Risk Of C. Difficile Infection Research Articles

2949. Emergency Department (ED) Discharge Antibiotic Prescription Review by Hospital Pharmacists at a Large Academic Medical Center

Abstract Background Direct patient discharge from the Emergency Department (ED) presents an ideal time to promote antimicrobial stewardship (AS). On March 1, 2021 we initiated a pilot program where ED pharmacists conduct a review of discharge antibiotic prescriptions (abx Rxs). The aim of this program is to ensure appropriate discharge abxs. Willow Pharmacy Epic Analysts, ED and AS pharmacists collaborated on this program which included Epic integration of Rx Discharge Track Board, ED Discharge InBasket, ED Discharge Rx iVent and AS-led education sessions. Methods Data for 2022 ED patients with discharge abx Rxs and iVents were extracted via Epic Reports. The first encounter per patient was included. We compared discharge abx Rxs and patient outcome data in Pharmacy vs No Pharmacy Review Groups (PRG, NPRG). Pharmacy iVents were used as a process measure. Results Among 5747 ED adult patients with discharge abx Rxs, 2638 (46%) were reviewed by pharmacy (PRG). PRG and NPRG had similar prevalence of chronic pulmonary disease (12% vs. 13%), diabetes mellitus (9% vs. 10%), malignancy (8% vs. 9%), peripheral vascular disease (6% vs. 8%), renal disease (4% vs. 5%), and HIV (1% vs. 2%) despite a difference in mean Charlson Comorbidity Index (0.64 vs 0.75, p< 0.01). The primary ED diagnosis was skin and soft tissue, urinary, intra-abdominal infections and pneumonia (25 vs 23%, 18 vs 17%, 8 vs 9%, 5 vs 6%, respectively all p=NS). In PRG, discharge abxs demonstrated an increase use of penicillin (26 vs 24%, p=0.017) and 2nd generation cephalosporin (17 vs 14%, p< 0.001). The PRG also decreased use of 3rd generation cephalosporin (11 vs 12%, p=NS), quinolones (6 vs 7%, p=NS) and clindamycin (1.7 vs 2.4%, p=NS). There was no difference in ED length of stay (LOS 4.8h in each group), C. difficile infection (CDI) within 8 weeks (0.1 vs 0.2%, p=NS), and 30 days repeat ED visit or inpatient admission with the same diagnosis as index ED encounter (2.8 vs 2.6%, p=NS). Pharmacists intervened in 10% (272/2638) of ED abx Rxs with 92% (249/272) acceptance rate. The top 3 pharmacy interventions were recommending alternative abx (42%), dose optimization (31%) and abx duration (6%). Conclusion Engaging pharmacists in ED discharge Rxs review resulted in use of narrower spectrum abx with lower CDI risk without any negative impact on ED LOS and clinical outcomes. Disclosures All Authors: No reported disclosures

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

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. A retrospective analysis was conducted in hospitalized patients in Veterans AffairsHospitals 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. Approximately156,107 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). Doxycycline is associated with a lower risk of CDI compared to azithromycinwhen 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.

Clostridioides difficile Infection in Pediatric Inflammatory Bowel Disease.

Children with inflammatory bowel disease (IBD) are at increased risk of C. difficile infection (CDI) and experience worse outcomes associated with an infection. In this article, we review recent research on the incidence, diagnosis, complications, and treatment options for CDI in children with IBD. Children with IBD have an elevated incidence of CDI, but their CDI risk does not associate with established risk factors in adults with IBD. Existing testing methodologies are inadequate at differentiating CDI from C. difficile colonization in children with IBD. Fecal microbiota transplantation offers a durable cure for recurrent CDI. CDI remains a frequent occurrence in children with IBD. Careful clinical monitoring should be used to diagnose CDI and patients with co-occurring IBD and CDI require careful surveillance for worse outcomes. Future research should explore the optimal diagnosis and treatment modalities in this unique patient population.

Clostridium difficile Infection: Risk and Poor Prognostic Factors at a Tertiary Hospital in the Eastern Region of Saudi Arabia.

