Clostridium difficile infection: a worldwide disease

Clostridium difficile, an anaerobic toxigenic bacterium, causes a severe infectious colitis that leads to significant morbidity and mortality worldwide. Both enhanced bacterial toxins and diminished host immune response contribute to symptomatic disease. C. difficile has been a well-established pathogen in North America and Europe for decades, but is just emerging in Asia. This article reviews the epidemiology, microbiology, pathophysiology, and clinical management of C. difficile. Prompt recognition of C. difficile is necessary to implement appropriate infection control practices.

Prevalence of gastrointestinal system infections acquired in Provincial Hospital in 2004-2013

INTRODUCTION

Gastrointestinal system infection (GI) is an infection which is frequently acquired in health- care settings. In Poland, there are limited data on the distribution of gastrointestinal system infections in the epidemiology of healthcare-associated infections (HAIs). Therefore, a study was initiated with the objective to assess the prevalence and distribution of healthcare-associated gastrointestinal system infections in patients hospitalized in St. Lukas Provincial Hospital in Tarnów.

MATERIALAND METHODS

Data of 297,545 patients hospitalized in 2004-2013 were subject to analysis. Standard epidemiological methods and unified definitions of healthcare-associated infections issued by the European Centre for Disease Prevention and Control (ECDC) were employed in the analysis.

RESULTS

A total of 944 healthcare-associated gastrointestinal system infections were indentified in the material analyzed. In a 10-year observation of HAI prevalence, GIs predominated over other HAIs registered in St. Lukas Provincial Hospital in Tarnów. Cumulative incidence rate (CIR) and incidence density rate (IDR) for GIs were 0.35% and 0.57/1,000 person-days, respectively. Infections with Clostridium difficile (GI-CDI), also referred to as C. difficile-associated diarrhoea (CDAD) were diagnosed in 301 patients. For GI-CDI, CIR and IDR were 0.11% and 0.18/1,000 person-days, respectively. Gastroenteritis excluding CDI (GI-GE) was identified in 643 patients with CIR and IDR amounting to 0.24% and 0.39/1,000 person-days, respectively. Gastroenteritis of rotavirus (CIR - 0.11% and IDR - 0.18/1,000), adenovirus (CIR - 0.01% and IDR - 0.02/1,000) and norovirus (CIR - 0.01% and IDR - 0.01/1,000) etiology was identified in 292, 32 and 17 patients, respectively. The highest number of infections was reported in paediatric ward, i.e. 307 persons (32.5%) (CIR - 1.84% and IDR - 2.79/1,000) and internal medicine and nephrology ward - 202 infections (21.4%) (CIR - 1.47% and IDR - 1.66/1,000).

CONCLUSIONS

A 10-year observation of healthcare-associated infections showed a change in the distribution of HAIs. In recent years, GIs predominated over all infections acquired in healthcare settings. The most prevalent etiological agent identified was Clostridium difficile.

The changing faces of Clostridium difficile: a personal reflection of the past 34 years

Late in 1978 my boss gave me a folder with "Clostridium difficile (diffikilé)" written on it. Inside were a few recent and now classic papers by Bartlett, Larson and co. It was suggested that this might be an interesting research topic. So began a continuing adventure which has resulted in at least 50 publications from my group. Over the years we have made several important contributions to the field. Beginning in 1982 we showed that C. difficile was a common cause of community-acquired infection! During the next few years we did extensive structural studies on the bacterium. This culminated in 1984 with a fingerprinting study (by immunoblotting surface antigens), on Swedish strains supplied by Carl-Erik Nord, which was probably the first study to demonstrate that C. difficile was really an infectious agent. This was later reinforced with strains sent from Amsterdam by Ed Kuijper. Later in the 1980s, in a study of recurrent disease, we showed that ca. 50% of recurrences were due to infection with a different strain. During my term as chair of the European Study Group for C. difficile, we began to define the status of C. difficile infection (CDI) in Europe and develop guidance for diagnosis and treatment. Recently we utilised our extensive culture collection, with isolates from the 1970s to the present, to observe how epidemiology has been driven largely by antibiotic usage. We have now come full circle: in the early years C. difficile infection was caused by many different strains. Then in the period beginning in the 1990s, characterised by often-large outbreaks and poor infection control, disease was caused by a few endemic strains highlighted by the 027/NAP1/BI pandemic. Now in a much-improved local situation, we are seeing again that the majority of cases (largely sporadic) is caused by multiple types. Current studies range from molecular studies on toxin and spore production, immune responses, novel observations on CDI in children, to what is the best way of decontaminating the anaerobe laboratory.

