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

A review of the economics of treating Clostridium difficile infection

Clostridium difficile infection (CDI) is a costly result of antibiotic use, responsible for an estimated 14,000 deaths annually in the USA according to the Centers for Disease Control and Prevention. Annual costs attributable to CDI are in excess of $US 1 billion. This review summarizes appropriate utilization of prevention and treatment methods for CDI that have the potential to reduce the economic and humanistic costs of the disease. Some cost-effective strategies to prevent CDI include screening and isolation of hospital admissions based on C. difficile carriage to reduce transmission in the inpatient setting, and probiotics, which are potentially efficacious in preventing CDI in the appropriate patient population. The most extensively studied agents for treatment of CDI are metronidazole, vancomycin, and fidaxomicin. Most economic comparisons between metronidazole and vancomycin favor vancomycin, especially with the emergence of metronidazole-resistant C. difficile strains. Metronidazole can only be recommended for mild disease. Moderate to severe CDI should be treated with vancomycin, preferably the compounded oral solution, which provides the most cost-effective therapeutic option. Fidaxomicin offers a clinically effective and potentially cost-effective alternative for treating moderate CDI in patients who do not have the NAP1/BI/027 strain of C. difficile. Probiotics and fecal microbiota transplant have variable efficacy and the US FDA does not currently regulate the content; the potential economic advantages of these treatment modalities are currently unknown.

A population-based spatio-temporal analysis of Clostridium difficile infection in Queensland, Australia over a 10-year period

OBJECTIVES

To identify the spatio-temporal patterns and environmental factors associated with Clostridium difficile infection (CDI) in Queensland, Australia.

METHODS

Data from patients tested for CDI were collected from 392 postcodes across Queensland between May 2003 and December 2012. A binomial logistic regression model, with CDI status as the outcome, was built in a Bayesian framework, incorporating fixed effects for sex, age, source of the sample (healthcare facility or community), elevation, rainfall, land surface temperature, seasons of the year, time in months and spatially unstructured random effects at the postcode level.

RESULTS

C. difficile was identified in 13.1% of the samples, the proportion significantly increased over the study period from 5.9% in 2003 to 18.8% in 2012. CDI peaked in summer (14.6%) and was at its lowest in autumn (10.1%). Other factors significantly associated with CDI included female sex (OR: 1.08; 95%CI: 1.01-1.14), community source samples (OR: 1.12; 95%CI: 1.05-1.20), and higher rainfall (OR: 1.09; 95%CI: 1.02-1.17). There was no significant spatial variation in CDI after accounting for the fixed effects in the model.

CONCLUSIONS

There was an increasing annual trend in CDI in Queensland from 2003 to 2012. Peaks of CDI were found in summer (December-February), which is at odds with the current epidemiological pattern described for northern hemisphere countries. Epidemiologically plausible explanations for this disparity require further investigation.

Assessing control bundles for Clostridium difficile: a review and mathematical model

Clostridium difficile is the leading cause of infectious diarrhea in hospitalized patients. Integrating several infection control and prevention methods is a burgeoning strategy for reducing disease incidence in healthcare settings. We present an up-to-date review of the literature on ‘control bundles' used to mitigate the transmission of this pathogen. All clinical studies of control bundles reported substantial reductions in disease rates, in the order of 33%–61%. Using a biologically realistic mathematical model we then simulated the efficacy of different combinations of the most prominent control methods: stricter antimicrobial stewardship; the administering of probiotics/intestinal microbiota transplantation; and improved hygiene and sanitation. We also assessed the health gains that can be expected from reducing the average length of stay of inpatients. In terms of reducing the rates of colonization, all combinations had the potential to give rise to marked improvements. For example, halving the number of inpatients on broad-spectrum antimicrobials combined with prescribing probiotics or intestinal microbiota transplantation could cut pathogen carriage by two-thirds. However, in terms of symptomatic disease incidence reduction, antimicrobials, probiotics and intestinal microbiota transplantation proved substantially less effective. Eliminating within-ward transmission by improving sanitation and reducing average length of stay (from six to three days) yielded the most potent symptomatic infection control combination, cutting rates down from three to less than one per 1000 hospital bed days. Both the empirical and theoretical exploration of C. difficile control combinations presented in the current study highlights the potential gains that can be achieved through strategically integrated infection control.

Impact of peri-transplant vancomycin and fluoroquinolone administration on rates of bacteremia in allogeneic hematopoietic stem cell transplant (HSCT) recipients: a 12-year single institution study

BACKGROUND

We analyzed the effect of peri-transplant prophylaxis on the epidemiology of bacteremia in a 12-year contemporary cohort of allogeneic HSCT recipients at our center.

METHODS

This was an observational study of 1052 consecutive adult HSCT from 2000 to 2011. Formal prophylaxis with vancomycin only, fluoroquinolone (FQ) only, or vancomycin + FQ was implemented in 2006. The cumulative incidence of day 100 bacteremia was compared between the Early Period (2000-2005) and the Recent Period (2006-2011). Predictors for pre-engraftment bacteremia were analyzed with Cox-proportional hazard models in a subcohort of 821 HSCT who received myeloablative or reduced intensity conditioning (MA/RIC).

RESULTS

The incidence of bacteremia decreased in the Recent Period (32% vs 27%; P = 0.002), whereas the rates of resistance in gram-negative rods (GNR) and vancomycin-resistant enterococci (VRE) were similar between the two Periods (P values are not statistically significant.) In multivariate analyses, prophylaxis with vancomycin only or vancomycin + FQ was protective (HR = 0.5; CI = 0.30-0.72) and (HR = 0.3; CI = 0.12-0.52, P < 0.01). Vancomycin or vancomycin + FQ eliminated viridans streptococcal bacteremia (VSB); vancomycin + FQ decreased GNR bacteremia (HR = 0.35; CI = 0.15-0.85).

