Stewardship's Effect on Clostridium difficile), we undertook an exploratory evaluation to determine a resource-efficient method for identifying antibiotic targets for antimicrobial stewardship interventions.

METHODS

The study compared a series of 6 focused case-control studies. Cases consisted of patients with laboratory-confirmed CDI admitted from July-October 2009. Controls were selected from patients without CDI hospitalized during the same period. Five groups of controls were matched to cases (2:1 ratio) using group-specific matching criteria, including admission date, age, type of admission, length of stay (LOS) to discharge, and/or LOS to CDI diagnosis. The final control group was selected from patients who received antibiotics during hospitalization. Data, including demographics and antibiotic usage, were compared between case and control groups.

RESULTS

A total of 126 cases were matched to 6 groups of 252 controls. For control groups 1-5, the use of piperacillin and tazobactam, ceftriaxone or cefepime, ciprofloxacin or moxifloxacin, intravenous vancomycin, azithromycin, and antibiotics of last resort were significantly more frequent in case than control patients. For the final control group, the associations between ceftriaxone or cefepime, and ciprofloxacin or moxifloxacin use and CDI no longer persisted. This could in part be explained by differences in comorbidities between case and control patients even with stringent matching criteria.

CONCLUSION

Use of a simple matching strategy to conduct case-control studies is an efficient and feasible compromise strategy, especially in resource-limited settings, to identify high-risk antibiotics associated with CDI.

Factors associated with Clostridium difficile diarrhea in a hospital in Beijing, China

Clostridium difficile is the most common cause of hospital-acquired diarrhea in patients treated with antibiotics, chemotherapeutic agents, and other drugs that alter the normal equilibrium of the intestinal flora. A better understanding of the risk factors for C. difficile-associated disease (CDAD) could be used to reduce the incidence of CDAD and the costs associated with its treatment. The aim of this study was to identify the risk factors for CDAD in a cohort of Chinese patients in a Beijing hospital. Medical charts of a total of 130 inpatients (62 males and 68 females) with hospital-acquired diarrhea (45 with CDAD; 85 without CDAD) were retrospectively reviewed. C. difficile toxins A and B were detected in fecal samples using enzyme-linked fluorescence assays. The drugs used by patients with and without CDAD before the onset of diarrhea were compared. Factors that differed significantly between the two groups by univariate analysis were analyzed by multivariate analysis using a logistic regression model. Multivariate analysis showed that cephalosporin treatment was associated with a significantly higher risk of CDAD in hospitalized patients, while treatment with glycopeptides was significantly associated with a reduction in CDAD (P<0.001 for cephalosporin; P=0.013 for glycopeptides). Our data confirmed previous findings that empirical treatment with cephalosporins is positively associated with CDAD compared to individuals using other CDAD-related drugs. Additionally, we showed that treatment with glycopeptides was negatively associated with CDAD, compared to individuals using other CDAD-related drugs.

Management of febrile neutropenia in the era of bacterial resistance

Managing cancer patients with fever and neutropenia must be considered as a medical emergency since any delay in initiating appropriate empirical antibacterial therapy may result in high rates of mortality and morbidity. Emerging antibacterial resistance in bacterial pathogens infecting febrile neutropenic patients complicates management, and choosing the type of empirical antimicrobial therapy has become a challenge. To further complicate the decision process, not all neutropenic patients are in same category of susceptibility to develop severe infection. While low-risk patients may be treated with oral antibiotics in the outpatient setting, high-risk patients usually need to be admitted to hospital and receive parenteral broad-spectrum antibiotics until the neutrophil levels recover. These strategies have recently been addressed in two international guidelines from the Infectious Diseases Society of America (IDSA) and the European Conference on Infections in Leukaemia (ECIL). This review gives a brief overview of current antimicrobial resistance problems and their effects in febrile neutropenic cancer patients by summarizing the suggestions from the IDSA and ECIL guidelines.

An agent-based simulation model for Clostridium difficile infection control

BACKGROUND

Control of Clostridium difficile infection (CDI) is an increasingly difficult problem for health care institutions. There are commonly recommended strategies to combat CDI transmission, such as oral vancomycin for CDI treatment, increased hand hygiene with soap and water for health care workers, daily environmental disinfection of infected patient rooms, and contact isolation of diseased patients. However, the efficacy of these strategies, particularly for endemic CDI, has not been well studied. The objective of this research is to develop a valid, agent-based simulation model (ABM) to study C. difficile transmission and control in a midsized hospital.

