Serial Evaluation of Preimmunization Antibody Titers in Lymphoma Patients Receiving Chimeric Antigen Receptor T Cell Therapy

Antibody titers and the potential need for immunization have not been formally studied in recipients of chimeric antigen receptor T cell therapy (CAR-T). Prior studies have shown that CD19-targeted CAR-T can induce persistent B cell aplasia but preserve plasma cells for humoral response. Aiming to assess the immune repertoire and antibody titer status of CAR-T recipients, we conducted a retrospective study of immune cell recovery and antibody titers to vaccines in anti-CD19 CAR-T recipients at Mayo Clinic, Rochester. In our cohort of 95 CAR-T recipients, almost one-half had low CD4 T and B cell counts prior to CAR-T that remained persistently low post-CAR-T. Prior to CAR-T, the seronegative rate was lowest for tetanus and highest for pneumococcus irrespective of prior transplantation status (within 2 years of CAR-T). At 3 months post-CAR-T, overall seronegativity rates were similar to pre-CAR-T rates for the prior transplantation and no prior transplantation groups. For patients who received IVIG, loss of seropositivity was seen for hepatitis A (1 of 7; 14%). No seroconversion was noted for pneumococcus. For patients who did not receive IVIG, loss of seropositivity was seen for pneumococcus (2 of 5; 40%) and hepatitis A (1 of 4; 25%). CAR-T recipients commonly experience T cell and B cell lymphopenia and might not have adequate antibody titers against vaccine-preventable diseases despite IVIG supplementation. Loss of antibody titers post-CAR-T is possible, highlighting the need for revaccination. Additional studies with long-term follow-up are needed to inform the optimal timing of immunization post-CAR-T.

Reduction in urinary tract infections in patients treated with fecal microbiota transplantation for recurrent Clostridioides difficile infection

We performed an updated study to investigate the rates of urinary tract infections (UTIs) in patients with recurrent Clostridioides difficile infection (CDI) who received fecal microbiota transplantation (FMT) for CDI. We found a significant reduction in number of UTIs after FMT compared to patients who received antibiotics for CDI treatment. After FMT, we also observed a trend towards reduction of antibiotic resistance in organisms causing UTI.

Critical Care Staffing in Pandemics and Disasters: A Consensus Report from a Sub-committee of the Task Force for Mass Critical Care- Systems Strategies to Sustain the Healthcare Workforce

BACKGROUND

The 2019 coronavirus disease (COVID-19) pandemic has led to unprecedented mental health disturbances, burnout, and moral distress among healthcare workers, impacting their ability to care for themselves and their patients.

METHODS

The Workforce Sustainment subcommittee of the Task Force for Mass Critical Care (TFMCC) utilized a consensus development process, incorporating evidence from literature review with expert opinion through a modified Delphi approach to determine factors impacting mental health, burnout, and moral distress in healthcare workers, in order to propose necessary actions to help prevent these issues and enhance workforce resilience, sustainment, and retention.

RESULTS

Consolidation of evidence gathered from literature review and expert opinion resulted in 197 total statements that were synthesized into 14 major suggestions. These suggestions were organized into three categories: (1) mental health and wellbeing for staff in medical settings, (2) system-level support and leadership, and (3) research priorities and gaps. Suggestions include both general and specific occupational interventions to support healthcare worker basic physical needs, psychological distress, reduce moral distress and burnout, and foster mental health and resilience.

CONCLUSIONS

The Workforce Sustainment subcommittee of the TFMCC offers evidence-informed operational strategies to assist healthcare workers and hospitals plan, prevent, and treat the factors impacting healthcare worker mental health, burnout, and moral distress to improve resilience and retention following the COVID-19 pandemic.

Prevention of monkeypox with vaccines: a rapid review

The largest outbreak of monkeypox in history began in May, 2022, and has rapidly spread across the globe ever since. The purpose of this Review is to briefly describe human immune responses to orthopoxviruses; provide an overview of the vaccines available to combat this outbreak; and discuss the various clinical data and animal studies evaluating protective immunity to monkeypox elicited by vaccinia virus-based smallpox vaccines, address ongoing concerns regarding the outbreak, and provide suggestions for the appropriate use of vaccines as an outbreak control measure. Data showing clinical effectiveness (~85%) of smallpox vaccines against monkeypox come from surveillance studies conducted in central Africa in the 1980s and later during outbreaks in the same area. These data are supported by a large number of animal studies (primarily in non-human primates) with live virus challenge by various inoculation routes. These studies uniformly showed a high degree of protection and immunity against monkeypox virus following vaccination with various smallpox vaccines. Smallpox vaccines represent an effective countermeasure that can be used to control monkeypox outbreaks. However, smallpox vaccines do cause side-effects and the replication-competent, second-generation vaccines have contraindications. Third-generation vaccines, although safer for use in immunocompromised populations, require two doses, which is an impediment to rapid outbreak response. Lessons learned from the COVID-19 pandemic should be used to inform our collective response to this monkeypox outbreak and to future outbreaks.

Monkeypox 2022: Gearing Up for Another Potential Public Health Crisis

Monkeypox virus, a member of the Orthopoxvirus genus, was first identified as the etiology of monkeypox in 1970 in the Democratic Republic of Congo and remains endemic in regions of Central and West Africa. Following the most recent outbreak of monkeypox in multiple countries throughout Europe and North America, the infection has been declared a public health emergency by the Centers for Disease Control and Prevention. Within this report, we aim to provide clinicians with a focused overview of the epidemiology, clinical manifestation, diagnosis, and approaches to treat and prevent monkeypox infection amidst the global outbreak.

Investigation of a cluster of rapidly growing mycobacteria infections associated with joint replacement surgery in a Kentucky hospital, 2013-2014 with 8-year follow-up

BACKGROUND

We describe the investigation of a nosocomial outbreak of rapidly growing mycobacteria (RGM) infections and the results of mitigation efforts after 8 years.

METHODS

A cluster of RGM cases in a Kentucky hospital in 2013 prompted an investigation into RGM surgical site infections following joint replacement surgery. A case-control study was conducted to identify risk factors.

RESULTS

Eight cases were identified, 5 caused by M. wolinskyi and 3 by M. goodii. The case-control study showed the presence of a particular nurse in the operating room was significantly associated with infection. Environmental sampling at the nurse's home identified an outdoor hot tub as the likely source of M. wolinskyi, confirmed by pulsed-field gel electrophoresis and whole genome sequencing. The hot tub reservoir was eliminated, and hospital policies were revised to correct infection control lapses. No new cases of RGM infections have been identified as of 2021.

