Evaluating the CT diagnosis of Clostridium difficile colitis: should CT guide therapy?

Cross-sectional imaging of mimics of inflammatory bowel disease: not everything is Crohn's disease or ulcerative colitis

Acute and chronic bowel pathologies can often be mistaken for manifestations of inflammatory bowel disease (IBD), and there are many entities with imaging and clinical features that overlap with IBD, making diagnosis difficult. We describe multiple inflammatory, infectious, neoplastic, and vascular entities with imaging and clinical features that may mimic IBD, and highlight differentiating features to assist in diagnosis.

Clostridioides difficile infection: history, epidemiology, risk factors, prevention, clinical manifestations, treatment, and future options

SUMMARYClostridioides difficile infection (CDI) is one of the major issues in nosocomial infections. This bacterium is constantly evolving and poses complex challenges for clinicians, often encountered in real-life scenarios. In the face of CDI, we are increasingly equipped with new therapeutic strategies, such as monoclonal antibodies and live biotherapeutic products, which need to be thoroughly understood to fully harness their benefits. Moreover, interesting options are currently under study for the future, including bacteriophages, vaccines, and antibiotic inhibitors. Surveillance and prevention strategies continue to play a pivotal role in limiting the spread of the infection. In this review, we aim to provide the reader with a comprehensive overview of epidemiological aspects, predisposing factors, clinical manifestations, diagnostic tools, and current and future prophylactic and therapeutic options for C. difficile infection.

Diagnostic Guidance for C. difficile Infections

Diagnosis of Clostridioides difficile infection (CDI) can be challenging. First of all, there has been debate on which of the two reference assays, cell cytotoxicity neutralization assay (CCNA) or toxigenic culture (TC), should be considered the gold standard for CDI detection. Although the CCNA suffers most from suboptimal storage conditions and subsequent toxin degradation, TC is reported to falsely increase CDI detection rates as it cannot differentiate CDI patients from patients asymptomatically colonised by toxigenic C. difficile. Several rapid assays are available for CDI detection and fall into three broad categories: (1) enzyme immunoassays for glutamate dehydrogenase, (2) enzyme immunoassays or single-molecule array assays for toxins A/B and (3) nucleic acid amplification tests detecting toxin genes. All three categories have their own limitations, being suboptimal specificity and/or sensitivity or the inability to discern colonised patients from CDI patients. In light of these limitations, multi-step algorithmic testing has been advocated by international guidelines (IDSA/SHEA and ESCMID) in order to optimize diagnostic accuracy. As a result, a survey performed in 2018-2019 in Europe revealed that most of all hospital sites reported using more than one test to diagnose CDI. CDI incidence rates are also influenced by sample selection criteria, as several studies have shown that if not all unformed stool samples are tested for CDI, many cases may be missed due to an absence of clinical suspicion. Since methods for diagnosing CDI remain imperfect, there has been a growing interest in alternative testing strategies like faecal microbiota biomarkers, immune modulating interleukins, cytokines and imaging methods. At the moment, these alternative methods might play an adjunctive role, but they are not suitable to replace conventional CDI testing strategies.

Does this patient have Clostridioides difficile infection? A systematic review and meta-analysis

BACKGROUND

The clinical features and predictors of Clostridioides difficile infection overlap with many conditions.

OBJECTIVES

We performed a systematic review to evaluate the diagnostic utility of clinical features (clinical examination, risk factors, laboratory tests, and radiographic findings) associated with C. difficile.

METHODS

Systematic review and meta-analysis of diagnostic features for C. difficile.

DATA SOURCES

MEDLINE, EMBASE, CINAHL, and Cochrane databases were searched up to September 2021.

STUDY ELIGIBILITY CRITERIA

Studies that reported clinical features of C. difficile, a valid reference standard test for confirming diagnosis of C. difficile, and a comparison among patients with a positive and negative test result.

PARTICIPANTS

Adult and paediatric patients across diverse clinical settings.

OUTCOMES

Sensitivity, specificity, likelihood ratios.

REFERENCE STANDARD

Stool nucleic acid amplification tests, enzyme immunoassays, cell cytotoxicity assay, and stool toxigenic culture.

ASSESSMENT OF RISK OF BIAS

Rational Clinical Examination Series and Quality Assessment of Diagnostic Accuracy Studies-2.

