Genomic surveillance of Clostridioides difficile transmission and virulence in a healthcare setting

Clostridioides difficile infection (CDI) is a major cause of healthcare-associated diarrhea, despite the widespread implementation of contact precautions for patients with CDI. Here, we investigate strain contamination in a hospital setting and the genomic determinants of disease outcomes. Across two wards over 6 months, we selectively cultured C. difficile from patients (n = 384) and their environments. Whole-genome sequencing (WGS) of 146 isolates revealed that most C. difficile isolates were from clade 1 (131/146, 89.7%), while only one isolate of the hypervirulent ST1 was recovered. Of culture-positive admissions (n = 79), 19 (24%) patients were colonized with toxigenic C. difficile on admission to the hospital. We defined 25 strain networks at ≤2 core gene single nucleotide polymorphisms; two of these networks contain strains from different patients. Strain networks were temporally linked (P < 0.0001). To understand the genomic correlates of the disease, we conducted WGS on an additional cohort of C. difficile (n = 102 isolates) from the same hospital and confirmed that clade 1 isolates are responsible for most CDI cases. We found that while toxigenic C. difficile isolates are associated with the presence of cdtR, nontoxigenic isolates have an increased abundance of prophages. Our pangenomic analysis of clade 1 isolates suggests that while toxin genes (tcdABER and cdtR) were associated with CDI symptoms, they are dispensable for patient colonization. These data indicate that toxigenic and nontoxigenic C. difficile contamination persist in a hospital setting and highlight further investigation into how accessory genomic repertoires contribute to C. difficile colonization and disease.

IMPORTANCE

Clostridioides difficile infection remains a leading cause of hospital-associated diarrhea, despite increased antibiotic stewardship and transmission prevention strategies. This suggests a changing genomic landscape of C. difficile. Our study provides insight into the nature of prevalent C. difficile strains in a hospital setting and transmission patterns among carriers. Longitudinal sampling of surfaces and patient stool revealed that both toxigenic and nontoxigenic strains of C. difficile clade 1 dominate these two wards. Moreover, quantification of transmission in carriers of these clade 1 isolates underscores the need to revisit infection prevention measures in this patient group. We identified unique genetic signatures associated with virulence in this clade. Our data highlight the complexities of preventing transmission of this pathogen in a hospital setting and the need to investigate the mechanisms of in vivo persistence and virulence of prevalent lineages in the host gut microbiome.

Evaluation of a surveillance system for Clostridioides difficile infections for Swiss hospitals

AIMS

This study evaluated an approach to establishing a comprehensive nationwide surveillance system for Clostridioides difficile infection in Switzerland. We report the results of patient-related surveillance and calculate the incidence rate of C. difficile infection in Switzerland in 2022.

METHODS

Initiated in 2017 by the National Centre for Infection Prevention (Swissnoso), in collaboration with the Swiss Centre for Antibiotic Resistance (ANRESIS), laboratory surveillance enables the automatic import of C. difficile infection laboratory data and is fully operational. However, the very limited number of participating laboratories impedes the generation of representative results. To address this gap, Swissnoso introduced patient-related surveillance, with a questionnaire-based survey used across Swiss acute care hospitals.

RESULTS

This survey revealed an incidence of 3.8 (Poisson 95% CI: 3.2-4.5) C. difficile infection episodes per 10,000 patient-days, just above the mean rate reported by the European Centre for Disease Prevention and Control (ECDC). Additionally, we report substantial heterogeneity in laboratory tests, diagnostic criteria and infection control practices among Swiss hospitals.

CONCLUSION

This study underscores the importance of a joint effort towards standardized surveillance practices in providing comprehensive insights into C. difficile infection epidemiology and effective prevention strategies in Swiss healthcare settings. The patient-related approach remains the gold standard for C. difficile infection surveillance, although it demands substantial resources and provides results only annually. The proposed implementation of nationwide automated laboratory-based surveillance would be pragmatic and efficient, empowering authorities and hospitals to detect outbreaks promptly and to correlate infection rates with antibiotic consumption.

