Clinical manifestations, treatment and control of infections caused by Clostridium difficile

Guidelines for Antibiotics Prescription in Critically Ill Patients

How to cite this article: Khilnani GC, Tiwari P, Mittal S, Kulkarni AP, Chaudhry D, Zirpe KG, et al. Guidelines for Antibiotics Prescription in Critically Ill Patients. Indian J Crit Care Med 2024;28(S2):S104-S216.

Mortality Attributable to Clostridioides difficile Infection: The Rising Burden of Disease in European Countries

Background and Objectives: Clostridioides difficile infection is a major public health issue, being among the main causes of mortality due to healthcare-associated diarrhea. This study aimed to assess the trends in mortality attributable to Clostridioides difficile infections in European countries over a period of 30 years. Materials and Methods: A descriptive epidemiological study was conducted, with the application of an ecological study design, to evaluate the trends in mortality due to Clostridioides difficile infection in the Central, Eastern, and Western European sub-regions from 1990 to 2019. The Global Burden of Disease study database was used. Trends were evaluated with the joinpoint regression analysis. Results: In both sexes, about 76% of all deaths attributable to Clostridioides difficile infections were recorded in the Western European sub-region in 2019. The age-standardized rates of the burden of Clostridioides difficile infection in 2019 were the highest in the Central European sub-region, followed by the Western European sub-region, while the lowest rates were observed in the Eastern European sub-region. A significantly increasing trend in mortality attributable to Clostridioides difficile infection from 1990 to 2019 was recorded both in males (by +2.1% per year) and females (by +2.8% per year). The burden of Clostridioides difficile infection showed increasing trends in most of the European countries, significantly correlating with the country's development, according to the Human Development Index. Conclusions: The rising burden of Clostridioides difficile infection in European countries in the last few decades suggests a need for improving public health measures, with a focus both on the hospital setting and community.

Tubo-ovarian abscess caused by Clostridioides difficile after eight months of surgery: Case report and review of extraintestinal abdominal abscess cases

We present a case of tubo-ovarian abscess (TOA) caused by Clostridioides difficile (CD) in a 43-year-old female. Despite lacking a history of sexually transmitted diseases, the patient had undergone paraovarian cystectomy nine months before admission. Transvaginal ultrasonography performed eight months post-surgery revealed left ovarian enlargement, accompanied by subsequent lower abdominal pain and fever exceeding 38 °C. As oral antibiotic treatment was ineffective, the patient was admitted to our hospital. Computed tomography upon admission revealed a massive TOA. Surgical drainage of the abscess was performed, and CD was identified in the culture from the pus. The TOA was treated with a three-month course of metronidazole and oral amoxicillin/clavulanic acid. While CD is commonly associated with colitis, extraintestinal manifestations are exceptionally rare. This case represents the inaugural report of TOA resulting from CD. A literature review on abdominal and pelvic CD abscesses found that patients undergoing surgical drainage had a favorable prognosis. Therefore, surgical intervention plays an important role in the management of CD abscesses.

Novel Dietary Proteins Selectively Affect Intestinal Health In Vitro after Clostridium difficile-Secreted Toxin A Exposure

Bacterial gastroenteritis forms a burden on a global scale, both socially and economically. The Gram-positive bacterium Clostridium difficile is an inducer of gastrointestinal bacterial infections, often triggered following disruption of the microbiota by broad-spectrum antibiotics to treat other conditions. The clinical manifestatiaons, e.g., diarrhea, are driven by its toxins secretion, toxin A (TcdA) and toxin B (TcdB). Current therapies are focused on discontinuing patient medication, including antibiotics. However, relapse rates upon therapy are high (20-25%). Here, eighteen dietary proteins were evaluated for their capacity to restore gut health upon C. difficile-derived TcdA exposure. We used bioengineered intestinal tubules to assess proteins for their beneficial effects by examining the epithelial barrier, cell viability, brush-border enzyme activity, IL-6 secretion, IL-8 secretion and nitric oxide (NO) levels upon TcdA challenge. TcdA effectively disrupted the epithelial barrier, increased mitochondrial activity, but did not affect alkaline phosphatase activity, IL-6, IL-8 and NO levels. Intervention with dietary proteins did not show a protective effect on epithelial barrier integrity or mitochondrial activity. However, bovine plasma and potato protein increased alkaline phosphatase activity, egg-white protein increased IL-6 and IL-8 release and wheat, lesser mealworm and yeast protein increased NO levels after TcdA exposure. Hence, dietary proteins can influence parameters involved in intestinal physiology and immune activation suggesting that supplementation with specific dietary proteins may be of benefit during C. difficile infections.