Epidemiology of Clostridium difficile-associated disease in internal medicine wards in northern Italy

Clostridium difficile-associated disease (CDAD) is a growing health care problem. Elderly patients with multiple comorbidities and repeated hospitalization are at high risk for developing the disease. Few data are available on epidemiology of CDAD in Italy and no studies have focused on CDAD burden in internal medicine wards. We retrospectively analysed all CDAD cases in four internal medicine wards of a city hospital in northern Italy and reviewed the medical records of patients who developed CDAD during hospitalization. We identified 146 newly acquired cases, yielding a cumulative incidence of 2.56 per 100 hospitalizations and an incidence rate of 23.3 per 10,000 patient-days. Main risk factors were advanced age and length of hospitalization. A high proportion of CDAD patients had several comorbidities and had been treated with more than one antibiotic. The incidence is among the highest previously reported, this may be due to the characteristics of patients admitted to internal medicine wards and to the wards per se. We conclude that efforts are needed to reduce CDAD's burden in this setting, paying attention to logistics, patients care and antibiotic use.

[Clostridium difficile infections, specific issues in the elderly]

Clostridium difficile is a well-established cause of infectious nosocomial diarrhea in adults. Each time diarrhea is observed in a patient receiving antibiotic treatment, Clostridium colitis should be suspected; diagnosis should be confirmed by the identification of toxin in the patient's stools. Its incidence is increasing due to growing use of several classes of antibiotics, and is associated with a high relapse rate and a significant case-fatality rate. The elderly are particularly at risk for this type of infection. Recent developments include the occurrence of epidemics in restricted communities and settings and the appearence of new virulent strains of this pathogen (especially PCR Ribotype 027). Vancomycin should be preferred over metronidazole in severe cases of diarrhea. New treatments are currently being tested and evaluated. Prevention remains a priority; high standards of hygiene and careful attention to the judicious prescription of antibiotics are crucial in this regard.

[Recurrent Clostridium difficile infections: the importance of the intestinal microbiota]

Clostridium difficile infections (CDI) represent 20-30% of diarrhea caused by antibiotics and relapse in more than 25% of cases after treatment with metronidazole or vancomycin. Given the high prevalence of CDI and the significant rate of recurrence despite successful initial treatment, CDI therapy represents a real challenge. A better understanding of the intestinal microbiota and its role in CDI opens the way to promising new therapeutic approaches, such as fecal transplantation. The studies published to date, although few, conclude a certain effectiveness of fecal transplantation in recurrent CDI. Further studies are needed to confirm its effectiveness, determine the long-term consequences as well as good administration practices.

Epidemiology of Clostridium difficile infection

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

Increased hospital length of stay attributable to Clostridium difficile infection in patients with four co-morbidities: an analysis of hospital episode statistics in four European countries

Hospital-onset Clostridium difficile infection (CDI) places a significant burden on health care systems throughout Europe, estimated at around €3 billion per annum. This burden is shared between national payers and hospitals that support additional bed days for patients diagnosed with CDI while in hospital or patients re-admitted from a previous hospitalisation. This study was performed to quantify additional hospital stay attributable to CDI in four countries, England, Germany, Spain, and The Netherlands, by analysing nationwide hospital-episode data. We focused upon patients at increased risk of CDI: with chronic obstructive pulmonary disease, heart failure, diabetes, or chronic kidney disease, and aged 50 years or over. Multivariate regression and propensity score matching models were developed to investigate the impact of CDI on additional length of hospital stay, controlling for confounding factors such as underlying disease severity. Patients in England had the longest additional hospital stay attributable to CDI at 16.09 days, followed by Germany at 15.47 days, Spain at 13.56 days, and The Netherlands at 12.58 days, derived using regression analysis. Propensity score matching indicated a higher attributable length of stay of 32.42 days in England, 15.31 days in Spain, and 18.64 days in The Netherlands. Outputs from this study consistently demonstrate that in European countries, for patients whose hospitalisation is complicated by CDI, the infection causes a statistically significant increase in hospital length of stay. This has implications for optimising resource allocation and budget setting at both the national and hospital level to ensure that levels of CDI-complicated hospitalisations are minimised.