Association Between Common Empiric Antibiotic Regimens and Clostridioides Difficile Infection in Pediatric Appendicitis

BACKGROUND

Clostridioides Difficile Infection (CDI) is a serious antibiotic related complication that has been reported among children undergoing treatment of appendicitis. CDI likelihood amongst different empiric antibiotic regimens for appendicitis remains unclear but likely has important implications for antibiotic stewardship.

METHODS

A retrospective cohort study of the Pediatric Health Information System was used to examine patients ages 1 through 18 who received operative management of acute appendicitis. Common empiric antibiotic regimens 1) Ceftriaxone & Metronidazole (CM) 2) Piperacillin & Tazobactam (PT) and 3) Cefoxitin were compared. Study outcomes were CDI within 28 days post-appendectomy and 30-day post-appendectomy percutaneous drainage procedures. Subset analyses were repeated to only include hospitals that standardized empiric antibiotic choice.

RESULTS

Of 105,911 patients, 220 (0.21 %) developed CDI. CDI was more common in patients that received CM (CM 0.29 % vs PT 0.15 % vs Cefoxitin 0.18 %; P < 0.01). On adjusted analysis, PT was associated with a lower likelihood of CDI (OR, 0.48; 95%CI, 0.31-0.74) compared to CM which was consistent in hospitals with standardized antibiotic choice. Exposure to more unique antibiotic regimens (OR, 1.70; 95 % CI, 1.50-1.93) and higher total antibiotic days (OR, 1.17; 95 % CI 1.13-1.21) were associated with an increased likelihood of CDI. There was no significant difference in the likelihood of post-appendectomy percutaneous drainage between antibiotic regimens.

CONCLUSIONS

CDI is rare following appendectomy for pediatric appendicitis. While PT was associated with statistically lower rates of CDI compared to CM, antibiotic stewardship efforts to avoid mixed regimens and decrease overall antibiotic exposure warrant exploration.

LEVEL OF EVIDENCE

Level III.

Describing the monthly variability of hospital-onset Clostridioides difficile during early coronavirus disease 2019 (COVID-19) using electronic health record data

OBJECTIVE

To assess the relative risk of hospital-onset Clostridioides difficile (HO-CDI) during each month of the early coronavirus disease 2019 (COVID-19) pandemic and to compare it with historical expectation based on patient characteristics.

DESIGN

This study used a retrospective cohort design. We collected secondary data from the institution's electronic health record (EHR).

SETTING

The Ohio State University Wexner Medical Center, Ohio, a large tertiary healthcare system in the Midwest.

PATIENTS OR PARTICIPANTS

All adult patients admitted to the inpatient setting between January 2018 and May 2021 were eligible for the study. Prisoners, children, individuals presenting with Clostridioides difficile on admission, and patients with <4 days of inpatient stay were excluded from the study.

RESULTS

After controlling for patient characteristics, the observed numbers of HO-CDI cases were not significantly different than expected. However, during 3 months of the pandemic period, the observed numbers of cases were significantly different from what would be expected based on patient characteristics. Of these 3 months, 2 months had more cases than expected and 1 month had fewer.

CONCLUSIONS

Variations in HO-CDI incidence seemed to trend with COVID-19 incidence but were not fully explained by our case mix. Other factors contributing to the variability in HO-CDI incidence beyond listed patient characteristics need to be explored.

The combined effect of systemic antibiotics and proton pump inhibitors on Clostridioides difficile infection and recurrence

BACKGROUND

Antibiotics and proton pump inhibitors (PPI) are recognized risk factors for acquisition and recurrence of Clostridioides difficile infection (CDI), yet combined effects remain unclear.

OBJECTIVES

To assess the short- and long-term effects of antibiotics and PPIs on CDI risk and recurrence.

METHODS

Population-based study including all 43 152 patients diagnosed with CDI in Sweden (2006-2019), and 355 172 matched population controls without CDI. The impact of antibiotics and PPIs on CDI risk and recurrence was explored for recent (0-30 days) and preceding (31-180 days) use prior to their first CDI diagnosis, using multivariable conditional logistic regression presented as odds ratios (ORs) and 95% confidence interval, adjusted for demographics, comorbidities and other drugs.

