Predictors of Clostridioides difficile Infection-Related Complications and Treatment Patterns among Nucleic Acid Amplification Test-Positive/Toxin Enzyme Immunoassay-Negative Patients.

The addition of toxin enzyme immunoassay (EIA) to nucleic acid amplification tests, including PCR, creates challenges in the diagnosis and management of Clostridioides difficile infection (CDI). There are limited data in large cohorts, with discordant results, that is, PCR-positive/EIA-negative (PCR+/EIA-) results. We conducted a retrospective cohort study on all PCR+/EIA- adult inpatients and assessed CDI-related complications and clinical failure. We identified 240 individuals. Twenty-three (9.6%) patients experienced a CDI-related complication, including 2 cases of megacolon, 1 colectomy, and 22 intensive care unit (ICU) admissions. In multivariable logistic regression analyses, baseline severe disease by Infectious Diseases Society of America (IDSA) criteria (odds ratio [OR], 5.84; 95% confidence interval [CI], 1.88 to 18.1; P = 0.002), baseline fulminant colitis (OR, 84.7; 95% CI, 14.3 to 500; P < 0.001), fever of >38.5°C (OR, 4.61; 95% CI, 1.42 to 15.0; P = 0.011), and proton pump inhibitor (PPI) use (OR, 3.50; 95% CI, 1.19 to 10.3; P = 0.023) were associated with increased odds of CDI-related complications. For 67 PCR+/EIA- patients who did not receive complete treatment, clinical failure was observed in 10 (15%) patients. A comparison of PCR+/EIA- patients who received complete treatment to all 112 PCR+/EIA+ patients showed no differences in CDI-related complications (11% and 13% for PCR+/EIA- and PCR+/EIA+ patients, respectively), 60-day all-cause mortality (17% and 18% for PCR+/EIA- and PCR+/EIA+ patients, respectively), or recurrent CDI (7% and 9% for PCR+/EIA- and PCR+/EIA+ patients, respectively). Predictors of CDI-attributable complications among PCR+/EIA- patients include baseline severe disease by IDSA criteria, baseline fulminant colitis, and fever of >38.5°C. Identifying the subgroup of PCR+/EIA- patients who could have true disease, and therefore allowing them to be targeted for treatment, is critical.

Monitoring the effectiveness of daily cleaning practices in an intensive care unit (ICU) setting using an adenosine triphosphate (ATP) bioluminescence assay.

BACKGROUND: The degree to which daily intensive care unit (ICU) cleaning practices impacts bacterial burden is controversial. The study aimed to assess the utility of using adenosine triphosphate (ATP) bioluminescence assays for monitoring effectiveness of daily cleaning in ICU environments. METHODS: We sampled 364 total samples from 57 patient rooms and 18 common areas in 3 medical ICUs over 12 weeks, before and after routine daily cleaning. Endpoints were ATP levels (relative light units, RLU) and bacterial bioburden (colony forming units, CFU). RESULTS: High-touch surfaces in ICU patient rooms and common areas were contaminated before and after cleaning. Routine cleaning significantly reduced bacterial burden in patient rooms (0.14 log10 CFU reduction, P = .008; 0.21 log10 RLU reduction, P < .001) and in ICU common areas (1.18 log10 CFU reduction, P < .001; 0.72 log10 RLU reduction, P < .001). Among sites with colony counts >20 CFUs, the proportion of sites with ATP readings >250 RLU was significantly higher than those with ATP readings ≤250 RLU (90.0% vs 10.0%, P < .05). CONCLUSION: Routine cleaning significantly reduced bacterial burden on ICU environment surfaces. Although not an alternative to culture methods, ATP assays may be a useful technique to provide rapid feedback on surface cleanliness in ICU settings.

Evaluation of Prophylactic Antibiotic Use for Delayed Sternal Closure After Cardiothoracic Operation.