Diverse sources of C. difficile infection identified on whole-genome sequencing

BACKGROUND

It has been thought that Clostridium difficile infection is transmitted predominantly within health care settings. However, endemic spread has hampered identification of precise sources of infection and the assessment of the efficacy of interventions.

METHODS

From September 2007 through March 2011, we performed whole-genome sequencing on isolates obtained from all symptomatic patients with C. difficile infection identified in health care settings or in the community in Oxfordshire, United Kingdom. We compared single-nucleotide variants (SNVs) between the isolates, using C. difficile evolution rates estimated on the basis of the first and last samples obtained from each of 145 patients, with 0 to 2 SNVs expected between transmitted isolates obtained less than 124 days apart, on the basis of a 95% prediction interval. We then identified plausible epidemiologic links among genetically related cases from data on hospital admissions and community location.

RESULTS

Of 1250 C. difficile cases that were evaluated, 1223 (98%) were successfully sequenced. In a comparison of 957 samples obtained from April 2008 through March 2011 with those obtained from September 2007 onward, a total of 333 isolates (35%) had no more than 2 SNVs from at least 1 earlier case, and 428 isolates (45%) had more than 10 SNVs from all previous cases. Reductions in incidence over time were similar in the two groups, a finding that suggests an effect of interventions targeting the transition from exposure to disease. Of the 333 patients with no more than 2 SNVs (consistent with transmission), 126 patients (38%) had close hospital contact with another patient, and 120 patients (36%) had no hospital or community contact with another patient. Distinct subtypes of infection continued to be identified throughout the study, which suggests a considerable reservoir of C. difficile.

CONCLUSIONS

Over a 3-year period, 45% of C. difficile cases in Oxfordshire were genetically distinct from all previous cases. Genetically diverse sources, in addition to symptomatic patients, play a major part in C. difficile transmission. (Funded by the U.K. Clinical Research Collaboration Translational Infection Research Initiative and others.).

Statewide costs of health care-associated infections: estimates for acute care hospitals in North Carolina

BACKGROUND

State-specific, health care-associated infection (HAI) cost estimates have not been calculated to guide Department of Public Health efforts and investments.

METHODS

We completed a cost identification study by conducting a survey of 117 acute care hospitals in NC to collect surveillance data on patient-days, device-days, and surgical procedures during 1 year. We then calculated expected rates and direct hospital costs of surgical site infections (SSI), Clostridium difficile infection, and 3 selected device-related HAIs for hospitals and the entire state using reference data sets such as the National Healthcare Safety Network.

RESULTS

In total, 67 (53%) hospitals responded to the survey. The median bed size of respondent hospitals was 140 (interquartile range, 66-350). A "standard" NC hospital diagnosed approximately 100 HAI each year with estimated costs of $985,000 to $2.7 million. The most common HAI was SSI (73%). Costs related to SSI accounted for 87% to 91% of overall costs. In total, the overall direct annual cost of these 5 selected HAIs was estimated to be between $124.1 and $347.8 million in 2009 for the state of NC.

CONCLUSION

Using conservative estimates, HAI led to costs of more than $100 million in acute care hospitals in the state of NC in 2009. The majority of costs were due to SSI.

Polymerase chain reaction test for Clostridium difficile toxin B gene reveals similar prevalence rates in children with and without inflammatory bowel disease

OBJECTIVE

Clinicians often evaluate for Clostridium difficile infection (CDI) in patients with inflammatory bowel disease (IBD) presenting with exacerbations. A highly sensitive polymerase chain reaction (PCR) test for the toxin B gene of C difficile is increasingly used to diagnose CDI. The aim of this study was to determine the prevalence of positive C difficile PCR results in children and young adults with and without active IBD compared with patients with non-IBD gastrointestinal disease.

