Antibiotic treatment for Clostridium difficile-associated diarrhea in adults

Calculated initial parenteral treatment of bacterial infections: Bacterial gastrointestinal infections

This is the fourteenth chapter of the guideline "Calculated initial parenteral treatment of bacterial infections in adults - update 2018" in the 2nd updated version. The German guideline by the Paul-Ehrlich-Gesellschaft für Chemotherapie e.V. (PEG) has been translated to address an international audience. Bacterial gastrointestinal infections are still the leading cause of death worldwide. The chapter describes the etiology of bacterial gastrointestinal infections in Germany and their frequency. Recommendations are given for the calculated therapy of these infections and for targeted antibiotic therapy for known pathogens. Particular attention is paid to Clostridium difficile. The diagnostic and therapeutic options of antibiotic therapy of the various infection patterns in this pathogen are discussed.

Follow-on RifAximin for the Prevention of recurrence following standard treatment of Infection with Clostridium Difficile (RAPID): a randomised placebo controlled trial

BACKGROUND

Clostridium difficile infection (CDI) recurs after initial treatment in approximately one in four patients. A single-centre pilot study suggested that this could be reduced using 'follow-on' rifaximin treatment. We aimed to assess the efficacy of rifaximin treatment in preventing recurrence.

METHODS

A multisite, parallel group, randomised, placebo controlled trial recruiting patients aged ≥18 years immediately after resolution of CDI through treatment with metronidazole or vancomycin. Participants received either rifaximin 400 mg three times a day for 2 weeks, reduced to 200 mg three times a day for a further 2 weeks or identical placebo. The primary endpoint was recurrence of CDI within 12 weeks of trial entry.

RESULTS

Between December 2012 and March 2016, 151 participants were randomised to either rifaximin or placebo. Primary outcome data were available on 130. Mean age was 71.9 years (SD 15.3). Recurrence within 12 weeks was 29.5% (18/61) among participants allocated to placebo compared with 15.9% (11/69) among those allocated to rifaximin, a difference between groups of 13.7% (95% CI -28.1% to 0.7%, p=0.06). The risk ratio was 0.54 (95% CI 0.28 to 1.05, p=0.07). During 6-month safety follow-up, nine participants died in each group (12%). Adverse event rates were similar between groups.

CONCLUSION

While 'follow-on' rifaximin after CDI appeared to halve recurrence rate, we failed to reach our recruitment target in this group of frail elderly patients, so the estimated effect of rifaximin lacks precision. A meta-analysis including a previous trial suggests that rifaximin may be effective; however, further, larger confirmatory studies are needed.

Clostridium difficile infection: review

Clostridium difficile (C. difficile) is a Gram-positive, spore-forming, anaerobic bacillus, which is widely distributed in the intestinal tract of humans and animals and in the environment. In the last decade, the frequency and severity of C. difficile infection has been increasing worldwide to become one of the most common hospital-acquired infections. Transmission of this pathogen occurs by the fecal-oral route and the most important risk factors include antibiotic therapy, old age, and hospital or nursing home stay. The clinical picture is diverse and ranges from asymptomatic carrier status, through various degrees of diarrhea, to the most severe, life threatening colitis resulting with death. Diagnosis is based on direct detection of C. difficile toxins in feces, most commonly with the use of EIA assay, but no single test is suitable as a stand-alone test confirming CDI. Antibiotics of choice are vancomycin, fidaxomicin, and metronidazole, though metronidazole is considered as inferior. The goal of this review is to update physicians on current scientific knowledge of C. difficile infection, focusing also on fecal microbiota transplantation which is a promising therapy.