RESULTS

Compared to controls, the combined effect of recent PPIs and antibiotics [ORAB+PPI = 17.51 (17.48-17.53)] on CDI risk was stronger than the individual effects [ORAB = 15.37 (14.83-15.93); ORPPI = 2.65 (2.54-2.76)]. Results were less pronounced for exposure during the preceding months. Dose-response analyses showed increasing exposure correlated with CDI risk [recent use: ORAB = 6.32 (6.15-6.49); ORPPI = 1.65 (1.62-1.68) per prescription increase].Compared to individuals without recurrence (rCDI), recent [ORAB = 1.30 (1.23-1.38)] and preceding [ORAB = 1.23 (1.16-1.31); ORPPI = 1.12 (1.03-1.21)] use also affected the risk of recurrence yet without significant interaction between both. Recent macrolides/lincosamides/streptogramins; other antibacterials including nitroimidazole derivates; non-penicillin beta lactams and quinolones showed the strongest association with CDI risk and recurrence, particularly for recent use. PPI use, both recent and preceding, further increased the CDI risk associated with almost all antibiotic classes.

CONCLUSION

Recent and less recent use of PPIs and systemic antibiotics was associated with an increased risk of CDI, particularly in combination.

Impact of doxycycline on Clostridioides difficile infection in patients hospitalized with community-acquired pneumonia

BACKGROUND

Antibiotic use is a significant risk factor associated with Clostridioides difficile (C difficile) infection (CDI). Community-acquired pneumonia (CAP) is a common infection leading to hospital admission and the use of antibiotics that are highly associated with CDI. It has been proposed that doxycycline, a tetracycline antibiotic, may be protective against CDI.

METHODS

A retrospective analysis was conducted in hospitalized patients in Veterans Affairs Hospitals across the United States to determine if doxycycline was associated with a decreased risk of CDI. The primary outcome was the development of CDI within 30 days of initiation of doxycycline or azithromycin, as part of a standard pneumonia regimen.

RESULTS

Approximately 156,107 hospitalized patients who received care at a Veterans Affairs Hospital and were diagnosed with CAP during the study timeframe were included. A 17% decreased risk of CDI was identified with doxycycline compared to azithromycin when used with ceftriaxone for the treatment of pneumonia (P = .03). In patients who had a prior history of CDI, doxycycline decreased the incidence of CDI by 45% (odds ratio 0.55; P = .02).

CONCLUSIONS

Doxycycline is associated with a lower risk of CDI compared to azithromycin when used for atypical coverage in CAP. Thus, patients who are at such risk may benefit from doxycycline as a first-line agent for atypical coverage, rather than the use of a macrolide antibiotic, if Legionella is not of concern.

Analysis of health care facility-onset Clostridioides difficile infection (CDI) in a hematopoietic cell transplant (HCT) unit: A call for diagnostic stewardship in a complex patient population

Nearly half the patients identified as having health care facility-onset Clostridioides difficile infections on a hematopoietic cell transplant unit had an alternative clinical explanation for diarrhea, including conditioning regimen toxicity or other medications. Our study supports that targeted diagnostic stewardship interventions should be explored and that additional risk-adjustments considered for facilities with oncology hematopoietic cell transplant wards in the National Healthcare Safety Network LabID Clostridioides difficile infection standardized infection ratio model.

Clostridioides difficile infections, recurrences, and clinical outcomes in real-world settings from 2015 to 2019: The RECUR England study

OBJECTIVE

To estimate the epidemiological and clinical burden of Clostridioides difficile infections (CDIs) and recurrences (rCDIs) in England.

METHODS

This retrospective study included adult patients diagnosed with CDI (community or hospital settings) over 2015-2019 from Clinical Practice Research Datalink and Hospital Episode Statistics databases. Incidences of CDI and rCDI were determined annually. Time to subsequent rCDI was estimated by Kaplan-Meier method. Rates of complications were assessed within 12 months from index episode. Association of risk factors with complications was evaluated using a Cox regression model.

RESULTS

A total of 52,443 CDI episodes were recorded among 36,913 patients. Of these, 75% were aged ≥65 years, 59% were women; 73% were treated in community settings. CDI incidence remained stable (111 episodes per 100,000 patients in 2019). Around 21% of patients had ≥1 rCDI. Sepsis (12%) was the most common complication, followed by colectomy and ulcerative colitis. Age, gender, comorbidities, rCDI, preindex medical procedures, hospitalizations and consultations, and CDI treatment in hospital, were found to increase the risk of complication.

