Executive Summary: State-of-the-Art Review: Fostering Collaborative Teamwork-A Comprehensive Approach to Vascular Graft Infection Following Arterial Reconstructive Surgery.

Vascular graft infection (VGI) is one of the most serious complications following arterial reconstructive surgery. VGI has received increasing attention over the past decade, but many questions remain regarding its diagnosis and management. In this review, we describe our approach to VGI through multidisciplinary collaboration and discuss decision-making for challenging presentations. This document will concentrate on VGI that impacts both aneurysms and pseudoaneurysms excluding the ascending thoracic aorta.

Fostering Collaborative Teamwork-A Comprehensive Approach to Vascular Graft Infection Following Arterial Reconstructive Surgery.

Vascular graft infection (VGI) is one of the most serious complications following arterial reconstructive surgery. VGI has received increasing attention over the past decade, but many questions remain regarding its diagnosis and management. In this review, we describe our approach to VGI through multidisciplinary collaboration and discuss decision making for challenging presentations. This review will concentrate on VGI that impacts both aneurysms and pseudoaneurysms excluding the ascending thoracic aorta.

Percutaneous mechanical aspiration in patients with right-sided infective endocarditis: An analysis of the national inpatient sample database-2016-2020.

BACKGROUND: Given the challenges of conventional therapies in managing right-sided infective endocarditis (RSIE), percutaneous mechanical aspiration (PMA) of vegetations has emerged as a novel treatment option. Data on trends, characteristics, and outcomes of PMA, however, have largely been limited to case reports and case series. AIMS: The aim of the current investigation was to provide a descriptive analysis of PMA in the United States and to profile the frequency of PMA with a temporal analysis and the patient cohort. METHODS: The International Classification of Diseases, 10th Revision codes were used to identify patients with RSIE in the national (nationwide) inpatient sample (NIS) database between 2016 and 2020. The clinical characteristics and temporal trends of RSIE hospitalizations in patients who underwent PMA was profiled. RESULTS: An estimated 117,955 RSIE-related hospital admissions in the United States over the 5-year study period were estimated and 1675 of them included PMA. Remarkably, the rate of PMA for RSIE increased 4.7-fold from 2016 (0.56%) to 2020 (2.62%). Patients identified with RSIE who had undergone PMA were young (medial age 36.5 years) and had few comorbid conditions (median Charlson Comorbidity Index, 0.6). Of note, 36.1% of patients had a history of hepatitis C infection, while only 9.9% of patients had a cardiovascular implantable electronic device. Staphylococcus aureus was the predominant (61.8%) pathogen. Concomitant transvenous lead extraction and cardiac valve surgery during the PMA hospitalization were performed in 18.2% and 8.4% of admissions, respectively. The median hospital stay was 19.0 days, with 6.0% in-hospital mortality. CONCLUSIONS: The marked increase in the number of PMA procedures in the United States suggests that this novel treatment option has been embraced as a useful tool in select cases of RSIE. More work is needed to better define indications for the procedure and its efficacy and safety.

Trimethoprim-sulfamethoxazole dosing and outcomes of pulmonary nocardiosis.

BACKGROUND: Nocardia often causes pulmonary infection among those with chronic pulmonary disease or immunocompromising conditions. Trimethoprim-sulfamethoxazole (TMP-SMX) is recommended as first-line treatment, though little data exists regarding outcomes of different dosing regimens. METHODS: We performed a multicenter retrospective cohort study of adult patients with non-disseminated pulmonary nocardiosis initially treated with TMP-SMX monotherapy. Patients' initial TMP-SMX dosing was categorized as high- (> 10 mg/kg/day), intermediate- (5-10 mg/kg/day) or low-dose (< 5 mg/kg/day). Outcomes included one-year mortality, post-treatment recurrence, and dose adjustment or early discontinuation of TMP-SMX. SMX serum concentrations and their effect on management were also assessed. Inverse probability of treatment weighting was applied to Cox regression analyses. RESULTS: Ninety-one patients were included with 24 (26.4%), 37 (40.7%), and 30 (33.0%) treated with high-, intermediate-, and low-dose TMP-SMX, respectively. Patients who initially received low-dose (HR 0.07, 95% CI 0.01-0.68) and intermediate-dose TMP-SMX (HR 0.27, 95% CI 0.07-1.04) had lower risk of one-year mortality than the high-dose group. Risk of recurrence was similar between groups. Nineteen patients had peak SMX serum concentrations measured which resulted in 7 (36.8%) dose changes and was not associated with one-year mortality or recurrence. However, 66.7% of the high-dose group required TMP-SMX dose adjustment/discontinuation compared to 24.3% of the intermediate-dose and 26.7% of the low-dose groups (p = 0.001). CONCLUSIONS: Low- and intermediate-dose TMP-SMX for non-disseminated pulmonary nocardiosis were not associated with poor outcomes compared to high-dose therapy, which had a higher rate of dose adjustment/early discontinuation. Historically used high-dose TMP-SMX may not be necessary for management of isolated pulmonary nocardiosis.