CONCLUSIONS

Vancomycin-based prophylaxis peri-transplant in MA/RIC HSCT was associated with elimination of VSB and may be considered at centers with high incidence of this infection.

Treatment of bacteriobilia decreases wound infection rates after pancreaticoduodenectomy

BACKGROUND

Although mortality following pancreaticoduodenectomy is decreasing, postoperative morbidity remains high. It was hypothesized that culture-directed treatment of bacteriobilia would decrease the incidence of infectious complications following pancreaticoduodenectomy.

METHODS

In a retrospective study of 197 pancreaticoduodenectomy patients, those in the control group (n = 128, 2005-2009) were given perioperative prophylactic antibiotics, whereas those in the treatment group (n = 69, 2009-2011) were continued on antibiotics until intraoperative bile culture results became available. Patients with bacteriobilia received 10 days of antibiotic treatment, which was otherwise discontinued in patients without bacteriobilia. Various complication rates were compared using Fisher's exact test for categorical variables, Wilcoxon rank sum test for ordinal variables, and a two-sample t-test for continuous variables.

RESULTS

Demographics, comorbidities, baseline clinical characteristics, and intraoperative and postoperative variables were similar between the two groups. There were higher incidences of elevated creatinine (19% versus 4%; P = 0.004) and preoperative hyperglycaemia (18% versus 7%; P = 0.053) in the control group. Fewer patients in the control group underwent preoperative biliary stenting (48% versus 67%; P = 0.017) and intraperitoneal drains were placed at the time of resection more frequently in the control group (85% versus 38%; P < 0.001). Bacteriobilia was found in 59% of patients. Treatment of bacteriobilia was associated with a decrease in the rate of postoperative wound infections (12% in the control group versus 3% in the treatment group; P = 0.036) and overall complication severity score (1 in the control group versus 0 in the treatment group; P = 0.027).

CONCLUSIONS

Prolonged antibiotic therapy for bacteriobilia may decrease postoperative wound infection rates after pancreaticoduodenectomy. A randomized prospective trial is warranted to provide evidence to further support this practice.

A retrospective analysis of clinical characteristics, hospitalization, and functional outcomes in residents with and without Clostridium difficile infection in US long-term care facilities

OBJECTIVE

Patients in long-term care (LTC) are at increased risk for acquiring Clostridium difficile infection (CDI). We compared the characteristics and outcomes of matched cohorts with and without CDI in the LTC setting.

METHODS

Using a retrospective cohort design, demographic characteristics, Minimum Data Set (MDS 2.0) assessments (years 2007-2010), and pharmacy records of residents were analyzed. Residents were required to have a CDI diagnosis, ≥1 MDS 2.0 assessment ≤120 days pre- and post-index event, and receipt of metronidazole (MET) or vancomycin (VAN) within ±7 days of index date. Baseline characteristics were compared between cases and controls matched 1:3 on age, gender, and index year. Cox regression (CR) analysis evaluated the relationship between CDI status, and post-index mortality and hospitalization.

RESULTS

A total of 1145 CDI residents were matched with 3488 non-CDI residents. A second sample used propensity score methods. CDI vs. non-CDI residents had a higher baseline comorbidity burden (Charlson score: 3.0 ± 1.9 vs. 2.2 ± 1.8, respectively), and were more likely to have had a recent hospitalization (63% vs. 9%, respectively) and shorter mean pre-index continuous length of stay (cLOS) in the LTC (386.4 d ± 536.3 d vs. 568.3 d ± 567.4 d, respectively), all P < 0.0001. CR analyses of both samples indicated that CDI was strongly associated with shorter times to hospitalization and mortality (hazard ratio (HR) = 1.3, P = 0.023 and 2.2, P < 0.0001, respectively; propensity-matched group). Pre-index LTC cLOS also remained an important variable in the CR analysis and was the strongest predictor of post-index hospitalization and mortality (HR = 0.999 and 0.996, respectively, P < 0.0001), indicating that residents with longer pre-index LTC cLOS had longer times to post-index hospitalization and mortality. Our reliance on the MDS records for case identification was our chief limitation; misclassification was mitigated by our requirement to include CDI treatment as part of our inclusion criteria.

CONCLUSIONS

Understanding factors that put LTC patients at risk for CDI can help guide better management and improvement of patient outcomes.

Surgical Management of Severe Colitis in the Intensive Care Unit

Severe colitis, an umbrella encompassing several entities, is one of the most common acute gastrointestinal disorders resulting in critical illness. Clostridium difficile infection is responsible for the majority of nosocomial diarrhea with fulminant C difficile colitis (CDC) carrying a high mortality. Optimal outcomes can be achieved by early identification and treatment of fulminant CDC, with appropriate surgical intervention when indicated. Ischemic colitis, on the other hand, is uncommon with a range of etiological factors including abdominal aortic surgery, inotropic drugs, rheumatoid diseases, or often no obvious triggering factor. Most cases resolve with nonsurgical management; however, prompt recognition of full-thickness necrosis and gangrene is crucial for good patient outcomes. Fulminant colitis is a severe disease secondary to progressive ulcerative colitis with systemic deterioration. Surgical intervention is indicated for hemorrhage, perforation, or peritonitis and failure of medical therapy to control the disease. Although, failure of medical management is the most common indication, it can be difficult to define objectively and requires a collaborative multidisciplinary approach. This article proposes some simple management algorithms for these clinical entities, with a focus on critically ill patients.