DISCUSSION

Breaches in infection control practices at multiple levels may have led to a chain of infection from a nurse's hot tub to surgical sites via indirect person-to-person transmission from a colonized health care worker (HCW).

CONCLUSIONS

The multifactorial nature of the outbreak's cause highlights the importance of overlapping or redundant layers of protection preventing patient harm. Future investigations of RGM outbreaks should consider the potential role of colonized HCWs as a transmission vector.

Mass Critical Care Surge Response During COVID-19: Implementation of Contingency Strategies - A Preliminary Report of Findings From the Task Force for Mass Critical Care

Background

After the publication of a 2014 consensus statement regarding mass critical care during public health emergencies, much has been learned about surge responses and the care of overwhelming numbers of patients during the COVID-19 pandemic. Gaps in prior pandemic planning were identified and require modification in the midst of severe ongoing surges throughout the world.

Research Question

A subcommittee from The Task Force for Mass Critical Care (TFMCC) investigated the most recent COVID-19 publications coupled with TFMCC members anecdotal experience in order to formulate operational strategies to optimize contingency level care, and prevent crisis care circumstances associated with increased mortality.

Study Design and Methods

TFMCC adopted a modified version of established rapid guideline methodologies from the World Health Organization and the Guidelines International Network-McMaster Guideline Development Checklist. With a consensus development process incorporating expert opinion to define important questions and extract evidence, the TFMCC developed relevant pandemic surge suggestions in a structured manner, incorporating peer-reviewed literature, “gray” evidence from lay media sources, and anecdotal experiential evidence.

Results

Ten suggestions were identified regarding staffing, load-balancing, communication, and technology. Staffing models are suggested with resilience strategies to support critical care staff. ICU surge strategies and strain indicators are suggested to enhance ICU prioritization tactics to maintain contingency level care and to avoid crisis triage, with early transfer strategies to further load-balance care. We suggest that intensivists and hospitalists be engaged with the incident command structure to ensure two-way communication, situational awareness, and the use of technology to support critical care delivery and families of patients in ICUs.

Interpretation

A subcommittee from the TFMCC offers interim evidence-informed operational strategies to assist hospitals and communities to plan for and respond to surge capacity demands resulting from COVID-19.

Incidence of Pneumocystis jirovecii pneumonia utilizing a polymerase chain reaction-based diagnosis in patients receiving bendamustine

BACKGROUND

Pneumocystis jirovecii pneumonia (PJP) is a life-threatening infection occurring in patients receiving bendamustine. The poorly defined incidence, particularly when utilizing polymerase chain reaction (PCR)-based diagnostic techniques, precipitates unclear prophylaxis recommendations. Our objective was to determine the cumulative incidence of PJP diagnosed by single copy target, non-nested PCR in patients receiving bendamustine.

METHODS

Patients were evaluated for PJP from initiation of bendamustine through 9 months after the last administration. The cumulative incidence of PJP was estimated using the Aalen-Johansen method. Cox proportional hazard models were used to demonstrate the strength of association between the independent variables and PJP risk.

RESULTS

This single-center, retrospective cohort included 486 adult patients receiving bendamustine from 1 January 2006 through 1 August 2019. Most patients received bendamustine-based combination therapy (n = 461, 94.9%), and 225 (46.3%) patients completed six cycles. Rituximab was the most common concurrent agent (n = 431, 88.7%). The cumulative incidence of PJP was 1.7% (95% CI 0.8%-3.3%, at maximum follow-up of 2.5 years), after the start of bendamustine (n = 8 PJP events overall). Prior stem cell transplant, prior chemotherapy within 1 year of bendamustine, and lack of concurrent chemotherapy were associated with the development of PJP in univariate analyses. Anti-Pneumocystis prophylaxis was not significantly associated with a reduction in PJP compared to no prophylaxis (HR 0.37, 95% CI (0.05, 3.04), p = 0.36).

CONCLUSIONS

Our incidence of PJP below 3.5%, the conventional threshold for prophylaxis implementation, indicates routine anti-Pneumocystis prophylaxis may not be necessary in this population. Factors indicating a high-risk population for targeted prophylaxis require further investigation.

Acute Epstein-Barr virus infection presenting as Guillain-Barre syndrome

An 18-year-old man presented with 5-days of a lower extremity rash, sore throat, rapidly progressive bilateral facial numbness and paresthesias in his distal extremities. His neurological examination acutely deteriorated to include moderate bilateral facial weakness in a lower motor neuron pattern, mild flaccid dysarthria, mild bilateral interossei weakness, and diffuse hyporeflexia. In addition to neurological examination, EMG results of acute demyelinating polyradiculoneuropathy were suggestive of Guillain-Barre Syndrome (GBS). Infectious laboratory testing demonstrated acute infection of Epstein-Barr Virus (EBV) with relatively low EBV DNA quantitative values. The patient subsequently developed fever and cervical lymphadenopathy during his hospital course. Contrasting typical GBS, which presents weeks after an acute infection, the patient's presenting symptom of EBV infection was GBS. GBS as a presenting symptom of EBV has not previously been described. This case may represent a unique mechanism for the pathogenesis of GBS in acute infections as opposed to the traditional post-infectious antibody-mediated process.

Incidence, clinical presentation, and outcomes of Pneumocystis pneumonia when utilizing Polymerase Chain Reaction-based diagnosis in patients with Hodgkin lymphoma

A Polymerase Chain Reaction-based diagnosis of Pneumocystis Pneumonia (PCP) and the need for anti-Pneumocystis prophylaxis in Hodgkin lymphoma patients receiving chemotherapy requires further investigation. This retrospective, single-center, study evaluated 506 consecutive adult patients diagnosed with Hodgkin lymphoma receiving chemotherapy between January 2006 and August 2018. The cumulative incidence of PCP 1 year after start of chemotherapy was 6.2% (95% CI 3.8-8.5%). Mortality 30 days from PCP diagnosis was 8% (n = 2) with one death attributable to PCP. Bleomycin-containing combination chemotherapy regimen was not significantly associated with a higher risk for PCP when compared to other regimens (HR = 1.59, 95% CI 0.55-4.62 p = 0.40). Anti-Pneumocystis prophylaxis was not significantly associated with a decreased incidence of PCP (HR = 0.51, 95% CI 0.15-1.71, p = 0.28). As the overall incidence is above the commonly accepted 3.5% threshold, clinicians should consider the potential value of prophylaxis. The utility of universal vs. targeted anti-Pneumocystis prophylaxis requires prospective, randomized investigation.