Clostridium difficile infection in hospitalized patients with inflammatory bowel disease: Prevalence, risk factors, and prognosis

To evaluate the frequency, possible risk factors, and outcome of Clostridium difficile infection (CDI) in inflammatory bowel disease (IBD) patients.There has been an upsurge of CDI in patients with IBD who has been associated with increased morbidity and mortality. Various risk factors have been found to predispose IBD patients to CDI.A retrospective case-control study on IBD patients admitted with exacerbation and tested for CDI at the Tel Aviv Medical Center in 2008 to 2013. Epidemiologic, laboratory, and prognostic data were retrieved from electronic files and compared between patients who tested positive (CDI+) or negative (CDI-) for CDI.CDI was identified in 28 of 311 (7.31%) IBD patients hospitalized with diarrhea. IBD-specific risk factors (univariate analysis) for CDI included: use of systemic steroids therapy (odds ratio [OR] = 3.6, 95% confidence interval [CI] 1.2-10.6) and combinations of ≥2 immunomodulator medications (OR = 2.6, 95% CI 1.1-6.3). Additional risk factors for CDI that are common in the general population were hospitalization in the preceding 2 months (OR = 6.0, 95% CI 2.6-14.1), use of antacids (OR = 3.8, 95% CI 1.7-8.4), and high Charlson comorbidity score (OR = 2.5, 95% CI 1.1-5.7). A multivariate analysis confirmed that only hospitalization within the preceding 2 months and use of antacids were significant risk factors for CDI. The prognosis of CDI+ patients was similar to that of CDI- patients.Hospitalized IBD patients with exacerbation treated with antacids or recently hospitalized are at increased risk for CDI and should be tested and empirically treated until confirmation or exclusion of the infection.

Antibiotic treatment for Clostridium difficile-associated diarrhoea in adults

BACKGROUND

Clostridium difficile (C. difficile) is recognized as a frequent cause of antibiotic-associated diarrhoea and colitis. This review is an update of a previously published Cochrane review.

OBJECTIVES

The aim of this review is to investigate the efficacy and safety of antibiotic therapy for C. difficile-associated diarrhoea (CDAD), or C. difficile infection (CDI), being synonymous terms.

SEARCH METHODS

We searched MEDLINE, EMBASE, CENTRAL and the Cochrane IBD Group Specialized Trials Register from inception to 26 January 2017. We also searched clinicaltrials.gov and clinicaltrialsregister.eu for ongoing trials.

SELECTION CRITERIA

Only randomised controlled trials assessing antibiotic treatment for CDI were included in the review.

DATA COLLECTION AND ANALYSIS

Three authors independently assessed abstracts and full text articles for inclusion and extracted data. The risk of bias was independently rated by two authors. For dichotomous outcomes, we calculated the risk ratio (RR) and corresponding 95% confidence interval (95% CI). We pooled data using a fixed-effect model, except where significant heterogeneity was detected, at which time a random-effects model was used. The following outcomes were sought: sustained symptomatic cure (defined as initial symptomatic response and no recurrence of CDI), sustained bacteriologic cure, adverse reactions to the intervention, death and cost.

MAIN RESULTS

Twenty-two studies (3215 participants) were included. The majority of studies enrolled patients with mild to moderate CDI who could tolerate oral antibiotics. Sixteen of the included studies excluded patients with severe CDI and few patients with severe CDI were included in the other six studies. Twelve different antibiotics were investigated: vancomycin, metronidazole, fusidic acid, nitazoxanide, teicoplanin, rifampin, rifaximin, bacitracin, cadazolid, LFF517, surotomycin and fidaxomicin. Most of the studies were active comparator studies comparing vancomycin with other antibiotics. One small study compared vancomycin to placebo. There were no other studies that compared antibiotic treatment to a placebo or a 'no treatment' control group. The risk of bias was rated as high for 17 of 22 included studies. Vancomycin was found to be more effective than metronidazole for achieving symptomatic cure. Seventy-two per cent (318/444) of metronidazole patients achieved symptomatic cure compared to 79% (339/428) of vancomycin patients (RR 0.90, 95% CI 0.84 to 0.97; moderate quality evidence). Fidaxomicin was found to be more effective than vancomycin for achieving symptomatic cure. Seventy-one per cent (407/572) of fidaxomicin patients achieved symptomatic cure compared to 61% (361/592) of vancomycin patients (RR 1.17, 95% CI 1.04 to 1.31; moderate quality evidence). Teicoplanin may be more effective than vancomycin for achieving a symptomatic cure. Eightly-seven per cent (48/55) of teicoplanin patients achieved symptomatic cure compared to 73% (40/55) of vancomycin patients (RR 1.21, 95% CI 1.00 to 1.46; very low quality evidence). For other comparisons including the one placebo-controlled study the quality of evidence was low or very low due to imprecision and in many cases high risk of bias because of attrition and lack of blinding. One hundred and forty deaths were reported in the studies, all of which were attributed by study authors to the co-morbidities of the participants that lead to acquiring CDI. Although many other adverse events were reported during therapy, these were attributed to the participants' co-morbidities. The only adverse events directly attributed to study medication were rare nausea and transient elevation of liver enzymes. Recent cost data (July 2016) for a 10 day course of treatment shows that metronidazole 500 mg is the least expensive antibiotic with a cost of USD 13 (Health Warehouse). Vancomycin 125 mg costs USD 1779 (Walgreens for 56 tablets) compared to fidaxomicin 200 mg at USD 3453.83 or more (Optimer Pharmaceuticals) and teicoplanin at approximately USD 83.67 (GBP 71.40, British National Formulary).