METHODS

Fecal samples were obtained from patients with ulcerative colitis (UC, n = 76) or Crohn disease (CD, n = 69) and 51 controls followed in our gastroenterology program. Samples were analyzed for C difficile using a PCR test for the C difficile toxin B gene (BD GeneOhm Cdiff assay). Proportions of positive tests in each group were compared using the Pearson χ2 test.

RESULTS

The prevalence of positive PCR results was 11.6% in patients with CD, 18.4% in patients with UC, and 11.8% in controls (P = 0.25). There were no significant differences in the prevalence of positive C difficile results among patients with IBD with and without active disease or among patients with and without diarrhea.

CONCLUSIONS

Positive C difficile PCR results occur with similar frequency in patients with IBD with and without active disease and in patients with other gastrointestinal diseases. A positive result in a highly sensitive PCR assay that detects low copy numbers of a toxin gene in C difficile may reflect colonization in a subset of patients with IBD, confounding clinical decision making in managing disease exacerbations.

Pigbel in the 21st century: still here, and still in need of an effective surveillance system

Pigbel remains a likely significant cause of morbidity and mortality in the highlands of Papua New Guinea (PNG), two decades after the administration of pigbel vaccination ceased. There is a need for an effective surveillance program for pigbel to better understand the disease burden and to target communities for preventive strategies. This paper reviews the epidemiology, pathogenesis, recent history and current data on the burden of pigbel in PNG. We propose a surveillance program based on clinical recognition of likely cases and laboratory confirmation using an ELISA assay for Clostridium perfringens type C beta-toxin. Research aimed at validating this approach in the clinical setting is outlined.

Tyzzer's disease in foals: retrospective studies from 1969 to 2010

Reports of 148 cases of Tyzzer's disease in foals in central Kentucky were analyzed to identify features of the disease and factors associated with it. The records indicate that Tyzzer's disease is a rapidly progressive, highly fatal hepatitis caused by Clostridium piliforme. Common clinical findings are lethargy, fever, anorexia, and icterus. Seizures, coma, and death may rapidly ensue. Laboratory findings are leukopenia, metabolic acidosis, hypoglycemia, and increased activity of hepatic enzymes. Diagnosis is primarily based on clinical signs and postmortem findings but a polymerase chain reaction (PCR) is now available to detect C. piliforme DNA in organs and feces. Disease occurred most frequently in foals between 9 and 30 days of age that were born in April to May and was associated with heavy rainfall in the spring and high protein and nitrogenous diets fed to nursing mares. The findings are consistent with the ingestion of C. piliforme in the feces of adult horses and overgrowth in the intestine of foals with a high level of nutrients in their intestine.

Severe Clostridium difficile infection in New Zealand associated with an emerging strain, PCR-ribotype 244

AIM

To compare disease severity and clinical outcome of Clostridium difficile infection (CDI) due to PCR-ribotype (RT) 244 with CDI due to other strains present in Auckland.

METHOD

A retrospective, case-control study was conducted. Ten cases with CDI due to RT 244 were compared with 20 controls infected with other C. difficile strains. RT 244 isolates were further analysed for antimicrobial susceptibility, binary toxin genes and mutations in the tcdC gene.

RESULTS

Cases were significantly more likely to have severe disease than controls (OR 9.33; p=0.015). 50% of cases had community-associated CDI compared with 15% of controls (p=0.078). All RT 244 isolates produced binary toxin and had a single-base pair deletion in tcdC at position 117.

CONCLUSION

C. difficile RT 244 is a newly recognised strain in New Zealand. It shares several features that characterise RT 027. Given its propensity to cause severe community-associated disease, a heightened awareness of this strain is needed to ensure early testing in patients admitted from the community with identified risk factors for CDI.

The effect of portable pulsed xenon ultraviolet light after terminal cleaning on hospital-associated Clostridium difficile infection in a community hospital

There is evidence that contamination of patient rooms from previous occupants is associated with hospital-associated Clostridium difficile infection (HA-CDI). During January 2011, the use of 2 portable pulsed xenon ultraviolet light devices (PPX-UV) to disinfect patient rooms was added to routine hospital discharge cleaning in a community hospital. In 2010, the HA-CDI rate was 9.46 per 10,000 patient-days; in 2011, the HA-CDI rates was 4.45 per 10,000 patient-days (53% reduction, P = .01). The number of deaths and colectomies attributable to hospital-associated C difficile infection also declined dramatically.