BACKGROUND: Clinical practice guidelines provide recommendations for surgical prophylaxis in patients undergoing cardiothoracic procedures. However, currently no recommendations guide the management of antibiotic prophylaxis in patients who require delayed sternal closure after cardiothoracic operation. METHODS: This is a single-center, retrospective analysis. Data were extracted from The Society of Thoracic Surgery database and electronic medical record from July 2011 through January 2016. Patients included are adults (≥18 years old) after cardiothoracic operation with delayed sternal closure. RESULTS: A total of 167 patients were included for analysis. The majority of patients (131, 78.4%) were continued on routine antibiotics and 36 patients (21.6%) were switched to broad-spectrum antibiotics for prophylaxis. Of patients on routine antibiotic prophylaxis, 6 (4.6%) experienced a sternal surgical site infection, whereas 3 patients (8.3%) switched to broad-spectrum agents before chest closure experienced a sternal surgical site infection (p = 0.407). Eleven patients (6.6%) received an abbreviated duration of antibiotics, 52 patients (31.1%) were continued on antibiotics until the time of sternal closure, and 104 patients (62.3%) were continued on antibiotics past the time of sternal closure. The incidence of infection based on duration of prophylactic antibiotic was 0, 1 (1.9%), and 8 (7.7%), respectively (p = 0.352). CONCLUSIONS: Substantial variation was found in the duration and selection of antibiotic prophylaxis for patients with delayed sternal closure after cardiothoracic operation. Broad-spectrum antimicrobial agents and extended durations of antibiotic prophylaxis were not associated with benefits in the incidence of sternal wound infection and may increase the risk of adverse effects.

Value of surgery for infective endocarditis in dialysis patients.

OBJECTIVES: To determine the value of surgery for infective endocarditis (IE) in patients on hemodialysis by comparing the nature and invasiveness of endocarditis in hemodialysis and nonhemodialysis patients and their hospital and long-term outcomes, and identifying risk factors for time-related mortality after surgery. METHODS: From January 1997 to January 2013, 144 patients on chronic hemodialysis and 1233 nonhemodialysis patients underwent valve surgery for IE at our institution. Propensity matching identified 99 well-matched hemodialysis and nonhemodialysis patient pairs for comparison of outcomes. RESULTS: Staphylococcus aureus infection was more common in hemodialysis patients than in nonhemodialysis patients (42% vs 21%; P < .0001), but invasive disease was similar in the 2 groups (47%; P = .3). Hospital mortality was 13% and 5-year survival was 20% for hemodialysis patients, 20% below that expected in a general hemodialysis population but 15% above that of hemodialysis patients treated nonsurgically for IE. For matched patients, hospital mortality was 13% for hemodialysis patients versus 5.1% for nonhemodialysis patients (P = .05), and survival at 1 and 5 years was 56% versus 83% and 24% versus 59%, respectively (P < .004). Use of an arteriovenous graft for dialysis access (P = .01) and preoperative placement of a pacemaker (P < .0001) were risk factors for late mortality in hemodialysis patients. For matched patients, freedom from reoperation was similar in the hemodialysis and nonhemodialysis groups (P > .9). CONCLUSIONS: Intermediate-term survival after surgery for IE in hemodialysis patients is substantially worse than that in nonhemodialysis patients, but only slightly worse than that in the general hemodialysis population and substantially better than that in hemodialysis patients with IE treated nonsurgically, supporting continued surgical intervention for IE.

Heart valve culture and sequencing to identify the infective endocarditis pathogen in surgically treated patients.

BACKGROUND: Testing excised valves in surgically treated infective endocarditis (IE) patients provides an opportunity to identify the microbial etiology of IE. Microbial sequencing (universal bacterial, mycobacterial, or fungal polymerase chain reaction followed by DNA sequencing) of valves can identify microorganisms accurately, but the value it adds beyond information provided by blood and valve cultures has not been adequately explored. METHODS: Three hundred fifty-six patients who underwent surgery for active IE from January 1, 2010, to January 1, 2013, were identified from our cardiovascular information registry and outpatient parenteral antibiotic therapy registry. Their records were reviewed to identify 174 patients whose valves were sent for sequencing. The microbial etiology of IE was defined using comprehensive clinical, pathologic, and microbiological criteria. Blood culture, valve culture, and valve sequencing were examined to determine how frequently they identified the definitive cause of IE. RESULTS: Of the 174 patients, 162 (93%) had acute inflammation on histopathologic examination of their valves. Valve sequencing was significantly more sensitive than valve culture in identifying the causative pathogen (90% versus 31%, p < 0.001), and yielded fewer false positive results (3% versus 33%, p <0.001). The pathogen would not have been identified in 25 patients (15%) had it not been for valve sequencing. All the value provided by sequencing was attributable to bacterial DNA sequencing; mycobacterial and fungal sequencing provided no additional information beyond that provided by blood culture, histopathology, and valve culture. CONCLUSIONS: Valve sequencing, not valve culture, should be considered the primary test for identifying bacteria in excised cardiac valves.