AUTHORS' CONCLUSIONS

No firm conclusions can be drawn regarding the efficacy of antibiotic treatment in severe CDI as most studies excluded patients with severe disease. The lack of any 'no treatment' control studies does not allow for any conclusions regarding the need for antibiotic treatment in patients with mild CDI beyond withdrawal of the initiating antibiotic. Nonetheless, moderate quality evidence suggests that vancomycin is superior to metronidazole and fidaxomicin is superior to vancomycin. The differences in effectiveness between these antibiotics were not too large and the advantage of metronidazole is its far lower cost compared to the other two antibiotics. The quality of evidence for teicoplanin is very low. Adequately powered studies are needed to determine if teicoplanin performs as well as the other antibiotics. A trial comparing the two cheapest antibiotics, metronidazole and teicoplanin, would be of interest.

Neomycin and bacitracin reduce the intestinal permeability in mice and increase the expression of some tight-junction proteins

BACKGROUND

Tight-junction (TJ) proteins regulate paracellular permeability. Gut permeability can be modulated by commensal microbiota. Manipulation of the gut microbiota with antibiotics like bacitracin and neomycin turned out to be useful for the treatment of diarrhoea induced by Clostridium difficile or chemotherapy drugs.

AIM

To evaluate the effects of the microbiota depletion evoked by the oral administration of neomycin and bacitracin on the intestinal permeability and expression of TJ proteins in mice.

METHODS

Mice received neomycin and bacitracin orally for 7 days. Intestinal permeability was measured by the fluorescein-isothiocyanate-dextran (FITC-dextran) method. The gene expression of TJ proteins in the intestine was determined by real time-PCR.

RESULTS

FITC-dextran levels in serum were reduced by half in antibiotic-treated mice, indicating a reduction of intestinal permeability. Antibiotics increased the expression of zonula occludens 1 (ZO-1), junctional adhesion molecule A (JAM-A, and occludin in the ileum and ZO-1, claudin-3, and claudin-4 in the colon.

CONCLUSION

The combination of neomycin and bacitracin reduce intestinal permeability and increase the gene expression of ZO-1, junctional adhesion molecule A (JAM-A), and occludin in the ileum and ZO-1, claudin-3, and claudin-4 in the colon.

Novel management strategies in the treatment of severe Clostridium difficile infection

CDI is increasing in incidence and severity. Clinicians must have a low threshold to consider the diagnosis and to treat patients with the clinical syndrome and risk factors before laboratory confirmation of the diagnosis. In patients who have signs of advanced disease, escalation of care with antimicrobial strategies and multidisciplinary care including surgical consultation is necessary. Furthermore, lowering the threshold for surgery compared with traditional approaches likely results in improved survival. Novel surgical approaches may obviate total abdominal colectomy and the associated immediate and long-term morbidity in this often fragile patient population, thus allowing clinicians to embrace surgical therapy earlier in the course of severe, complicated disease.