Clostridium difficile (C. difficile) is a common cause of hospital-acquired diarrhea. It is associated with significantly higher mortality and morbidity in addition to the cost-effectiveness burden on the healthcare system. The primary risk factors for C. difficile infection (CDI) are past C. difficile exposure, proton pump inhibitors, and antibiotic usage. These risk factors are also associated with poor prognosis. This study was performed in Dr. Sulaiman Al Habib Tertiary Hospital in the Eastern Region of Saudi Arabia. The aim was to evaluate the risk and prognostic factors of CDI and their association with the outcomes of hospital stay, such as complications, length of stay (LOS), and treatment duration. This is a retrospective cohort study for all patients who tested for C. difficile in the medical department. The target population was all adult patients ≥16 years with positive stool toxins for C. difficile between April 2019 and July 2022. The main outcome measures are risk and poor prognostic factors for CDI. C. difficle infection patients were included in the study; 12 (52.2%) were female, and 11 (47.8%) were male. The mean age of the patients was 58.3 (SD: 21.5) years; 13 (56.5%) patients were below 65 years, and 10 were above 65 years. Only four patients were without comorbidities, and 19 (82.6%) patients had various comorbidities. Importantly, hypertension was the most common comorbidity in 47.8% of the patients. Furthermore, advanced age significantly impacted the hospital LOS as the mean age among patients who stayed at the hospital less than four days and those who stayed ≥4 days was 49.08 (19.7) and 68.36 (19.5), respectively (P = .028). Advanced age was the most frequent poor prognostic factor among our inpatient participants with positive CDI. It was significantly associated with longer hospital LOS, more complications, and longer treatment duration.

Antibiotics for Dental Implant Surgery: Extracting Available Evidence, Risks, Benefits, and Insights to Consider.

Antibiotics for Dental Implant Surgery: Extracting Available Evidence, Risks, Benefits, and Insights to Consider.

Melatonin as an Antimicrobial Adjuvant and Anti-Inflammatory for the Management of Recurrent Clostridioides difficile Infection.

Background:Clostridioides difficile (C. difficile) infection (CDI) is strongly associated with inflammation and has the potential to cause recurrent infections. Pre-clinical data suggest that melatonin has beneficial effects in the gastrointestinal tract due to its anti-inflammatory and antibacterial properties. This analysis examines the association between melatonin and the risk of recurrent CDI. Methods: A retrospective cohort study was conducted among patients with an inpatient diagnosis of CDI along with a positive C. difficile polymerase chain reaction (PCR) or enzyme immunoassay (EIA) test result. Patients were followed until the first study end point (death) or the first instance of recurrent infection. Propensity-score weighting was utilized accounting for confounding factors and weighted Cox models were estimated. Results: A total of 24,782 patients met the inclusion criteria, consisting of 3457 patients exposed to melatonin and 21,325 patients with no melatonin exposure. The results demonstrate that those exposed to melatonin were associated with a 21.6% lower risk of recurrent CDI compared to patients without melatonin exposure (HR = 0.784; 95% CI = 0.674-0.912). Conclusion: Our results demonstrate a decreased rate of recurrent CDI in patients exposed to melatonin. Further research on melatonin as an antimicrobial adjuvant and anti-inflammatory is warranted for the management of recurrent CDI.

S214 Clostridium difficile Infection and COVID-19 Pandemic: Insights From Google Trends Analysis

Introduction: The Coronavirus Disease- 19 (COVID-19) pandemic has significantly impacted the healthcare system across the United States. The virus has been predominantly found to spread via contact, droplet, and airborne routes. Both healthcare personnel and the general public have employed cautionary measures such as maintaining physical distance, handwashing, and masks to prevent transmission. Co-incidentally, these precautions should also be beneficial for halting the spread of other infectious pathogens such as Clostridium difficile. Methods: Google Trends is a tool used to track topics that are being searched on Google. It creates a normalized statistic called “search volume index” (SVI) which assigns each search topic a value from 0-100 based on the number of relative searches for that topic. SVI is well studied as a surrogate for general public interest in health-related topics. Results: We searched Google Trends for COVID-19 and Clostridium difficile from 10/01/2019 to 08/30/2020 in the US. There was a statistically significant increase (p< 0.05) in the SVI before and after declaration of COVID-19 as a national emergency by President Donald Trump. Incidentally, there was also a statistically significant decrease (p< 0.05) in C. difficile SVI (Figure 1). However, in a noncommunicable disease like heart failure, there was no change. Figure 1 shows the temporal trends in SVI of the three topics pre- and post-declaration of COVID-19 as a national emergency. Overall, the peak in interest for COVID-19 was found to coincide with the decline in C. difficile related searches on Google. However, the interest in a non-communicable disease like heart failure remained stable throughout the same time period. Conclusion: The on-going pandemic has necessitated the practice of appropriate hand hygiene and social distancing in order to decrease new cases. We hypothesized that these techniques should also have translated to a decrease in the spread of communicable diseases like C. difficile infection (CDI). Another consideration includes the increased use of antibiotics during this pandemic as well which could increase the risk of C. difficile. One study has shown that patients with COVID do not have an increased risk of CDI while another study showed that during the initial 3-month period of COVID there was a decrease in CDI. We need to continue to investigate the impact of the COVID-19 pandemic on the incidence of CDI and the subsequent impact on healthcare costs and overall outcomes in hospitalized patients.Figure 1.: Temporal trends in Google Trends search volume indices for COVID-19, Clostridium difficile infection and heart failure in the United States. (COVID-19 was declared as a national emergency in the United States on March 13,2020). (x-axis is the date and y-axis is the SVI).