Clinical utility of cerebral angiography in the preoperative assessment of endocarditis.

Cerebral angiography is an invasive procedure utilized without supporting guidelines in preoperative evaluations of infective endocarditis (IE). It is used to identify mycotic intracranial aneurysm, which is suspected to increase the risk of intracranial bleeding during cardiac surgery. Our objectives were to: (1) assess the utility of cerebral angiography by determining which subset of IE patients benefit from its performance; and (2) identify clinical and noninvasive screening tests that can preclude the need for invasive cerebral angiography. Retrospective analysis was performed of all patients treated surgically for IE from 7/2007 to 1/2012 and discharged with medical treatment for IE from 7/2007 to 7/2009 presenting to a large academic center. Of the 151 patients who underwent cerebral angiography, mycotic aneurysm was identified in seven (prevalence=4.6%; 95% CI 2.3-9.3%). Five had viridans group streptococci as the causative IE microorganism (p=0.0017). Noninvasive imaging and particularly absence of intracranial bleed on magnetic resonance imaging conveys a negative predictive value (NPV) of 0.977 (95% CI 0.879-0.996). Absence of a focal neurologic deficit or altered mental status convey a NPV of 0.990 (95% CI 0.945-0.998) and 0.944 (95% CI 0.883-0.974), respectively. Clinical suspicion for mycotic aneurysm and thus utilization of cerebral angiography is likely necessary only in the setting of acute neurologic deficits and when noninvasive imaging demonstrates acute intracranial bleed. A novel association between viridans group streptococci and intracranial mycotic aneurysm is demonstrated.

Clostridium difficile infection after cardiac surgery: prevalence, morbidity, mortality, and resource utilization.

OBJECTIVE: Despite increasing efforts to prevent infection, the prevalence of hospital-associated Clostridium difficile infections (CDI) is increasing. Heightened awareness prompted this study of the prevalence and morbidity associated with CDI after cardiac surgery. METHODS: A total of 22,952 patients underwent cardiac surgery at Cleveland Clinic from January 2005 to January 2011. CDI was diagnosed by enzyme immunoassay for toxins and, more recently, polymerase chain reaction (PCR) testing. Hospital outcomes and long-term survival were compared with those of the remaining population in propensity-matched groups. RESULTS: One hundred forty-five patients (0.63%) tested positive for CDI at a median of 9 days postoperatively, 135 by enzyme immunoassay and 11 by PCR. Its prevalence more than doubled over the study period. Seventy-seven patients (48%) were transfers from outside hospitals. Seventy-three patients (50%) were exposed preoperatively to antibiotics and 79 (56%) to proton-pump inhibitors. Patients with CDI had more baseline comorbidities, more reoperations, and received more blood products than patients who did not have CDI. Presenting symptoms included diarrhea (107; 75%), distended abdomen (48; 34%), and abdominal pain (27; 19%). All were treated with metronidazole or vancomycin. Sixteen patients (11%) died in hospital, including 5 of 10 who developed toxic colitis; 3 of 4 undergoing total colectomy survived. Among matched patients, those with CDI had more septicemia (P < .0001), renal failure (P = .0002), reoperations (P < .0001), prolonged postoperative ventilation (P < .0001), longer hospital stay (P < .0001), and lower 3-year survival, 52% versus 64% (P = .03), than patients who did not have CDI. CONCLUSIONS: Although rare, the prevalence of CDI is increasing, contributing importantly to morbidity and mortality after cardiac surgery. If toxic colitis develops, mortality is high, but colectomy may be lifesaving.