Variations in virulence and molecular biology among emerging strains of Clostridium difficile

Clostridium difficile is a Gram-positive, spore-forming organism which infects and colonizes the large intestine, produces potent toxins, triggers inflammation, and causes significant systemic complications. Treating C. difficile infection (CDI) has always been difficult, because the disease is both caused and resolved by antibiotic treatment. For three and a half decades, C. difficile has presented a treatment challenge to clinicians, and the situation took a turn for the worse about 10 years ago. An increase in epidemic outbreaks related to CDI was first noticed around 2003, and these outbreaks correlated with a sudden increase in the mortality rate of this illness. Further studies discovered that these changes in CDI epidemiology were associated with the rapid emergence of hypervirulent strains of C. difficile, now collectively referred to as NAP1/BI/027 strains. The discovery of new epidemic strains of C. difficile has provided a unique opportunity for retrospective and prospective studies that have sought to understand how these strains have essentially replaced more historical strains as a major cause of CDI. Moreover, detailed studies on the pathogenesis of NAP1/BI/027 strains are leading to new hypotheses on how this emerging strain causes severe disease and is more commonly associated with epidemics. In this review, we provide an overview of CDI, discuss critical mechanisms of C. difficile virulence, and explain how differences in virulence-associated factors between historical and newly emerging strains might explain the hypervirulence exhibited by this pathogen during the past decade.

Fidaxomicin: a minimally absorbed macrocyclic antibiotic for the treatment of Clostridium difficile infections

Fidaxomicin was approved for the treatment of Clostridium difficile infections in 2011. It has a novel mechanism of action and narrow spectrum of activity that makes it unique among the currently used therapies for this disease. Phase III clinical studies demonstrated a benefit of fidaxomicin over vancomycin for the outcomes of recurrence and global cure or sustained clinical response. This observation was confirmed within specific populations, including those of older age, immunocompromised due to active cancers, and patients taking concomitant antibiotics. Additionally, fidaxomicin significantly reduced recurrence rates compared to vancomycin among patients receiving treatment for recurrent C. difficile episodes. Fidaxomicin represents an advance in therapy for the treatment of C. difficile infections.

Epidemiology of Clostridium difficile infection

There has been dramatic change in the epidemiology of Clostridium difficile infection (CDI) since the turn of the 21st century noted by a marked increase in incidence and severity, occurring at a disproportionately higher frequency in older patients. Historically considered a nosocomial infection associated with antibiotic exposure, CDI has now also emerged in the community in populations previously considered low risk. Emerging risk factors and disease recurrence represent continued challenges in the management of CDI. The increased incidence and severity associated with CDI has coincided with the emergence and rapid spread of a previously rare strain, ribotype 027. Recent data from the United States and Europe suggest that the incidence of CDI may have reached a crescendo in the recent years and is perhaps beginning to plateau. The acute care direct costs of CDI were estimated to be US$4.8 billion in 2008. However, nearly all the published studies have focused on CDI diagnosed and treated in the acute care hospital setting and fail to measure the burden outside the hospital, including recently discharged patients, outpatients, and those in long-term care facilities. Enhanced surveillance methods are needed to monitor the incidence, to identify populations at risk, and to characterize the molecular epidemiology of strains causing CDI.

Infection control and prevention considerations

Due to the nature of their underlying illness and treatment regimens, cancer patients are at increased risk of infection. Though the advent and widespread use of anti-infective agents has allowed for the application of ever-greater immune-suppressing therapies with successful treatment of infectious complications, prevention of infection remains the primary goal. The evolutionary changes of microorganisms, whereby resistance to anti-infective therapy is increasingly common, have facilitated a paradigm shift in the field of healthcare epidemiology. No longer is the focus on "control" of infection once established in a healthcare environment. Rather, the emphasis is on prevention of infection before it occurs. The most basic tenet of infection prevention, and the cornerstone of all well-designed infection prevention and control programs, is hand hygiene. The hands of healthcare workers provide a common potential source for transmission of infectious agents, and effective decontamination of the hands reduces the risk of transmission of infectious material to other patients. Once infection is suspected or established; however, implementation of effective control strategies is important to limit the spread of infection within a healthcare environment. This chapter outlines the basic tenets of infection prevention, principles of isolation precautions and control measures, and elements for a successful infection control and prevention program.

Role of doxycycline in Clostridium difficile infection acquisition

OBJECTIVE

To evaluate and review the literature surrounding the potential protective benefit of tetracyclines, particularly doxycycline, in reducing Clostridium difficile infection (CDI) acquisition.

DATA SOURCES

MEDLINE/PubMed, Google Scholar, and International Pharmaceutical Abstracts were searched through January 2014 using the search terms doxycycline, tetracycline, and Clostridium difficile.

STUDY SELECTION AND DATA EXTRACTION

Relevant studies, case reports, and review articles were screened for inclusion. Bibliographies of articles were extensively reviewed for additional sources.

DATA SYNTHESIS

Doxycycline is a second-generation tetracycline antibiotic indicated for use in a variety of clinical syndromes and has activity against aerobic Gram-positive and -negative, anaerobic, and atypical bacteria as well as protozoan parasites. Although not used therapeutically to treat CDI, doxycycline may prevent or attenuate the virulence factors of toxigenic C difficile. Current literature does not indicate an increased risk of development of CDI with doxycycline use. In 3 retrospective studies, the use of doxycycline was associated with a protective effect.

CONCLUSIONS

Doxycycline has been shown to have potential protective effects against the development of CDI. Although further randomized placebo-controlled studies are needed, available data suggest that the use of doxycycline in place of alternative antimicrobials, when appropriate, may be a useful antimicrobial stewardship strategy aimed at reducing the incidence of CDI.