Heart of the matter-infection and xenotransplantation.

In this clinicopathological conference, invited experts discussed a previously published case of a patient with nonischemic cardiomyopathy who underwent heart transplantation from a genetically modified pig source animal. His complex course included detection of porcine cytomegalovirus by plasma microbial cell-free DNA and eventual xenograft failure. The objectives of the session included discussion of selection of immunosuppressive regimens and prophylactic antimicrobials for human xenograft recipients, description of infectious disease risk assessment and mitigation in potential xenograft donors and understanding of screening and therapeutic strategies for potential xenograft-related infections.

Comparison of Oral and Intravenous Definitive Antibiotic Therapy for Beta-Hemolytic Streptococcus Species Bloodstream Infections from Soft Tissue Sources: a Propensity Score-Matched Analysis.

Beta-hemolytic streptococci are common causes of bloodstream infection (BSI). There is emerging data regarding oral antibiotics for BSI but limited for beta-hemolytic streptococcal BSI. We conducted a retrospective study of adults with beta-hemolytic streptococcal BSI from a primary skin/soft tissue source from 2015 to 2020. Patients transitioned to oral antibiotics within 7 days of treatment initiation were compared to those who continued intravenous therapy, after propensity score matching. The primary outcome was 30-day treatment failure (composite of mortality, infection relapse, and hospital readmission). A prespecified 10% noninferiority margin was used for the primary outcome. We identified 66 matched pairs of patients treated with oral and intravenous antibiotics as definitive therapy. Based on an absolute difference in 30-day treatment failure of 13.6% (95% confidence interval 2.4 to 24.8%), the noninferiority of oral therapy was not confirmed (P = 0.741); on the contrary, the superiority of intravenous antibiotics is suggested by this difference. Acute kidney injury occurred in two patients who received intravenous treatment and zero who received oral therapy. No patients experienced deep vein thrombosis or other vascular complications related to treatment. In patients treated for beta-hemolytic streptococcal BSI, those who transitioned to oral antibiotics by day 7 showed higher rates of 30-day treatment failure than propensity-matched patients. This difference may have been driven by underdosing of oral therapy. Further investigation into optimal antibiotic choice, route, and dosing for definitive therapy of BSI is needed.

Risk factors and prophylaxis for nocardiosis in solid organ transplant recipients: A nested case-control study.

BACKGROUND: Nocardia is an opportunistic pathogen that primarily affects immunocompromised individuals, including solid organ transplant (SOT) recipients. Up to 2.65% of SOT recipients develop nocardiosis; however, few studies have examined risk factors and prophylaxis for nocardiosis. METHODS: We performed a multicenter, matched nested case-control study of adult SOT recipients with culture-confirmed nocardiosis from 2000 through 2020. Controls were matched up to 2:1 by sex, first transplanted organ, year of transplant, transplant center, and adequate post-transplant follow-up. Multivariable conditional logistic regression was performed to analyze associations with nocardiosis. Cox proportional hazards regression compared 12-month mortality between infection and uninfected patients. RESULTS: One hundred and twenty-three SOT recipients were matched to 245 uninfected controls. Elevated calcineurin inhibitor level, acute rejection, cytomegalovirus infection, lymphopenia, higher prednisone dose, and older age were significantly associated with nocardiosis while trimethoprim-sulfamethoxazole prophylaxis was protective (odds ratio [OR] .34; 95% confidence interval [CI] .13-.84). The effect of prophylaxis was similar, though not always statistically significant, in sensitivity analyses that only included prophylaxis dosed more than twice-per-week (OR .30; 95% CI .11-.80) or restricted to years 2015-2020 (OR .33, 95% CI .09-1.21). Nocardiosis was associated with increased 12-month mortality (hazard ratio 5.47; 95% confidence interval 2.42-12.35). CONCLUSIONS: Multiple measures of immunosuppression and lack of trimethoprim-sulfamethoxazole prophylaxis were associated with nocardiosis in SOT recipients. Effectiveness of prophylaxis may be related to trimethoprim-sulfamethoxazole dose or frequency. Trimethoprim-sulfamethoxazole should be preferentially utilized over alternative agents in SOT recipients with augmented immunosuppression or signs of heightened immunocompromise.