Clostridium difficile infection in a patient with Crohn disease

Crohn disease is a chronic inflammatory disorder, which is rare in pediatric patients. The definite etiology and mechanism to induce an acute exacerbation of Crohn disease remains mostly unknown. The authors report on a 14-year-old girl with Crohn disease who has acute gastrointestinal symptoms caused by toxin A-producing Clostridium difficile, which mimicked a flare-up of Crohn disease. There was no preceding antibiotic prescription before the episode. The disease activity did not improve after steroid treatment, which is unusual for Crohn disease. However, all symptoms were dramatically relieved after eradication of C difficile, and led to a symptom-free period for more than 3 years. This case report aims to address the unusual presentation of a usual pathogen, C difficile, in a pediatric patient with Crohn disease.

[Bacterial colitis]

The question of whether there are inflammatory changes in colorectal biopsy specimens is frequently asked, especially when the patient reports diarrhea or when the mucosa is reddened on endoscopy. The pathologist first has to find out whether there is, in fact, an increase in the inflammatory infiltrate of the colorectal mucosa which warrants the diagnosis of inflammation. If so, the second challenge is to ascertain the etiology of these inflammatory changes, in particular to differentiate between infectious and non-infectious causes. In principle, we can distinguish forms of colitis with distinct morphological hallmarks confirming the diagnosis (e.g. microscopic detection of the causative organism, as well as lymphocytic or collagenous colitis) from other forms of colitis which have a characteristic pattern of findings not necessarily allowing to deduce the etiology (e.g. infectious colitis without microscopic evidence of the germ vs. inflammatory bowel disease). The present article discusses the pathomorphology and differential diagnosis of the most important forms of bacterial colitis.

Faecal pharmacokinetics of orally administered vancomycin in patients with suspected Clostridium difficile infection

Background

Oral vancomycin (125 mg qid) is recommended as treatment of severe Clostridium difficile infection (CDI). Higher doses (250 or 500 mg qid) are sometimes recommended for patients with very severe CDI, without supporting clinical evidence. We wished to determine to what extent faecal levels of vancomycin vary according to diarrhoea severity and dosage, and whether it is rational to administer high-dose vancomycin to selected patients.

Methods

We recruited hospitalized adults suspected to have CDI for whom oral vancomycin (125, 250 or 500 mg qid) had been initiated. Faeces were collected up to 3 times/day and levels were measured with the AxSYM fluorescence polarization immunoassay.

Results

Fifteen patients (9 with confirmed CDI) were treated with oral vancomycin. Patients with ≥4 stools daily presented lower faecal vancomycin levels than those with a lower frequency. Higher doses of oral vancomycin (250 mg or 500 mg qid) led to consistently higher faecal levels (> 2000 mg/L), which were 3 orders of magnitude higher than the MIC₉₀ of vancomycin against C. difficile. One patient receiving 125 mg qid had levels below 50 mg/L during the first day of treatment.

Conclusions

Faecal levels of vancomycin are proportional to the dosage administered and, even in patients with increased stool frequency, much higher than the MIC₉₀. Patients given the standard 125 mg qid dosage might have low faecal levels during the first day of treatment. A loading dose of 250 mg or 500 mg qid during the first 24-48 hours followed by the standard dosage should be evaluated in larger studies, since it might be less disruptive to the colonic flora and save unnecessary costs.

Clostridium difficile colitis

Clostridium difficile enterocolitis is endemic in most modern hospitals. The spectrum of clinical presentation varies from the asymptomatic carrier state to fulminant colitis with toxic megacolon and perforation. Highly toxigenic and lethal strains of C. difficile have emerged worldwide. Medical treatment consists of discontinuing the precipitating antibiotic, supportive measures and bowel rest, and antibiotic treatment with metronidazole or vancomycin. Surgical treatment may be necessary in cases of fulminant disease. Subtotal colectomy with end ileostomy is the operation of choice.

Teicoplanin versus vancomycin for proven or suspected infection

BACKGROUND

Vancomycin and teicoplanin are commonly used to treat gram-positive infections, particularly those caused by methicillin-resistant Staphylococcus aureus (MRSA). There is uncertainty regarding the effects of teicoplanin compared to vancomycin on kidney function with some previous studies suggesting teicoplanin is less nephrotoxic than vancomycin.

OBJECTIVES

To investigate the efficacy and safety of vancomycin versus teicoplanin in patients with proven or suspected infection.