Prospective Multicenter Study of Chemotherapy-Induced Clostridium (Clostridioides) difficile Infection in Patients With Lung Cancer: North Japan Lung Cancer Study Group Trial 1204

BackgroundDiarrhea post-antibiotic use is primarily attributed to mucosal lesions induced by Clostridium (Clostridioides) difficile (C. difficile) infection (CDI). Cancer patients undergoing chemotherapy might have a higher risk of CDI even when prior antibiotics are not used. Thus far, the relationship between lung cancer chemotherapy and the incidence of diarrhea remains unclear. This prospective multicenter study aimed to determine the incidence of CDI in lung cancer patients undergoing chemotherapy.MethodsThe presence of C. difficile and its toxins was investigated in lung cancer patients experiencing diarrhea during chemotherapy including paclitaxel (PTX), nanoparticle albumin-bound paclitaxel (nab-PTX), docetaxel (DOC), tegafur-gimeracil-oteracil (S-1), or irinotecan (CPT-11). If grade 2 or higher diarrhea occurred, then a stool culture was performed to detect anaerobic organisms and C. difficile toxins A and B. Additional data were collected through patient interviews and medical chart review.ResultsA total of 263 consecutive patients were enrolled in the study; grade 2 or higher diarrhea was observed in 22 patients (8.4%); CDI was confirmed in five of them (1.9%). The incidence of CDI was 22.7% of all diarrhea cases, and 50% of patients treated with PTX were CDI positive; the incidence of CDI was significantly higher in patients treated with PTX (P=0.039). Among the diarrhea cases, CDI patients had significantly worse ECOG performance status (PS) (P=0.043) and a significantly higher neutrophil count (P=0.028) than non-CDI patients. No CDI patients received antibiotics before cancer chemotherapy.ConclusionsAlthough diarrhea does not always affect a large portion of lung cancer chemotherapy recipients, clinicians should consider the possibility of CDI occurrence in lung cancer patients receiving chemotherapy, particularly PTX, without prior antibiotic exposure.

Clostridioides difficile Is Not Difficult to Predict in Hospital Settings

Background:Clostridioides difficile is a gram-positive bacteria that is the most common cause of hospital-associated infectious diarrhea among traditional and nontraditional high-risk populations. Excess healthcare costs associate with C. difficile infection (CDI) prevalence, morbidity, and mortality is shown to economically impact the US healthcare system with at least an additional $1 billion in annual cost. Exposure to antimicrobial agents resulted in increased risk for hospital-onset CDI (HO-CDI) at an inner-city hospital during 2010 and 2011. Methods: A retrospective case-control study of all persons with HO-CDI in the MICU was conducted at an inner-city hospital between January 1, 2010, and December 31, 2011. A patient was considered to have developed HO-CDI if diarrhea developed after 72 hours of admission into the MICU and a confirmed laboratory stool specimen for Clostridioides difficile infection (CDI) was obtained. A non–HO-CDI person was randomly selected using “risk set sampling.” After the application of inclusion and exclusion criteria, 88 cases were eligible for the study. Of these cases, 29 met the definition for HO-CDI, and 59 met the definition for non–HO-CDI. The relationship between antimicrobial use and the development of HO-CDI in patients in the MICU at an inner-city hospital was investigated using a logistic regression model in which the variable of total antibiotics was used as a possible predictor for predicting a positive HO-CDI. Results: Logistic regression was utilized to determine the relationships between selected study variables and presence or absence of HO-CDI. Total antibiotics was significantly related to HO-CDI. The results of this analysis showed that total antibiotics was a significant predictor for HO-CDI. The total value of the coefficient B for this predictor was 0.47, and the exponentiated value (exp[B]) of this coefficient was 1.60 (95% CI, 1.08–2.35). In this sample, patients who had 1 or more antibiotics were at a 60% greater risk of having a positive HO-CDI culture. There was a significant association between the use of metronidazole and HO-CDI (p &lt; .001). Conclusions: Antimicrobial stewardship is an integral part of patient safety. The findings from this study were instrumental in the implementation of a fledging antimicrobial stewardship program and the use of evidence-based practices at this inner-city hospital.Funding: NoDisclosures: None