Post-treatment outcomes of ceftriaxone versus antistaphylococcal penicillins or cefazolin for definitive therapy of methicillin-susceptible Staphylococcus aureus bacteremia.

Methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia is associated with poor outcomes. Ceftriaxone offers logistical advantages over other standard therapies, though in vitro studies have questioned its efficacy and clinical studies of ceftriaxone in MSSA bacteremia are conflicting.We performed a multicenter, retrospective cohort study of adult patients who received ceftriaxone, cefazolin, or antistaphylococcal penicillins as definitive therapy for MSSA bacteremia from 2018 to 2019. Definitive therapy was defined as the antibiotic used in the outpatient setting. Patients were excluded if they received less than 7 days of outpatient therapy. Follow-up started on the date of definitive therapy completion. The primary outcome was 90-day treatment failure, defined as a composite of mortality and microbiologic recurrence. This was analyzed with multivariable Cox regression. A total of 223 patients were included, 37 (16.6%) of whom received ceftriaxone. The most common ceftriaxone dose was 2 g daily (83.8%). The most common primary site of infection was skin/soft tissue (37.2%), unknown (21.1%), and catheter-related (15.2%). Twenty-six (11.7%) developed infective endocarditis. Median total duration of treatment was 31.0 days, and median outpatient duration was 24.0 days. Twenty-six (11.7%) developed 90-day treatment failure. After adjusting for Charlson comorbidity index, duration of therapy, and use of transesophageal echocardiography, definitive treatment with ceftriaxone was associated with treatment failure (hazard ratio 2.66, 95% confidence interval 1.15-6.12; p=0.022). Among patients with MSSA bacteremia, definitive treatment with ceftriaxone was associated with a higher risk of treatment failure within 90 days as compared to cefazolin or antistaphylococcal penicillins.

Clinical characteristics and outcomes of pancreatic fungal infection in patients with necrotizing pancreatitis.

Pancreatic fungal infection (PFI) in patients with necrotizing pancreatitis can lead to significant morbidity and mortality. The incidence of PFI has increased during the past decade. Our study aimed to provide contemporary observations on the clinical characteristics and outcomes of PFI in comparison to pancreatic bacterial infection and necrotizing pancreatitis without infection. We conducted a retrospective study of patients with necrotizing pancreatitis (acute necrotic collection or walled-off necrosis), who underwent pancreatic intervention (necrosectomy and/or drainage) and had tissue/fluid culture between 2005 and 2021. We excluded patients with pancreatic procedures prior to hospitalization. Multivariable logistic and Cox regression models were fitted for in-hospital and 1-year survival outcomes. A total of 225 patients with necrotizing pancreatitis were included. Pancreatic fluid and/or tissue was obtained from endoscopic necrosectomy and/or drainage (76.0%), CT-guided percutaneous aspiration (20.9%), or surgical necrosectomy (3.1%). Nearly half of the patients had PFI with or without concomitant bacterial infection (48.0%), while the remaining patients had either bacterial infection alone (31.1%) or no infection (20.9%). In multivariable analysis to assess the risk of PFI or bacterial infection alone, only previous pancreatitis was associated with an increased odds of PFI vs. no infection (OR 4.07, 95% CI 1.13-14.69, p = .032). Multivariable regression analyses revealed no significant differences in in-hospital outcomes or one-year survival between the 3 groups. Pancreatic fungal infection occurred in nearly half of necrotizing pancreatitis. Contrary to many of the previous reports, there was no significant difference in important clinical outcomes between the PFI group and each of the other two groups.