Bone and Joint Infections among Hematopoietic Stem Cell Transplant Recipients

Background: Hematopoietic stem cell transplantation (HSCT) recipients are at increased risk for infection. This study describes bone and joint infections (BJI) among HSCT recipients.

Methods: We reviewed 5861 patients who underwent HSCT at Mayo Clinic, Rochester, MN from January 1, 2005 through January 1, 2015 for study inclusion. BJI was defined as native septic arthritis, prosthetic joint infection, osteomyelitis, and orthopedic implant infection. All adults with BJI after HSCT were included in the analysis.

Results: Of 5861 patients, 33 (0.6%) developed BJI. Native joint septic arthritis was the most common BJI occurring in 15/33 (45.4%) patients. Patients were predominantly male (24/33, 72.7%), with median age of 58 (range 20-72) years. BJI was diagnosed a median of 39 (range 1-114) months after allogeneic (14/33, 42.4%) or autologous (19/33, 57.6%) HSCT. Organisms were recovered via tissue (24/27, 88.9%), synovial fluid (13/17, 76.5%), and/or blood cultures (16/25, 64%). Most underwent surgical debridement (23/33, 69.7%). Patients were followed a median of 78.3 months (range 74-119). Therapy was unsuccessful in 4/33 (12.1%), with death related to the underlying BJI in two (50%). Failure occurred a median of 3.4 (0.1-48.5) months from diagnosis. At last follow up, 7/33 (21.2%) patients were alive. Median overall survival was 13 months (0.07-70.6).

Conclusion: BJI among HSCT recipients is infrequent. The most common infection is native joint septic arthritis. Pathogens appear similar to patients without HSCT. Treatment involving surgical-medical modalities is successful, with most patients surviving >1 year after BJI.

Efficacy of Antitoxin Therapy in Treating Patients With Foodborne Botulism: A Systematic Review and Meta-analysis of Cases, 1923-2016

Background

Botulism is a rare, potentially severe illness, often fatal if not appropriately treated. Data on treatment are sparse. We systematically evaluated the literature on botulinum antitoxin and other treatments.

Methods

We conducted a systematic literature review of published articles in PubMed via Medline, Web of Science, Embase, Ovid, and Cumulative Index to Nursing and Allied Health Literature, and included all studies that reported on the clinical course and treatment for foodborne botulism. Articles were reviewed by 2 independent reviewers and independently abstracted for treatment type and toxin exposure. We conducted a meta-analysis on the effect of timing of antitoxin administration, antitoxin type, and toxin exposure type.

Results

We identified 235 articles that met the inclusion criteria, published between 1923 and 2016. Study quality was variable. Few (27%) case series reported sufficient data for inclusion in meta-analysis. Reduced mortality was associated with any antitoxin treatment (odds ratio [OR], 0.16; 95% confidence interval [CI], .09-.30) and antitoxin treatment within 48 hours of illness onset (OR, 0.12; 95% CI, .03-.41). Data did not allow assessment of critical care impact, including ventilator support, on survival. Therapeutic agents other than antitoxin offered no clear benefit. Patient characteristics did not predict poor outcomes. We did not identify an interval beyond which antitoxin was not beneficial.

Conclusions

Published studies on botulism treatment are relatively sparse and of low quality. Timely administration of antitoxin reduces mortality; despite appropriate treatment with antitoxin, some patients suffer respiratory failure. Prompt antitoxin administration and meticulous intensive care are essential for optimal outcome.

Increasing antibiotic resistance in Clostridioides difficile: A systematic review and meta-analysis

BACKGROUND

Decreases in clinical response of Clostridioides difficile to antibiotics used for its treatment have raised concerns regarding antibiotic resistance. We conducted a systematic review and meta-analysis to study the resistance rates of C. difficile to various antibiotics over time.

METHODS

We systematically searched MEDLINE, Embase, and Web of Science from inception through 03/31/2017 for observational studies assessing antibiotic resistance rates in C. difficile. Weighted summary estimates were calculated using inverse variance heterogeneity models [MetaXL software (v. 5.3)]. A priori subgroup analyses were done (by study year, continent, susceptibility testing method, origin of isolates); ribotype 027 strains were analyzed separately.

RESULTS

From 1982 to 2017, 60 studies (8336 isolates) were analyzed. Fifty-three studies reported vancomycin resistance; weighted pooled resistance (WPR), 2.1% (95% CI, 0%-5.1%; I² = 95%). Fifty-five studies reported metronidazole resistance; WPR, 1.9% (95% CI, 0.5%-3.6%; I² = 89%). Compared to the period before 2012, vancomycin resistance increased by 3.6% (95% CI, 2.9%-4.2%; P < 0.001) after 2012, and metronidazole resistance decreased by 0.8% (95% CI, 0.1%-1.5%; P = 0.02). No isolates were resistant to fidaxomicin.

CONCLUSION

Resistance of C. difficile to vancomycin is increasing, with a smaller, declining resistance to metronidazole; there is significant heterogeneity between studies. Ongoing monitoring of resistance to commonly used antibiotics is required.

Standardizing Febrile Neutropenia Management: Antimicrobial Stewardship in the Hematologic Malignancy Population

Patients with febrile neutropenia (FN) often are subject to antibiotic and diagnostic test overuse. We sought to improve appropriate use of antimicrobials and diagnostic tests for patients with FN. We used a blended quality approach with Lean Six Sigma tools and iterative improvement of a clinical decision aid to guide providers through empirical antimicrobial selection and diagnostic evaluation of patients with FN during a yearlong period. We evaluated the incidence of nonadherence to best practice before, during, and after rollout of a clinical decision aid in conjunction with an educational initiative. At baseline, 71% of patients with FN had at least one critical deviation from best practice. During the project, the percentage decreased to 27.3%; 4 months after the project was completed, the percentage was 33.3% (P = .04). A clinical decision aid can improve adherence to best practices for the empirical management of FN.

QT prolongation in patients with acute leukemia or high-risk myelodysplastic syndrome prescribed antifungal prophylaxis during chemotherapy-induced neutropenia

Benefits of serial electrocardiographic (ECG) monitoring to detect QT prolongation in patients with hematological malignancies remain unclear. This retrospective, single-center, study evaluated 316 adult acute leukemia and high-risk MDS patients who received 11,775 patient-days of voriconazole prophylaxis during induction chemotherapy. Of these, 37 patients (16.2%) experienced QTc prolongation. Medications associated with QTc prolongation included furosemide, haloperidol, metronidazole, mirtazapine, prochlorperazine, and venlafaxine. Hypokalemia and hypomagnesemia were also significantly associated with QTc prolongation (HR 3.15; p = .003 and HR 6.47, p = .007, respectively). Management modifications due to QTc prolongation included discontinuation of QT prolonging medications (n = 25), more aggressive electrolyte repletion (n = 5), and enhanced ECG monitoring (n = 3). One patient with multiple QT prolonging factors experienced possible Torsades de Pointes. Overall mortality was 15% with no cardiac-related deaths. Serial ECG monitoring during induction chemotherapy can be tailored proportionally to QT-prolonging risk factors. Management should include aggressive electrolyte repletion and avoidance of concurrent QT prolonging medications.