Age-associated defects in the adaptive immune response to Clostridium difficile infection impair the development of a protective immune response in the elderly

Abstract Clostridium difficile is the number one cause of healthcare-associated infection in the United States and the most lethal acute enteric pathogen. The elderly (≥65) have the greatest risk of C. difficile infection (CDI) and severe morbidity and mortality due to CDI. Additionally, most recurrent CDIs occur within the elderly. To better understand why the elderly are at greater risk of severe and recurrent CDI, our lab has conducted a longitudinal study of the aging immune response to primary and recurrent CDI in patients at Hahnemann University Hospital. Both elderly and young CDI patients were enrolled in the study, and stool and blood samples were collected at enrollment and 12 days after diagnosis of CDI. Analysis of the samples looking at the humoral response in elderly versus young CDI patients shows that the early humoral response in elderly patients is impaired when compared to young CDI patients. In addition, recurrent CDI patients have similarly defective humoral responses. Finally, preliminary work in an aging mouse model of CDI further supports that age-related defects within the adaptive immune response impair the development of a protective immune response. Since the adaptive immune response to CDI plays an important role in neutralizing toxins produced by C. difficile, an impaired humoral response in both aged and recurrent CDI patients may contribute to the increased risk of infection, morbidity, and mortality observed in elderly patients. Future studies will seek to further characterize the aging immune response using patient samples as well as aging mouse models of CDI.

The Butyrate-Producing Bacterium Clostridium butyricum Suppresses Clostridioides difficile Infection via Neutrophil- and Antimicrobial Cytokine-Dependent but GPR43/109a-Independent Mechanisms.

Short-chain fatty acids, such as butyrate, are major gut microbial metabolites that are beneficial for gastrointestinal health. Clostridium butyricum MIYAIRI588 (CBM588) is a bacterium that produces a robust amount of butyrate and therefore has been used as a live biotherapeutic probiotic in clinical settings. Clostridioides difficile causes life-threatening diarrhea and colitis. The gut resident microbiota plays a critical role in the prevention of C. difficile infection (CDI), as the disruption of the healthy microbiota by antibiotics greatly increases the risk for CDI. We report that CBM588 treatment in mice significantly improved clinical symptoms associated with CDI and increased the number of neutrophils and Th1 and Th17 cells in the colonic lamina propria in the early phase of CDI. The protective effect of CBM588 was abolished when neutrophils, IFN-γ, or IL-17A were depleted, suggesting that induction of the immune reactants is required to elicit the protective effect of the probiotic. The administration of tributyrin, which elevates the concentration of butyrate in the colon, also increased the number of neutrophils in the colonic lamina propria, indicating that butyrate is a potent booster of neutrophil activity during infection. However, GPR43 and GPR109a, two G protein-coupled receptors activated by butyrate, were dispensable for the protective effect of CBM588. These results indicate that CBM588 and butyrate suppress CDI, in part by boosting antimicrobial innate and cytokine-mediated immunity.

729. Real World Efficacy of Bezlotoxumab for Prevention of Clostridioides Difficile Recurrence in Immunosuppressed Patients

BackgroundBezlotoxumab has been shown to prevent recurrent episodes of C. difficile infection (CDI) in high risk patients. Current studies define therapeutic efficacy within the first 12 weeks when the risk of recurrence is greatest. However, the risk of recurrent CDI can occur beyond the 12-week window in the immunosuppressed population. Given that bezlotoxumab has detectable serum levels for up to 24 weeks after infusion, the primary endpoint is to determine overall efficacy in immunosuppressed patients with recurrent CDI at 4 weeks, 12 weeks, and 24 weeks after initial infusion. Secondary endpoints consist of risk factors for recurrent CDI, treatment of CDI, and antibiotics usage before and after bezlotoxumab.MethodsThis analysis included immunosuppressed patients at high risk for CDI recurrence who received bezlotoxumab from February 2017 to December 2019. Patients were excluded if they were not immunosuppressed, had no follow-up appointments, and/or without a C. difficile positive test. High risk antibiotics included fluoroquinolones, beta lactamase inhibitors, third generation cephalosporins, or carbapenems.ResultsTwenty-seven bezlotoxumab doses were given to 26 patients. Baseline characteristics for CDIs prior to bezlotoxumab is reported in Table 1. The overall CDI recurrence rate at all intervals after bezolotoxumab was 4 (15%), one recurrent CDIs occurred at < 4 weeks, two recurrent CDIs occurred at 5-12 weeks, and one recurrent CDI at 13-24 weeks. High risk antibiotics were given in 2/4 (50%) of CDIs recurrences and 22/75 (29%) in the non-recurrence group. Of the four CDI recurrences, all were mild to moderate in disease severity given no evidence of colitis was seen on CT scan and a median Zar score of 1 (range 0-1) due to age > 60 years.Table 1: Baseline Characteristics ConclusionIn immunosuppressed patients with CDI, bezlotoxumab is effective at reducing CDI episodes up to 24 weeks. Additionally, this highly antibiotic exposed population continued to receive benefit up to 24 weeks after bezlotoxumab.Disclosures All Authors: No reported disclosures