The descriptive epidemiology of central line-associated bloodstream infection among patients in non-intensive care unit settings.

OBJECTIVE: To review and describe device utilization and central line-associated bloodstream (CLABSI) events among patients in a non-intensive care unit (ICU) setting and to examine the morbidity and mortality associated with these events. DESIGN: One-year descriptive review. SETTING: A single tertiary center with a 1,200-bed hospital and 209 adult ICU beds. PATIENTS: Hospitalized patients identified as having a CLABSI event attributed to a non-ICU setting. METHODS: The cohort was identified from a prospective infection prevention database. Charts and administrative data sets were reviewed to further characterize the patients. Device utilization ratios (DURs) and CLABSI rates were calculated using National Health and Safety Network (NHSN) CLABSI definitions. Need for ICU stay and crude mortality rates were recorded. RESULTS: A total of 136 patients with 156 CLABSIs were identified, of whom 78 (57%) were being treated for a hematological malignancy (HM). The overall DUR was 0.27. A tunneled line was in place for 118 (76%) of the CLABSI events, and a peripherally inserted central catheter was in place for 32 (21%) of the CLABSI events. The non-ICU CLABSI rate was significantly higher than the concurrent ICU rate (2.1 CLABSIs per 1,000 catheter-days vs 1.5 CLABSIs per 1,000 catheter-days; [Formula: see text]). Hospital mortality was 23% in the affected group and was significantly higher in patients with HM. CONCLUSIONS: CLABSI rates over a 1-year period were higher in patients outside the ICU at our hospital and were associated with significant mortality.

Development of a modified surveillance definition of central line-associated bloodstream infections for patients with hematologic malignancies.

OBJECTIVE: To develop a modified surveillance definition of central line-associated bloodstream infection (mCLABSI) specific for our population of patients with hematologic malignancies to better support ongoing improvement efforts at our hospital. DESIGN: Retrospective cohort study. PATIENTS: Hematologic malignancies population in a 1,200-bed tertiary care hospital on a 22-bed bone marrow transplant (BMT) unit and a 22-bed leukemia unit. METHODS: An mCLABSI definition was developed, and pathogens and rates were compared against those determined using the National Healthcare Safety Network (NHSN) definition. RESULTS: By the NHSN definition the CLABSI rate on the BMT unit was 6.0 per 1,000 central line-days, and by the mCLABSI definition the rate was 2.0 per 1,000 line-days ([Formula: see text]). On the leukemia unit, the NHSN CLABSI rate was 14.4 per 1,000 line-days, and the mCLABSI rate was 8.2 per 1,000 line-days ([Formula: see text]). The top 3 CLABSI pathogens by the NHSN definition were Enterococcus species, Klebsiella species, and Escherichia coli. The top 3 CLABSI pathogens by the mCLABSI definition were coagulase-negative Staphylococcus (CONS), Pseudomonas aeruginosa, and Staphylococcus aureus. The difference in the incidence of CONS as a cause of CLABSI under the 2 definitions was statistically significant ([Formula: see text]). CONCLUSIONS: A modified surveillance definition of CLABSI was associated with an increase in the identification of staphylococci as the cause of CLABSIs, as opposed to enteric pathogens, and a decrease in CLABSI rates.

Challenges of interferon-γ release assay conversions in serial testing of health-care workers in a TB control program.

BACKGROUND: Clinical data with use of serial interferon-γ release assay (IGRA) testing in US health-care workers (HCWs) are limited. METHODS: A single-center, retrospective chart review was done from 2007 to 2010 of HCWs who underwent preemployment QuantiFERON-TB Gold In-Tube testing. Demographic data, bacille Calmette-Guérin history, prior tuberculin skin test result if done, and baseline and serial IGRA values were obtained. The number of IGRA converters and reverters and their subsequent management by infectious disease physicians were reviewed. Quantitative IGRA-negative values were not available. RESULTS: A total of 7,374 IGRAs were performed on newly hired HCWs. Of these tests, 486 (6.6%) were positive at baseline, 305 (4.1%) were indeterminate, and 6,583 (89.3%) were negative. From 2007 to 2010, 52 of 1,857 HCWs (2.8%) with serial IGRA tests were identified as converters, with a serial IGRA median value of 0.63 IU/mL. Seventy-one percent of HCWs with IGRA conversion had values ≤ 1 IU/mL. None of the converters had active TB or were part of an outbreak investigation. CONCLUSIONS: Clinical significance of most QuantiFERON-TB Gold In-Tube conversions in serial testing remains a challenging task for clinicians. The use of a single cutoff point criterion for IGRA may lead to overdiagnosis of new TB infections. Clinical assessment and evaluation may help to prevent unnecessary therapy in these cases. The criteria for defining conversions and reversions by establishing new cutoffs needs to be evaluated further, especially in HCWs.