Faecal microbiota transplantation for eradicating carriage of multidrug-resistant organisms: a systematic review

BACKGROUND

Multidrug-resistant (MDR) microorganism development in the gut is frequently the result of inappropriate antibiotic use. Faecal microbiota transplantation (FMT) restores normal gut microbiota in patients with Clostridium difficile infection. We hypothesized that it may help in decolonizing MDR organisms (MDROs) and in preventing recurrent MDR infections.

OBJECTIVES

To assess FMT efficacy (eradication rate) for decolonizing MDROs and preventing recurrent MDR infections.

DATA SOURCES

Medline, Embase and Web of Science (inception through 11 February 2019).

STUDY ELIGIBILITY CRITERIA

Clinical trials, retrospective studies, case reports and case series.

PARTICIPANTS

Patients with MDR infections or MDRO colonization treated with FMT.

INTERVENTIONS

FMT.

METHODS

Systematic review.

RESULTS

Twenty-one studies (one randomized clinical trial, seven uncontrolled clinical trials, two retrospective cohort studies, two case series, nine case reports) assessing 192 patients were included. Three studies assessed FMT efficacy in preventing MDR infections; 16 assessed its effect on MDRO colonization; two assessed both. Data from 151 patients were included in the final analyses. In studies with low to moderate risk of bias, the eradication rate was 37.5% to 87.5%. Efficacy was similar in studies looking at infection or colonization and did not differ by length of follow-up. No serious adverse events from FMT were reported. Seven patients died of other causes.

CONCLUSIONS

FMT could be used as a treatment for eradicating MDR colonization and possibly preventing recurrent MDR infections, once more supporting efficacy and safety data are available. Larger well-designed randomized controlled trials are needed to further explore this therapy.

Preadmission Corticosteroid Therapy and the Risk of Respiratory Failure in Adults Without HIV Presenting With Pneumocystis Pneumonia

BACKGROUND

Corticosteroid therapy is a well-recognized risk factor for Pneumocystis pneumonia (PCP); however, it has also been proposed as an adjunct to decrease inflammation and respiratory failure.

OBJECTIVE

To determine the association between preadmission corticosteroid use and risk of moderate-to-severe respiratory failure at the time of PCP presentation.

METHODS

This retrospective cohort study evaluated HIV-negative immunosuppressed adults diagnosed with PCP at Mayo Clinic from 2006 to 2016. Multivariable regression models were used to evaluate the association between preadmission corticosteroid exposure and moderate-to-severe respiratory failure at presentation.

RESULTS

Of the 323 patients included, 174 (54%) used preadmission corticosteroids with a median daily dosage of 20 (interquartile range: 10-40) mg of prednisone or equivalent. After adjustment for baseline demographics, preadmission corticosteroid therapy did not decrease respiratory failure at the time of PCP presentation (odds ratio: 1.23, 95% confidence interval: 0.73-2.09, P = .38). Additionally, after adjusting for inpatient corticosteroid administration, preadmission corticosteroid use did not impact the need for intensive care unit admission (P = .98), mechanical ventilation (P = .92), or 30-day mortality (P = .11).

CONCLUSIONS

Corticosteroid exposure before PCP presentation in immunosuppressed HIV-negative adults was not associated with a reduced risk of moderate-to-severe respiratory failure.

A comparison of levofloxacin and oral third-generation cephalosporins as antibacterial prophylaxis in acute leukaemia patients during chemotherapy-induced neutropenia

Background

There is demonstrated benefit with fluoroquinolones as infection prophylaxis in neutropenic patients; however, side effects, drug interactions and increasing resistance necessitate investigation of alternative therapies.

Objectives

To compare the incidence of febrile neutropenia in high-risk patients with haematological malignancy receiving a fluoroquinolone with those receiving an oral third-generation cephalosporin (OTGC) as antibacterial prophylaxis during chemotherapy-induced neutropenia.

Methods

A retrospective, matched, single-centre study comparing clinical and microbiological outcomes in acute leukaemia patients receiving fluoroquinolones versus OTGCs as antibacterial prophylaxis after chemotherapy.

Results

A total of 120 patients (levofloxacin n = 80, OTGC n = 40) were included and matched. The 30 day incidence of febrile neutropenia was 89.7% (95% CI = 82.4-93.9). The rates of febrile neutropenia were similar between antimicrobials (OTGC versus levofloxacin HR = 0.90, 95% CI = 0.54-1.52, P = 0.70). The most frequent site of infection was the bloodstream (line related) (n = 24, 62%) and the majority (n = 28, 72%) of infections were caused by Gram-positive organisms. Groups were similar in terms of site of infection (P = 0.91) and morphology of recovered microorganisms (P = 0.74). There were significantly more cultures positive for Enterobacter spp. in the OTGC group (P = 0.043). Three patients died during follow-up (from first dose up to 30 days after the last dose) (30 day survival = 99.2%, 95% CI = 97.5-100), with only two of the reported deaths attributable to infection.

Conclusions

These findings demonstrate comparable rates of febrile neutropenia and culture positivity with an increase in cultures positive for Enterobacter spp. when OTGCs are compared with levofloxacin for antibacterial prophylaxis during chemotherapy-induced neutropenia. Further prospective, randomized investigation is warranted.

Fecal Microbiota Transplantation for Recurrent Clostridium difficile Infection Reduces Recurrent Urinary Tract Infection Frequency

Broad-spectrum antibiotics for recurrent multidrug-resistant urinary tract infections (UTIs) disrupt the gut microbiome and promote antibiotic resistance. Fecal microbiota transplantation led to resolution of recurrent Clostridium difficile, significantly decreased recurrent UTI frequency, and improved antibiotic susceptibility profile of UTI-causing organisms.