CONCLUSIONS

CDI remains a concern in England. The study highlights the importance of managing primary and rCDI episodes via effective and improved therapies to prevent fatal complications.

Incidence and risk factors for recurrent Clostridioides difficile infection in pediatric at-risk groups in selected Pediatric Investigators Collaborative Network on Infections in Canada (PICNIC) hospitals

OBJECTIVES

Incidence and risk factors for recurrent Clostridioides difficile infection (rCDI) are well established in adults, though data are lacking in pediatrics. We aimed to determine incidence of and risk factors for rCDI in pediatrics.

METHODS

This retrospective cohort study of pediatric patients was conducted at 3 tertiary-care hospitals in Canada with laboratory-confirmed CDI between April 1, 2012, and March 31, 2017. rCDI was defined as an episode of CDI occurring 8 weeks or less from diagnostic test date of the primary episode. We used logistic regression to determine and quantify risk factors significantly associated with rCDI.

RESULTS

In total, 286 patients were included in this study. The incidence proportion for rCDI was 12.9%. Among hospitalized patients, the incidence rate was estimated at 2.6 cases of rCDI per 1,000 hospital days at risk (95% confidence interval [CI], 1.7-3.9). Immunocompromised patients had higher incidence of rCDI (17.5%; P = .03) and higher odds of developing rCDI independently of antibiotic treatment given for the primary episode (odds ratio [OR], 2.31; 95% CI, 1.12-5.09). Treatment with vancomycin monotherapy did not show statistically significant protection from rCDI, independently of immunocompromised status (OR, 0.33; 95% CI, 0.05-1.15]).

CONCLUSIONS

The identification of increased risk of rCDI in immunocompromised pediatric patients warrants further research into alternative therapies, prophylaxis, and prevention strategies to prevent recurrent disease burden within these groups. Treatment of the initial episode with vancomycin did not show statistically significant protection from rCDI.

Rethinking Clostridioides difficile infection (CDI) surveillance definitions based on changing healthcare utilisation and a more realistic incubation period: reviewing data from a tertiary-referral hospital, Ireland, 2012 to 2021

BackgroundCommunity-associated Clostridioides difficile infections (CA-CDI) have increased worldwide. Patients with CDI-related symptoms occurring < 48 hours after hospitalisation and no inpatient stay 12 weeks prior are classified as CA-CDI, regardless of hospital day attendances 3 months before CDI onset. Healthcare-associated (HA) CDIs include those with symptom onset ≥ 48 hours post hospitalisation.AimTo consider an incubation period more reflective of CDI, and changing healthcare utilisation, we measured how varying surveillance specifications to categorise patients according to their CDI origin resulted in changes in patients' distribution among CDI origin categories.MethodsNew CDI cases between 2012-2021 from our hospital were reviewed. For patients with CA-CDI, hospital day attendances in the 3 months prior were recorded. CA-CDI patients with hospital day attendances and recently discharged CDI patients (RD-CDI; CDI onset 4-12 weeks after discharge) were combined into a new 'healthcare-exposure' category (HE-CDI). Time from hospitalisation to disease onset was varied and the midpoint between optimal and balanced cut-offs was used instead of 48 hours to categorise HA-CDI.ResultsOf 1,047 patients, 801 (76%) were HA-CDI, 205 (20%) CA-CDI and 41 (4%) were RD-CDI. Of the CA-CDI cohort, 45 (22%) met recent HE-CDI criteria and, when reassigned, reduced CA-CDI to 15%. Sensitivity analysis indicated a day 4 cut-off for assigning HA-CDI. Applying this led to 46 HA-CDI reassigned as CA-CDI. Applying both HE and day 4 criteria led to 72% HA-CDI, 20% CA-CDI, and 8% HE-CDI (previously RD-CDI).ConclusionCDI surveillance specifications reflecting healthcare exposure and an incubation period more characteristic of C. difficile may improve targeted CDI prevention interventions.

Diagnostic prediction models to identify patients at risk for healthcare-facility-onset Clostridioides difficile: A systematic review of methodology and reporting

OBJECTIVE

To systematically review the methodology, performance, and generalizability of diagnostic models for predicting the risk of healthcare-facility-onset (HO) Clostridioides difficile infection (CDI) in adult hospital inpatients (aged ≥18 years).