Recommendations for the diagnosis and treatment of Clostridioides difficile infection: An official clinical practice guideline of the Spanish Society of Chemotherapy (SEQ), Spanish Society of Internal Medicine (SEMI) and the working group of Postoperative Infection of the Spanish Society of Anesthesia and Reanimation (SEDAR)

This document gathers the opinion of a multidisciplinary forum of experts on different aspects of the diagnosis and treatment of Clostridioides difficile infection (CDI) in Spain. It has been structured around a series of questions that the attendees considered relevant and in which a consensus opinion was reached. The main messages were as follows: CDI should be suspected in patients older than 2 years of age in the presence of diarrhea, paralytic ileus and unexplained leukocytosis, even in the absence of classical risk factors. With a few exceptions, a single stool sample is sufficient for diagnosis, which can be sent to the laboratory with or without transportation media for enteropathogenic bacteria. In the absence of diarrhoea, rectal swabs may be valid. The microbiology laboratory should include C. difficile among the pathogens routinely searched in patients with diarrhoea. Laboratory tests in different order and sequence schemes include GDH detection, presence of toxins, molecular tests and toxigenic culture. Immediate determination of sensitivity to drugs such as vancomycin, metronidazole or fidaxomycin is not required. The evolution of toxin persistence is not a suitable test for follow up. Laboratory diagnosis of CDI should be rapid and results reported and interpreted to clinicians immediately. In addition to the basic support of all diarrheic episodes, CDI treatment requires the suppression of antiperistaltic agents, proton pump inhibitors and antibiotics, where possible. Oral vancomycin and fidaxomycin are the antibacterials of choice in treatment, intravenous metronidazole being restricted for patients in whom the presence of the above drugs in the intestinal lumen cannot be assured. Fecal material transplantation is the treatment of choice for patients with multiple recurrences but uncertainties persist regarding its standardization and safety. Bezlotoxumab is a monoclonal antibody to C. difficile toxin B that should be administered to patients at high risk of recurrence. Surgery is becoming less and less necessary and prevention with vaccines is under research. Probiotics have so far not been shown to be therapeutically or preventively effective. The therapeutic strategy should be based, rather than on the number of episodes, on the severity of the episodes and on their potential to recur. Some data point to the efficacy of oral vancomycin prophylaxis in patients who reccur CDI when systemic antibiotics are required again.

Clostridium difficile Colitis Following Revision Total Knee Arthroplasty: Incidence and Risk Factors

BACKGROUND

Clostridium difficile-associated diarrhea (CDAD) is associated with adverse events and financial liability. As institutions continue to adopt CDAD rates as a quality control metric, it is important to identify patients at risk before surgery, including revision total knee arthroplasty (rTKA). This study was conducted to (1) determine the incidence of CDAD within 30 days of rTKA and (2) identify perioperative risk factors for CDAD following rTKA.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program was queried to identify 6023 rTKA procedures from 2015-2016. Preoperative and perioperative variables, including patient demographics, lab values, comorbidities, operative time, procedure type, presence of postoperative infections, and rates of CDAD were collected. Chi-square and Fisher's exact tests were used to detect differences between categorical variables, and t-tests were used to compare continuous variables. A stepwise logistic regression model was used to identify the risk factors for CDAD.

RESULTS

The rate of CDAD within 30 days of rTKA was found to be 0.4% (24/6024). The CDAD rate following aseptic revision was 0.2% (12/4893), while the incidence of CDAD after septic revision was 1.1% (12/1130). Preoperative functional dependence (odds ratio [OR] = 5.14; P = .002), septic revision (OR = 2.77; P = .026), and cancer (OR = 14.26; P = .016) were statistically significant independent risk factors for CDAD after rTKA.

CONCLUSION

The incidence of CDAD after rTKA is approximately 0.4% in the United States. Independent risk factors for CDAD include septic revision, preoperative functional dependence, and cancer. Prevention of CDAD in these higher risk patients must be considered before surgery and antibiotic selection for other infections should be managed judiciously.

Fecal Microbiota Transplant

Clostridium difficile infection (CDI) has steadily increased in incidence since the 1990s, with an associated increase in recurrence and severity, which has in turn lead to more intensive care unit (ICU) admissions. The development of recurrent CDI, in particular, has been associated with increasing patient morbidity and mortality as well as an immense financial burden on the health care system. Recently, fecal microbiota transplantation (FMT) has received much publicity as an effective means of treatment for recurrent CDI. The goal of this review is to provide evidence-based recommendations for the diagnosis and management of CDI, with a particular focus on FMT and its utilization in the ICU.