Reprocessing of single-use endoscopic variceal band ligation devices: a pilot study

Background and study aims The preferred management of bleeding esophageal varices includes endoscopic band ligation. Endoscopic ligation devices (ELDs) are expensive and designed for single use, limiting their uptake in developing countries. We aimed to assess the efficacy of reprocessing ELDs using terminal microbial cultures and adenosine triphosphate (ATP) testing. Materials and methods ELDs were recovered after clinical use and their components (cap, handle, and cord) were subjected to reprocessing. This included manual cleaning, automated high-level disinfection (HLD), and drying with forced air. Using sterile technique, ELD components were sampled for ATP at three stages: before manual cleaning, after manual cleaning, and after HLD. Components were sent to an external laboratory for culturing. Cultures were interpreted as positive upon identification of Gram-negative bacilli. Results A total of 14 clinically used ELDs were studied, and 189 ATP tests and 41 cultures were evaluated. Overall, 95 % (39/41) of components and 86 % (12/14) of ELDs were culture-negative or did not yield Gram-negative bacilli. Two components (5 %; one handle and one cord) harbored Gram-negative bacilli in quantities of 1 CFU per component. There was no apparent correlation between ATP at any juncture of reprocessing and terminal cultures. Conclusions Reprocessing of ELDs is effective, resulting in infrequent and minimal microbial contamination. Microbial culturing can be used to ensure adequacy of ELD reprocessing if pursued. Until reusable ELDs are commercially available, continued efforts to better define the adequacy and long-term effects of reprocessing ELDs are needed.

Extremely Elevated Erythrocyte Sedimentation Rates: Associations With Patients' Diagnoses, Demographic Characteristics, and Comorbidities

OBJECTIVE

To study associations between extreme erythrocyte sedimentation rate (ESR) elevations (≥100 mm/h) and diseases, age, sex, race, Charlson Comorbidity Index (CCI), and C-reactive protein (CRP) level.

PATIENTS AND METHODS

This was a retrospective cohort study of 4807 patients with extreme ESR values examined at Mayo Clinic, Rochester, Minnesota, from January 1, 2002, through December 31, 2011. Independent variables included diseases (infection, autoimmune, malignancy, renal disease, or miscellaneous), subcategories of diseases, patient demographic characteristics (age, sex, and race), CRP level, and CCI. The Wilcoxon rank sum test was used to assess comparisons of ESR between patients with and without disease as well as relationships between extreme ESR values and demographic characteristics of patients within disease categories. Associations between ESR and CRP level were determined using the Pearson correlation coefficient.

RESULTS

The leading diagnosis associated with extreme ESR elevations (n [%]) was infection (1932 [40]), followed by autoimmune (1839 [38]) and malignancy (1736 [36]) (P<.01). Extreme elevations in ESR varied by sex, with higher ESRs in men (mean, 117±13.3 mm/h) than in women (mean, 115.9±12.5 mm/h) (P=.008). Extreme ESR elevations correlated inversely with the CCI (P=.008) and did not correlate with the CRP level. There were no correlations between extreme elevations in ESR and age or race.

CONCLUSION

We found that almost all patients have an identifiable etiology for extreme ESR elevations and that infection is the most common disease association. Unlike previous research, we identified higher ESRs in men than in women and no associations with age, race, and comorbid illness. These findings may enhance the diagnostic evaluation of patients with extreme ESR elevations.

Hospital influenza pandemic stockpiling needs: A computer simulation

BACKGROUND

A severe influenza pandemic could overwhelm hospitals but planning guidance that accounts for the dynamic interrelationships between planning elements is lacking. We developed a methodology to calculate pandemic supply needs based on operational considerations in hospitals and then tested the methodology at Mayo Clinic in Rochester, MN.

METHODS

We upgraded a previously designed computer modeling tool and input carefully researched resource data from the hospital to run 10,000 Monte Carlo simulations using various combinations of variables to determine resource needs across a spectrum of scenarios.

RESULTS

Of 10,000 iterations, 1,315 fell within the parameters defined by our simulation design and logical constraints. From these valid iterations, we projected supply requirements by percentile for key supplies, pharmaceuticals, and personal protective equipment requirements needed in a severe pandemic.

DISCUSSION

We projected supplies needs for a range of scenarios that use up to 100% of Mayo Clinic-Rochester's surge capacity of beds and ventilators. The results indicate that there are diminishing patient care benefits for stockpiling on the high side of the range, but that having some stockpile of critical resources, even if it is relatively modest, is most important.

CONCLUSIONS

We were able to display the probabilities of needing various supply levels across a spectrum of scenarios. The tool could be used to model many other hospital preparedness issues, but validation in other settings is needed.

Erysipelothrix rhusiopathiae bloodstream infection - A 22-year experience at Mayo Clinic, Minnesota

Erysipelothrix rhusiopathiae is a facultatively anaerobic Gram-positive bacillus found mostly in swine, fish and sheep. E. rhusiopathiae classically causes cutaneous eruptions in butchers, fish handlers and veterinarians. Based solely on case reports, 90% of E. rhusiopathiae bloodstream infections (BSI) have been associated with infective endocarditis (IE). To assess the true frequency of IE in E. rhusiopathiae BSI as well as other clinical associations, we performed a retrospective cohort analysis of E. rhusiopathiae BSI at Mayo Clinic. This is a single-centre, retrospective study conducted between 1/1/1994 and 20/6/2016 at Mayo Clinic in Rochester, MN. Medical records were reviewed for demographics, E. rhusiopathiae BSI, anti-microbial susceptibilities, incidence of IE, patient comorbidities, intensive care unit (ICU) admission and duration of antibiotics. Five cases of E. rhusiopathiae BSI were identified. Risk factors included animal exposures, immunosuppression, diabetes and kidney disease. All cases involved penicillin-sensitive strains and high-grade BSI. Four cases showed no signs of IE on transesophageal echocardiogram. All patients recovered fully with intravenous antibiotics. Our retrospective review illustrates that E. rhusiopathiae can cause invasive BSI in the absence of IE and that the previously reported 90% association between BSI and IE may be overestimated due to reporting bias. E. rhusiopathiae should be suspected in any patient with Gram-positive bacilli in blood cultures and the aforementioned risk factors. A limitation of our study was the low sample size, and future studies may involve multicentre collaborations and the use of polymerase chain reaction (PCR) or serologic testing to increase the number of diagnoses..