BACKGROUND

CDI is the most common cause of healthcare-associated diarrhea. Prediction models that identify inpatients at risk of HO-CDI have been published; however, the quality and utility of these models remain uncertain.

METHODS

Two independent reviewers evaluated articles describing the development and/or validation of multivariable HO-CDI diagnostic models in an inpatient setting. All publication dates, languages, and study designs were considered. Model details (eg, sample size and source, outcome, and performance) were extracted from the selected studies based on the CHARMS checklist. The risk of bias was further assessed using PROBAST.

RESULTS

Of the 3,030 records evaluated, 11 were eligible for final analysis, which described 12 diagnostic models. Most studies clearly identified the predictors and outcomes but did not report how missing data were handled. The most frequent predictors across all models were advanced age, receipt of high-risk antibiotics, history of hospitalization, and history of CDI. All studies reported the area under the receiver operating characteristic curve (AUROC) as a measure of discriminatory ability. However, only 3 studies reported the model calibration results, and only 2 studies were externally validated. All of the studies had a high risk of bias.

CONCLUSION

The studies varied in their ability to predict the risk of HO-CDI. Future models will benefit from the validation on a prospective external cohort to maximize external validity.

Epidemiology of Clostridioides difficile infection at a tertiary care facility in Saudi Arabia: Results of prospective surveillance

OBJECTIVES

To determine the incidence of Clostridioides difficile infection (CDI) and the frequency of known risk factors.

METHODS

A prospective hospital-based surveillance for CDI, according to the Centers for Disease Control and Prevention criteria, was carried out from July 2019 to March 2022 for all inpatients aged more than one year in Prince Sultan Military Medical City, Riyadh, Saudi Arabia.

RESULTS

A total of 139 cases of CDI were identified during the survey among 130 patients admitted in the hospital. Most cases were incident (n=130; 93.5%), and almost three-quarters (n=102; 73.4%) were hospital-onset (HO) CDI, with an incidence rate of 1.62 per 10,000 patient days (PD). The highest rates were noted in intensive care units with an incidence rate of 3 per 10,000 PD and wards for immunocompromised patients with an incidence rate of 2.72 per 10,000 PD. The most prevalent risk factor for CDI was acid-reducing drugs (72.6%). Vancomycin (48%) and ciprofloxacin (25%) were the most frequently prescribed antibiotics for patients with CDI. Clostridioides difficile infection complications were identified in 5.7% of the cases, with a reported 28-day mortality rate of 3.8%.

CONCLUSION

In our hospital, HO-CDI incidence rate is lower than that in high-income countries. National multicenter surveillance is needed to evaluate the actual burden of CDI in Saudi Arabia.

Increased Prevalence of Clostridioides difficile Infection Among Pediatric Oncology Patients: Risk Factors for Infection and Complications

BACKGROUND

Pediatric oncology patients, who are typically immunosuppressed, exposed to medications associated with increased Clostridioides difficile infection (CDI) risk and hospitalized, are expected to be at substantial risk for infection and complications. Although certain C. difficile ribotypes have been associated with more severe infection in adults, such an association has not been described in children.

METHODS

To characterize CDI epidemiology, including risk factors and complications among pediatric oncology patients, we retrospectively reviewed charts of patients 1-18 years old treated at a designated cancer center during 2000-2017. We used fluorescence-based polymerase chain reaction to identify ribotypes causing disease at our institution.

RESULTS

In 11,366 total patients, we identified 207 CDI cases during the study period. CDI prevalence in our pediatric oncology population was 18 cases per 1000 patients. CDI was highest among patients with acute myeloid leukemia, neuroblastoma, and desmoplastic small round cell tumor (105, 66 and 111 cases per 1000 patients, respectively; P < 0.01). Fever, leukocytosis, elevated creatinine and abdominal radiation and fluoroquinolone exposure concurrent with treatment of CDI were associated with complications. Patients with severe CDI experienced increased mortality. Ribotypes previously associated with severe infection were observed infrequently and were not associated with mortality.