Consequences of Clostridium difficile infection: understanding the healthcare burden

Clostridium difficile is the leading cause of infectious nosocomial diarrhoea in developed countries, with a measured incidence of approximately five episodes per 10,000 days of hospital stay in Europe. Accurate diagnosis of C. difficile infection (CDI) is a prerequisite for obtaining reliable epidemiological data, but in many European countries diagnosis is probably suboptimal. A significant percentage of CDI cases are missed because clinicians often fail to request tests for C. difficile toxins in cases of unexplained diarrhoea. In addition, some laboratories continue to use tests of low sensitivity or apply them inappropriately. In one study in Spain, failure to request CDI testing in more than two-thirds of patients with unexplained diarrhoea led to significant underdiagnosis of cases. A recent pan-European survey revealed huge discrepancies in the rate of CDI testing across Europe, which suggests that epidemiological reports underestimate the true incidence of CDI in many parts of Europe. This is important because, as this review of the clinical and economic burden of CDI illustrates, infection with C. difficile imposes a significant burden not only on patients, owing to increased morbidity and mortality, but also on healthcare systems and society in general. On the basis of current incidence rates, annual costs for management of CDI amount to approximately $800 million in the USA and €3000 million in Europe. Moreover, estimates suggest that costs associated with recurrent CDI can exceed those of primary CDI. Measures to more effectively prevent CDI and reduce CDI recurrence rates may help to reduce this burden.

Asymptomatic carriers of clostridium difficile in serbian population

The aim of the research was to determine the intestinal carriers of C. difficile in different human population groups in Serbia. The research enrolled 877 persons with formed stools: (newborn children in maternity hospitals for up to two weeks old) (23), group A; children aged from two weeks to two years (121), group B; children aged two to 10 years (54), group C, healthy individuals aged 10 and over (516), group D; patients hospitalized for at least 48 hours (100), group E; staff of the Clinical Center in Nis, Serbia, (63), group F. The toxins A and B of C. difficile were detected by ELISA-ridascreen Clostridium difficile Toxin A/B (R — Biopharm AG, Darmstadt, Germany). The toxin A of C. difficile was detected using ColorPAC Toxin A test (BectonDickinson, New Jersey, USA). Out of the total number of persons (877), the carriers of certain types of toxin-producing strains of C. difficile were distributed as: 6.04% (A−/B−), 1.83% (A+/B+) and 0.11% (A−/B+). In most groups (5/6), the dominance of non-toxigenic (A−/B−) isolates was established, with the rate of carriers 1.75 – 30.43% depending on the group. Toxigenic isolates were prevalent only in the group F in relation to non — toxigenic (7.94% versus 4.76% of persons). In other groups, the carriers of toxigenic strains ranged from 0.00 – 17.45%. The presence of asymptomatic intestinal carriers of C. difficile in the human population, indicate the possible reservoirs and sources of infection.

Clinical importance and representation of toxigenic and non-toxigenic Clostridium difficile cultivated from stool samples of hospitalized patients

The aim of this study was to fortify the clinical importance and representation of toxigenic and non-toxigenic Clostridium difficile isolated from stool samples of hospitalized patients. This survey included 80 hospitalized patients with diarrhea and positive findings of Clostridium difficile in stool samples, and 100 hospitalized patients with formed stool as a control group. Bacteriological examination of a stool samples was conducted using standard microbiological methods. Stool sample were inoculated directly on nutrient media for bacterial cultivation (blood agar using 5% sheep blood, Endo agar, selective Salmonella Shigella agar, Selenite-F broth, CIN agar and Skirrow's medium), and to selective cycloserine-cefoxitin-fructose agar (CCFA) (Biomedics, Parg qe tehnicologico, Madrid, Spain) for isolation of Clostridium difficile. Clostridium difficile toxin was detected by ELISA-ridascreen Clostridium difficile Toxin A/B (R-Biopharm AG, Germany) and ColorPAC ToxinA test (Becton Dickinson, USA). Examination of stool specimens for the presence of parasites (causing diarrhea) was done using standard methods (conventional microscopy), commercial concentration test Paraprep S Gold kit (Dia Mondial, France) and RIDA(®)QUICK Cryptosporidium/Giardia Combi test (R-Biopharm AG, Germany). Examination of stool specimens for the presence of fungi (causing diarrhea) was performed by standard methods. All stool samples positive for Clostridium difficile were tested for Rota, Noro, Astro and Adeno viruses by ELISA - ridascreen (R-Biopharm AG, Germany). In this research we isolated 99 Clostridium difficile strains from 116 stool samples of 80 hospitalized patients with diarrhea. The 53 (66.25%) of patients with diarrhea were positive for toxins A and B, one (1.25%) were positive for only toxin B. Non-toxigenic Clostridium difficile isolated from samples of 26 (32.5%) patients. However, other pathogenic microorganisms of intestinal tract cultivated from samples of 16 patients. Examination of cultivated colonies revealed that most of cultivated species belonged to genera of Campylobacter spp., Salmonella spp., and Candida spp.. In control group, toxigenic Clostridium difficile cultivated from stool samples of two patients (2%) and non-toxigenic Clostridium difficile from samples of five patients (5%). This research confirmed clinical importance of toxigenic Clostridium difficile found in liquid stool samples of hospitalized patient, and the possibility of asymptomatic carriage in 2% of patients with formed stool.