METHODS OF DATA SYNTHESIS

Univariate and bivariate analyses.

RESULTS

We screened 11 231 articles of which 40 were included, enabling the evaluation of 66 features for their diagnostic utility for C. difficile (10 clinical examination findings, 4 laboratory tests, 10 radiographic findings, prior exposure to 13 antibiotic types, and 29 clinical risk factors). Of the ten features identified on clinical examination, none were significantly clinically associated with increased likelihood of C. difficile infection. Some features that increased likelihood of C. difficile infection were stool leukocytes (LR+ 5.31, 95% CI 3.29-8.56) and hospital admission in the prior 3 months (LR+ 2.14, 95% CI 1.48-3.11). Several radiographic findings also strongly increased the likelihood of C. difficile infection like ascites (LR+ 2.91, 95% CI 1.89-4.49).

DISCUSSION

There is limited utility of bedside clinical examination alone in detecting C. difficile infection. Accurate diagnosis of C. difficile infection requires thoughtful clinical assessment for interpretation of microbiologic testing in all suspected cases.

The Current Knowledge on Clostridioides difficile Infection in Patients with Inflammatory Bowel Diseases

Clostridioides difficile (C. difficile) represents a major health burden with substantial economic and clinical impact. Patients with inflammatory bowel diseases (IBD) were identified as a risk category for Clostridioides difficile infection (CDI). In addition to traditional risk factors for C. difficile acquisition, IBD-specific risk factors such as immunosuppression, severity and extension of the inflammatory disease were identified. C. difficile virulence factors, represented by both toxins A and B, induce the damage of the intestinal mucosa and vascular changes, and promote the inflammatory host response. Given the potential life-threatening complications, early diagnostic and therapeutic interventions are required. The screening for CDI is recommended in IBD exacerbations, and the diagnostic algorithm consists of clinical evaluation, enzyme immunoassays (EIAs) or nucleic acid amplification tests (NAATs). An increased length of hospitalization, increased colectomy rate and mortality are the consequences of concurrent CDI in IBD patients. Selection of CD strains of higher virulence, antibiotic resistance, and the increasing rate of recurrent infections make the management of CDI in IBD more challenging. An individualized therapeutic approach is recommended to control CDI as well as IBD flare. Novel therapeutic strategies have been developed in recent years in order to manage severe, refractory or recurrent CDI. In this article, we aim to review the current evidence in the field of CDI in patients with underlying IBD, pointing to pathogenic mechanisms, risk factors for infection, diagnostic steps, clinical impact and outcomes, and specific management.

Drug-induced bowel complications and toxicities: imaging findings and pearls

The use of diverse types of drugs can result in a variety of acute and chronic complications that affect almost any organ. The bowel is one of the organs impacted by the side effects of medications. Imaging frequently plays a crucial role in the detection and characterization of complications occurring in the bowel. They include pseudomembranous colitis or antibiotic-associated colitis; angioedema induced by angiotensin-converting enzyme inhibitors; nonsteroidal anti-inflammatory drug-induced enteropathy; cocaine toxicity; clozapine-induced hypomobility; and bowel toxicity induced by chemotherapeutic agents. It is imperative that radiologists are fully aware of these complications and toxicities as well as the relevant findings. In this way, proper treatment can be implemented immediately. The treatment will involve discontinuation of a drug or a change in regimen.

Determining the optimal surgical timing of fulminant Clostridium difficile colitis by using four objective factors and computed tomography findings: A case report

INTRODUCTION AND IMPORTANCE

Clostridium difficile colitis is increasingly seen in everyday clinical situations, and most cases are treated with antibiotics. Fulminant C. difficile colitis (FCDC) is rare; however, it is extremely virulent, and understanding its appropriate surgical treatment is critical. The surgical timing is controversial because of the lack of concrete decision-making factors. We report a case of FCDC with a favourable outcome, which was achieved by using four objective factors and computed tomography (CT) findings.

CASE PRESENTATION

A patient with head trauma developed pneumonia at 2 days post-admission. He was prescribed with antibiotics. Fever and leucocytosis persisted on hospital day 10. Clostridium was detected in the stool on day 12, and metronidazole was administered. His condition did not improve; thus, he was started on vancomycin on day 14. The marked deterioration in the four laboratory parameters (white blood cell, albumin [Alb], creatinine, and body temperature) on day 15 and CT findings contributed to the decision to perform emergency subtotal colectomy and ileostomy. His condition improved dramatically postoperatively.