Endovascular infections caused by Histoplasma capsulatum: a case series and review of the literature.

CONTEXT: Endovascular infection is an uncommon but devastating manifestation of histoplasmosis, which is often diagnosed late in disease. OBJECTIVES: To evaluate the clinical and pathologic characteristics of patients with endovascular infections caused by Histoplasma capsulatum. DESIGN: All cases of patients with documented endovascular histoplasmosis at a single tertiary care center in an endemic region during the period 1993-2010 were reviewed. RESULTS: Patients presented with a subacute febrile illness and a history of endovascular devices. All patients had positive Histoplasma serology. Routine bacterial culture results were negative for all patients. In addition to yeast forms typical of histoplasmosis, pathologic findings also revealed mycelial forms in 4 of 5 patients. Inflammation was scant. Urinary antigen detection was positive in 4 of 5 patients and Histoplasma blood culture results were positive for 3 of 5 patients. Four patients were treated with a combination of surgical and medical therapy, which consisted of amphotericin B followed by itraconazole; these 4 patients had complete resolution of symptoms and no documented relapse. One patient died before planned surgery. CONCLUSIONS: Histoplasma capsulatum endovascular infections are clinically characterized by a subacute febrile illness with negative bacterial cultures in patients with prosthetic endografts or valves. Noninvasive diagnostics are often the initial clue to the diagnosis. Combined medical and surgical treatment is associated with survival. On histopathologic examination both mycelial and yeast forms are often observed, with absent to minimal tissue inflammatory reaction.

Epidemiology and outcome of major postoperative infections following cardiac surgery: risk factors and impact of pathogen type.

BACKGROUND: Major postoperative infections (MPIs) are poorly understood complications of cardiac surgery. We examined the epidemiology, microbiology, and outcome of MPIs occurring after cardiac surgery. METHODS: The study cohort was drawn from the Society of Thoracic Surgeon National Cardiac Database and comprised adults who underwent cardiac surgery at 5 tertiary hospitals between 2000 and 2004. We studied the incidence, microbiology, and risk factors of MPI (bloodstream or chest wound infections within 30 days after surgery), as well as 30-day mortality. We used multivariate regression analyses to evaluate the risk of MPI and mortality. RESULTS: MPI was identified in 341 of 10,522 patients (3.2%). Staphylococci were found in 52.5% of these patients, gram-negative bacilli (GNB) in 24.3%, and other pathogens in 23.2%. High body mass index, previous coronary bypass surgery, emergency surgery, renal impairment, immunosuppression, cardiac failure, and peripheral/cerebrovascular disease were associated with the development of MPI. Median postoperative duration of hospitalization (15 days vs 6 days) and mortality (8.5% vs 2.2%) were higher in patients with MPIs. Compared with uninfected individuals, odds of mortality were higher in patients with S aureus MPIs (adjusted odds ratio, 3.7) and GNB MPIs (adjusted odds ratio, 3.0). CONCLUSIONS: Staphylococci accounted for the majority of MPIs after cardiac surgery. Mortality was higher in patients with Staphylococcus aureus- and GNB-related MPIs than in patients with MPIs caused by other pathogens and uninfected patients. Preventive strategies should target likely pathogens and high-risk patients undergoing cardiac surgery.

Outcomes after surgical treatment of native and prosthetic valve infective endocarditis.