Clostridium difficile in the ICU: the struggle continues

Clostridium difficile infection (CDI) management has become more daunting over the past decade because of alarming increases in CDI incidence and severity both in the hospital and in the community. This increase has concomitantly caused significant escalation of the health-care economic burden caused by CDI, and it will likely be translated to increased ICU admission and attributable mortality. Some possible causes for difficulty in management of CDI are as follows: (1) inability to predict and prevent development of severe/complicated or relapsing CDI in patients who initially present with mild symptoms; (2) lack of a method to determine who would have benefited a priori from initiating vancomycin treatment first instead of treatment with metronidazole; (3) lack of sensitive and specific CDI diagnostics; (4) changing epidemiology of CDI, including the emergence of a hypervirulent, epidemic C difficile strain associated with increased morbidity and mortality; (5) association of certain high-usage nonantimicrobial medications with CDI; and (6) lack of treatment regimens that leave the normal intestinal flora undisturbed while treating the primary infection. The objective of this article is to present current management and prevention guidelines for CDI based on recommendations by the Society for Healthcare Epidemiology of America and Infectious Diseases Society of America and potential new clinical management strategies on the horizon.

Differential risk of Clostridium difficile infection with proton pump inhibitor use by level of antibiotic exposure

PURPOSE

Clostridium difficile infection (CDI) is a major cause of hospital-acquired diarrhea worldwide. We examined the risk of CDI associated with the use of acid-suppressive agents (proton pump inhibitors [PPI] and histamine-2 receptor blockers) and determined whether this risk varied by number or type of antibiotic (high or low CDI risk) received during hospitalization.

METHODS

We conducted a retrospective cohort study of hospitalizations among adult patients at an academic teaching hospital in Rochester, New York, during which two or more days of antibiotics were prescribed. Multivariable marginal Cox proportional hazards models with time-varying exposures were used to examine time to the development of CDI.

RESULTS

A total of 10 154 hospitalizations and 241 cases of CDI, defined as detection of C. difficile toxin in a diarrheal stool sample within 60 days of discharge, were identified. PPI use was independently associated with an increased risk of CDI (adjusted hazard ratio = 4.5; 95% confidence interval [CI] = 2.3-9.0). Among hospitalizations during which one, two, three or four, and five or more antibiotics were prescribed, the adjusted hazard ratios for PPI use were 15.7 (CI = 6.4-38.8), 4.9 (CI = 2.2-11.2), 4.3 (CI = 1.9-9.9), and 2.7 (CI = 1.2-5.9), respectively (p for interaction = .002).

CONCLUSIONS

The use of PPI is common among patients receiving antibiotics during hospitalization. The greater risk of CDI in relation to PPI among hospitalizations during which fewer or low-risk antibiotics were prescribed suggests a potentially clinically relevant interaction between antibiotics and PPI. Further study is needed to elucidate possible mechanisms for the observed effect.

The ecology and pathobiology of Clostridium difficile infections: an interdisciplinary challenge

Clostridium difficile is a well recognized pathogen of humans and animals. Although C. difficile was first identified over 70 years ago, much remains unknown in regards to the primary source of human acquisition and its pathobiology. These deficits in our knowledge have been intensified by dramatic increases in both the frequency and severity of disease in humans over the last decade. The changes in C. difficile epidemiology might be due to the emergence of a hypervirulent stain of C. difficile, ageing of the population, altered risk of developing infection with newer medications, and/or increased exposure to C. difficile outside of hospitals. In recent years, there have been numerous reports documenting C. difficile contamination of various foods, and reports of similarities between strains that infect animals and strains that infect humans as well. The purposes of this review are to highlight the many challenges to diagnosing, treating, and preventing C. difficile infection in humans, and to stress that collaboration between human and veterinary researchers is needed to control this pathogen.