CLINICAL DISCUSSION

Many factors of FCDC are already suggested for surgical intervention in the guidelines; however, they are often seen at the late stage of FCDC. Early detection of FCDC is the key to favourable surgical outcome. Following the trend of these objective factors guides in making appropriate surgical decisions.

CONCLUSION

Focusing on the four objective factors and CT findings of FCDC could help surgeons detect FCDC at an early stage and decide the optimal surgical timing.

Recent advances in the treatment of Clostridioides difficile infection: the ever-changing guidelines

Clostridioides difficile infection (CDI), formerly known as Clostridium difficile, continues to be the most common healthcare-associated infection worldwide. With the shifting epidemiology towards higher a incidence of community-acquired CDI and the continued burden on the healthcare system posed by high rates of CDI recurrence, there has been an impetus to advance the diagnostic testing and treatment strategies. Recent advancements over the past decade have led to rapidly changing guidelines issued by the Infectious Diseases Society of America and European Society of Clinical Microbiology and Infectious Diseases. With our comprehensive review, we aim to summarize the latest advances in diagnosing and treating CDI and thus attempt to help readers guide best practices for patient care. This article also focusses on cost-effectiveness of various therapies currently available on the market and provides an analysis of the current evidence on a relatively new monoclonal antibody therapy, Bezlotoxumab, to treat recurrent CDI.

Discordant Clostridioides difficile diagnostic assay and treatment practice: a cross-sectional study in a tertiary care hospital, Geneva, Switzerland

OBJECTIVES

To determine the proportion of patients who received a treatment for Clostridioides difficile infection (CDI) among those presenting a discordant C. difficile diagnostic assay and to identify patient characteristics associated with the decision to treat CDI.

DESIGN

Cross-sectional study.

SETTING

Monocentric study in a tertiary care hospital, Geneva, Switzerland.

PARTICIPANTS

Among 4562 adult patients tested for C. difficile between March 2017 and March 2019, 208 patients with discordant tests' results (positive nucleic acid amplification test (NAAT+)/negative enzyme immunoassay (EIA-)) were included.

MAIN OUTCOME MEASURES

Treatment for CDI.

RESULTS

CDI treatment was administered in 147 (71%) cases. In multivariate analysis, an abdominal CT scan with signs of colitis (OR 14.7; 95% CI 1.96 to 110.8) was the only factor associated with CDI treatment.

CONCLUSIONS

The proportion of NAAT+/EIA- patients who received treatment questions the contribution of the EIA for the detection of toxin A/B after NAAT to limit overtreatment. Additional studies are needed to investigate if other factors are associated with the decision to treat.

Early Surgical Intervention for Fulminant Pseudomembranous Colitis

The objective of this study of a retrospective case series was to determine factors associated with survival after surgical intervention in pseudomembranous colitis (PMC). The study was conducted at a tertiary care medical center and comprised 36 patients who underwent colectomy for fulminant PMC from 1995 to 2006. Patients including 21 females ranged from 40 to 89 years of age (mean, 70 years). Comorbidities included diabetes (39%), cardiovascular disease (77%), chronic obstructive pulmonary disease (47%), and intake of immunosuppressive medications (45%). Seventy-two per cent received antibiotics in the previous 2 months. Only patients with a confirmation of PMC on pathology specimens were included in the study. All patients underwent colectomy. Patients were stratified into two groups: survivors and nonsurvivors. Various clinical factors/parameters used in the management of patients with PMC were studied in these two groups. Survival was correlated with mean white blood cell count (23,000 survivors versus 40,000 nonsurvivors, P < 0.01); multisystem organ failure (16 per cent survivors versus 47 per cent nonsurvivors, P < 0.05); and preoperative pressors (16 per cent survivors versus 47 per cent nonsurvivors, P < 0.05). Overall mortality for the study period was 47 per cent. Mortality rate analysis revealed a lower rate for the more recent years (32 per cent for 2000 to 2006 versus 65 per cent for 1995 to 1999, P < 0.05). In the more recent years, the time elapsing before colectomy was also lower (1.4 days versus 2.5 days, nonsignificant), and patients had less preoperative hemodynamic instability (70 per cent versus 31 per cent, P < 0.03). In one institution, survival after surgery for PMC was found to be associated with a mean white blood cell count (<37,000), nondependence on preoperative vasopressors, and surgical intervention before the onset of hemodynamic instability.

