Clostridioides difficile colonization and infection in patients admitted for a first autologous transplantation: Incidence, risk factors, and patient outcomes

Clostridioides difficile infection: history, epidemiology, risk factors, prevention, clinical manifestations, treatment, and future options

SUMMARYClostridioides difficile infection (CDI) is one of the major issues in nosocomial infections. This bacterium is constantly evolving and poses complex challenges for clinicians, often encountered in real-life scenarios. In the face of CDI, we are increasingly equipped with new therapeutic strategies, such as monoclonal antibodies and live biotherapeutic products, which need to be thoroughly understood to fully harness their benefits. Moreover, interesting options are currently under study for the future, including bacteriophages, vaccines, and antibiotic inhibitors. Surveillance and prevention strategies continue to play a pivotal role in limiting the spread of the infection. In this review, we aim to provide the reader with a comprehensive overview of epidemiological aspects, predisposing factors, clinical manifestations, diagnostic tools, and current and future prophylactic and therapeutic options for C. difficile infection.

An Algorithm Addressing the Problem of Overdiagnoses of Clostridioides difficile Infections in Hematopoietic Stem-Cell Transplant Recipients: Effects on CDI Rates and Patient Outcomes

BACKGROUND

Diarrhea of other causes and Clostridioides difficile colonization are common in patients hospitalized for hematopoietic stem-cell transplants (HSCT). It has been well recognized that these issues tend to decrease the specificity of stool testing for C. difficile infection (CDI). The best way to address this problem is uncertain.

OBJECTIVE

In September 2018, we initiated a project with the goal of addressing the apparent problem of overdiagnosis of CDIs in our HSCT population. Using the quality improvement tool Model for Improvement we introduced a C. difficile stool testing and CDI diagnosis algorithm with the aim of decreasing unnecessary inpatient CDI diagnoses and treatments. In this study we examine the effects of the algorithm.

STUDY DESIGN

We reviewed all HSCT admissions for the 2 years before the algorithm introduction and the 3 years following recording all stool submissions for C. difficile determination and CDI. At the close of the study, we recruited our advanced practice providers (APPs) to review all CDI following algorithm initiation and provide feedback on the ease of use of the algorithm and potential improvements to the overall process.

RESULTS

Stool submissions for C. difficile determination decreased from 38.0 to 20.6/1000 inpatient days (p=<0.001) and CDI from 5.5 to 2.4/1000 days (p=0.007). Patients admitted for a first allogeneic-HSCT, a first autologous-HSCT, or an HSCT readmission showed similar proportionate reductions. No detrimental effects on length of stay, overall survival, progression free survival, rates of readmission following transplant, incidence of acute graft vs. host disease, or incidence of recurrent CDI were noted following algorithm introduction. A strategy of education, monitoring/feedback, and ease of algorithm access proved effective in inducing provider compliance. APPs rated the algorithm high on ease of use.

CONCLUSIONS

Use of an algorithm defining criteria for C. difficile testing, diagnosis, and treatment was associated with significantly decreased CDI diagnoses on a HSCT inpatient unit without apparent adverse effects.

Early Clostridioides difficile infection characterizations, risks, and outcomes in allogeneic hematopoietic stem cell and solid organ transplant recipients

BACKGROUND

Clostridioides difficile infection (CDI) frequently complicates allogeneic hematopoietic stem cell (allo-HCT) and solid organ transplantation (SOT).

METHODS

We retrospectively analyzed risk factors and outcomes of CDI occurring within 30 days of transplant.

RESULTS

Between March 2010 and June 2015, 466 allo-HCT and 1454 SOT were performed. The CDI cumulative incidence (95% CI) was 10% (8-13) and 4% (3-5), following allo-HCT and SOT, respectively (p < .01), occurring at a median (range) 7.5 days (1-30) and 11 (1-30), respectively (p = .18). In multivariate analysis, fluoroquinolones use within 14 days pre-transplantation was a risk factor for CDI following allo-HCT (HR 4.06 [95% CI 1.31-12.63], p = .02), and thoracic organ(s) transplantation was a risk factor for CDI following SOT (HR 3.03 [95% CI 1.31-6.98]) for lung and 3.90 (1.58-9.63) for heart and heart/kidney transplant, p = .02. Compared with no-CDI patients, the length of stay (LOS) was prolonged in both allo-HCT (35 days [19-141] vs. 29 [13-164], p < .01) and SOT with CDI (16.5 [4-101] vs. 7 [0-159], p < .01), though not directly attributed to CDI. In allo-HCT, severe acute graft-versus-host disease (aGVHD) occurred more frequently in patients with CDI (33.3% vs. 15.8% without CDI, p = .01) and most aGVHD (87.5%) followed CDI. Non-relapse mortality or overall survival, not attributed to CDI, were also similar in both allo-HCT and SOT.

CONCLUSIONS

Early post-transplant CDI is frequent, associated with fluoroquinolones use in allo-HCT and the transplanted organ in SOT, and is associated with longer LOS in both the groups without difference in survival but with increased aGVHD in allo-HCT.