METHODS

We develop an ABM of a midsized hospital with agents such as patients, health care workers, and visitors. We model the natural progression of CDI in a patient using a Markov chain and the transmission of CDI through agent and environmental interactions. We derive input parameters from aggregate patient data from the 2007-2010 Wisconsin Hospital Association and published medical literature. We define a calibration process, which we use to estimate transition probabilities of the Markov model by comparing simulation results to benchmark values found in published literature.

RESULTS

In a comparison of CDI control strategies implemented individually, routine bleach disinfection of CDI-positive patient rooms provides the largest reduction in nosocomial asymptomatic colonization (21.8%) and nosocomial CDIs (42.8%). Additionally, vancomycin treatment provides the largest reduction in relapse CDIs (41.9%), CDI-related mortalities (68.5%), and total patient length of stay (21.6%).

CONCLUSION

We develop a generalized ABM for CDI control that can be customized and further expanded to specific institutions and/or scenarios. Additionally, we estimate transition probabilities for a Markov model of natural CDI progression in a patient through calibration.

The evolution of urban C. difficile infection (CDI): CDI in 2009-2011 is less severe and has better outcomes than CDI in 2006-2008

OBJECTIVES

Over the past decade, the epidemiology of Clostridium difficile infection (CDI) has shown a remarkable increase in incidence with an associated increase in severity. This study was designed to compare the demographics, medication exposure, evaluation, treatment patterns, and outcomes of patients with CDI in two different time periods: 2006-2008 and 2009-2011. We hypothesized that mortality is decreasing with increasing appropriateness of medical management.

METHODS

We retrospectively identified consecutive patients admitted to Montefiore Medical Center between 1/1/2006 and 12/31/2011 with symptomatic diarrhea and a positive C. difficile toxin assay. The cohort was subdivided into those diagnosed in 2006-2008 (CDI 06-08) and 2009-2011 (CDI 09-11). We obtained key parameters at the time of diagnosis including demographics, medication exposure, medical comorbidities, laboratory data, CDI evaluation, and various outcome measures. We created a subcohort for each time frame of patients diagnosed with severe CDI defined by white blood cell count (WBC) >15,000 cells/μl and albumin <3.0 g/dl and made the same comparisons as for the overall cohort. The two cohorts were compared using SPSS (16.0).

RESULTS

Cohorts and the number of patients who met criteria for inclusion were as follows: CDI 06-08 (n=1189), CDI 09-11 (n=1,907), severe CDI 06-08 (n=243), and severe CDI 09-11 (n=382). CDI 09-11 patients were older (P=0.01) and had higher Charlson comorbidity scores (P=0.02) than did those in the CDI 06-08 cohort. There were no significant demographic differences in the severe cohort. For both the overall and severe cohorts, there was more macrolide exposure before diagnosis with CDI and lower rates of quinolone exposure in the more recent era. The disease process also appeared less severe in the CDI 09-11 cohort with lower peak WBC during admission and at diagnosis. Treatment patterns appeared more aggressive during the more recent time frame, with shorter durations of oral metronidazole (P<0.001), longer durations of IV metronidazole (P=0.04), more frequent use of vancomycin as the sole therapy (P<0.001), more frequent switching from metronidazole to vancomycin (P<0.001), and less frequent exposure to any metronidazole throughout treatment (P<0.001) in the overall cohort. The 30-day mortality decreased significantly in both the overall (17.1 vs. 13.1%, P<0.01) and the severe (31.3 vs. 23.3%, P<0.05) cohorts from CDI 06-08 to CDI 09-11, with mortality decreasing significantly in the 8th and 9th decades of life in the overall cohort and in the 8th, 9th, and 10th decades in the severe cohort.

CONCLUSIONS

In an urban United States population, CDI 09-11 showed changes in medication exposures, less severe disease, and more aggressive management with better outcomes and decreased mortality compared with CDI 06-08. The most important factors associated with 30-day mortality in both an overall and severe CDI population include age, WBC, and albumin level at the time of diagnosis.