CONCLUSIONS

This is the largest study of CDI in pediatric oncology patients to date. The study identifies specific oncologic diagnoses with increased CDI risk and factors predictive of poor outcomes. As CDI treatment guidelines are developed for this population, these data will be useful for risk stratification of patients in need of early, aggressive treatment.

Clostridium Difficile Infection in Rectal Cancer Patients after Diverted Loop Ileostomy Closure

AIM

Clostridium difficile infection is a cause of increased morbidity and mortality in hospitals, particularly in patients with cancer pathology. There are several factors favouring the development of Clostridium difficile infection among cancer patients, including age, exposure to antibiotic and proton pump inhibitors therapy, and chemotherapy. This study was conducted to observe the prevalence of Clostridium difficile infection after the reversal of ileostomy loop for rectal cancer surgery, which were initially operated either open or laparoscopic.

METHOD

A retrospective study was performed on patients who were operated in a single surgical team for rectal cancer who benefited of a diverted loop ileostomy over a 4-year period. Results: 23 patients were documented with Clostridium difficile infection out of a total of 63. All 23 patients underwent ileostomy closure later than 3 months after primary surgery, and postoperatively received antibiotic therapy associated with proton pump inhibitors in the first 24 hours. Conclusions: Closure of ileostomy later than 3 months after primary surgery, combined with chemotherapy, antibiotic therapy and proton pump inhibitors, increases the risk of developing Clostridium difficile infection.

Impact of mandatory nucleic acid amplification test (NAAT) testing approval on hospital-onset Clostridioides difficile infection (HO-CDI) rates: A diagnostic stewardship intervention

Misclassification of Clostridioides difficile colonization as hospital-onset C. difficile infection (HO-CDI) can lead to unnecessary treatment of patients and substantial financial penalties for hospitals. We successfully implemented mandatory C. difficile PCR testing approval as a strategy to optimize testing, which was associated with a significant decline in the monthly incidence of HO-CDI rates and lowering of our standardized infection ratio to 0.77 (from 1.03) 18 months after this intervention. Approval request served as an educational opportunity to promote mindful testing and accurate diagnosis of HO-CDI.

Recent trends and risk factors associated with Clostridioides difficile infections in hospitalized patients with inflammatory bowel disease

BACKGROUND

Clostridioides difficile infections (CDIs) are common among patients with inflammatory bowel disease (IBD) and can mimic and exacerbate IBD flares, thus warranting appropriate testing during flares.

AIMS

To examine recent trends in rates of CDI and associated risk factors in hospitalized IBD patients, which may better inform targeted interventions to mitigate the risk of infection.

METHODS

This is a retrospective analysis using the Nationwide Readmissions Database from 2010 to 2020 of hospitalized individuals with Crohn's disease (CD) or ulcerative colitis (UC). Longitudinal changes in rates of CDI were evaluated using International Classification of Diseases codes. Multivariable logistic regression evaluated the association between patient- and hospital-related factors and CDI.

RESULTS

There were 2,521,935 individuals with IBD who were hospitalized at least once during the study period. Rates of CDI in IBD-related hospitalizations increased from 2010 to 2015 (CD: 1.64%-3.32%, p < 0.001; UC: 4.15%-5.81%, p < 0.001), followed by a steady decline from 2016 to 2020 (CD: 3.15%-2.27%, p < 0.001; UC: 5.04%-4.27%, p < 0.001). In multivariable models, CDI was associated with the Charlson-Deyo comorbidity index, public insurance, and hospital size. CDI was associated with increased mortality.

CONCLUSIONS

Rates of CDI among hospitalized patients with IBD had initially increased, but have declined since 2015. Increased comorbidity, large hospital size, public insurance, and urban teaching hospitals were associated with higher rates of CDI. CDI was associated with increased mortality in hospitalized patients with IBD. Continued vigilance, infection control, and treatment of CDI can help continue the trend of declining infection rates.

A 7-year analysis of attributable costs of healthcare-associated infections in a network of community hospitals in the southeastern United States

We calculated the attributable cost of several healthcare-associated infections in a community hospital network: central-line-associated bloodstream infections (CLABSIs), catheter-associated urinary tract infections (CAUTIs), hospital-onset Clostridioides difficile infections (CDI-HOs) (43 hospitals); surgical site infections (SSIs) (40 hospitals). From 2016 to 2022, the total cost of CLABSIs, CAUTIs, CDI-HOs, and SSIs was $420,012,025.