Significance of Clostridium difficile in community-acquired diarrhea in a tertiary care center in Lebanon

Clostridium difficile infection (CDI) is becoming a cause of community-acquired diarrhea. The aim is to describe (CDI) as a cause of acute diarrhea in patients presenting from the community to the Emergency Department (ED) of a tertiary care center in Lebanon. A retrospective study conducted in the ED at the American University of Beirut Medical Center (AUBMC). Adult patients presenting with the chief complaint of diarrhea and having positive CDI by stool laboratory testing (toxins A and B), during a three-year period were included. 125 patients with CDI were included. Average age was 61.43 (±20.42) with roughly equal sex prevalence. 30% (n = 36) of patients had neither antibiotic exposure nor recent hospitalization prior to current CDI. Mortality was 9.6% (n = 12), CDI was attributed as the cause in 16.7% (n = 2) and a contributing factor in 41.6% (n = 5). Recurrence within 3 months occurred in 9.6% (n = 11) in mainly those taking Proton Pump Inhibitors (PPIs) and having multiple co-morbidities. There is a high rate of community acquired CDI in Lebanon. Review of patients’ medications (PPIs and antibiotics) is crucial. More studies are needed to assess mortality associated with CDI and the outcome of coinfection with other enteric pathogens.

Clostridium difficile colitis: CT findings and differential diagnosis

Clostridium difficile infection (CDI) is a severe and potentially deadly infectious colitis whose incidence is dramatically increasing in the last decades, with more virulent strains. CDI should be suspected in case of unexplained diarrhea and abdominal pain in patients with a recent history of antibiotic use and healthcare exposures; diagnosis is based on a combination of clinical and laboratory findings with demonstration of C. difficile toxins by stool test. The advantages of contrast-enhanced computed tomography (CECT) are the noninvasiveness and the ability to evaluate both the colonic wall and the adjacent soft tissues. Considerable overlap exists between the CECT findings of CDI and those of colitis of other origins, such as typhlitis, ischemic colitis, graft-versus-host disease, radiation colitis and inflammatory bowel diseases; however, some features may help distinguish between these conditions. This paper provides a comprehensive overview of the imaging features of Clostridium difficile colitis and its mimics, with a view to assist the radiologist in reaching the correct diagnosis.

Myeloproliferative Neoplasms: A Primer for Radiologists

The myeloproliferative neoplasms (MPNs) are a heterogeneous group of diseases including polycythemia vera, essential thrombocythemia, and primary myelofibrosis. Knowledge of the radiological and clinical features of MPNs and their associated complications is critical for interpreting radiologists. The purpose of this article is to provide a primer to radiologists summarizing the modern understanding of MPNs from an imaging-based perspective, including common disease-related findings and complications related to hematopoietic cell transplant.

2019 update of the WSES guidelines for management of Clostridioides (Clostridium) difficile infection in surgical patients

In the last three decades, Clostridium difficile infection (CDI) has increased in incidence and severity in many countries worldwide. The increase in CDI incidence has been particularly apparent among surgical patients. Therefore, prevention of CDI and optimization of management in the surgical patient are paramount. An international multidisciplinary panel of experts from the World Society of Emergency Surgery (WSES) updated its guidelines for management of CDI in surgical patients according to the most recent available literature. The update includes recent changes introduced in the management of this infection.