Community-acquired Clostridium difficile infection: an increasing public health threat

There has been a startling shift in the epidemiology of Clostridium difficile infection over the last decade worldwide, and it is now increasingly recognized as a cause of diarrhea in the community. Classically considered a hospital-acquired infection, it has now emerged in populations previously considered to be low-risk and lacking the traditional risk factors for C. difficile infection, such as increased age, hospitalization, and antibiotic exposure. Recent studies have demonstrated great genetic diversity for C. difficile, pointing toward diverse sources and a fluid genome. Environmental sources like food, water, and animals may play an important role in these infections, apart from the role symptomatic patients and asymptomatic carriers play in spore dispersal. Prospective strain typing using highly discriminatory techniques is a possible way to explore the suspected diverse sources of C. difficile infection in the community. Patients with community-acquired C. difficile infection do not necessarily have a good outcome and clinicians should be aware of factors that predict worse outcomes in order to prevent them. This article summarizes the emerging epidemiology, risk factors, and outcomes for community-acquired C. difficile infection.

Control of Clostridium difficile infection in the hospital setting

Clostridium difficile infection (CDI) has emerged as a leading challenge in the control of healthcare-associated infection (HCAI). The epidemiology of CDI has changed dramatically, this is associated with emergence of 'hypervirulent' strains, particularly PCR ribotype 027. Despite the epidemic spread of these strains, there are recent reports of decreasing incidence from healthcare facilities where multi-facetted targeted control programs have been implemented. We consider these changes in epidemiology and reflect on the tools available to control CDI in the hospital setting. The precise repertoire of measures adopted and emphasis on different interventions will vary, not only between healthcare systems, but also within different institutions within the same healthcare system. Finally, we consider both the sustainability of reductions already achieved, and the potential to reduce CDI further. This takes account of newly emerging data on more recent changes in the epidemiology of CDI, and the potential of novel interventions to decrease the burden of disease.

Clostridium difficile infection: management strategies for a difficult disease

Clostridium difficile was first described as a cause of diarrhea in 1978 and in the last three decades has reached an epidemic state with increasing incidence and severity in both healthcare and community settings. There also has been a rise in severe outcomes from C. difficile infection (CDI). There have been tremendous advancements in the field of CDI with the identification of newer risk factors, recognition of CDI in populations previously thought not at risk and development of better diagnostic modalities. Several treatment options are available for CDI apart from metronidazole and vancomycin, and include new drugs such as fidaxomicin and other options such as fecal microbiota transplantation. This review discusses the epidemiology, risk factors and outcomes from CDI, and focuses primarily on existing and evolving treatment modalities.

Epidemiology and outcomes of community-acquired Clostridium difficile infections in Medicare beneficiaries

BACKGROUND

The incidence of community-acquired Clostridium difficile (CACD) is increasing in the United States. Many CACD infections occur in the elderly, who are predisposed to poor outcomes. We aimed to describe the epidemiology and outcomes of CACD in a nationally representative sample of Medicare beneficiaries.

STUDY DESIGN

We queried a 5% random sample of Medicare beneficiaries (2009-2011 Part A inpatient and Part D prescription drug claims; n = 864,604) for any hospital admission with a primary ICD-9 diagnosis code for C difficile (008.45). We examined patient sociodemographic and clinical characteristics, preadmission exposure to oral antibiotics, earlier treatment with oral vancomycin or metronidazole, inpatient outcomes (eg, colectomy, ICU stay, length of stay, mortality), and subsequent admissions for C difficile.

RESULTS

A total of 1,566 (0.18%) patients were admitted with CACD. Of these, 889 (56.8%) received oral antibiotics within 90 days of admission. Few were being treated with oral metronidazole (n = 123 [7.8%]) or vancomycin (n = 13 [0.8%]) at the time of admission. Although 223 (14%) patients required ICU admission, few (n = 15 [1%]) underwent colectomy. Hospital mortality was 9%. Median length of stay among survivors was 5 days (interquartile range 3 to 8 days). One fifth of survivors were readmitted with C difficile, with a median follow-up time of 393 days (interquartile range 129 to 769 days).

CONCLUSIONS

Nearly half of the Medicare beneficiaries admitted with CACD have no recent antibiotic exposure. High mortality and readmission rates suggest that the burden of C difficile on patients and the health care system will increase as the US population ages. Additional efforts at primary prevention and eradication might be warranted.

Antibiotic prophylaxis in hematopoietic stem cell transplantation. A meta-analysis of randomized controlled trials

OBJECTIVES

We performed a meta-analysis to evaluate the impact of systemic antibiotic prophylaxis in hematopoietic stem cell transplantation (HSCT) recipients.

METHODS

We collected reports from PubMed, the Cochrane Library, EMBASE, CINAHL, and Web of Science, along with references cited therein. We included prospective, randomized studies on systemic antibiotic prophylaxis in HSCT recipients.

RESULTS

Seventeen trials with 1453 autologous and allogeneic HSCT recipients were included. Systemic antibiotic prophylaxis was compared with placebo or no prophylaxis in 10 trials and with non-absorbable antibiotics in two trials. Systemic antibiotics other than fluoroquinolones were evaluated in five of these 12 trials. Four trials evaluated the effect of the addition of antibiotics for gram-positive bacteria to fluoroquinolones. One trial compared two different systemic antibiotic regimens: fluoroquinolones versus trimethoprim-sulfamethoxazole. As a result, systemic antibiotic prophylaxis reduced the incidence of febrile episodes (OR 0.16; 95%CI 0.09-0.30), clinically or microbiologically documented infection (OR 0.38; 95%CI 0.22-0.63) and bacteremia (OR 0.31; 95%CI 0.16-0.59) without significantly affecting all-cause mortality or infection-related mortality.

CONCLUSIONS

Systemic antibiotic prophylaxis successfully reduced the incidence of infection. However, there was no significant impact on mortality. The clinical benefits of prophylaxis with fluoroquinolones were inconclusive because of the small number of clinical trials evaluated.

