Risk Factors for Candidemia After Open Heart Surgery: Results From a Multicenter Case-Control Study

Risk Factors and Outcomes of Invasive Candida Infections in Heart Transplant Recipients: A Case-Control Study

BACKGROUND

Invasive Candida infections (ICI) are the most common invasive fungal infections in solid organ transplant recipients. There are limited contemporary data on the risk factors for infection in heart transplant (HT) recipients especially since the expansion of temporary mechanical circulatory support (MCS) use.

METHODS

This was a case-control study conducted at a tertiary care academic hospital of HT recipients from January 2022 to January 2024. All patients who developed ICI by the detection of Candida species from a normally sterile site were included as cases. Four controls who underwent HT, two before the case and two after the case, were selected. ​Fisher's exact or Mann-U-Whitney tests were used for the analysis.

RESULTS

There were 12 cases and 48 controls out of a total of 117 transplants during the study period​. The proportion of ICI was 10.6%. The median time to ICI from transplant was 16 days (IQR 10, 83). The most common organisms isolated were Candida parapsilosis and Candida albicans. The majority of infections were mediastinitis. Risk factors for ICI included receipt of antibiotics for more than 7 days within 1 month prior to transplant (58.3% vs. 22.9%, p = 0.03), tracheostomy (41.7% vs. 10.4%, p = 0.02), prolonged chest tube placement (13 vs. 9 days, p = 0.02), and temporary MCS (p = 0.042). Patients who developed ICI had increased 90-day all-cause mortality compared to controls (33.3% vs. 4.2%, p = 0.01).

CONCLUSION

This study identified several risk factors for ICI following HT. Further research is essential to develop interventions that mitigate these risk factors in this patient population.

Alarming Increase of Azole-Resistant Candida Causing Blood Stream Infections in Oncology Patients in Egypt

Candidemia is a life-threatening invasive fungal infection in immunocompromised patients. The widespread use of azoles and the shift toward non-albicans Candida (NAC) species remarkably increase azole resistance in developing countries. We aimed to study candidemia trends and associated risk factors in oncology patients since they vary geographically, and rapid and appropriate treatment improves outcomes. Vitek 2 was used to identify the Candida species, and the E-test determined their susceptibility to azoles. Candida was the cause of 3.1% (n = 53/1701) of bloodstream infections (BSIs) during a 1-year study. Candida tropicalis was the most predominant species among the 30 candidemia episodes studied (36.7%), followed by C. albicans (33.3%). However, C. krusei, C. guilliermondii, C. pelliculosa, C. parapsilosis, C. famata, and C. inconspicua accounted for 30.0% of the isolates. An increased risk of NAC BSI was significantly associated with chemotherapy and leucopenia (P = 0.036 and 0.016, respectively). However, the multivariable analysis revealed that leucopenia was the only independent risk factor (P = 0.048). Fluconazole and voriconazole resistance were 58.3% and 16.7%, with NAC species showing higher resistance rates than C. albicans. Both fluconazole and voriconazole minimum inhibitory concentration (MIC) median values were higher in NAC than in C. albicans, but only voriconazole was significantly higher (0.220 versus 0.048 μg/ml, P = 0.047). In conclusion, the increased prevalence of NAC BSIs and incredibly high fluconazole resistance rates in cancer patients emphasize the necessity of antifungal stewardship to preserve voriconazole effectiveness, continued surveillance of candidemia, and future studies into azole resistance molecular mechanisms.

Nosocomial Extracardiac Infections After Cardiac Surgery

Purpose of Review

Nosocomial extracardiac infections after cardiac surgery are a major public health issue affecting 3–8.2% of patients within 30–60 days following the intervention.

Recent Findings

Here, we have considered the most important postoperative infective complications that, in order of frequency, are pneumonia, surgical site infection, urinary tract infection, and bloodstream infection. The overall picture that emerges shows that they cause a greater perioperative morbidity and mortality with a longer hospitalization time and excess costs. Preventive interventions and corrective measures, diminishing the burden of nosocomial extracardiac infections, may reduce the global costs. A multidisciplinary team may assure a more appropriate management of nosocomial extracardiac infections leading to a reduction of hospitalization time and mortality rate.

Summary

The main and most current data on epidemiology, prevention, microbiology, diagnosis, and management for each one of the most important postoperative infective complications are reported. The establishment of an antimicrobial stewardship in each hospital seems to be, at the moment, the more valid strategy to counteract the challenging problems.

The Diagnostic Relevance of β-D-Glucan for Candidemia within Internal Medicine Wards

Candidemia diagnosis is based on the combination of clinical, microbiological and laboratory data. We aimed to evaluate performances and accuracy of (1,3)-β-D-glucan (BDG) at various cut-offs in internal medicine patients. An observational retrospective−prospective study was performed. Patients with at least two determinations of BDG and paired, associated blood cultures within ±48 h were considered. A total of 140 patients were included: 26 with Candida spp. blood-stream infections (BSI) and 114 without candidemia. Patients with candidemia were older and had higher BDG values, need of parenteral nutrition, higher colonization by Candida in more than one site, presence of percutaneous gastrostomy and higher Candida or Charlson scores. BDG maintained the best compromise between sensitivity, specificity and optimal negative predictive value was 150 pg/mL. BDG values at cut-off of 150 pg/mL increase the strength of association between BDG and development of candidemia (Odds Ratio—OR 5.58; CI 2.48−12.53 vs. OR 1.06; CI 1.003−1.008). Analyzing BDG > 150 pg/mL along with Candida score > 2 and Charlson score > 4, the strength of the association amongst BDG, clinical scores and development of candidemia is increased. The overall clinical evaluation with the help of scores that consider BDG values > 150 pg/mL, Candida score > 2 and Charlson score > 4 in combination seems to predict better the need of antifungal empiric treatment.