S0650 Fecal Microbiota Transplantation Decolonizes C. difficile in Patients With Inflammatory Bowel Disease and Concomitant C. difficile Infection

INTRODUCTION: Patients with inflammatory bowel disease (IBD) are at increased risk for C. difficile infection (CDI) and associated morbidity and mortality. Persistent C. difficile colonization occurs even after standard-of-care CDI antibiotics, and may contribute to the increased risk of recurrent CDI. Additionally, C. difficile colonization has public health consequences as patients may spread C. difficile and may lead to contact isolation and high-cost cleaning procedures in a healthcare setting. Fecal microbiota transplantation (FMT) is a promising therapy for recurrent CDI, however its efficacy among IBD patients is limited and the rate of decolonization is unknown. Accordingly, we assessed the safety, efficacy and C. difficile decolonization rate in in IBD patients with recurrent CDI following FMT. METHODS: This open-label, prospective single-arm multicenter cohort study enrolled patients from 4 tertiary care centers. Patients with IBD and 2 or more episodes of CDI received a single colonoscopic FMT from a universal stool bank. CDI testing (GDH/Toxin EIA and PCR) was performed pre-FMT, and at 1, 8, and 12 weeks post-FMT. The primary outcome was FMT failure through week 8 (defined as diarrhea and Toxin EIA positive for C. difficile). The secondary outcome assessed was C. difficile decolonization post-FMT (defined as negative PCR testing) at week 12. RESULTS: 50 participants were enrolled with a mean age of 43.3 years (range 21–91) and primarily female (n = 28, 56%), 14 of which had Crohn's disease (CD) (mean HBI = 6.4) and 36 had ulcerative colitis (UC) (mean Partial Mayo Score = 4.5). One patient did not receive FMT after enrollment. There were no treatment-related serious adverse events. Among the treated patients, 8% (4/49) participants experienced a confirmed FMT failure and received a second FMT. Two additional patients received a repeat FMT based on investigator discretion. In terms of C. difficile decolonization, 88.9% (40/45 eligible participants) experienced decolonization at week 12 follow-up period. CONCLUSION: To our knowledge, this is the largest prospective trial to assess the safety, efficacy and C. difficile decolonization rate of FMT in patients with IBD-CDI. This data suggests FMT is a safe and promising therapy for preventing CDI recurrence and achieving C. difficile decolonization which may have public health and economic implications. Future randomized controlled trials are needed.

Assessing the Efficacy and Unintended Consequences of Utilizing a Behavioral Approach to Reduce Inappropriate Clostridioides difficile Testing

Background: Effective strategies to improve diagnostic stewardship around C. difficile infection (CDI) remain elusive. Electronic medical record-based solutions, such as ‘hard’ and ‘soft’ stops, have been associated with reductions in testing, but may not be sustainable due to alert fatigue. Additionally, data on the potential for undertesting, missed diagnoses, and the implications regarding patient harm or clusters of transmission are limited. In this study, we assessed the efficacy of a behavioral approach to diagnostic stewardship, while monitoring for unintended consequences. Methods: This quality improvement study was conducted January 2018–May 2019; baseline period: January–April 2018, implementation period: May–December 2018, sustainment period: January 2019–May 2019. First, we conducted an internal analysis and identified 3 barriers to appropriate testing: clinician’s perceived risk of CDI, inconsistent definition of diarrhea, and lack of involvement of nurses in diagnostic stewardship. A multidisciplinary team to address these barriers was then convened. The team utilized the Bristol stool scale to improve the reliability of diarrhea description, and created a guideline-concordant testing algorithm with clinicians and nurses. The primary outcome was the number of tests ordered. The secondary outcomes were the proportion of inappropriate tests and the proportion of delayed tests. Delayed tests were defined as CDI-compatible diarrhea based on the algorithm where the test was sent &gt;24 hours after symptom onset. Results: During the baseline period, we detected no significant change in number of tests ordered month to month, with 194.2 tests ordered per month on average. During the postimplementation period, the number of tests ordered decreased by ~4.5 each month between January 2018 and May 2019 (P &lt; .0001). The proportion of inappropriate tests steadily decreased from 54% to 30% across the 3 study periods, and the number of delayed testing changed from 11% to 1% then increased to 20% in the sustainment period. There were no cases of toxic megacolon associated with delayed testing. Conclusions: The decision to test for CDI is complex. Interventions that address this issue as a simple ‘right’ and ‘wrong’ fail to address the root cause of CDI overdiagnosis, and they have no embedded mechanism to detect unintended consequences. Our study demonstrates that by taking a behavioral approach and addressing clinicians’ safety concerns, we were able to sustain a significant reduction in testing. We could not determine the significance of the increase in delayed testing given the low numbers; however, further studies are needed to evaluate the safety of CDI reduction strategies through diagnostic stewardship only.Funding: NoneDisclosures: None