A cluster of fulminant Clostridium difficile colitis in an intensive care unit in Italy

We describe, for the first time, a cluster of lethal fulminant health-care associated Clostridium difficile (CD) colitis in Italy, observed in the intensive care unit (ICU) of an Italian tertiary care hospital in Rome. For all cases the cause of ICU admission was CD-related septic shock. Three out of seven patients were residents in a long-term care facility in Rome, and the others had been transferred to the ICU from different medical wards of the same hospital. Five patients died within 96 h of ICU admission. Because of a clinical deterioration after 4 days of adequate antibiotic therapy, two patients underwent subtotal colectomy: both of them died within 30 days of surgical intervention. In four cases, ribotyping assay was performed and ribotype 027 was recognized. This high mortality rate could be attributable to three findings: the extent of disease severity induced by the strain 027, the delay in antimicrobial therapy administration, and the lack of efficacy of the standard antibiotic treatment for fulminant CD colitis compared to an earlier surgical approach. In order to contain a CD infection epidemic, control and surveillance measures should be implemented, and empirical therapy should be administered. Because of potential 027 ribotype CD spread in Italy, CDI should be regarded with a high index of suspicion in all patients presenting with shock and signs or symptoms suggesting abdominal disease, and an early surgical approach should be considered.

Ribotype 027 Clostridium difficile infections with measurable stool toxin have increased lactoferrin and are associated with a higher mortality

We evaluated clinical and diagnostic indicators of severe C. difficile infection (CDI) and their association with poor clinical outcome. A total of 210 patients positive according to PCR (toxin B: tcdB) were included, with patients having a median age of 62 years and a Charlson co-morbidity index (CI) score of 5. Ninety-one percent (n = 191) were positive by toxigenic culture and 61 % (n = 129) had stool toxin. Toxin-positive patients had significantly higher fecal lactoferrin (mean 316 μg/g versus 106 μg/g stool; p < 0.0001). Forty percent of patients (n = 85) were infected with ribotype 027 and significantly more of these patients had measurable stool toxin (79 % vs. 50 %; p < 0.0001). The mean fecal lactoferrin was significantly higher for toxin-positive 027 CDI compared with the 027 toxin-negative group (317 vs 60 μg/g; p = 0.0014). Ribotype 027 CDI with stool toxin showed a higher all-cause, 100-day mortality compared with non-027 with stool toxin (36 % vs 18 %; p = 0.017). Logistic regression univariate analysis for odds ratio (OR) and p values revealed that age (OR = 1.1), intensive care unit treatment (OR = 2.7), CI (OR = 1.2), 027 CDI (OR = 2.1), white blood cell count (OR = 1.0), albumin level (OR = 0.1), and stool toxin-positive 027 CDI (OR = 2.5) were significantly associated with 100-day mortality (p < 0.05). In conclusion, CDI PCR-positive patients with 027 infection and stool toxin have increased lactoferrin and are at an increased risk of death.

Bacterial enteric infections in children: etiology, clinical manifestations and antimicrobial therapy

Bacterial enteric infections have a huge impact on human health, particularly among the pediatric population. Despite the explosion of knowledge of the pathogenesis of bacterial enteric infections experienced in the past decade, the number of diarrheal episodes and childhood deaths reported continues to increase in many areas of the world. Specific antimicrobial therapy is indicated for certain confirmed infections, notably shigellosis, enterotoxigenic and enteroinvasive Escherichia coli infections, typhoid fever and cholera. Antimicrobial therapy may have a role in severe and prolonged gastrointestinal illness caused by nontyphoid Salmonella and Campylobacter. However, the use of antimicrobial agents may increase the risk of hemolytic uremic syndrome in children with E. coli O157:H7 infection. Bacterial genome sequencing and better understanding of the pathogenic mechanisms involved in the onset of diarrhea are leading to new preventive interventions, such as enteric vaccines, which may have a significant impact on the magnitude of this human plague.

Enteric infections

Cancer patients, particularly those with neutropenia, are at risk for enteric and intra-abdominal infections. Specific infections and infectious syndromes in this setting include neutropenic enterocolitis, bacterial infections such as Clostridium difficile infection (CDI), viral infections such as CMV colitis, and parasitic infections such as strongyloidiasis. Diagnosing and gauging the severity of CDI presents challenges, as chemotherapy may produce symptoms that mimic CDI and laboratory findings such as leukocytosis are not reliable in this population. Treatment for enteric infections should be pathogen specific, although broad-spectrum antibiotics are often required as initial empiric therapy in patients with neutropenia.

Community-associated Clostridium difficile infection: how real is it?

Community-associated Clostridium difficile infection (CA-CDI) represents 32% of all CDI cases based on U.S. population-based data. The current epidemic strain, NAP1, is the most prevalent strain causing these infections. Although complications, recurrence and death are uncommon, one-fourth of the CA-CDI patients are hospitalized within 7 days after the diagnosis.

The simple predictors of pseudomembranous colitis in patients with hospital-acquired diarrhea: a prospective observational study

Background/Aims

As the incidence rate of and mortality from pseudomembranous colitis (PMC) are increasing worldwide, it is important to study the simple predictive risk factors for PMC among patients with hospital-acquired diarrhea (HAD). This study focused on identifying the clinical risk factors that can easily predict PMC.

Methods

The presumed HAD patients were prospectively recruited at the Hallym University Kangdong Sacred Heart Hospital.

Results

Age of 70 and older (adjusted odds ratio [OR], 1.76; 95% confidence interval [CI], 1.12 to 0.75), use of proton pump inhibitors (adjusted OR, 4.07; 95% CI, 2.512 to 6.57), use of cephalosporins (adjusted OR, 2.99; 95% CI, 1.82 to 4.94), and underlying cancer (adjusted OR, 1.72; 95% CI, 1.04 to 2.82) were independent risk factors for PMC in the multivariate logistic regression analysis. The prevalence of PMC was very low in the patients with HAD who exhibited no risk factors.