Low incidence of pneumocystis pneumonia utilizing PCR-based diagnosis in patients with B-cell lymphoma receiving rituximab-containing combination chemotherapy

Recent literature has demonstrated concern over the risk of Pneumocystis jirovecii pneumonia (PJP) when administering rituximab with combination chemotherapy such as in R-CHOP; however, the exact risk and potential need for prophylaxis is unknown. We sought to determine the incidence of PJP infection following R-CHOP administration in patients with B-cell lymphoma. Consecutive patients diagnosed with B-cell lymphoma receiving R-CHOP were evaluated from chemotherapy initiation until 180 days after the last administration. The primary outcome was cumulative incidence of PJP infection. Secondary endpoints included the association of rituximab, prednisone and subsequent chemotherapy with PJP infection risk. A total of 689 patients (53% male, median age 66 years) were included. Seventy-three percent of patients completed at least 6 cycles of R-CHOP treatment. Median rituximab and prednisone cumulative doses were 3950 mg and 5325 mg, respectively. Median daily prednisone dose through end of treatment was 45 mg (range 7.6 mg to 119 mg). The cumulative incidence of PJP was 1.51% (95% CI 0.57-2.43, at maximum follow-up of 330 days), below 3.5%, the conventional threshold for prophylaxis. Univariate analysis did not detect a statistically significant association between PJP and rituximab, steroids, or receipt of additional chemotherapy in this patient population. Our results demonstrate a low occurrence of Pneumocystis pneumonia during R-CHOP treatment of B-cell lymphoma and argue against universal anti-Pneumocystis prophylaxis in this setting. Further investigations should focus on targeted anti-Pneumocystis prophylaxis for patients presenting with high-risk baseline characteristics or when receiving rituximab-inclusive intensive combination chemotherapy regimens as treatment for other aggressive lymphoma subtypes. Am. J. Hematol. 91:1113-1117, 2016. © 2016 Wiley Periodicals, Inc.

Influenza infection in neutropenic adults

While lymphopenia is a well-defined risk factor for severe influenza, the effect of neutropenia is unknown. This was a retrospective single centre study of adult patients with documented neutropenia and influenza between 2005 and 2013. Forty patients were included with a median follow-up of 2 years (IQR 0.8-4.0). Median ANC at influenza diagnosis was 0.3 × 10⁹/L (IQR 0.1-0.4 × 10⁹/L). Outcomes included hospitalization (N = 28, 70%), pneumonia (N = 9, 23%), ICU admission (N = 9, 23%) and mechanical ventilation (N = 7, 18%). Three deaths (7.5%) were attributed to influenza, all of whom had lower respiratory tract infection (LRTI). Patients with LRTI (N = 18, 45%) also had a higher 30-day mortality (37 versus 0%) and 90-day mortality (42 versus 0%) than those with upper respiratory tract infection. In summary, neutropenic patients have high rates of influenza complications. Our study highlights the need for early diagnosis and aggressive management of influenza in this population.

A Cluster ofMycobacterium wolinskyiSurgical Site Infections at an Academic Medical Center

Objective

To study a cluster ofMycobacterium wolinskyisurgical site infections (SSIs).

Design

Observational and case-control study.

Setting

Academic hospital.

Patients.

Subjects who developed SSIs withM. wolinskyifollowing cardiothoracic surgery.

Methods

Electronic surveillance was performed for case finding as well as electronic medical record review of infected cases. Surgical procedures were observed. Medical chart review was conducted to identify risk factors. A case-control study was performed to identify risk factors for infection; Fisher exact or Kruskal-Wallis tests were used for comparisons of proportions and medians, respectively. Patient isolates were studied using pulsed-field gel electrophoresis (PFGE). Environmental microbiologic sampling was performed in operating rooms, including high-volume water sampling.

Results

Six definite cases ofM. wolinskyiSSI following cardiothoracic surgery were identified during the outbreak period (October 1, 2008–September 30, 2011). Having cardiac surgery in operating room A was significantly associated with infection (odds ratio, 40;P= .0027). Observational investigation revealed a cold-air blaster exclusive to operating room A as well a microbially contaminated, self-contained water source used in heart-lung machines. The isolates were indistinguishable or closely related by PFGE. No environmental samples were positive forM. wolinskyi.

Conclusions

No single point source was established, but 2 potential sources, including a cold-air blaster and a microbially contaminated, self-contained water system used in heart-lung machines for cardiothoracic operations, were identified. Both of these potential sources were removed, and subsequent active surveillance did not reveal any further cases ofM. wolinskyiSSI.

Infect Control Hosp Epidemiol2014;35(9):1169-1175

Failure mode and effects analysis to reduce risk of anticoagulation levels above the target range during concurrent antimicrobial therapy

PURPOSE

A failure mode and effects analysis (FMEA) was conducted to analyze the clinical and operational processes leading to above-target International Normalized Ratios (INRs) in warfarin-treated patients receiving concurrent antimicrobial therapy.

METHODS

The INRs of patients on long-term warfarin therapy who received a course of trimethoprim-sulfamethoxazole, metronidazole, fluconazole, miconazole, or voriconazole (highly potentiating antimicrobials, or HPAs) between September 1 and December 31, 2011, were compared with patients on long-term warfarin therapy who did not receive any antimicrobial during the same period. A multidisciplinary team of physicians, pharmacists, and a systems analyst was then formed to complete a step-by-step outline of the processes involved in warfarin management and concomitant HPA therapy, followed by an FMEA.

RESULTS

Patients taking trimethoprim-sulfamethoxazole, metronidazole, or fluconazole demonstrated a significantly increased risk of having an INR of >4.5. The FMEA identified 134 failure modes. The most common failure modes were as follows: (1) electronic medical records did not identify all patients receiving warfarin, (2) HPA prescribers were unaware of recommended warfarin therapy when HPAs were prescribed, (3) HPA prescribers were unaware that a patient was taking warfarin and that the drug interaction is significant, and (4) warfarin managers were unaware that an HPA had been prescribed for a patient.

CONCLUSION

An FMEA determined that the risk of adverse events caused by concomitantly administering warfarin and HPAs can be decreased by preemptively identifying patients receiving warfarin, having a care process in place, alerting providers about the patient's risk status, and notifying providers at the anticoagulation clinic.