SEARCH STRATEGY

We searched the Cochrane Renal Group's Specialised Register, CENTRAL, MEDLINE, EMBASE, reference lists of nephrology textbooks, review articles with relevant studies and sent letters seeking information about unpublished or incomplete studies to investigators involved in previous studies.

SELECTION CRITERIA

We searched for randomised controlled trials (RCTs) in any language comparing teicoplanin to vancomycin for patients with proven or suspected infection.

DATA COLLECTION AND ANALYSIS

Two authors independently evaluated methodological quality and extracted data using standardised data extraction forms. Study investigators were contacted for information not available in the original manuscripts. Random effects model was used to estimate the pooled risk ratio (RR) with 95% confidence interval (CI).

MAIN RESULTS

We included 24 studies (2,610 patients) in this review. Teicoplanin reduced the risk of nephrotoxicity compared to vancomycin (RR 0.66, 95% CI 0.48 to 0.90).The effects of teicoplanin or vancomycin were similar for clinical cure (RR 1.03, 95% CI 0.98 to 1.08), microbiological cure (RR 0.98, 95% CI 0.93 to 1.03) and mortality (RR 1.02, 95% CI 0.79 to1.30). Six studies reported no cases of acute kidney injury (AKI) needing dialysis. Adverse events were less frequent with teicoplanin including cutaneous rash (RR 0.57, 95% CI 0.35 to 0.92), red man syndrome (RR 0.21, 95% CI 0.08 to 0.59) and total adverse events (RR 0.73, 95% CI 0.53 to 1.00). A lower risk of nephrotoxicity with teicoplanin was observed in patients either with (RR 0.51, 95% CI 0.30 to 0.88) or without aminoglycosides (RR 0.31, 95% 0.07 to 1.50), and also when vancomycin dosing was guided by serum levels (RR 0.22, 95% CI 0.10 to 0.52).

AUTHORS' CONCLUSIONS

Teicoplanin and vancomycin are both effective in treating those with proven or suspected infection; however the incidence of adverse effects including nephrotoxicity was lower with teicoplanin. There were no cases of AKI needing dialysis. It remains unclear whether the differential effect on kidney function should influence which antibiotic be prescribed, although it may be reasonable to consider teicoplanin for patients at higher risk for AKI needing dialysis.

A prospective study of risk factors and historical trends in metronidazole failure for Clostridium difficile infection

BACKGROUND & AIMS

Recent studies of Clostridium difficile infection (CDI) have indicated a dramatic increase in metronidazole failure. The aims of this study were to compare current and historical rates of metronidazole failure and to identify risk factors for metronidazole failure.

METHODS

Eighty-nine patients with CDI in 2004 to 2006 were followed for 60 days and were compared with a historical cohort of 63 CDI patients studied prospectively in 1998. Metronidazole failure was defined as persistent diarrhea after 10 days of therapy or a change of therapy to vancomycin. Stool samples were analyzed for the presence of the North American pulsed-field gel electrophoresis type-1 (NAP-1) strain.

RESULTS

Metronidazole failure rates were 35% in both cohorts. There was no difference in the median time to resolution of diarrhea (8 vs 5 d; P = .52) or the proportion with >10 days of diarrhea (35% vs 29%; P = .51). Risk factors for metronidazole failure included recent cephalosporin use (odds ratio [OR], 32; 95% confidence interval [CI], 5-219), CDI on admission (OR, 23; 95% CI, 3-156), and transfer from another hospital (OR, 11; 95% CI, 2-72). The frequency of NAP-1 infection in patients with and without metronidazole failure was similar (26% vs 21%; P = .67).

CONCLUSIONS

We found no difference in metronidazole failure rates in 1998 and 2004 to 2006. Patients with recent cephalosporin use, CDI on admission, and transfer from another hospital were more likely to metronidazole failure. Infection with the epidemic NAP-1 strain was not associated with metronidazole failure in endemic CDI.