BACKGROUND: The risk of death and complications of infective endocarditis (IE) treated medically has to be balanced against those from surgery in constructing a therapeutic approach. Recent literature has drawn conflicting conclusions on the benefit of surgery for IE. We reviewed patients treated surgically for IE at the Cleveland Clinic from 2003 to 2007 to examine their outcomes. METHODS: A retrospective review of consecutive patients who underwent surgery for native and prosthetic valve endocarditis between January 1, 2003, and December 31, 2007, was conducted. Surgical outcomes were reviewed to include survival and postoperative complications. Survival was evaluated at end of hospital stay, 30 days, 1 year, and at last follow-up. RESULTS: Four hundred twenty-eight patients underwent surgery for IE during the study period: 248 (58%) had native valve endocarditis and 180 (42%) had prosthetic valve endocarditis. Overall 90% of patients survived to hospital discharge. When compared with patients with native valve infection, patients with prosthetic infection had significantly higher 30-day mortality (13% versus 5.6%; p<0.01), but long-term survival was not significantly different (35% versus 29%; p=0.19). Patients with IE caused by Staphylococcus aureus had significantly higher hospital mortality (15% versus 8.4%; p<0.05), 6-month mortality (23% versus 15%; p=0.05), and 1-year mortality (28% versus 18%; p=0.02) compared with non-S aureus IE. CONCLUSIONS: Surgical treatment of IE was associated with 90% hospital survival. Outcomes within the 30 days were better for native valve than for prosthetic valve endocarditis. Long-term outcomes were similar. Finally, S aureus was associated with significantly higher mortality compared with other pathogens.

Incidence of and preoperative risk factors for Staphylococcus aureus bacteremia and chest wound infection after cardiac surgery.

OBJECTIVE: Staphylococcus aureus infections after cardiac surgery result in significant morbidity and mortality. Identifying patients at elevated risk for these infections preoperatively could facilitate efforts to reduce infection rates. The objectives of this study were to estimate the incidence of postoperative S. aureus infections in cardiac surgery patients, to identify preoperative risk factors for these infections, and to establish a patient risk profile by means of data available to clinicians prior to surgery. DESIGN: Cohort study. SETTING: Eight medical centers that participate in the Society of Thoracic Surgeons National Cardiac Database. PATIENTS: Patients who were undergoing elective cardiac surgery during the period January 1, 2000 through December 31, 2004. METHODS: Clinical and microbiological data from 16,386 patients were combined. Multivariable stepwise logistic regression analysis was performed to predict S. aureus infection, which was defined by culture results. RESULTS: Of the 16,386 patients, 205 (1.3%) developed S. aureus bloodstream or chest wound infection within 90 days after surgery. On multivariable analysis, bootstrap-validated preoperative risk factors for S. aureus bloodstream or chest wound infection included a body mass index greater than 40 (adjusted odds ratio [aOR], 1.9 [95% confidence interval {CI}, 1.1-3.2]), chronic renal failure (aOR, 1.8 [95% CI, 1.1-2.9]), and chronic lung disease (aOR, 1.4 [95% CI, 1.0-2.0]). Only 8 patients had all 3 risk factors. CONCLUSIONS: Although preoperative risk factors can be easily identified, the majority of patients who developed S. aureus infections after cardiac surgery did not have any risk factors. Preventive measures should not be restricted to a select group of cardiac surgery patients and should rather address the entire patient population.

The use of real-time polymerase chain reaction for rapid diagnosis of skeletal tuberculosis.

We identified Mycobacterium tuberculosis DNA using real-time polymerase chain reaction on a specimen from an osteolytic lesion of a femoral condyle, in which the frozen section demonstrated granulomas. The process was much more rapid than is possible with culture. The rapid detection of M tuberculosis and the concomitant exclusion of granulomatous disease caused by nontuberculous mycobacteria or systemic fungi are necessary to appropriately treat skeletal tuberculosis. The detection and identification of M tuberculosis by culture may require several weeks using traditional methods. The real-time polymerase chain reaction method used has been shown to be rapid and reliable, and is able to detect and differentiate both tuberculous and nontuberculous mycobacteria. Real-time polymerase chain reaction may become a diagnostic standard for the evaluation of clinical specimens for the presence of mycobacteria; this case demonstrates the potential utility of this assay for the rapid diagnosis of skeletal tuberculosis.