Profiles of influenza A/H1N1 vaccine response using hemagglutination-inhibition titers

To identify distinct antibody profiles among adults 50-to-74 years old using influenza A/H1N1 HI titers up to 75 days after vaccination. Healthy subjects 50 to 74 years old received the 2010-2011 trivalent inactivated influenza vaccine. We measured venous samples from Days 0, 28, and 75 for HI and VNA and B-cell ELISPOTs. Of 106 subjects, HI titers demonstrated a ceiling effect for 11 or 10% for those with a pre-vaccination HI titer of 1:640 where no subject post-vaccination had an increase in titer. Of the remaining 95 subjects, only 37 or 35% overall had at least a 4-fold increase by Day 28. Of these 37, 3 waned at least 4-fold, and 13 others 2-fold. Thus 15% of the subjects showed waning antibody titers by Day 75. More than half failed to respond at all. The profiles populated by these subjects as defined by HI did not vary with age or gender. The VNA results mimicked the HI profiles, but the profiles for B-cell ELISPOT did not. HI titers at Days 0, 28, and 75 populate 4 biologically plausible profiles. Limitations include lack of consensus for operationally defining waning as well as for the apparent ceiling. Furthermore, though well accepted as a marker for vaccine response, assigning thresholds with HI has limitations. However, VNA closely matches HI in populating these profiles. Thus, we hold that these profiles, having face- and content-validity, may provide a basis for understanding variation in genomic and transcriptomic response to influenza vaccination in this age group.

Statistical modeling using early markers of innate immunity to explain variation in humoral responses to influenza vaccine in older adults

Greater understanding of the factors associated with a protective response to influenza vaccine in older adults could have tremendous public health benefits. We studied 158 participants age 50-74 years vaccinated with 2010-2011 inactivated influenza vaccine and performed innate immunity and humoral immunity assays directed against influenza A/California/2009 (H1N1) as measured through hemagglutination inhibition (HAI), microneutralization, and B cell ELISPOT at days 0, 3, and 28 postvaccination. We report the results of statistical modeling using Day 3 cytokines, chemokines, and innate cell populations to model Day 0 to Day 28 HAI seroconversion, viral neutralization seroconversion, and B cell ELISPOT results.

Emerging issues in gram-negative bacterial resistance: an update for the practicing clinician

The rapid and global spread of antimicrobial-resistant organisms in recent years has been unprecedented. Although resistant gram-positive infections have been concerning to clinicians, the increasing incidence of antibiotic-resistant gram-negative infections has become the most pressing issue in bacterial resistance. Indiscriminate antimicrobial use in humans and animals coupled with increased global connectivity facilitated the transmission of gram-negative infections harboring extended-spectrum β-lactamases in the 1990s. Carbapenemase-producing Enterobacteriaceae, such as those containing Klebsiella pneumoniae carbapenemases and New Delhi metallo-β-lactamases, have been the latest scourge since the late 1990s to 2000s. Besides β-lactam resistance, these gram-negative infections are often resistant to multiple drug classes, including fluoroquinolones, which are commonly used to treat community-onset infections. In certain geographic locales, these pathogens, which have been typically associated with health care-associated infections, are disseminating into the community, posing a significant dilemma for clinicians treating community-onset infections. In this Concise Review, we summarize emerging trends in antimicrobial resistance. We also review the current knowledge on the detection, treatment, and prevention of infection with these organisms, with a focus on the carbapenemase-producing gram-negative bacilli. Finally, we discuss emerging therapies and areas that need further research and effort to stem the spread of antimicrobial resistance.

Prevalence of and Risk Factors for Vancomycin-Resistant Staphylococcus aureus Precursor Organisms in Southeastern Michigan

We assessed for vancomycin-resistantStaphylococcus aureus(VRSA) precursor organisms in southeastern Michigan, an area known to have VRSA. The prevalence was 2.5% (pSK41-positive methicillin-resistantS. aureus, 2009–2011) and 1.5% (Inc18-positive vancomycin-resistantEnterococcus, 2006–2013); Inc18 prevalence significantly decreased after 2009 (3.7% to 0.82%). Risk factors for pSK41 included intravenous vancomycin exposure.

Infect Control Hosp Epidemiol2014;35(12):1531–1534

Business and continuity of operations: care of the critically ill and injured during pandemics and disasters: CHEST consensus statement

BACKGROUND

During disasters, supply chain vulnerabilities, such as power, transportation, and communication, may affect the delivery of medications and medical supplies and hamper the ability to deliver critical care services. Disasters also have the potential to disrupt information technology (IT) in health-care systems, resulting in interruptions in patient care, particularly critical care, and other health-care business functions. The suggestions in this article are important for all of those involved in a large-scale pandemic or disaster with multiple critically ill or injured patients, including front-line clinicians, hospital administrators, and public health or government officials.

METHODS

The Business and Continuity of Operations Panel followed the American College of Chest Physicians (CHEST) Guidelines Oversight Committee's methodology in developing key questions regarding medication and supply shortages and the impact disasters may have on healthcare IT. Task force members met in person to develop the 13 key questions believed to be most relevant for Business and Continuity of Operations. A systematic literature review was then performed for relevant articles and documents, reports, and gray literature reported since 2007. No studies of sufficient quality were identified upon which to make evidence-based recommendations. Therefore, the panel developed expert opinion-based suggestions using a modified Delphi process.

RESULTS

Eighteen suggestions addressing mitigation strategies for supply chain vulnerabilities including medications and IT were generated. Suggestions offered to hospitals and health system leadership regarding medication and supply shortages include: (1) purchase key medications and supplies from more than one supplier, (2) substituted medications or supplies should ideally be similar to those already used by an institution's providers, (3) inventories should be tracked electronically to monitor medication/supply levels, (4) consider higher inventories of medications and supplies known or projected to be in short supply, (5) institute alternate use protocols when a (potential) shortage is identified, and 6) support government and nongovernmental organizations in efforts to address supply chain vulnerability. Health-care IT can be damaged in a disaster, and hospitals and health system leadership should have plans for urgently reestablishing local area networks. Planning should include using portable technology, plans for providing power, maintenance of a patient database that can accompany each patient, and protection of patient privacy. Additionally, long-term planning should include prioritizing servers and memory disk drives and possibly increasing inventory of critical IT supplies in preparedness planning.

CONCLUSIONS

The provision of care to the critically ill or injured during a pandemic or disaster is dependent on key processes, such as the supply chain, and infrastructure, such as IT systems. Hospitals and health systems will help minimize the impact of medication and supply shortages with a focused strategy using the steps suggested. IT preparedness for maintaining local area networks, functioning clinical information systems, and adequate server and memory storage capacity will greatly enhance preparedness for hospital and health system clinical and business operations.

Engagement and education: care of the critically ill and injured during pandemics and disasters: CHEST consensus statement

BACKGROUND

Engagement and education of ICU clinicians in disaster preparedness is fragmented by time constraints and institutional barriers and frequently occurs during a disaster. We reviewed the existing literature from 2007 to April 2013 and expert opinions about clinician engagement and education for critical care during a pandemic or disaster and offer suggestions for integrating ICU clinicians into planning and response. The suggestions in this article are important for all of those involved in a pandemic or large-scale disaster with multiple critically ill or injured patients, including front-line clinicians, hospital administrators, and public health or government officials.