Treatment of Clostridium difficile infection

Recent outbreaks of Clostridium difficile infection (CDI) in North America have been due to a more virulent, possibly more resistant strain that causes more-severe disease, making prompt recognition of cases and optimal management of infection essential for a successful therapeutic outcome. Treatment algorithms are presented to help guide the management of patients with CDI. Metronidazole has been recommended as initial therapy since the late 1990s and continues to be the first choice for all but seriously ill patients and those with complicated or fulminant infections or multiple recurrences of CDI, for whom vancomycin is recommended. Other options for recurrent CDI, such as probiotics and currently available anion-exchange resins, have limited efficacy and are potentially harmful. Intravenous immunoglobulin may benefit patients with refractory, recurrent, or severe disease, but no controlled data are available. Two antimicrobials available in the United States for other indications, nitazoxanide and rifaximin, have been used successfully for CDI treatment but, like metronidazole, lack United States Food and Drug Administration approval for this indication. Experimental treatments currently in clinical development include a toxin-binding polymer, tolevamer; 2 poorly absorbed antimicrobials, OPT-80 (formerly known as Difimicin) and ramoplanin; monoclonal antibodies; and a C. difficile vaccine.

Probiotics for treatment of Clostridium difficile-associated colitis in adults

BACKGROUND

Probiotics are live microorganisms consisting of non-pathogenic yeast and bacteria that are believed to restore the microbial balance of the gastrointestinal tract altered by infection with Clostridium difficile (C. difficile).

OBJECTIVES

To assess the efficacy of probiotics in the treatment of antibiotic associated C. difficile colitis.

SEARCH STRATEGY

The databases MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials and Cochrane IBD/FBD Specialized Trials register were searched to locate all published reports from 1966 to 2007.

SELECTION CRITERIA

Randomized, prospective studies using probiotics alone or in conjunction with conventional antibiotics for the treatment of documented C. difficile colitis were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Data extraction and analysis was done independently by two authors.

MAIN RESULTS

Four studies met the inclusion criteria and were included in the review. The four studies examined the use of probiotics in conjunction with conventional antibiotics (vancomycin or metronidazole) for the treatment of recurrence or an initial episode of C. difficile colitis in adults. The studies were small in size and had methodological problems. A statistically significant benefit for probiotics combined with antibiotics was found in one study. McFarland 1994 found that patients receiving S. boulardii were significantly less likely than patients receiving placebo to experience recurrence of C. difficile diarrhea (RR 0.59; 95% CI 0.35 to 0.98). No benefit of probiotics treatment was found in the other studies.

AUTHORS' CONCLUSIONS

There is insufficient evidence to recommend probiotic therapy as an adjunct to antibiotic therapy for C. difficile colitis. There is no evidence to support the use of probiotics alone in the treatment of C. difficile colitis.

Epidemiology, pathogenesis, and management of Clostridium difficile infection

Clostridium difficile infection is an important health problem worldwide and leads to increased morbidity and mortality, particularly among the elderly population. Antibiotics, especially those with a broad spectrum, often trigger the infection; hence the use of unnecessary antibiotics should be avoided. Mild to moderate cases respond to metronidazole or vancomycin. Severe cases may require bowel resection. Chronic relapsing cases require a prolonged course of antibiotics, immunoglobulin, probiotics, and, occasionally, feces enema. This review provides a comprehensive update on pathogenesis and management of Clostridium difficile infection for health professionals all over the world.

Clostridium difficile-associated diarrhoea

Clostridium difficile is an important nosocomial pathogen and the most frequently diagnosed cause of infectious hospital-acquired diarrhoea. Toxigenic strains usually produce toxin A and toxin B, which are the primary virulence factors of C. difficile. Some recently described strains produce an additional toxin, an adenosine-diphosphate ribosyltransferase known as binary toxin, the role of which in pathogenicity is unknown. There has been concern about the emergence of a hypervirulent fluoroquinolone-resistant strain of C. difficile in North America and Europe. The use of fluoroquinolone antimicrobials appears to be acting as a selective pressure in the emergence of this strain. In this review, we describe the current state of knowledge about C. difficile as a cause of diarrhoeal illness.

Intensive Session: New Approaches to Medical Issues in Long-Term Care

This article, based on a series of presentations at the American Medical Directors Association, briefly highlights new advances in medical areas of interest to long-term care physicians. The areas discussed are heart failure, vitamin D, falls, new treatments for diabetes mellitus, blood pressure measurement, anemia, clinical nutrition, pressure ulcers, Clostridium difficile, insomnia, and antipsychotic therapy.