Economic Burden of Clostridioides difficile Infection in European Countries

Clostridioides difficile infection (CDI) remains a considerable challenge to healthcare systems worldwide. Although CDI represents a significant burden on healthcare systems in Europe, few studies have attempted to estimate the consumption of resources associated with CDI in Europe. The reported extra costs attributable to CDI vary widely according to the definitions, design, and methodologies used, making comparisons difficult to perform. In this chapter, the economic burden of healthcare facility-associated CDI in Europe will be assessed, as will other less explored areas such as the economic burden of recurrent CDI, community-acquired CDI, pediatric CDI, and CDI in outbreaks.

The Need for European Surveillance of CDI

Since the turn of the millennium, the epidemiology of Clostridioides difficile infection (CDI) has continued to challenge. Changes in clinical presentation, severity of disease, descriptions of new risk factors and the occurrence of outbreaks all emphasised the importance of early diagnosis and standardised surveillance systems. However, a lack of consensus on case definitions, clinical guidelines and optimal laboratory diagnostics across Europe has led to the underestimation of CDI and impeded comparison between countries. These inconsistencies have prevented the true burden of disease from being appreciated.Acceptance that a multi-country CDI surveillance program and optimised diagnostic strategies are required has built the foundations for a more robust, unified surveillance. The concerted efforts of the European Centre for Disease Prevention and Control (ECDC) CDI networks led to the development of the European surveillance protocol and an over-arching long-term CDI surveillance strategy for 2014-2020, which has been followed by the development of surveillance systems in at least 20 European countries. However, surveillance activities in individual countries have slowed during the COVID-19 pandemic as resources were diverted to the global health crisis. A renewed and strengthened focus on CDI surveillance and prevention is therefore urgently needed post COVID-19.

Fluoroquinolone-associated adverse events of interest among hospitalized veterans affairs patients with community-acquired pneumonia who were treated with a fluoroquinolone: A focus on tendonitis, Clostridioides difficile infection, and aortic aneurysm

STUDY OBJECTIVE

The objectives of this study were to (i) quantify the incidence of three concerning fluoroquinolone adverse events of interest (FQAEI, i.e., adverse tendon event (TE), clostridioides difficile infection (CDI), and aortic aneurysm/dissection (AAD)), (ii) identify the patient-level factors that predict these events, and (iii) develop clinical risk scores to estimate the predicted probabilities of each FQAEI based on patient-level covariates available on clinical presentation.

DESIGN

Retrospective cohort study.

SETTING

Upstate New York Veterans' Healthcare Administration from 2011 to 2016.

PATIENTS

Hospitalized patients with community-acquired pneumonia receiving care in the Upstate New York Veterans' Healthcare Administration from 2011 to 2016.

INTERVENTION

N/A.

MEASUREMENTS

The outcomes of interest for this study were the occurrence of TE, CDI, and AAD. We also evaluated a composite of these three outcomes, FQAEI.

MAIN RESULTS

The study population consisted of 1071 patients. The overall incidence of FQAEI, TE, AAD, and CDI was 6.5%, 1.8%, 4.5%, and 0.3%, respectively. For each outcome evaluated, the probability of the event of interest was predicted by the presence of certain comorbidities, previous healthcare exposure, choice of specific FQ antibiotic, or therapy duration. Concomitant steroids, pneumonia in preceding 180 days, and creatinine clearance <30 mL/min predicted FQAEI.

CONCLUSIONS

Individual frequencies of three important FQAEIs were quantified, and risk scores were developed to estimate the probabilities of experiencing these events to help clinicians individualize treatment decisions for patients and reduce the potential risks of select FQAEIs.

Treated, hospital-onset Clostridiodes difficile infection: An evaluation of predictors and feasibility of benchmarking comparing 2 risk-adjusted models among 265 hospitals

OBJECTIVES

To evaluate the incidence of a candidate definition of healthcare facility-onset, treated Clostridioides difficile (CD) infection (cHT-CDI) and to identify variables and best model fit of a risk-adjusted cHT-CDI metric using extractable electronic heath data.