METHODS

A systematic literature review was performed and suggestions formulated according to the American College of Chest Physicians (CHEST) Consensus Statement development methodology. We assessed articles, documents, reports, and gray literature reported since 2007. Following expert-informed sorting and review of the literature, key priority areas and questions were developed. No studies of sufficient quality were identified upon which to make evidence-based recommendations. Therefore, the panel developed expert opinion-based suggestions using a modified Delphi process.

RESULTS

Twenty-three suggestions were formulated based on literature-informed consensus opinion. These suggestions are grouped according to the following thematic elements: (1) situational awareness, (2) clinician roles and responsibilities, (3) education, and (4) community engagement. Together, these four elements are considered to form the basis for effective ICU clinician engagement for mass critical care.

CONCLUSIONS

The optimal engagement of the ICU clinical team in caring for large numbers of critically ill patients due to a pandemic or disaster will require a departure from the routine independent systems operating in hospitals. An effective response will require robust information systems; coordination among clinicians, hospitals, and governmental organizations; pre-event engagement of relevant stakeholders; and standardized core competencies for the education and training of critical care clinicians.

What clinicians should know about the 2014 Ebola outbreak

The ongoing Ebola outbreak that began in Guinea in February 2014 has spread to Liberia, Sierra Leone, Nigeria, Senegal, Spain, and the United States and has become the largest Ebola outbreak in recorded history. It is important for frontline medical providers to understand key aspects of Ebola virus disease (EVD) to quickly recognize an imported case, provide appropriate medical care, and prevent transmission. Furthermore, an understanding of the clinical presentation, clinical course, transmission, and prevention of EVD can help reduce anxiety about the disease and allow health care providers to calmly and confidently provide medical care to patients suspected of having EVD.

Prevalence of and risk factors for vancomycin-resistant Staphylococcus aureus precursor organisms in Southeastern Michigan

We assessed for vancomycin-resistant Staphylococcus aureus (VRSA) precursor organisms in southeastern Michigan, an area known to have VRSA. The prevalence was 2.5% (pSK41-positive methicillin-resistant S. aureus, 2009-2011) and 1.5% (Inc18-positive vancomycin-resistant Enterococcus, 2006-2013); Inc18 prevalence significantly decreased after 2009 (3.7% to 0.82%). Risk factors for pSK41 included intravenous vancomycin exposure.

Prevalence of rectal colonization with multidrug-resistant Enterobacteriaceae among international patients hospitalized at Mayo Clinic, Rochester, Minnesota

Rectal colonization with multidrug-resistant Enterobacteriaceae was found in 23 of 94 consecutively enrolled international patients hospitalized at Mayo Clinic, Rochester, Minnesota. No carbapenemase producers were detected. Twenty-one isolates were extended-spectrum β-lactamase-producing Escherichia coli. Colonization was associated with gastrointestinal disease and central venous catheter placement within the antecedent year.

Serum peak sulfamethoxazole concentrations demonstrate difficulty in achieving a target range: a retrospective cohort study

OBJECTIVES

Trimethoprim (TMP)/sulfamethoxazole (SMX) has consistently demonstrated great interindividual variability. Therapeutic drug monitoring may be used to optimize dosing. Optimal peak SMX concentration has been proposed as 100 to 150 μg/mL. The objective of our work was to determine the success rate of a TMP/SMX dosing guideline in achieving a targeted serum peak SMX concentration range.

METHODS

Our retrospective cohort study enrolled 305 adult hospitalized patients who received treatment with TMP/SMX and underwent serum peak SMX concentration monitoring from January 2003 to November 2011. Patients receiving low-dose TMP/SMX therapy (TMP <15 mg/kg/d) were compared with those receiving high-dose therapy (TMP >15 mg/kg/d).

RESULTS

Patients were classified into peak and modified peak SMX concentration cohorts based on time between TMP/SMX dose and SMX quantification. The association between dosing group and the outcome of the SMX level within the goal range was measured using logistic regression models. The primary outcome measured was serum peak SMX concentration 100 to 150 μg/mL. Serum peak SMX concentrations were attained within range for the peak and modified peak cohort 29% and 26% of the time, respectively. The median peak SMX concentration was 144 μg/mL (range 25-471 μg/mL). The low daily dose cohort demonstrated a trend toward improvement in the odds of target peak concentration range attainment. The results were similar regardless of the method used to adjust for baseline characteristics. The pure peak and modified peak cohorts had 44% and 46% of patients with above-target SMX peak concentrations, respectively.

CONCLUSIONS

Attainment of the intended target concentration range was low with no difference in attainment between the low-dose and high-dose cohorts. Higher proportions of patients had an above-target SMX peak, which may indicate that the dosing algorithm is overly aggressive in obtaining the therapeutic goal.

Secondarily infected nonstruvite urolithiasis: a prospective evaluation

OBJECTIVE

To characterize patients who form nonstruvite stones associated with infection (secondarily infected calculi), and to define the bacteria associated with these.

MATERIALS AND METHODS

Patients undergoing percutaneous nephrolithotomy were prospectively recruited. Medical records were reviewed, and stones were analyzed using micro computed tomography and infrared spectroscopy. A fragment of each stone was sent for bacterial culture. Patients were categorized by stone culture results (SC ±) and the presence of struvite (ST ±). The Fisher exact test was used for comparison of proportion. Sterility of intraoperative SC was established with independently collected controls.

RESULTS

In total, 125 patients were enrolled: 24 SC+/ST-, 19 SC+/ST+, and 82 SC-/ST-. Proportions of patients with prior urologic surgery, diabetes, and immunodeficiency were similar between groups. Patients with neurogenic bladder were more likely to have SC+/ST+ stones or SC+/ST- stones than SC-/ST- stones (26% vs 8% vs 0%, respectively; P <.01). Among patients with metabolic evaluations, hypocitraturia was found in 31.6% (6 of 19) SC+/ST- patients, 46.7% (7 of 15) SC+/ST+ patients, and 26.0% (19 of 73) of SC-/ST- patients (P = .28). Approximately 40% of cultured organisms in the secondarily infected calculi possessed urease and another 40% citrate lyase activities.

CONCLUSION

Secondarily infected stones were detected in approximately 20% of this surgical cohort and may be more common than previously appreciated. Neurogenic bladder appeared to predispose patients to either struvite or secondarily infected stones. The role of bacterial infection in stone formation is unclear but may include alteration of urinary components, acting as a nidus for crystallization, or inducing inflammation.