Colonization with Gastrointestinal Pathogens Prior to Hematopoietic Cell Transplantation and Associated Clinical Implications

Infectious diarrhea following hematopoietic cell transplantation (HCT) significantly contributes to morbidity and mortality. Most HCT recipients experience diarrhea in the post-transplantation period, and infectious pathogens are frequently detected during diarrheal episodes. However, little is known about how frequently these patients are colonized with gastrointestinal (GI) pathogens before their transplantation and whether colonization predicts future diarrheal illness. We sought to determine how frequently HCT recipients are colonized with GI pathogens before HCT and the degree to which pre-HCT colonization predicts post-transplantation infectious diarrheal illness. We conducted a prospective cohort study of allogeneic and autologous HCT recipients at a single center between December 2016 and January 2019. Stool samples were collected during the week before HCT, and formed samples were evaluated for the presence of 22 diarrheal pathogens using the BioFire FilmArray GI panel. We determined the frequency with which participants were colonized with each pathogen and identified factors associated with colonization. We then determined how frequently pretransplantation colonization led to post-transplantation diarrheal infections due to the colonizing pathogen and whether colonization was associated with increased number of days of post-transplantation diarrhea during the transplant hospitalization. We enrolled 112 asymptomatic patients (allogeneic, 61%; autologous, 39%) who had a formed stool specimen before HCT, of whom 41 (37%) had a GI pathogen detected. The most commonly detected organisms were Clostridioides difficile (n = 21; 19%), Yersinia enterocolitica (n = 9; 8%), enteropathogenic Escherichia coli (EPEC) (n = 6; 6%), and norovirus (n = 5; 4%). Female sex and previous C. difficile infection were associated with C. difficile colonization, and having non-Hodgkin lymphoma was associated with being colonized with a diarrheal pathogen other than C. difficile. Thirteen of 21 patients (62%) with pretransplantation C. difficile colonization developed a clinical C. difficile infection post-transplantation, and 8 of 10 patients (80%) colonized with EPEC or enteroaggregative E. coli developed post-transplantation infections due to their colonizing pathogen. Pretransplantation C. difficile colonization was also associated with an increased duration of post-transplantation diarrhea (P = .048). Conversely, none of the 9 patients with pretransplantation Yersinia enterocolitica colonization developed a post-transplantation Y. enterocolitica infection. Patients admitted for HCT are frequently colonized with a diverse range of GI pathogens. Colonization with C. difficile colonization and diarrheagenic E. coli is frequently associated with post-transplantation diarrheal infections caused by these organisms, but the clinical significance of colonization with other GI pathogens is not clear.

Risk Factors and Outcome of C. difficile Infection after Hematopoietic Stem Cell Transplantation

Patients who undergo hematopoietic stem cell transplants (HSCT) are at major risk of C. difficile (CD) infection (CDI), the most common cause of nosocomial diarrhea. We conducted a retrospective study, which enrolled 481 patients who underwent autologous (220) or allogeneic HSCT (261) in a 5-year period, with the aim of identifying the incidence, risk factors and outcome of CDI between the start of conditioning and 100 days after HSCT. The overall cumulative incidence of CDI based upon clinical evidence was 5.4% (95% CI, 3.7% to 7.8%), without any significant difference between the two types of procedures. The median time between HSCT and CDI diagnosis was 12 days. Out of 26 patients, 19 (73%) with clinical and symptomatic evidence of CDI were positive also for enzymatic or molecular detection of toxigenic CD; in particular, in 5 out of 26 patients (19%) CD binary toxin was also detected. CDI diagnoses significantly increased in the period 2018-2019, since the introduction in the microbiology lab unit of the two-step diagnostic test based on GDH immunoenzymatic detection and toxin B/binary toxin/027 ribotype detection by real-time PCR. Via multivariate analysis, abdominal surgery within 10 years before HSCT (p = 0.002), antibiotic therapy within two months before HSCT (p = 0.000), HCV infection (p = 0.023) and occurrence of bacterial or fungal infections up to 100 days after HSCT (p = 0.003) were significantly associated with a higher risk of CDI development. The 26 patients were treated with first-line vancomycin (24) or fidaxomicine (2) and only 2 patients needed a second-line treatment, due to the persistence of stool positivity. No significant relationship was identified between CDI and the development of acute graft versus host disease (GVHD) after allogeneic HSCT. At a median follow-up of 25 months (range 1-65), the cumulative incidence of transplant related mortality (TRM) was 16.6% (95% CI 11.7% to 22.4%) and the 3-year overall survival (OS) was 67.0% (95% CI 61.9% to 71.6%). The development of CDI had no significant impact on TRM and OS, which were significantly impaired in the multivariate analysis by gastrointestinal and urogenital comorbidities, severe GVHD, previous infections or hospitalization within two months before HSCT, active disease at transplant and occurrence of infections after HSCT. We conclude that 20% of all episodes of diarrhea occurring up to 100 days after HSCT were related to toxigenic CD infection. Patients with a history of previous abdominal surgery or HCV infection, or those who had received broad spectrum parenteral antibacterial therapy were at major risk for CDI development. CDIs were successfully treated with vancomycin or fidaxomicin after auto-HSCT as well as after allo-HSCT.