Obesity as a risk factor for Clostridium difficile infection

BACKGROUND

Obesity and Clostridium difficile infection (CDI) are both related to an increased Firmicutes/Bacteroidetes ratio in the intestinal microbiota. However, an association between obesity and CDI is unknown. We aimed to assess the association between obesity and CDI in hospitalized patients.

METHODS

We conducted a retrospective case-control study. From January to December 2011, all consecutive patients hospitalized with CDI, in 2 internal medical departments in 2 hospitals, were included. Patients with CDI were compared to hospitalized patients without diarrhea, during the same period and in the same departments, and matched by age, sex, Charlson score, length of hospitalization, and antibiotic use during the last 3 months.

RESULTS

Of the 6300 patients hospitalized, 178 were diagnosed with CDI. CDI prevalence was 2.8% (178/6300). Thirty patients were excluded from the study. The 148 cases with CDI were compared to 148 hospitalized controls. Mean body mass index (BMI) in the CDI group was 33.6 (SD, 4.3) versus 28.9 (SD, 5.4) in the control group (P = .001). The multivariable model of conditional logistic regression for matched pairs showed that a history of intra-abdominal surgery (odds ratio [OR] = 2.865; 95% confidence interval [CI], 1.26-6.52) and a high BMI value (OR = 1.196 per 1-unit increase in the BMI scale; 95% CI, 1.12-1.27) were the only variables found to be significantly associated with CDI.

CONCLUSIONS

Our findings suggest that obesity is associated with the risk of CDI. Further studies are needed to reveal the exact mechanisms underlying this association.

Clostridium difficile infection in children: a comprehensive review

OBJECTIVE

To provide a comprehensive review of the literature relating to Clostridium difficile (C. difficile) infection (CDI) in the pediatric population.

METHODS

Two investigators conducted independent searches of PubMed, Web of Science, and Scopus until March 31st, 2013. All databases were searched using the terms 'Clostridium difficile infection', 'Clostridium difficile associated diarrhea' 'antibiotic associated diarrhea', 'C. difficile', in combination with 'pediatric' and 'paediatric'. Articles which discussed pediatric CDI were reviewed and relevant cross references also read and evaluated for inclusion. Selection bias could be a possible limitation of this approach.

FINDINGS

There is strong evidence for an increased incidence of pediatric CDI. Increasingly, the infection is being acquired from the community, often without a preceding history of antibiotic use. The severity of the disease has remained unchanged. Several medical conditions may be associated with the development of pediatric CDI. Infection prevention and control with antimicrobial stewardship are of paramount importance. It is important to consider the age of the child while testing for CDI. Traditional therapy with metronidazole or vancomycin remains the mainstay of treatment. Newer antibiotics such as fidaxomicin appear promising especially for the treatment of recurrent infection. Conservative surgical options may be a life-saving measure in severe or fulminant cases.

CONCLUSIONS

Pediatric providers should be cognizant of the increased incidence of CDI in children. Early and judicious testing coupled with the timely institution of therapy will help to secure better outcomes for this disease.

Clostridium difficile colitis acquired in the intensive care unit: outcome and prognostic factors

PURPOSE

We assessed factors associated with mortality and complicated course in the case of Clostridium difficile infection (CDI) acquired in the intensive care unit (ICU).

METHOD

Retrospective cohort study conducted from 1 January 2002 through 1 January 2012. All patients who acquired CDI in our ICU were included.

RESULTS

Thirty-one patients were included. Twenty patients (65 %) had mild colitis, 8 (25 %) moderate colitis, and 3 (10 %) severe colitis. Initial antibiotherapy was metronidazole (n = 30, 97 %) and vancomycin (n = 1, 3 %). Seventeen patients (55 %) experienced at least one complication: failure of initial treatment (n = 16, 52 %), shock (n = 11, 34 %), need for surgery (n = 1, 3 %) or renal replacement (n = 4, 13 %), or death (n = 8, 26 %). Risk factors of ICU mortality were history of corticosteroids prescription, prolonged ICU stay, low serum albumin level, and high Sequential Organ Failure Assessment (SOFA) score at the time of CDI diagnosis. Factors associated with a complicated course were high Simplified Acute Physiology Score (SAPS II), high SOFA score, and low serum albumin level at the time of CDI onset.