Diagnostic Guidance for C. difficile Infections

Diagnosis of Clostridium difficile infection (CDI) can be challenging. First of all, there has been debate on which of the two reference assays, cell cytotoxicity neutralization assay (CCNA) or toxigenic culture (TC) should be considered the gold standard for CDI detection. Although the CCNA suffers most from suboptimal storage conditions and subsequent toxin degradation, TC is reported to falsely increase CDI detection rates as it cannot differentiate CDI patients from patients asymptomatically colonised by toxigenic C. difficile. Several rapid assays are available for CDI detection and fall into three broad categories: (1) enzyme immunoassays for glutamate dehydrogenase, (2) enzyme immunoassays for toxins A/B and (3) nucleic acid amplification tests detecting toxin genes. All three categories have their own limitations, being suboptimal specificity and/or sensitivity or the inability to discern colonised patients from CDI patients. In light of these limitations, multi-step algorithmic testing has now been advocated by international guidelines in order to optimize diagnostic accuracy. Despite these recommendations, testing methods between hospitals vary widely, which impacts CDI incidence rates. CDI incidence rates are also influenced by sample selection criteria, as several studies have shown that if not all unformed stool samples are tested for CDI, many cases may be missed due to an absence of clinical suspicion. Since methods for diagnosing CDI remain imperfect, there has been a growing interest in alternative testing strategies like faecal biomarkers, immune modulating interleukins, cytokines and imaging methods. At the moment, these alternative methods might play an adjunctive role, but they are not suitable to replace conventional CDI testing strategies.

Detection and diagnosis of colitis on computed tomography using deep convolutional neural networks

PURPOSE

Colitis refers to inflammation of the inner lining of the colon that is frequently associated with infection and allergic reactions. In this paper, we propose deep convolutional neural networks methods for lesion-level colitis detection and a support vector machine (SVM) classifier for patient-level colitis diagnosis on routine abdominal CT scans.

METHODS

The recently developed Faster Region-based Convolutional Neural Network (Faster RCNN) is utilized for lesion-level colitis detection. For each 2D slice, rectangular region proposals are generated by region proposal networks (RPN). Then, each region proposal is jointly classified and refined by a softmax classifier and bounding-box regressor. Two convolutional neural networks, eight layers of ZF net and 16 layers of VGG net are compared for colitis detection. Finally, for each patient, the detections on all 2D slices are collected and a SVM classifier is applied to develop a patient-level diagnosis. We trained and evaluated our method with 80 colitis patients and 80 normal cases using 4 × 4-fold cross validation.

RESULTS

For lesion-level colitis detection, with ZF net, the mean of average precisions (mAP) were 48.7% and 50.9% for RCNN and Faster RCNN, respectively. The detection system achieved sensitivities of 51.4% and 54.0% at two false positives per patient for RCNN and Faster RCNN, respectively. With VGG net, Faster RCNN increased the mAP to 56.9% and increased the sensitivity to 58.4% at two false positive per patient. For patient-level colitis diagnosis, with ZF net, the average areas under the ROC curve (AUC) were 0.978 ± 0.009 and 0.984 ± 0.008 for RCNN and Faster RCNN method, respectively. The difference was not statistically significant with P = 0.18. At the optimal operating point, the RCNN method correctly identified 90.4% (72.3/80) of the colitis patients and 94.0% (75.2/80) of normal cases. The sensitivity improved to 91.6% (73.3/80) and the specificity improved to 95.0% (76.0/80) for the Faster RCNN method. With VGG net, Faster RCNN increased the AUC to 0.986 ± 0.007 and increased the diagnosis sensitivity to 93.7% (75.0/80) and specificity was unchanged at 95.0% (76.0/80).

CONCLUSION

Colitis detection and diagnosis by deep convolutional neural networks is accurate and promising for future clinical application.

Efficacy of computed tomography for the prediction of colectomy and mortality in patients with clostridium difficile infection

AIM

To develop a CT predictor scale for the need for colectomy and to evaluate predictors of all-cause mortality within 30 days after diagnosis ofC. difficile infection (CDI).

METHODS

We conducted a retrospective study of adult hospitalized patients whounderwent abdominal CT within 72 h of diagnosis of CDI.

RESULTS

Presence of abnormal wall thickening in caecum (OR 8.0; CI 1.37-46.81; p = 0.021), transverse colon (OR 6.7; CI 1.15-35.60; p = 0.034), sigmoid colon (OR 12.6; CI 1.37-115.97; p = 0.025), pancolitis (OR 7.0; CI 1.36-36.01; p = 0.02) and bowel dilation (OR 16.5; CI 2.41-112.83; p = 0.004) predicted colectomy. With these values, a five parameter radiological scale from 0 to 24 was developed (sensitivity and NPV of 100%, cut-off of 6). Furthermore, wall thickening of caecum (OR 6.2; CI 1.06-35.57; p = 0.043), ascending colon (OR 12.0; CI 1.29-111.32; p = 0.029), descending colon (OR 17.0; CI 1.81-160.05; p = 0.013) and sigmoid (OR 10.2; CI 1.10-94.10; p = 0.041) independently predicted mortality within 30 days of CDI diagnosis.