We examined 225 patients with necrotizing pancreatitis who had tissue/fluid culture available and found that nearly half of the patients had pancreatic fungal infection. Interestingly, there was no difference in clinical outcomes between the fungal infection group and non-fungal infection groups.

Clinical characteristics of central nervous system phaeohyphomycosis: A brief report of 20 years' experience.

Central nervous system (CNS) phaeohyphomycosis is a rare and often fatal fungal infection. Our study reported a case series of eight CNS phaeohyphomycosis cases at our institution over the past 20 years. We did not observe the common pattern of risk factors, abscess location, or number of abscesses among them. Most patients were immunocompetent without classic risk factors for fungal infection. Early diagnosis and aggressive management with surgical intervention and prolonged antifungal therapy can lead to a favorable outcome. The study highlights the need for further research to better understand the pathogenesis and optimal management of this challenging rare infection.

Association of adverse effects with high serum posaconazole concentrations.

Posaconazole therapeutic drug monitoring (TDM) is widely utilized to assess therapeutic efficacy and safety; however, clinical effects of very high serum concentrations are unknown. A retrospective review of 90 patients receiving posaconazole for treatment or prophylaxis of invasive fungal infections with serum concentrations ≥3000 ng/mL from 1/1/2019 to 4/30/2021 evaluated the incidence and type of adverse drug reactions (ADRs). Symptomatic ADRs were very common in patients with posaconazole concentrations of ≥5000 ng/mL and 3000-4999 ng/mL (80% vs. 58.8%; P = 0.31). Posaconazole TDM should be performed for both treatment and prophylaxis indications and dose decrease for serum concentrations >3000 ng/mL should be considered.

Drug level monitoring is commonly used to evaluate appropriate dosing and effectiveness of posaconazole, a medication used to treat fungal infections. Patients with high levels commonly had side effects. Posaconazole monitoring should be completed, and doses reduced when levels are high.

Immunomodulators for severe coronavirus disease-2019 in transplant patients: Do they increase the risk of secondary infection?

BACKGROUND: Current guidelines recommend immunomodulators, tocilizumab or baricitinib, for the management of severe coronavirus disease-2019 (COVID-19) in patients with increasing oxygen requirements. Given their immunosuppressive effects, there is a concern for higher rates of infection among transplant recipients. METHODS: A retrospective cohort study of transplant patients with severe COVID-19 between April 2020 and January 2022 was performed at the Mayo Clinic. The primary outcome was incidence of secondary infections after COVID-19 diagnosis. Secondary outcomes were 90-day mortality, ventilatory days, and thromboembolic events. RESULTS: A total of 191 hospitalized transplant patients were studied, including 77 (40.3%) patients who received an immunomodulator. Overall, 89% were solid organ transplant recipients, with kidney as the most common transplanted organ (50.3%). The majority (89.0%) required oxygen supplementation on admission, and 39.8% of these patients required mechanical ventilation during the hospital course. There was no significant difference in the incidence of secondary infections between those who received or did not receive an immunomodulator (p = .984). Likewise, there was no difference in 90-day mortality between patients who received or did not receive an immunomodulator (p = .134). However, higher mortality was observed among patients that developed a secondary infection (p < .001). CONCLUSION: The use of immunomodulators in transplant patients with severe COVID-19 was not significantly associated with an increased risk of secondary infections. Secondary infections were associated with higher risk of all-cause mortality. Future studies of larger cohorts are needed to explore the effect of immunomodulators on survival among transplant patients with COVID-19.

Outcomes of transplant recipients with pretransplant Nocardia colonization or infection.