CONCLUSION

Risk factors of poor outcome in patients with CDI acquired in the ICU are different from those in the general population suffering from CDI. The implementation of treatment algorithms taking into account these factors may reduce complication rates in this specific population.

Clostridium difficile in the ICU: study of the incidence, recurrence, clinical characteristics and complications in a university hospital

OBJECTIVE

Although several studies have established the association between antibiotics and Clostridium difficile infection (CDI), there is a lack of epidemiological studies on the incidence of CDI in European Intensive Care Units outside the context of infection outbreaks. The present study describes the incidence, patient characteristics, complications, and recurrence rates of CDI in a Spanish ICU.

DESIGN

A retrospective study was carried out.

SETTING

A clinical-surgical ICU with 34 beds, a tertiary referral hospital with 1400 beds.

PATIENTS

All patients over 18 years of age admitted to the ICU from January 2010 to December 2011 with diarrhea for more than 48 h.

INTERVENTIONS

None.

STUDY VARIABLES

Underlying diseases, risk factors, fever, leukocyte count, complications, recurrence of infection.

RESULTS

A total of 1936 adult patients were admitted. Seven patients acquired CDI (0.36%), representing an infection rate of 3.1 per 10,000 bed-days and a cumulative incidence rate of 3.6 in two years. The mean age was 61 years. Six patients showed some degree of immunosuppression. The mean APACHE II score at ICU admission was 17 (IQR 13-24). Severe sepsis was reported in 5 cases of CDI, three of which presented shock and multiorgan dysfunction. Four patients presented recurrence of CDI during hospitalization. ICU admission was prolonged for a mean of 24 days (SD 17.8) after diagnosis.

CONCLUSIONS

Less than 1% of the patients admitted to a clinical-surgical ICU in a large teaching institution in Spain developed CDI. However, a high risk of recurrence/complications was associated with prolonged ICU stay.

Proportional mortality: A study of 152 goats submitted for necropsy from 13 goat herds in Quebec, with a special focus on caseous lymphadenitis

The objectives of this study were to determine the main causes of mortality, with a special focus on caseous lymphadenits as a cause of death or wasting in caprine herds from Quebec. Goats (n = 152) from 13 herds were submitted for necropsy; the cause of mortality, and the presence, location, and cause of abscesses (if present) were recorded. Proportional mortalities were distributed as: Clostridium perfringens type D enterotoxemia (17.1%), pneumonia (13.8%), paratuberculosis (10.5%), listeriosis (6.6%), pregnancy toxemia (5.3%), caprine arthritis-encephalitis (4.6%), and caseous lymphadenitis (3.9%). Caseous lymphadenitis was diagnosed in 24.3% of the submitted goats, but was not a major cause of wasting or mortality. Abscesses were localized internally in 54.1% of the cases. Paratuberculosis was diagnosed in 29 goats (16 as cause of death) and was considered a major cause of wasting and/or mortality.

Clostridium difficile infection in the elderly

The incidence of C. difficile infections (CDI) in the elderly continues to rise and infection is associated with increased morbidity and mortality when compared to those affected in younger age-groups. Immunosenescence may be a contributory factor yet the exact immune responses that may protect against CDI are incompletely understood. Increased exposure to antibiotics, frequent and/or prolonged hospital admissions and residing in long-term care facilities provide multiple opportunities for host and pathogen to coincide. This review explores the epidemiology, diagnostic parameters and management of the spectrum of disease in the geriatric population. Deaths attributed to CDI are most common in the elderly population and are a major contributor to gastroenteritis-associated mortality in many countries. The elderly represent an at-risk population from this pathogen and efforts must be directed to preventing infection and optimising treatment in this group.