Clostridium difficile-associated disease: changing epidemiology and implications for management

Clostridium difficile-associated disease (CDAD) is increasingly being reported in many regions throughout the world. The reasons for this are unknown, are likely to be multifactorial, and are the subject of several current investigations. In addition to the upsurge in frequency of CDAD, an increased rate of relapse/recurrence, disease severity and refractoriness to traditional treatment have also been noted. Moreover, severe disease has been reported in non-traditional hosts (e.g. younger age, seemingly healthy, non-institutionalised individuals residing in the community, and some without apparent antimicrobial exposure). A previously uncommon and more virulent strain of C. difficile has been reported at the centre of multiple transcontinental outbreaks. The appearance of this more virulent strain, in association with certain environmental and antimicrobial exposure factors, may be combining to create the 'perfect storm'. It is human nature to be reactive; however, the successful control of C. difficile will require healthcare systems (including administrators, and leadership within several departments such as environmental services, infection control, infectious diseases, gastroenterology, surgery, microbiology and nursing), clinicians, long-term care and rehabilitation facilities, and patients themselves to be proactive in a collaborative effort. Guidelines for the management of CDAD were last published over a decade ago, with the next iteration due in the fall (autumn) of 2007. Several newer therapies are under investigation but it is unclear whether they will be superior to current treatment options.

A case of recurrent Clostridium difficile diarrhea

Clostridium difficile is an important and increasingly common cause of nosocomial diarrhea. Recent epidemics of C. difficile-associated disease (CDAD) reveal a pathogen that is becoming more virulent, leading to an increase in disease severity, treatment failures, and relapses. Those of advanced age are at a particular risk of acquiring this debilitating and costly disease. This case describes CDAD recurring in an 87-year-old resident of a long-term care facility, which caused hospitalization. After five days of therapy on oral metronidazole with minimal improvement in diarrheal symptoms, the patient was switched to oral vancomycin. The patient subsequently improved and completed a 14-day course of metronidazole/vancomycin. The patient's stool was recultured shortly before finishing therapy and revealed C. difficile antigen; the patient was asymptomatic at that time, and it was therefore recommended to stop therapy after the 14-day treatment course. The patient was concurrently prescribed lactobacillus, a probiotic, for treatment of CDAD. The use of probiotics in the treatment of CDAD needs further study.

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.

An update on diagnosis, treatment, and prevention of Clostridium difficile-associated disease

Clostridium difficile is an important cause of nosocomial morbidity and mortality and is implicated in recent epidemics. Data support the treatment of colitis with oral metronidazole in a dose of 1.0 to 1.5 g/d, with oral vancomycin as a second-line agent, not because its efficacy is questioned but because of environmental concerns. Nitazoxanide and other drugs are currently under intense study as alternatives. Treatment of asymptomatic patients is not recommended. Current management strategies appear to be increasingly ineffective, especially for patients who experience multiple recurrences. Biotherapy and vaccination are currently being explored as treatment options for patients who have recurrent disease. Greater attention should be paid to hospital infection control policies and restriction of broad-spectrum antibiotics.

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Treatment of Clostridium difficile-associated disease: old therapies and new strategies

Clostridium difficile-associated disease (CDAD) causes substantial morbidity and mortality. The pathogenesis is multifactorial, involving altered bowel flora, production of toxins, and impaired host immunity, often in a nosocomial setting. Current guidelines recommend treatment with metronidazole; vancomycin is a second-line agent because of its potential effect on the hospital environment. We present the data that led to these recommendations and explore other therapeutic options, including antimicrobials, antibody to toxin A, probiotics, and vaccines. Treatment of CDAD has increasingly been associated with failure and recurrence. Recurrent disease may reflect relapse of infection due to the original infecting organism or infection by a new strain. Poor antibody responses to C difficile toxins have a permissive role in recurrent infection. Hospital infection control and pertinent use of antibiotics can limit the spread of CDAD. A vaccine directed against C difficile toxin may eventually offer a solution to the CDAD problem.