Toxic megacolon associated Clostridium difficile colitis

Toxic megacolon is a severe complication of Clostridium difficile (C. difficile) colitis. As the prevalence of C. difficile colitis increases and treatments become more refractory, clinicians will encounter more patients with C. difficile associated toxic megacolon in the future. Here, we review a case of toxic megacolon secondary to C. difficile colitis and review the current literature on diagnosis and management. We identify both clinical and radiologic criteria for diagnosis and discuss both medical and surgical options for management. Ultimately, we recommend using the Jalen criteria in conjunction with daily abdominal radiographs to help establish the diagnosis of toxic megacolon and to make appropriate treatment recommendations. Aggressive medical management using supportive measures and antibiotics should remain the mainstay of treatment. Surgical intervention should be considered if the patient does not clinically improve within 2-3 d of initial treatment.

Review of medical and surgical management of Clostridium difficile infection

Clostridium difficile infection (CDI) has become an important area in our daily clinical practice. C. difficile is known to cause a broad spectrum of conditions ranging from asymptomatic carriage, through mild or moderately severe disease with watery diarrhoea, to the life-threatening pseudomembranous colitis (PMC), with toxic megacolon and ileus. Peoples who have been treated with broad-spectrum antibiotics, patients with serious underlying co-morbidities and the elderly are at greatest risk. Over 80% of CDIs reported are in people aged over 65. Due to the alarming increase in its frequency, appearance of more virulent strains and occasional need for life-saving surgical intervention, a more coherent multidisciplinary approach is needed. Combination of rapid turn round time and accurate diagnosis will result in a better management of CDI and a timely implementation of infection control measure. Discontinuation of causative agents such as antibiotic treatment is often curative. In more serious cases, oral administration of metronidazole or vancomycin is the treatment of choice. Relapses of CDI have been reported in about 20-25% of cases, this may increase to 45-60% after the first recurrence. Patients should be treated as soon as possible when the diagnosis of Clostridium difficile colitis is made to avoid sepsis or bowel perforation. Colectomy may improve the outcome of the patient with systemic or complicated Clostridium difficile colitis. This article reviews the changing epidemiological picture, microbiology, histopathology and both medical and surgical managements.

Prevention and treatment of health care-acquired infections

Health care-acquired infections present a tremendous challenge to the care of hospitalized patients. Unfortunately, the risk of acquiring a health care-associated infection (HAI) is rising. The vast majority of HAI are of four types: urinary tract infections, surgical site infections, bloodstream infections, and pneumonia. This chapter aims to provide current data and strategies relating to the prevention of HAIs among hospitalized patients.

Prevalence and risk factors for Clostridium difficile colonization in dogs and cats hospitalized in an intensive care unit

Clostridium difficile is the most common cause of hospital- and antimicrobial-associated diarrhea in hospitalized humans however the role of C. difficile in diarrhea in dogs has not been defined. A prospective study of C. difficile colonization in dogs and cats was conducted in a veterinary teaching hospital intensive care unit (ICU). Rectal swabs were taken from patients upon admission to the ICU and every third day of hospitalization until discharge or death. C. difficile was isolated from 73/402 (18%) animals; 69% of isolates were toxigenic. Community-associated colonization was identified in 39/366 (11%) of animals that were sampled at the time of admission, while C. difficile was subsequently isolated from 27 of the remaining 327 (8.3%) animals that had a negative admission swab. C. difficile was isolated from seven other dogs during hospitalization, but the origin was unclear because the admission swab was not collected. Administration of antimicrobials prior to admission and administration of immunosuppressive drugs during hospitalization were risk factors for hospital-associated colonization (P=0.006, OR 4.05, 95% CI 1.4-10.8). Acquisition of C. difficile during hospitalization in the ICU was associated with the development of diarrhea (P=0.004). Two ribotypes, one toxigenic and one non-toxigenic, predominated.

Molecular and structural discrimination of proline racemase and hydroxyproline-2-epimerase from nosocomial and bacterial pathogens

The first eukaryotic proline racemase (PRAC), isolated from the human Trypanosoma cruzi pathogen, is a validated therapeutic target against Chagas' disease. This essential enzyme is implicated in parasite life cycle and infectivity and its ability to trigger host B-cell nonspecific hypergammaglobulinemia contributes to parasite evasion and persistence. Using previously identified PRAC signatures and data mining we present the identification and characterization of a novel PRAC and five hydroxyproline epimerases (HyPRE) from pathogenic bacteria. Single-mutation of key HyPRE catalytic cysteine abrogates enzymatic activity supporting the presence of two reaction centers per homodimer. Furthermore, evidences are provided that Brucella abortus PrpA [for 'proline racemase' virulence factor A] and homologous proteins from two Brucella spp are bona fide HyPREs and not 'one way' directional PRACs as described elsewhere. Although the mechanisms of aminoacid racemization and epimerization are conserved between PRAC and HyPRE, our studies demonstrate that substrate accessibility and specificity partly rely on constraints imposed by aromatic or aliphatic residues distinctively belonging to the catalytic pockets. Analysis of PRAC and HyPRE sequences along with reaction center structural data disclose additional valuable elements for in silico discrimination of the enzymes. Furthermore, similarly to PRAC, the lymphocyte mitogenicity displayed by HyPREs is discussed in the context of bacterial metabolism and pathogenesis. Considering tissue specificity and tropism of infectious pathogens, it would not be surprising if upon infection PRAC and HyPRE play important roles in the regulation of the intracellular and extracellular amino acid pool profiting the microrganism with precursors and enzymatic pathways of the host.