2369. Prescribing Choices and C. difficile Infection Risk: A Longitudinal Cohort Study of Nursing Home Residents in Ontario, Canada

BackgroundAntibiotics are the primary modifiable risk factor for C. difficile infection (CDI). However, the comparative risks of different prescribing choices are not known. Our objective was to quantify the benefits of: (1) preventing antibiotic initiation, (2) substituting high-risk antibiotics for low-risk antibiotics, (3) reducing antibiotic duration.MethodsWe conducted a cohort study of residents of over 600 Ontario nursing homes in the 2014 to 2017 period. All non-acute care hospital antibiotic exposures were identified from the Ontario Drug Benefit database, while CDI was identified using outpatient billings and/or hospital ICD-10 codes. Logistic regression models were used to examine the risk of CDI as a function of time-varying antibiotic exposures, while controlling for 14 different risk factors. Based on the models, we estimated the comparative risks of specific antibiotic regimens.ResultsWe identified 1,944 cases of CDI, for an incidence of 1.60 per 100,000 person-days. The 90-day risk among residents without antibiotics was 0.84 per 1,000 residents (‰), compared with 1.85‰ in those with a 7-day course of antibiotics. Preventing a 7-day course reduced CDI risk by 45% (see table, adjusted relative risk [RR] = 0.55, 95% confidence interval [CI] = 0.50, 0.60). The antibiotics conferring the highest risks were clindamycin at 4.1‰, moxifloxacin at 3.2‰, and amoxiclav at 3.0‰. Comparing 7-day courses of antibiotics with similar indications: nitrofurantoin engendered 37% less risk than ciprofloxacin, amoxicillin resulted in 31% less risk than amoxicillin-clavulanate, and cephalexin had 51% less risk than clindamycin. Reduced antibiotic durations were associated with less C. difficile risk. Compared with a 10-day course, a 7-day course was associated with 12% less risk, while a 5-day course was associated with 21% less risk.ConclusionWe have quantified, using a real-world population-based cohort of nursing home residents, the reduction in CDI risk incurred by preventing unnecessary antibiotic initiations, preferring low-risk agents over high-risk agents, and reducing duration. These figures will help clinicians compare risks and benefits of different prescribing choices with regards to CDI prevention. Disclosures All authors: No reported disclosures.

2378. Corticosteroid Use Prevents Primary Clostridioides difficile Infection in the Setting of Broad-Spectrum Antibiotic Use Among Hospitalized Patients

Background Clostridioides difficile is the most common pathogen causing healthcare-associated infections in the United States and a Centers for Disease Control and Prevention urgent threat-level pathogen. The pathophysiology of C. difficile infection (CDI) involves neutrophil invasion of the colon associated with an inflammatory response. Previous case–control studies investigating an anti-inflammatory corticosteroid (CS) effect on CDI risk demonstrated conflicting results but were unable to control for antibiotic use. We hypothesized that CS use would decrease the risk of CDI in a well-matched, high-risk population.MethodsThis nested case–control study included hospitalized patients admitted to a single quaternary care hospital in the Texas Medical Center. The case population included adults who were diagnosed with CDI and received at least one dose of an antibiotic of interest (piperacillin–tazobactam, cefepime, or meropenem) in the 90 days prior to CDI diagnosis. The control population included hospitalized adults who received one of the same antibiotics during their hospital stay but did not develop CDI in the 90 days following their first dose. Patients were excluded if they had a documented history of CDI. CS use was defined as ≥ 20 mg prednisone or equivalent administered in the 48 hours prior to CDI diagnosis (cases) or antibiotic start (controls). The primary study outcome was the development of CDI. A logistic regression model was developed modeling CDI diagnosis as a function of available patient covariates.ResultsA total of 321 patients met the inclusion criteria; 56 patients had a history of CDI, leaving a final study cohort of 265 patients (104 cases and 161 controls). Antibiotic days of therapy were significantly higher in the control group (8 vs. 6 days; P = 0.02). The odds of CDI diagnosis were lower among patients administered CS (OR, 0.17; 95% CI, 0.08–0.38; P < 0.001), which remained protective in the multivariable model after adjusting for age, gender, and invasive GI surgery within 6 months.ConclusionWe observed an association between CS use and decreased risk of developing primary CDI in hospitalized patients receiving broad-spectrum antibiotics. Future studies are needed to delineate the dose and duration of CS needed to realize this effect.Disclosures All authors: No reported disclosures.