CONCLUSION

We designed a CT scale to predict colectomy, able to rule out the development of fulminant colitis and the need for surgical procedure. Patients with wall thickening of the caecum, ascending, descending or sigmoid colon were more likely to die within 30 days of CDI diagnosis.

WSES guidelines for management of Clostridium difficile infection in surgical patients

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

Clostridium difficile infection: update on diagnosis, epidemiology, and treatment strategies

BACKGROUND

Clostridium difficile infection (CDI) has increased in incidence and severity over the past quarter century, and is now considered a major cause of healthcare-associated infections.

METHODS

Review of the pertinent English-language medical literature.

RESULTS

There has been a substantial change in the management of CDI. The emergence of the NAP1/BI/O27 strain in the early to mid-2000s has been associated with more severe forms of CDI. The pathophysiology, epidemiology, clinical manifestations and diagnosis, as well as new strategies for medical and surgical management are discussed in this review.

CONCLUSIONS

Clostridium difficile infection can range from benign diarrhea to severe disease associated with substantial morbidity and mortality. Treatment modalities vary based on disease severity and timing of onset. The mainstay of medical treatment remains metronidazole and oral/rectal vancomycin. New management strategies are evolving, including adjunctive treatments such as monoclonal antibodies, vaccination, and fecal transplant. In patients with severe disease or clinical deterioration, early surgical consultation for total colectomy or loop ileostomy may be life-saving. Infection control measures are vital to mitigating the spread of CDI.

Colorectal emergencies and related complications: a comprehensive imaging review--imaging of colitis and complications

OBJECTIVE

Colorectal emergencies are a common presentation in the emergency medicine setting and their timely diagnosis plays a crucial role in avoiding dreaded complications. The quintessential role of a radiologist lies in identifying the cause, narrowing the differential diagnosis according to imaging features, and, most importantly, identifying the associated complications.

CONCLUSION

This review focuses on imaging features of the spectrum of colitides and the complications related to colitides.

Fulminant Clostridium difficile Colitis: Comparing Computed Tomography with Histopathology: Are They Concordant?

A Total abdominal colectomy (TAC) is recommended for fulminant Clostridium difficile colitis (FCDC) because intraoperative assessment of diseased segments is inaccurate. To determine whether computerized tomography (CT) provides an accurate assessment of disease, we examined the concordance between CT and histopathologic colitis distribution in patients undergoing TAC for FCDC. The ileocolon was divided into seven distinct segments. Of 20 patients meeting criteria, the median interval between preoperative CT and TAC was 1.5 days (range, 0 to 23 days), and mortality was 65 per cent. The CT distribution of colitis was pancolitis in 12 patients and segmental in eight. Nine of the 12 patients with CT pancolitis had histologic pancolitis (75% concordance). Four of the eight patients with CT-diagnosed segmental disease had histologic segmental disease (50% concordance). For patients with FCDC, the distribution of colitis on CT agrees with the histopathologic extent of disease in the majority of patients. However, discordance between CT and histologic extent of disease was present in 25 to 50 per cent of patients. Therefore, the recommendation for TAC rather than segmental resection for FCDC remains justified.

Clostridium difficile Infection: Clinical Challenges and Management Strategies

Clostridium difficile has become the leading cause of nosocomial diarrhea in adults. A substantial increase has occurred in morbidity and mortality associated with disease caused by C difficile and in the identification of new hypervirulent strains, warranting a high clinical index of suspicion for infections due to this organism. Prevention of infection requires a multidisciplinary approach, including early recognition of disease, effective contact isolation precautions, adherence to disinfectant policies, and judicious use of antibiotics. Current treatment approaches are based on the severity of illness. As hypervirulent strains evolve, unsuccessful treatments are more common. Complicated colitis caused by C difficile may benefit from surgical intervention. Subtotal colectomy and end ileostomy have been the procedures of choice, but are associated with a high mortality rate because of late surgical consultation and use of surgery as a salvage therapy. A promising surgical alternative is creation of a diverting loop ileostomy with colonic lavage.