BACKGROUND: Specific pretransplant infections have been associated with poor posttransplant outcomes. However, the impact of pretransplant Nocardia isolation has not been studied. METHODS: We performed a retrospective study from three centers in Arizona, Florida, and Minnesota of patients with Nocardia infection or colonization who subsequently underwent solid organ or hematopoietic stem cell transplantation from November 2011 through April 2022. Outcomes included posttransplant Nocardia infection and mortality. RESULTS: Nine patients with pretransplant Nocardia were included. Two patients were deemed colonized with Nocardia, and the remaining seven had nocardiosis. These patients underwent bilateral lung (N = 5), heart (N = 1), heart-kidney (N = 1), liver-kidney (N = 1), and allogeneic stem cell transplantation (N = 1) at a median of 283 (interquartile range [IQR] 152-283) days after Nocardia isolation. Two (22.2%) patients had disseminated infection, and two were receiving active Nocardia treatment at the time of transplantation. One Nocardia isolate was resistant to trimethoprim-sulfamethoxazole (TMP-SMX) and all patients received TMP-SMX prophylaxis posttransplant, often for extended durations. No patients developed posttransplant nocardiosis during a median follow-up of 1.96 (IQR 0.90-6.33) years. Two patients died during follow-up, both without evidence of nocardiosis. CONCLUSIONS: This study did not identify any episodes of posttransplant nocardiosis among nine patients with pretransplant Nocardia isolation. As patients with the most severe infections may have been denied transplantation, further studies with larger sample sizes are needed to better analyze any impact of pretransplant Nocardia on posttransplant outcomes. However, among patients who receive posttransplant TMP-SMX prophylaxis, these data suggest pretransplant Nocardia isolation may not impart a heightened risk of posttransplant nocardiosis.

Risk of Cardiac Implantable Electronic Device Infection in Patients with Bloodstream Infection: Microbiologic Effect in the Era of Positron Emission Tomography-Computed Tomography.

PURPOSE OF REVIEW: Bloodstream infection (BSI) in patients with cardiac implantable electronic devices (CIEDs) is common and can prompt challenges in defining optimal management. We provide a contemporary narrative review of this topic and propose a pathogen-dependent clinical approach to patient management. RECENT FINDINGS: BSI due to staphylococci, viridans group streptococci, and enterococci is associated with an increased risk of underlying CIED infection, while the risk of CIED infection due to other organisms is poorly defined. There is growing evidence that positron emission tomography-computed tomography may be helpful in some patients with BSI and underlying CIED. Twenty studies were included to examine the impact of microbiologic findings on the risk of CIED infection among patients with BSI. Diagnosis of CIED infection in patients with BSI without pocket findings is often difficult, necessitating the use of novel diagnostic tools to help guide the clinician in subsequent patient management.

Infectious complications in acute graft-versus-host disease after liver transplantation.

Graft-versus-hostdisease (GVHD) following liver transplantation (LT) is rare but can lead tosignificant mortality. The leading cause of death following GVHD diagnosis isinfectious complications. However, there is a lack of clear descriptions concerning infection and antimicrobial management patterns. Our study aims toprovide the focused details of all infectious complications of acute GVHDfollowing LT. We retrospectively reviewed all adult LT recipients with acute GVHD at Mayo Clinic's Transplant Centers from January 1, 2010, to December 31, 2021. Detailed characteristics of infection in each case were described. Among 4,585 LTs performed during this period, 12 (0.3%) patients developed acuteGVHD. The median time from transplantation to GVHD diagnosis was 49.0 days [IQR 31.5-99.0]. Ten (83.3%) patients developed severe infections leading tomortality. The most common cause of infection was nosocomial bacteremia fromenteric bacteria such as vancomycin-resistant enterococci and gram-negative bacilli. Other infections included breakthrough invasive fungal infections,cytomegalovirus (CMV) reactivation, and Clostridioides difficile colitis. Antimicrobial prophylaxis strategies in most cases were based on the degree of neutropenia-these include levofloxacin for bacterial prophylaxis, nebulized pentamidine for Pneumocystis jiroveci pneumonia prophylaxis, posaconazole for invasive fungal prophylaxis, and valganciclovir based on CMVstatus. All GVHD patients with severe infections succumbed to thesecomplications. Ourstudy reiterates that despite prophylaxis, infectious complications in GVHDfollowing LT are common and lead to exceptionally high mortality. Individualizedantimicrobial treatment, prophylaxis and monitoring strategies remain a criticalcomponent of GVHD management. Further study to optimize these practices isrequired.

The utility of postoperative systemic antibiotic prophylaxis following cardiovascular implantable electronic device implantation: A systematic review and meta-analysis.