1137 C. difficile Infection (CDI) in Bariatric Patients: A Case Series and Brief Review

INTRODUCTION: Abdominal operations are known to be associated with a higher risk of CDI, although no current studies explore the association of post-operative CDI and patients who undergo bariatric surgery. We aimed to analyze the clinical characteristics and outcomes of morbidly obese patients who developed CDI after bariatric surgery. METHODS: This is a retrospective case series in which we describe 7 patients who underwent gastric bypass surgery from January 2012 to January 2016 and who developed CDI within 30 days after surgery. RESULTS: Mean patient age was 36.5 years. 100% of patients were female and mean body mass index (BMI) was 47.6kg/m2. 3 of 7 (42.8%) patients had controlled Type 2 Diabetes Mellitus (Table 1). All 7 patients had undergone laparoscopic Roux-en-Y gastric bypass. 4 of 7 (57.1%) patients were on proton pump inhibitors after gastric bypass. 3 of 7 (42.8%) patients developed non- C. difficile-related complications after their procedure, primarily intra-abdominal and abdominal wall abscesses that required antibiotics. None of the patients developed complications related to CDI and all patients had clinical resolution of symptoms on follow up within one month (Table 2). CONCLUSION: While numerous articles have characterized complications from bariatric surgery, many have not reported CDI as a potential complication. Given the ubiquity of studies demonstrating change in the intestinal microbiota population of obese patients, and the subsequent change of fecal microbiota after bariatric surgery, we believe further study into CDI after bariatric surgery is warranted. In this limited case series, all patients who developed CDI had undergone a laparoscopic Roux-en-Y gastric bypass. No major complications related to CDI were observed in this surgical cohort and clinical resolution was achieved by one month. We propose the need for larger, randomized control trials in future analysis of the association between various types of bariatric surgery, risk of post-operative CDI, and the impact on subsequent morbidity and mortality.

210 Clostridioides (Clostridium) difficile PCR Amplification Cycle Threshold: More Than Just a Number?

INTRODUCTION: The optimal diagnostic approach for C. difficile infection (CDI) is controversial. Infectious Disease Society of America currently recommends a high sensitivity test such as a nucleic acid amplification test (NAAT) PCR, followed by a stool toxin enzyme immunoassay to confirm clinical suspicion of CDI. C. difficile PCR cycle threshold (Ct) is the number of cycles required for a signal to exceed background fluorescence with low numbers reflecting a larger C. difficile nucleic acid burden. Recent reports correlate Ct in symptomatic patients with disease severity and mortality. Data regarding the predictive value of PCR Ct in recurrence of CDI is preliminary. We aim to determine the association between Ct and recurrence of CDI. METHODS: This was an IRB approved, single-center retrospective chart review cohort of 76 randomly chosen patients ≥18 y.o., with completely unformed stools that were C.difficile NAAT positive. 10 patients were excluded due to lack of Ct values. Recurrence defined as any positive test for C. difficile within 3 months after treatment for CDI. Severe CDI defined as WBC &gt;15,000 or creatinine ≥1.5 md/dL and fulminant disease as refractory hypotension, ileus or megacolon. Poor clinical outcome defined as severe or fulminant CDI, or death within 30 days of diagnosis. A t-test or Mann Whitney U test was performed on populations with or without a normal distribution, respectively. A scatterplot was generated with Ct values for patients with initial vs recurrent episodes of CDI. RESULTS: Of 66 patients, mean Ct values of 8 patients with recurrent CDI (12.1%) and 58 without recurrence were 25.71 and 26.15 respectively (P = 0.79). Recurrence rates after the initial episode of CDI (n = 4), 1st recurrence (n = 1), and 2nd/subsequent recurrence (n = 3) were 9.1%, 12.5% and 21.2%, respectively. Mean Ct values trended lower for patients with poor outcomes (25.40 vs 26.42, P = 0.37). CONCLUSION: In our single center study, Ct values did not associate with a recurrence of CDI. Our findings suggest that Ct cannot be used to predict which patients will be at risk for recurrent CDI. The trend of lower Ct values associating with worse outcomes is worth a prospective study. Interestingly, there was no association with Ct values and common risk factors for CDI such as prior antibiotic use, suggesting that Ct values may not clarify current controversies in testing for CDI.