Implementation of hospital-wide enhanced terminal cleaning of targeted patient rooms and its impact on endemic Clostridium difficile infection rates

BACKGROUND

Implementation of a hospital-wide program of terminal cleaning of patient rooms revolving around hydrogen peroxide vapor (HPV) technology and evaluation of its impact on endemic nosocomial Clostridium difficile-associated diarrhea (CDAD) have not been previously reported.

METHODS

This was a retrospective quasiexperimental study involving a 900-bed community hospital. During the preintervention period (January 2007-November 2008), rooms vacated by patients with CDAD or on contact precautions for other targeted pathogens underwent 1 or more rounds of cleaning with bleach. During the intervention period (January-December 2009), targeted newly evacuated rooms underwent "enhanced cleaning" consisting of use of bleach followed by HPV decontamination utilizing a priority scale based on the pathogen and room location. Rooms vacated by patients with CDAD but for which HPV decontamination was not possible the same day underwent 4 rounds of cleaning with bleach instead.

RESULTS

During the intervention period, 1,123 HPV decontamination rounds were performed involving 96.7% of hospital rooms. Of 334 rooms vacated by patients with CDAD (May-December 2009), 180 (54%) underwent HPV decontamination. The rate of nosocomial CDAD rate dropped significantly from 0.88 cases/1,000 patient-days to 0.55 cases/1,000 patient-days (rate ratio, 0.63; 95% confidence interval: 0.50-0.79, P < .0001).

CONCLUSION

A hospital-wide program of enhanced terminal cleaning of targeted patient rooms revolving around HPV technology was practical and was associated with a significant reduction in CDAD rates.

Asymptomatic Clostridium difficile colonization in a tertiary care hospital: admission prevalence and risk factors

BACKGROUND

The role of Clostridium difficile (CD) carriers in health care-associated CD transmission has been identified as an area needing research. We investigated the prevalence of, and risk factors for, asymptomatic CD colonization at hospital admission.

METHODS

Adults admitted to a tertiary care hospital in Minnesota on predetermined study days between March 1 and April 30, 2009, and without symptoms of C difficile infection, were eligible. The first stool sample after admission was requested from each consenting patient and tested for toxigenic CD using polymerase chain reaction (PCR) that detects tcdC. Clinical data were obtained through interviews and chart reviews.

RESULTS

Of 320 participants, 31 (9.7%) were positive for toxigenic CD. Using multivariate logistic regression, independent predictors of CD colonization were recent hospitalization (odds ratio [OR], 2.45; 95% confidence interval [CI]: 1.02-5.84), chronic dialysis (OR, 8.12; 95% CI: 1.80-36.65), and corticosteroid use (OR, 3.09; 95% CI: 1.24-7.73). Screening patients with risk factors (48% participants) would identify 74% (95% CI: 55%-88%) of CD carriers.

CONCLUSION

Asymptomatic CD colonization at hospital admission was detected in nearly 1 of 10 patients. The majority of colonized patients had one or more identifiable risk factors. These data could provide the basis for designing studies of targeted surveillance for C difficile.

Clostridium difficile is an autotrophic bacterial pathogen

During the last decade, Clostridium difficile infection showed a dramatic increase in incidence and virulence in the Northern hemisphere. This incessantly challenging disease is the leading cause of antibiotic-associated and nosocomial infectious diarrhea and became life-threatening especially among elderly people. It is generally assumed that all human bacterial pathogens are heterotrophic organisms, being either saccharolytic or proteolytic. So far, this has not been questioned as colonization of the human gut gives access to an environment, rich in organic nutrients. Here, we present data that C. difficile (both clinical and rumen isolates) is also able to grow on CO₂+H₂ as sole carbon and energy source, thus representing the first identified autotrophic bacterial pathogen. Comparison of several different strains revealed high conservation of genes for autotrophic growth and showed that the ability to use gas mixtures for growth decreases or is lost upon prolonged culturing under heterotrophic conditions. The metabolic flexibility of C. difficile (heterotrophic growth on various substrates as well as autotrophy) could allow the organism in the gut to avoid competition by niche differentiation and contribute to its survival when stressed or in unfavorable conditions that cause death to other bacteria. This may be an important trait for the pathogenicity of C. difficile.