Fulminant colitis

Fulminant colitis is an ill-defined entity that is usually viewed as the most severe form of uncomplicated acute colitis. It usually occurs in the course of ulcerative colitis and infectious colitis, but can also be seen in other forms of colitis. Every patient with clinical criteria for severe or fulminant colitis should be approached in a systematic way, based on two premises - intense medical treatment and early surgery in non-responders.

The effects of statins on the clinical outcomes of Clostridium difficile infection in hospitalised patients

BACKGROUND

An association between exposure to statin drugs and favourable treatment outcomes for various types of infections has been established.

AIM

To determine the clinical characteristics and treatment outcomes of Clostridium difficile infection (CDI) among hospitalised patients taking statin drugs.

METHODS

The medical records were reviewed for consecutive in-patients with CDI confirmed by positive toxin assay (A or B), C. difficile culture, or the presence of pseudomembrane on endoscopy. Treatment success was defined as the resolution of diarrhoea within 6 days of therapy. The primary end points were assessed by average symptom recovery time and treatment response (success or failure).

RESULTS

Among 949 patients, the overall response to metronidazole was 91.9%. The baseline characteristics showed some differences between statin users and statin non-users with respect to mean disease severity score. In the multivariate analysis, successful treatment response was significantly associated with the absence of exposure to proton pump inhibitors (PPIs) (OR = 0.690, 95% CI = 0.513-0.929, P = 0.014) and with exposure to statins (OR = 1.449, 95% CI = 1.015-2.070, P = 0.041). Contrary to the treatment response, univariate and multivariate analyses failed to show that exposure to PPIs or statins affected symptom recovery times. Sixty-day CDI recurrence rates for those patients with statin exposure were significantly lower compared with those patients without statin exposure (3% vs. 7.3%, respectively; RR = 0.393, 95% CI = 0.167-0.926, P = 0.033).

CONCLUSION

Prior statin exposure in patients with C. difficile infection is associated with a successful response to treatment.

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.

Guidelines for diagnosis, treatment, and prevention of Clostridium difficile infections

Clostridium difficile infection (CDI) is a leading cause of hospital-associated gastrointestinal illness and places a high burden on our health-care system. Patients with CDI typically have extended lengths-of-stay in hospitals, and CDI is a frequent cause of large hospital outbreaks of disease. This guideline provides recommendations for the diagnosis and management of patients with CDI as well as for the prevention and control of outbreaks while supplementing previously published guidelines. New molecular diagnostic stool tests will likely replace current enzyme immunoassay tests. We suggest treatment of patients be stratified depending on whether they have mild-to-moderate, severe, or complicated disease. Therapy with metronidazole remains the choice for mild-to-moderate disease but may not be adequate for patients with severe or complicated disease. We propose a classification of disease severity to guide therapy that is useful for clinicians. We review current treatment options for patients with recurrent CDI and recommendations for the control and prevention of outbreaks of CDI.

New Drugs and Strategies for Management of Clostridium difficile Colitis

Approaches for management of Clostridium difficile infection continually evolve as research reveals shifts in epidemiology, microbial pathogenesis, disease severity states, and response to therapy. These new discoveries significantly impact diagnostic and therapeutic strategies, given the high morbidity associated with this common nosocomial infectious diarrhea. Critically ill patients are at an increased risk of developing diarrheal illness like C. difficile and succumbing to potentially fatal complications of this infection. Early diagnosis of severe disease state may improve patient outcomes. In this article, we review treatment strategies and new approaches for the management of C. difficile in critically ill patients.

An unexpected CT finding in a patient with abdominal pain

A fit and well 16-year-old girl presented to the emergency department with signs and symptoms suggestive of appendicitis. A transabdominal ultrasound scan revealed a normal appendix but there was significant free fluid in the pelvis. Consequently, a CT scan of her abdomen was performed which showed mucosal oedema and inflammation involving virtually the entire length of her large bowel (the 'accordion sign'). Clostridium difficile colitis was thus suspected; however, the toxin was not detected in her stool. The patient was treated conservatively with intravenous fluids and antibiotics and had an uneventful recovery. She was subsequently discharged home 3 days later with a full recovery. In this case, the radiological appearance of the accordion sign which is traditionally known to be pathognomonic of pseudomembranous colitis, reveals that it may also be indicative of severe colonic luminal inflammation.