METHODS

We analyzed 9,134,276 admissions from 265 hospitals during 2015-2020. The cHT-CDI events were defined based on the first positive laboratory final identification of CD after day 3 of hospitalization, accompanied by use of a CD drug. The generalized linear model method via negative binomial regression was used to identify predictors. Standardized infection ratios (SIRs) were calculated based on 2 risk-adjusted models: a simple model using descriptive variables and a complex model using descriptive variables and CD testing practices. The performance of each model was compared against cHT-CDI unadjusted rates.

RESULTS

The median rate of cHT-CDI events per 100 admissions was 0.134 (interquartile range, 0.023-0.243). Hospital variables associated with cHT-CDI included the following: higher community-onset CDI (CO-CDI) prevalence; highest-quartile length of stay; bed size; percentage of male patients; teaching hospitals; increased CD testing intensity; and CD testing prevalence. The complex model demonstrated better model performance and identified the most influential predictors: hospital-onset testing intensity and prevalence, CO-CDI rate, and community-onset testing intensity (negative correlation). Moreover, 78% of the hospitals ranked in the highest quartile based on raw rate shifted to lower percentiles when we applied the SIR from the complex model.

CONCLUSIONS

Hospital descriptors, aggregate patient characteristics, CO-CDI burden, and clinical testing practices significantly influence incidence of cHT-CDI. Benchmarking a cHT-CDI metric is feasible and should include facility and clinical variables.

Characteristics and outcomes of Clostridioides difficile infection after a change in the diagnostic testing algorithm

BACKGROUND

Polymerase chain reaction (PCR) testing for the detection of C. difficile is a highly sensitive test. Some clinical laboratories have included a 2-step testing algorithm utilizing PCR plus toxin enzyme immunoassays (EIAs) to increase specificity.

OBJECTIVE

To determine the risk factors and outcomes of C. difficile PCR-positive/toxin-positive encounters compared to PCR-positive/toxin-negative encounters.

DESIGN

Retrospective study.

SETTING

A Veterans' Affairs hospital.

METHODS

A retrospective case-control study of patient encounters with a positive C. difficile test by PCR and either a toxin EIA-positive assay (ie, cases) or toxin EIA-negative assay (ie, controls). Clinically relevant exposures and risk factors were determined to assess CDI recurrence at 30 days. Available encounter stool specimens were cultured for C. difficile and were subjected to restriction endonuclease analysis (REA) strain typing.

RESULTS

Among 130 C. difficile PCR-positive patient encounters, 80 (61.5%) were toxin EIA negative and 50 (38.5%) were toxin EIA positive. Encounters that were toxin positive were more frequently treated (96.0%) compared to toxin-negative encounters (71.3%; P < .01). A multivariable logistic regression model revealed that toxin-negative encounters were less likely to suffer a recurrent CDI episode within 30 days (odds ratio [OR], 0.20, 95% confidence interval [CI], 0.05-0.83). Additionally, a higher C. difficile PCR cycle threshold predicted a lower risk of CDI recurrence at 30 days. (OR, 0.82; 95% CI, 0.68-0.98). During the study period, the REA group Y strain accounted for most toxin-negative encounters (32.5%; P = .05), whereas REA group BI strain accounted for most toxin-positive encounters (24.3%; P = .02).

CONCLUSIONS

A testing strategy of PCR plus toxin EIA helped predict recurrent CDI.

A genomic survey of Clostridioides difficile isolates from hospitalized patients in Melbourne, Australia

IMPORTANCE

There has been a decrease in healthcare-associated Clostridioides difficile infection in Australia, but an increase in the genetic diversity of infecting strains, and an increase in community-associated cases. Here, we studied the genetic relatedness of C. difficile isolated from patients at a major hospital in Melbourne, Australia. Diverse ribotypes were detected, including those associated with community and environmental sources. Some types of isolates were more likely to carry antimicrobial resistance determinants, and many of these were associated with mobile genetic elements. These results correlate with those of other recent investigations, supporting the observed increase in genetic diversity and prevalence of community-associated C. difficile, and consequently the importance of sources of transmission other than symptomatic patients. Thus, they reinforce the importance of surveillance for in both hospital and community settings, including asymptomatic carriage, food, animals, and other environmental sources to identify and circumvent important sources of C. difficile transmission.