Conclusions

The risk factors for PMC in patients with HAD included cephalosporin use, proton pump inhibitor use, old age, and cancer. Considering the strongly negative predictive values of these risk factors, endoscopic evaluation can be delayed in patients with HAD without risk of developing PMC.

The impact of cefepime as first line therapy for neutropenic fever on Clostridium difficile rates among hematology and oncology patients

After changing empiric treatment of febrile neutropenia from meropenem to cefepime, the effect on Clostridium difficile infection (CDI) was investigated. The change was assessed using an autoregressive model. A significant increase in CDI rates occurred following the introduction of cefepime. There may be an association between increased cefepime usage and CDI.

Epidemiology of Clostridium difficile infection

There has been dramatic change in the epidemiology of Clostridium difficile infection (CDI) since the turn of the 21st century noted by a marked increase in incidence and severity, occurring at a disproportionately higher frequency in older patients. Historically considered a nosocomial infection associated with antibiotic exposure, CDI has now also emerged in the community in populations previously considered low risk. Emerging risk factors and disease recurrence represent continued challenges in the management of CDI. The increased incidence and severity associated with CDI has coincided with the emergence and rapid spread of a previously rare strain, ribotype 027. Recent data from the United States and Europe suggest that the incidence of CDI may have reached a crescendo in the recent years and is perhaps beginning to plateau. The acute care direct costs of CDI were estimated to be US$4.8 billion in 2008. However, nearly all the published studies have focused on CDI diagnosed and treated in the acute care hospital setting and fail to measure the burden outside the hospital, including recently discharged patients, outpatients, and those in long-term care facilities. Enhanced surveillance methods are needed to monitor the incidence, to identify populations at risk, and to characterize the molecular epidemiology of strains causing CDI.

Clostridium difficile infection in the twenty-first century

Clostridium difficile is a spore-forming gram-positive bacillus, and the leading cause of antibiotic-associated nosocomial diarrhea and colitis in the industrialized world. With the emergence of a hypervirulent strain of C. difficile (BI/NAP1/027), the epidemiology of C. difficile infection has rapidly changed in the last decade. C. difficile infection, once thought to be an easy to treat bacterial infection, has evolved into an epidemic that is associated with a high rate of mortality, causing disease in patients thought to be low-risk. In this review, we discuss the changing face of C .difficile infection and the novel treatment and prevention strategies needed to halt this ever growing epidemic.

Hype or hypervirulence: a reflection on problematic C. difficile strains

Clostridium difficile infections (CDI) have emerged as a major cause of healthcare associated disease, and recent epidemiological evidence also suggests an important role in community-acquired diarrhea. This increase is associated with specific types, especially PCR ribotypes 027 and 078, which are sometimes referred to as “hypervirulent”. Over the past years major advances have been made in our understanding of C. difficile pathogenicity, with the identification and characterization of the major clostridial toxins TcdA and TcdB. However, the relation between the toxins, their regulation, and “hypervirulence” remain unclear. Here I review our current understanding of C. difficile pathogenicity and argue that “hypervirulent” is an inadequate term to describe PCR ribotypes 027 and 078, that the ability of C. difficile to cause problematic infections is a consequence of a multifactorial process that extends beyond toxins, sporulation, and antimicrobial resistance, and that vigilance is in order toward types that are closely related to ribotypes 027 and 078, but are currently not considered problematic.

Antimicrobial susceptibility of animal and human isolates of Clostridium difficile by broth microdilution

A total of 188 human (n = 92) and animal (n = 96) isolates of Clostridium difficile of different PCR ribotypes were screened for susceptibility to 30 antimicrobials using broth microdilution. When comparing the prevalence of antimicrobial resistance, the isolates of animal origin were significantly more often resistant to oxacillin, gentamicin and trimethoprim/sulfamethoxazole (P<0.01). The most significant difference between the animal and human populations (P = 0.0006) was found in the level of imipenem resistance, with a prevalence of 53.3 % in isolates of human origin and 28.1 % in isolates of animal origin. Overall, the results show similar MICs for the majority of tested antimicrobials for isolates from human and animal sources, which were collected from the same geographical region and in the same time interval. This supports the hypothesis that C. difficile could be transmissible between human and animal hosts. Resistant isolates have been found in all animal species tested, including food and companion animals, and also among non-toxigenic isolates. The isolates of the most prevalent PCR ribotype 014/020 had low resistance rates for moxifloxacin, erythromycin, rifampicin and daptomycin, but a high resistance rate for imipenem. Multiresistant strains were found in animals and humans, belonging to PCR ribotypes 012, 017, 027, 045, 046, 078 and 150, and also to non-toxigenic strains of PCR ribotypes 010 and SLO 080.

Treatment of Clostridium difficile infection: recent trial results

Clostridium difficile is a major cause of infection worldwide and is associated with increasing morbidity and mortality in vulnerable patient populations. Metronidazole and oral vancomycin are the currently recommended therapies for the treatment of C. difficile infection (CDI) but are associated with unacceptably high rates of disease recurrence. Novel therapies for the treatment of CDI and prevention of recurrent CDI are urgently needed. Important developments in the treatment of CDI are currently underway and include: novel antibacterial agents with narrower antimicrobial spectra of activity, manipulation of the gut microbiota and enhancement of the host antibody immune response.

Risk factors, preemptive therapy, and antiperistaltic agents for Clostridium difficile infection in cancer patients

BACKGROUND

Clostridium difficile infection (CDI) is a serious complication of chemotherapy including high-dose regimens with autologous stem cell transplantation (ASCT). Antiperistaltic agents are contraindicated in CDI and preemptive CDI therapy is not recommended. We assessed the incidence, risk factors, and outcomes of CDI in patients with newly diagnosed multiple myeloma (MM) receiving similar antineoplastic therapy and supportive care including antiperistaltic agents and preemptive CDI antibiotics for significant diarrhea.