Cystic fibrosis: a polymicrobial infectious disease

Cystic fibrosis (CF) is the most common lethal genetic disease in the Caucasian population, and should be considered an infectious disease because of the basic pathophysiology. Chronic lower airway infections cause a progressive pathologic deterioration of lung tissue, a decline in pulmonary function and, ultimately, respiratory failure and death in 90% of CF patients. Historically, very few bacterial species have been implicated as principal CF pathogens. However, molecular evidence suggests the presence of a diverse mosaic of bacteria in CF lungs, and infections can be defined as polymicrobial. Here we review the work that supports this concept and we discuss the potential significance of the polymicrobial community in lung pathology. Understanding the dynamics of polymicrobial infections, the interplay between pathogen(s), normal oropharyngeal flora and the host immune system may lead to future advances in the therapeutic management of chronic lung infections.

Yield of stool culture with isolate toxin testing versus a two-step algorithm including stool toxin testing for detection of toxigenic Clostridium difficile

We examined the incremental yield of stool culture (with toxin testing on isolates) versus our two-step algorithm for optimal detection of toxigenic Clostridium difficile. Per the two-step algorithm, stools were screened for C. difficile-associated glutamate dehydrogenase (GDH) antigen and, if positive, tested for toxin by a direct (stool) cell culture cytotoxicity neutralization assay (CCNA). In parallel, stools were cultured for C. difficile and tested for toxin by both indirect (isolate) CCNA and conventional PCR if the direct CCNA was negative. The "gold standard" for toxigenic C. difficile was detection of C. difficile by the GDH screen or by culture and toxin production by direct or indirect CCNA. We tested 439 specimens from 439 patients. GDH screening detected all culture-positive specimens. The sensitivity of the two-step algorithm was 77% (95% confidence interval [CI], 70 to 84%), and that of culture was 87% (95% CI, 80 to 92%). PCR results correlated completely with those of CCNA testing on isolates (29/29 positive and 32/32 negative, respectively). We conclude that GDH is an excellent screening test and that culture with isolate CCNA testing detects an additional 23% of toxigenic C. difficile missed by direct CCNA. Since culture is tedious and also detects nontoxigenic C. difficile, we conclude that culture is most useful (i) when the direct CCNA is negative but a high clinical suspicion of toxigenic C. difficile remains, (ii) in the evaluation of new diagnostic tests for toxigenic C. difficile (where the best reference standard is essential), and (iii) in epidemiologic studies (where the availability of an isolate allows for strain typing and antimicrobial susceptibility testing).

Clostridium difficile–associated Diarrhea in Heart Transplant Recipients: Is Hypogammaglobulinemia the Answer?

BACKGROUND

Information regarding Clostridium difficile-associated diarrhea (CDAD) after solid-organ transplantation (SOT) is scarce, particularly after heart transplantation (HT). Although host immune response to C. difficile plays a substantial role in the outcome of this infection, the responsibility of hypogammaglobulinemia (HGG) as a predisposing condition for CDAD has not been studied in SOT. We analyzed the incidence, clinical presentation, outcome and risk factors, including HGG, of CDAD after HT.

METHODS

Two hundred thirty-five patients who underwent HT (1993 to 2005) were included. Transplantation procedure and immunosuppression were standard. From January 1999 HGG was systematically searched and corrected when IgG levels were <400 mg/dl or severe infection was present. Toxin-producing C. difficile was detected by means of cytotoxin assay and culture of stool samples. Patients with and without CDAD were compared for identification of risk factors.

RESULTS

CDAD was detected in 35 patients (14.9%). Incidence decreased significantly since HGG was sought and treated: 29 (20.6%) in the first period, and 6 (6.4%) in the second (p = 0.003). CDAD appeared a mean of 32 days (range 5 to 3,300 days) after HT. No related death or episode of fulminant colitis was detected. At least one episode of recurrence was noted in 28.6% of patients. Severe HGG was found to be the only independent risk factor for CDAD after HT (RR 5.8; 95% CI: 1.05 to 32.1; p = 0.04).