Clostridium difficile infection in HIV-seropositive individuals and transplant recipients

Immunocompromise is a commonly cited risk factor for Clostridium difficile infection (CDI). We reviewed the experimental and epidemiological literature on CDI in three immunocompromised groups, HIV-seropositive individuals, haematopoietic stem cell or bone marrow transplant recipients and solid organ transplant recipients. All three groups have varying degrees of impairment of humoral immunity, a major factor influencing the outcome of CDI. Soluble HIV proteins such as nef and immunosuppressive agents such as cyclosporin, azathioprine and mycophenalate mofetil modify signalling from the key cellular pathways triggered by C. difficile toxin A, although there is a paucity of data on how these factors may interact with pathways activated by toxin B. Despite this, there has been little direct investigation into the effect of immunosuppression on the pathogenesis of CDI. Epidemiological studies consistently show increased rates of CDI in these populations, which are higher in those with greater degrees of immunocompromise such as individuals with advanced AIDS not receiving combination antiretroviral therapy or allogeneic haematopoietic stem cell transplant recipients. Less consistently data suggests immunocompromise in each group also impacts rates of severe, recurrent or complicated CDI. However all these conditions are characterised by high levels of antibiotic use and prolonged hospital stay, both powerful drivers of CDI risk.

Clinical approach to severe Clostridium difficile infection: update for the hospital practitioner

The rising incidence of Clostridium difficile (C. difficile) infection or CDI is now a problem of pandemic proportions. The NAP1 hypervirulent strain of C. difficile is responsible for a majority of recent epidemics and the widespread use of fluoroquinolone antibiotics may have facilitated the selective proliferation of this strain. The NAP1 strain also is more likely to cause severe and fulminant colitis characterized by marked leukocytosis, renal failure, hemodynamic instability, and toxic megacolon. No single test suffices to diagnose severe CDI, instead; the clinician must rely on a combination of clinical acumen, laboratory testing, and radiologic and endoscopic modalities. Although oral vancomycin and metronidazole are considered standard therapies in the medical management of CDI, recently it has been demonstrated that vancomycin is the more effective antibiotic in cases of severe disease. Moreover, early surgical consultation is necessary in patients who do not respond to medical therapy or who demonstrate rising white blood cell counts or hemodynamic instability indicative of fulminant colitis. Subtotal colectomy with end ileostomy is the procedure of choice for fulminant colitis. When applied to select patients in a judicious and timely fashion, surgery can be a life-saving intervention. In addition to these therapeutic approaches, several investigational treatments including novel antibiotics, fecal bacteriotherapy and immunotherapy have shown promise in the care of patients with severe CDI.

Predictors of Fatal Outcome after Colectomy for Fulminant Clostridium difficile Colitis: A 10-Year Experience

Surgical treatment of fulminant Clostridium difficile colitis has high mortality rates. Identification of a set of preoperative characteristics that could predict outcome after surgery is necessary to optimize clinical management and guide surgical timing. Data were retrospectively collected on patients operated on for C. difficile colitis between 2000 and 2010 at our institution. Statistical analysis was performed to identify predictors of mortality. We reviewed the records of 13 inpatients diagnosed as having C. difficile colitis and who underwent colectomy during the same admission. The in-hospital mortality rate for patients undergoing colectomy for colitis was 46.2 per cent. Independent predictors of mortality included the following: white blood cell count (34,600/μL or greater), hypoalbuminemia (1.5 g/dL or less), septic shock with requirements of vasopressors, and respiratory failure. Patients who underwent colectomy earlier (mean time from presentation to surgery 2.4 ± 1.5 days) had decreased mortality ( P = 0.019).). Longer length of hospital stay to the time of diagnosis was associated with higher rates of fatal outcome ( P = 0.031). Parameters without significant difference ( P > 0.05) included patient age, presenting symptoms, other comorbidities, creatinine levels, and CT scan findings. Identified factors can predict unfavorable outcomes after colectomy. Aggressive surgical intervention early in the course of the disease might be associated with improved survival.