METHODS

A total of 303 consecutive MM patients (2004-2007) were enrolled in a protocol consisting of induction chemotherapy, tandem melphalan (MEL)-ASCT, and consolidation. Patients with grade 2-4 diarrhea were simultaneously tested for CDI, and initiated on antiperistaltic agents (loperamide) and preemptive anti-CDI therapy. Risk factors, including prior CDI and MM immunoglobulin (Ig) isotype, were evaluated. Multinomial logistic regression was used to compute the relative risk ratio (RRR) and 95% confidence intervals (CIs).

RESULTS

There were 43 cases of CDI (14.2%) during 1529 chemotherapy courses (536 ASCT). IgA MM protected against CDI (RRR 0.35; 95% CI 0.13-0.93, P = 0.04) whereas CDI during first induction markedly increased the risk of recurrence during second induction (RRR = 10.94; 95% CI 1.90, 62.92, P = 0.01) and following MEL-ASCT (RRR = 6.63; 95% CI 1.51, 29.12, P = 0.01). No CDI-related surgical intervention or death ensued despite use of antiperistaltic agents.

CONCLUSIONS

CDI was not uncommon in cancer patients receiving chemotherapy. IgA myeloma appears to be protective. Concurrent antiperistaltic (loperamide) and preemptive CDI therapies were associated with excellent outcomes. Prior CDI history increased the risk for recurrence during successive chemotherapy courses.

Bed occupancy rates and hospital-acquired Clostridium difficile infection: a cohort study

BACKGROUND

An emergent strain (ribotype 027) of Clostridium difficile infection (CDI) has been implicated in epidemics worldwide. Organizational factors such as bed occupancy have been associated with an increased incidence of CDI; however, the data are sparse, and the association has not been widely demonstrated. We investigated the association of bed occupancy and CDI within a large hospital organization in the United Kingdom.

OBJECTIVE

To establish whether bed occupancy rates are a significant risk factor for CDI in the general ward setting.

METHODS

A retrospective cohort study was carried out on data from 2006 to 2008. Univariate and multivariate Cox regression modeling was used to examine the strength and significance of the associations. Variables included patient characteristics, antibiotic policy exposure, case mix, and bed occupancy rates.

RESULTS

A total of 1,589 cases of hospital-acquired CDI were diagnosed (1.7% of admissions), with an overall infection rate of 2.16 per 1,000 patient-days. Median bed occupancy was 93.3% (interquartile range, 83.3%-100%) Univariate and multivariate analyses showed positive and statistically significant associations. In the adjusted model, patients on wards with occupancy rates of 80%-89.9% had rates of CDI that were 56% higher (hazard ratio, 1.56 [95% confidence interval, 1.18-2.04]; P < .001) compared with baseline (0%-69.9% occupancy). CDI rates were 55% higher for patients on wards with maximal bed occupancy (100%).

CONCLUSIONS

There is strong evidence of an association between high bed occupancy and CDI. Without effective interventions at high levels of bed occupancy, the economic benefits sought from reducing bed numbers may be negated by the increased risk of CDI.

Clostridium difficile exposure as an insidious source of infection in healthcare settings: an epidemiological model

BACKGROUND

Clostridium difficile is the leading cause of infectious diarrhea in hospitalized patients. Its epidemiology has shifted in recent years from almost exclusively infecting elderly patients in whom the gut microbiota has been disturbed by antimicrobials, to now also infecting individuals of all age groups with no recent antimicrobial use.

METHODS

A stochastic mathematical model was constructed to simulate the modern epidemiology of C. difficile in a healthcare setting, and, to compare the efficacies of interventions.

RESULTS

Both the rate of colonization and the incidence of symptomatic disease in hospital inpatients were insensitive to antimicrobial stewardship and to the prescription of probiotics to expedite healthy gut microbiota recovery, suggesting these to be ineffective interventions to limit transmission. Comparatively, improving hygiene and sanitation and reducing average length of stay more effectively reduced infection rates. Although the majority of new colonization events are a result of within-hospital ward exposure, simulations demonstrate the importance of imported cases with new admissions.

CONCLUSIONS

By analyzing a wide range of screening sensitivities, we identify a previously ignored source of pathogen importation: although capturing all asymptomatic as well as symptomatic introductions, individuals who are exposed but not yet colonized will be missed by even a perfectly sensitive screen on admission. Empirical studies to measure the duration of this latent period of infection will be critical to assessing C. difficile control strategies. Moreover, identifying the extent to which the exposed category of individual contributes to pathogen importation should be explicitly considered for all infections relevant to healthcare settings.

Overview of severe Clostridium difficile infection

Clostridium difficile is an anaerobic, spore-forming, gram-positive bacillus that can produce severe colitis resulting in death. There has been an overall increase in the incidence of Clostridium difficile-associated disease and, particularly, an increase in the more virulent forms of the disease. Treatment of severe C difficile infection includes management of severe sepsis and shock, pathogen-directed antibiotic therapy, and, in selected cases, surgical intervention. Ultimately, prevention is the key to limiting the devastating effects of this microorganism.