BACKGROUND: There is insufficient evidence regarding postoperative systemic antibiotic prophylaxis use for more than 24 h following cardiovascular implantable electronic devices (CIED) implantation and its impact on infection prevention. However, this strategy remains a common practice in many institutions. METHODS: We conducted a systematic review and meta-analysis including studies that compared the outcomes of patients: (1) who received preoperative plus 24 h or more of postoperative antibiotic prophylaxis (intervention group); and (2) who received either preoperative only or preoperative plus less than 24 h of antibiotic prophylaxis (control group). Risk of bias was assessed with ROBINS-I and ROB-2 tools. Risk ratio (RR) was pooled using random-effect meta-analyses with inverse variance method. RESULTS: Eight studies that included two randomized controlled trials (RCTs) and six cohort studies with a total of 26,187 patients were included in the analysis. Overall, there were no differences in outcomes between the two groups, which included rates of CIED infection (RR 0.77, 95% CI 0.42, 1.42), mortality (RR 1.19, 95% CI 0.69, 2.06), pocket hematoma (RR 1.15, 95% CI 0.44, 3.00) or reintervention (RR 0.87, 95% CI 0.22, 3.46). Of note, the results were primarily impacted by the larger RCT. CONCLUSIONS: There was no benefit of postoperative antibiotic prophylaxis for more than 24 h following CIED implantation in the current systematic review and meta-analysis. This supports the practice advocated by current guidelines which foster antibiotic stewardship and may result in reductions of adverse drug events, selection for antibiotic resistance, and financial costs of prolonged postoperative antibiotic prophylaxis.

Diagnostic accuracy of interferon-gamma release assays for diagnosis of smear-negative pulmonary tuberculosis: a systematic review and meta-analysis.

INTRODUCTION: The diagnosis of smear-negative pulmonary tuberculosis (SNPTB) is challenging. Interferon gamma-release assays (IGRAs) may be helpful in early diagnosis among these patients resulting in prompt treatment and favorable outcomes. METHODS: We performed a comprehensive search from each databases' inception to April 5, 2021. The studies that provided sufficient data regarding the sensitivity and specificity of IGRAs included QuantiFERON-TB Gold In-Tube (QFT-GIT), T-SPOT.TB, or QuantiFERON-TB Gold Plus for diagnosis of SNPTB were included. RESULTS: Of 1,312 studies screened, 16 studies were included; 11 QFT-GIT, 2 T-SPOT.TB, and 3 QFT-GIT and T-SPOT.TB. For diagnosis of SNPTB, QFT-GIT had sensitivity of 0.77 (95% CI 0.71-0.82), specificity of 0.70 (95% CI 0.58-0.80), diagnostic odds ratio (DOR) of 8.03 (95% CI 4.51-14.31), positive likelihood ratio (LR) of 2.61 (95% CI 1.80-3.80), negative LR of 0.33 (95% CI 0.25-0.42), and area under receiver operating characteristic (AUROC) of 0.81 (95% CI 0.77-0.84). T-SPOT.TB had sensitivity of 0.74 (95% CI 0.71-0.78), specificity of 0.71 (95% CI 0.49-0.86), DOR of 6.96 (95% CI 2.31-20.98), positive LR of 2.53 (95% CI 1.26-5.07), negative LR of 0.36 (95% CI 0.24-0.55), and AUROC of 0.77 (95% CI 0.73-0.80). The specificity seemed lower in the subgroup analyses of studies from high tuberculosis burden counties compared to the studies from low tuberculosis burden. CONCLUSION: IGRAs do have insufficient diagnostic performance for SNPTB. However, the tests are still helpful to exclude tuberculosis among patients with low pre-test probability. Registry: PROSPERO: CRD42021274653.

Disseminated blastomycosis in a kidney transplant recipient.

Disseminated blastomycosis in solid organ transplant is uncommon. The diagnosis is usually challenging due to vague clinical presentations, which could lead to a devastating outcome. We reported a unique case of disseminated blastomycosis with laryngeal involvement in a kidney transplant recipient who presented with hoarseness. The diagnosis was made by histopathology and culture of laryngeal mass.

A tale of two unusual anaerobic bacterial infections in an immunocompetent man: A case report and literature review.

We report a case of an immunocompetent man who presented with Desulfovibrio fairfieldensis bacteremia, followed by an epidural abscess due to Parvimonas micra. Only few cases have described unique clinical features related to both organisms, and this report illustrates two distinct sequential, if not concurrent, syndromes due to these anaerobes.