CONCLUSIONS

C. difficile is a significant cause of diarrhea in HT recipients and post-transplant HGG is independently associated with an increased risk. The potential role of immunoglobulin administration in this population requires further study.

Probiotics for Clostridium difficile-associated diarrhea: focus on Lactobacillus rhamnosus GG and Saccharomyces boulardii

OBJECTIVE

To review the literature on the use of probiotics to treat or prevent recurrences of Clostridium difficile-associated diarrhea (CDAD) by replacing normal gastric flora.

DATA SOURCES

PubMed (1970-March 2007) was searched using the terms probiotics, Clostridium difficile, colitis, diarrhea, prevention, and treatment.

STUDY SELECTION AND DATA EXTRACTION

Case reports, case series, and clinical trials describing the use of probiotics in the treatment or prevention of recurrences of CDAD as primary outcome were included.

DATA SYNTHESIS

A variety of controlled trials, case series, and case reports have evaluated probiotics to treat first or recurrent episodes of CDAD. In addition, a meta-analysis has been conducted to try to determine the role of probiotics in CDAD. In general, most case series and case reports have shown favorable results with Lactobacillus rhamnosus GG or Saccharomyces boulardii. However, other reports have shown lack of benefit. The meta-analysis showed that these probiotics may be useful in treating or preventing recurrences of CDAD. Nonetheless, the heterogeneity of the studies makes definite conclusions difficult. In addition, several cases of bacteremia or fungemia associated with probiotic use have been reported, particularly in the last decade. Patients most commonly affected by these complications are immunosuppressed. Unfortunately, these are also the patients more likely to have severe CDAD or are at risk for recurrences.

CONCLUSIONS

Additional experience with and study of probiotics are warranted due to numerous unanswered questions. Given the potential for complications in debilitated and immunosuppressed patients, the risks may outweigh benefits, and rational antibiotic use may be a better option to prevent a first episode or recurrence of CDAD.

Past, present, and future therapies for Clostridium difficile-associated disease

OBJECTIVE

To describe and examine the past, present, and potential future treatment options for Clostridium difficile-associated disease (CDAD).

DATA SOURCES

A PubMed search, restricted to English-language articles concerning CDAD, was conducted (1965-October 2006) using the key words Clostridium difficile, diarrhea, vancomycin, metronidazole, immunoglobulin, and recurrence. Additional references were located through review of the bibliographies of cited articles and by visiting www.clinicaltrials.gov.

STUDY SELECTION AND DATA EXTRACTION

Articles related to the clinical manifestations, diagnosis, and treatment of CDAD, as well as articles addressing current issues related to CDAD, were included.

DATA SYNTHESIS

There have been many investigations into CDAD because of the recent increased incidence and morbidity and mortality of the disease. Various studies examining the changing epidemiology and pathogenicity of C. difficile, as well as new therapies for CDAD with agents such as tolevamer and nitazoxanide, are ongoing. In addition, researchers are investigating probiotics and vaccines to evaluate their effectiveness in preventing CDAD and/or preventing recurrences of CDAD. Studies assessing therapies for refractory CDAD are lacking, although case reports have been published citing treatment strategies using vancomycin enemas, intravenous metronidazole, colestipol and cholestyramine, fecal enemas, bowel irrigation, and immunoglobulin. Furthermore, judicious use of antimicrobials, contact precautions, and adequate environmental cleaning are being evaluated in healthcare institutions as methods for controlling and preventing the spread of C. difficile.

CONCLUSIONS

Oral metronidazole is the drug of choice for an initial CDAD episode. Oral vancomycin is an option for patients who cannot take or fail treatment with oral metronidazole. Clinical trials are necessary to define the therapy for initial CDAD that is most appropriate and produces lower recurrence rates compared with oral metronidazole or vancomycin treatment. Moreover, appropriate treatment for patients with multiple recurrences of or refractory CDAD needs to be determined. More studies are also needed assessing prevention of recurrences of CDAD.

Antimicrobial therapy of Clostridium difficile-associated diarrhea

Clostridium difficile-associated diarrhea (CDAD) is the most common etiologically-defined cause of hospital-acquired diarrhea. Caused by the toxins of certain strains of C difficile, CDAD represents a growing concern, with epidemic outbreaks in some hospitals where very aggressive and difficult-to-treat strains have recently been found. Incidence of CDAD varies ordinarily between 1 to 10 in every 1,000 admissions. Evidence shows that CDAD increases morbidity, length of stay, and costs. This article described the clinical manifestations of CDAD, related risk factors, considerations for confirming CDAD, antimicrobial and non-antimicrobial treatment of CDAD, and issues related to relapses. The article concludes with a discussion of recent epidemic outbreaks involving CDAD.