Clostridium difficile 027/BI/NAP1 encodes a hypertoxic and antigenically variable form of TcdB

The Clostridium difficile exotoxin, TcdB, which is a major virulence factor, varies between strains of this pathogen. Herein, we show that TcdB from the epidemic BI/NAP1/027 strain of C. difficile is more lethal, causes more extensive brain hemorrhage, and is antigenically variable from TcdB produced by previously studied strains of this pathogen (TcdB₀₀₃). In mouse intoxication assays, TcdB from a ribotype 027 strain (TcdB₀₂₇) was at least four fold more lethal than TcdB₀₀₃. TcdB₀₂₇ caused a previously undescribed brain hemorrhage in mice and this correlated with a heightened sensitivity of brain microvascular endothelial cells to the toxin. TcdB₀₀₃ and TcdB₀₂₇ also differed in their antigenic profiles and did not share cross-neutralizing epitopes in a major immunogenic region of the protein. Solid phase humoral mapping of epitopes in the carboxy-terminal domains (CTD) of TcdB₀₂₇ and TcdB₀₀₃ identified 11 reactive epitopes that varied between the two forms of TcdB, and 13 epitopes that were shared or overlapping. Despite the epitope differences and absence of neutralizing epitopes in the CTD of TcdB₀₂₇, a toxoid form of this toxin primed a strong protective response. These findings indicate TcdB₀₂₇ is a more potent toxin than TcdB₀₀₃ as measured by lethality assays and pathology, moreover the sequence differences between the two forms of TcdB alter antigenic epitopes and reduce cross-neutralization by antibodies targeting the CTD.

During the past decade, the C. difficile BI/NAP1/027 strain has emerged and in some settings predominated as the cause of C. difficile infection. Moreover, in some reports C. difficile BI/NAP1/027 has been associated with more severe disease. The reasons for association of this strain with more severe disease and relapse are poorly understood. We compared the toxicity and antigenic profiles of the major C. difficile virulence factor, TcdB, from a previously studied reference strain and a BI/NAP1/027 strain. The results indicate TcdB₀₂₇, the toxin from the BI/NAP1/027 strain, is more lethal and causes more extensive brain hemorrhaging than TcdB₀₀₃, the toxin produced by a reference strain of C. difficile. Furthermore, the results show that the antigenic carboxy-terminal domain (CTD) encodes at least 11 epitopes that differ between the two forms of TcdB. In line with this, experiments demonstrate that antiserum against the CTD does not cross-neutralize TcdB₀₀₃ and TcdB₀₂₇ toxicity against CHO cells, and TcdB₀₂₇ appears to be devoid of neutralizing epitopes in this domain. These findings indicate differences in TcdB₀₀₃ and TcdB₀₂₇ contribute to increased virulence of C. difficile BI/NAP1/027 and reduce the likelihood of acquired immunity providing cross-protection against infection by these strains.

Fulminant Clostridium difficile colitis: a complication of perioperative antibiotic prophylaxis

Antibiotic prophylaxis for maxillofacial surgical wounds remains common practice. Surgeons must weigh the risks (e.g., Clostridium difficile colitis) against the benefits before administering antibiotics for any reason and the relative risk and morbidity of C difficile colitis against those of a potential postoperative wound infection. In addition, the possibility of C difficile infection as a complication of perioperative antibiotic prophylaxis should be discussed with patients before surgery, especially those with concomitant baseline risk factors. This report describes the case of a young healthy patient with few risk factors for C difficile infection who received a standard perioperative course of antibiotic therapy. Subsequently, the patient developed severe fulminant C difficile infection that required a protracted hospital admission, subtotal colectomy, and ileostomy. This case underscores that antibiotic prophylaxis continues in widespread use and is not benign therapy.

Assessment of treatment patterns and patient outcomes before vs after implementation of a severity-based Clostridium difficile infection treatment policy

BACKGROUND

National guidelines recommend oral vancomycin for severe Clostridium difficile infection (CDI) based on results from recent clinical trials demonstrating improved clinical outcomes. However, real-world data to support these clinical trials are scant.

AIM

To compare treatment patterns and patient outcomes of those treated for CDI before and after implementation of a severity-based CDI treatment policy at a tertiary teaching hospital.

METHODS

This study evaluated adult patients with a positive C. difficile toxin before and after implementation of a policy where patients with severe CDI given metronidazole were switched to oral vancomycin unless contra-indicated. Patients were stratified according to disease severity using a modified published severity score. Treatment patterns based on CDI severity and rates of refractory CDI were assessed.

FINDINGS

In total, 256 patients with CDI (mean age 66 years, standard deviation 17, 52% female) were evaluated (before implementation: N = 144; after implementation: N = 112). Use of oral vancomycin for severe CDI increased significantly from 14% (N = 8) to 91% (N = 48) following implementation of the policy (P < 0.0001). Refractory disease in patients with severe CDI decreased significantly from 37% to 15% following implementation of the policy (P = 0.035). No significant differences were noted among patients with mild to moderate CDI.

CONCLUSION

A severity-based CDI treatment policy at a tertiary teaching hospital increased the use of oral vancomycin and was associated with decreased rates of refractory CDI.

Epidemiology, diagnosis and treatment of Clostridium difficile infection

Clostridium difficile infection (CDI) is considered to be the main cause of bacterial infectious diarrhea in nosocomial settings. Since the beginning of the new century a continuous rise in the incidence of severe CDI has been observed worldwide. Even though some CDI cases are not associated with previous antibiotic exposure, this remains as the principal risk factor for the development of CDI. The rate of recurrences represents perhaps one the most challenging aspect on the management of CDI. There are several microbiological tests available, but glutamate dehydrogenase antigen test can be selected as the first screening step in a diagnostic algorithm, with positive samples then confirmed using a toxin(s) test, to distinguish toxinogenic from nontoxinogenic CDI. Although metronidazole and vancomycin are and have been the mainstay treatment options for CDI, there are some unmet medical and therapeutical needs. Usually oral metronidazole is recommended for initial treatment of nonsevere CDI and vancomycin for treatment of severe disease. Fidaxomicin may be considered in patients who cannot tolerate vancomycin, although more data are needed. For treatment of a nonsevere initial recurrence of CDI, oral metronidazole should be used, but for treatment of subsequent recurrences or more severe cases fidaxomicin may be helpful.