Predictors of Clostridioides difficile Infection Among Asymptomatic, Colonized Patients: A Retrospective Cohort Study

Asymptomatic patients colonized with Clostridioides difficile are at risk of developing C. difficile infection (CDI), but the factors associated with disease onset are poorly understood. Our aims were to identify predictors of hospital-onset CDI (HO-CDI) among colonized patients and to explore the potential benefits of primary prophylaxis to prevent CDI. We conducted a retrospective cohort study in a tertiary academic institution. Colonized patients were identified by detecting the tcdB gene by polymerase chain reaction on a rectal swab. Univariate and multivariate logistic regression analyses were used to identify predictors of HO-CDI. There were 19 112 patients screened, from which 960 (5%) colonized patients were identified: 513 met the inclusion criteria. Overall, 39 (7.6%) developed a HO-CDI, with a 30-day attributable mortality of 15%. An increasing length of stay (adjusted odds ratio [aOR] per day, 1.03; P = .006), exposure to multiple classes of antibiotics (aOR per class, 1.45; P = .02), use of opioids (aOR, 2.78; P = .007), and cirrhosis (aOR 5.49; P = .008) were independently associated with increased risks of HO-CDI, whereas the use of laxatives was associated with a lower risk of CDI (aOR 0.36; P = .01). Among the antimicrobials, B-lactam with B-lactamase inhibitors (OR 3.65; P < .001), first-generation cephalosporins (OR 2.38; P = .03), and carbapenems (OR 2.44; P = .03) correlated with the greatest risk of HO-CDI. By contrast, patient age, the use of proton pump inhibitors, and the use of primary prophylaxis were not significant predictors of HO-CDI. This study identifies several factors that are associated with CDI among colonized patients. Whether modifying these variables could decrease the risk of CDI should be investigated.

Risk Factors of Clostridium Difficile Infection in Hematopoietic Stem Cell Transplant Recipients: A Systemic Review and Meta-Analysis

Introduction:C. difficile infection (CDI) is a common nosocomial infection. Immune suppression is thought to be a major risk factor for CDI. Hematopoietic stem cell transplant (HSCT) recipients represent a major subgroup of immunologically vulnerable patients. It is unclear if these patients have novel risk factors for CDI development. We, therefore, performed a systematic review and meta-analysis to evaluate the predictors of CDI in HSCT recipients.Methods:A systematic search of Medline, Embase, and Web of Science was performed from January 2000 up to June 2018. All studies that assessed risk factors associated with CDI development in HSCT recipients were eligible for inclusion. Data on clinical characteristics and risk factors associated with CDI development were collected. Study quality was assessed using the Newcastle-Ottawa scale. Meta-analyses were performed using random effects models and pooled odds ratios with 95% confidence interval (CI) for risk factors reported in ≥ 2 studies were calculated.Results:Overall, 17 studies, including 6328 HSCT patients were included. Of those 874 patients developed CDI. The rate of CDI development in these patients was 13.81% with a follow up ranging from 1- 36 months. A total of 34 different risk factors were studied, of which 20 were identified in ≥ 2 studies. Our analysis showed that cephalosporin use (Odds ratio [OR] 2.21, 95% confidence interval [CI] 1.26-3.87), cord blood transplant (OR 1.36, 95% CI 1.01-1.83), graft versus host disease (GVHD) (OR 1.63, 95% CI 1.07-2.48) & prior hospitalization within 90 days of HSCT (OR 1.85, 95% CI 1.21-2.83) were associated with statistically significant increased risk of CDI in HSCT patients (Figure 1). On the other hand, many characteristics of HSCT patients including age, diabetes, lung disease, fluoroquinolones, proton pump inhibitors, rituximab, mucositis, myeloablative therapy, melphalan use before BMT, total body irradiation, growth factor use during admission, neutropenia, autologous vs allogenic transplant and use of matched related donor were not associated with increased risk of CDI.Conclusion:HSCT recipients are at an increased risk of CDI compared to general population. In addition to the common risk factors like cephalosporin use and prior hospitalization, these patients have novel characteristics including presence of GVHD and cord blood transplant that puts them at a higher risk of CDI. HSCT patients with these risk factors may warrant a closer surveillance for early detection and treatment of CDI. DisclosuresNo relevant conflicts of interest to declare.