Risk factors for Clostridium difficile toxin-positive nosocomial diarrhoea

Data were retrieved from the records of all patients from whom stool was sent for Clostridium difficile toxin testing during the year 2001. Toxin-positive and -negative patients were compared by bivariate analysis and regression models. Eight hundred samples from 610 patients were sent for C. difficile toxin testing. Charts of 535 patients (88%) were available for analysis. Of those, 17% had a positive toxin test whilst 83% had a negative toxin test. There was no difference in the number of daily bowel movements between the two groups. Toxin-positive patients were older (P<0.0001), more often came from nursing homes (P<0.05), had higher leukocyte counts (P<0.001), higher blood urea nitrogen (P<0.01), lower serum albumin (P<0.01) and more often received diuretics (P<0.01) and clindamycin (P<0.05). Logistic regression analysis showed that previous antibiotic-associated diarrhoea was the most significant risk factor for toxin-positive diarrhoea (P<0.001), followed by clindamycin treatment (P<0.005), diuretics (P<0.005) and older age (P<0.05). Another logistic model showed the contribution of macrolides (P<0.05) to the development of hospital-acquired diarrhoea.

Proton pump inhibitor use and risk of community-acquired Clostridium difficile-associated disease defined by prescription for oral vancomycin therapy

BACKGROUND

The association between the use of proton pump inhibitors and the risk of Clostridium difficile-associated disease (CDAD) is controversial. In this study we re-examined a previously reported association between the use of proton pump inhibitors and the development of community-acquired CDAD, this time using an alternative case definition of the disease.

METHODS

We performed a case-control study of community-acquired CDAD using a United Kingdom clinical research database. Patients receiving oral vancomycin therapy were identified as having CDAD, the only indication for this drug. Each case subject was matched with up to 10 control subjects. Neither the cases nor the controls had been admitted to hospital in the year before the date of the vancomycin prescription (index date). Conditional logistic regression analysis was used to adjust for key covariates.

RESULTS

We identified 317 cases of community-acquired CDAD treated with oral vancomycin therapy and 3167 matched control subjects. Exposure to a proton pump inhibitor in the 90 days before the index date was associated with an increased risk of CDAD (odds ratio [OR] 3.5, 95% confidence interval [CI] 2.3-5.2). Antibiotic exposure in the 90 days before the index date was also a significant risk factor for community-acquired CDAD (OR 8.2, 95% CI 6.1- 11.0), even though 45% of the case subjects had not received a prescription for an antibiotic during that period. Certain comorbidities, in particular renal failure, inflammatory bowel disease and malignant disease, as well as prior methicillin-resistant Staphylococcus aureus infection, were also associated with an increased risk.

INTERPRETATION

Proton pump inhibitor use was associated with an increased risk of community-acquired CDAD, when cases were defined by receipt of prescription for oral vancomycin therapy. Prior antibiotic exposure was also a significant risk factor, but a significant proportion of the patients with community-acquired CDAD had no such exposure.

Colitis due to Clostridium difficile toxins: underdiagnosed, highly virulent, and nosocomial

Clostridium difficile colitis is a major complication of antibiotic therapy. Antibiotics cause a reduction in bacteria that normally reside in the colon. If an antibiotic-treated patient ingests C. difficile bacteria, this organism may proliferate in the colon because it is resistant to most antibiotics and because it does not have to compete with the normal bacteria for nutrients. If the C. difficile organism has the gene for toxin production, the toxin can produce a colitis. In addition to antibiotics, other proposed risk factors for development of C. difficile colitis include advanced age, contact with infected patients and with their health care providers, impaired immune function, suppression of gastric acid secretion by a proton pump inhibitor, and postpyloric tube feeding. Many of the risk factors become simultaneously focused on patients admitted to the hospital. The incidence of C. difficile disease has been rising, and strains have become more virulent. In some forms of the disease, the patient doesn't have diarrhea, and in such patients C. difficile can be deadly but difficult to diagnose. The standard treatment, with metronidazole or vancomycin, fails to work in up to 25% of patients with the fulminant form of colitis. Since C. difficile causes only 20% of cases of antibiotic-associated diarrhea, a specific test is needed to diagnose this organism. Toxigenic cultureis highly specific but not available at most institutions. The tests that are available--enzyme-linked immunosorbent assay and fecal cytotoxicity assay--have high false-negative rates, even in patients with severe clinical disease, creating a diagnostic dilemma. The only proven way to reduce the risk of C. difficile disease is implementation of an antibiotic management program in conjunction with enhanced infection control procedures.