Machine Learning in Infectious Disease for Risk Factor Identification and Hypothesis Generation: Proof of Concept Using Invasive Candidiasis

Background

Machine learning (ML) models can handle large datasets without assuming underlying relationships and can be useful for evaluating disease characteristics; yet, they are more commonly used for predicting individual disease risk rather than identifying factors at the population level. We offer a proof of concept applying random forest (RF) algorithms to Candida-positive hospital encounters in an electronic health record database of patients in the U.S.

Methods

Candida-positive encounters were extracted from the Cerner HealthFacts database; invasive infections were laboratory positive sterile site Candida infections. Features included demographics, admission source, care setting, physician specialty, diagnostic and procedure codes, and medications received prior to the first positive Candida culture. We used RF to assess risk factors for three outcomes: any invasive candidiasis (IC) vs non-IC, within-species IC vs non-IC (e.g. invasive C. glabrata vs non-invasive C. glabrata), and between-species IC (e.g. invasive C. glabrata vs all other IC).

Results

14 of 169 (8%) variables were consistently identified as important features in the ML models. When evaluating within-species IC, for example invasive C. glabrata vs non-invasive C. glabrata, we identified known features like central venous catheters, ICU stay, and gastrointestinal operations. In contrast, important variables for invasive C. glabrata vs all other IC included renal disease and medications like diabetes therapeutics, cholesterol medications, and antiarrhythmics.

Conclusions

Known and novel risk factors for IC were identified using ML, demonstrating the hypotheses generating utility of this approach for infectious disease conditions about which less is known, specifically at the species-level or for rarer diseases.

Epidemiology of nosocomial candidemia, mortality and antifungal resistance, 7-year experience, in Turkey

Candidemia is an important clinical condition that prolongs the period of hospitalization and increases morbidity, mortality, and hospital costs. In this retrospective study, we aimed to evaluate the epidemiological and microbiological characteristics of patients with candidemia, between January 2013 and December 2019. Two hundred forty-one candidemia episodes were observed in the 230 patients, of whom 45% were female. The median age was 63 and 53.9% of the episodes were in the ICU. Frequently observed predisposing factors for candidemia included the use of antibiotics (71.3%), urinary catheterization (56.3%), Central venous catheter placement (50.3%), total parenteral nutrition (47.9%), solid-organ malignancy (46%), a surgical intervention (48.6%), chemotherapy (37%), steroid treatment (25.5%). The crude mortality rate was 52.7%. A significant difference was found between survivors and non-survivors (p = 0.007) with the Charlson comorbidity index. However, no statistically significant association was found between mortality and age, sex, surgical intervention, catheter-related candidemia, or Candida spp. The most frequently isolated Candida spp. was C. albicans (51%). Overall resistance to fluconazole, voriconazole, caspofungin, micafungin and flucytosine was 3.7%, 0%, 2.5%, 1.8%,1.8%, respectively. Consequently, there is a need for tests that yield higher success rates and rapid in diagnosis candidemia and local epidemiological data for antifungal resistance.

Clinical Profile of Prosthetic Valve Endocarditis due to Candida parapsilosis: An 11-year Retrospective Observational Study from a Quaternary Cardiac Referral Institute in India

Background: Recent changes in the diagnostic criteria and the introduction of newer technologies like prosthetic valve replacement require the need to identify the changing epidemiology of prosthetic valve endocarditis (PVE).

Materials and methods: This is a retrospective, cross-sectional, observational study. Patients diagnosed with Candida parapsilosis definite and possible PVE as per modified Duke’s criteria for a period of 11 years from January 2010 to December 2020 were included for the analysis.

Results: Twelve of the 47 PVE cases (25.5%) were caused by C. parapsilosis. The median age of the patients was 52 years. Males were predominantly affected (58%). Based on the modified Duke’s criteria, eight (67%) were definite infective endocarditis (IE) cases. The single valve was affected in 11 cases (92%) with the mitral valve being the commonest (n = 8, 67%). The type of valve commonly involved was mechanical [n = 10, 83%]. The mean size of the vegetation was 13.15 mm. Most cases (n = 7, 58%) were late-onset PVE. The mean C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and procalcitonin (PCT) levels for C. parapsilosis PVE were 70.2 mg/L, 51.08 mm/hour, and 0.3 ng/mL, respectively. The rates of complications and in-hospital mortality were 75% each. The most common observed complication was embolic events (n = 8, 67%). Statistical significance (p ≤ 0.05) was observed for mean vegetation size, overall complications, embolic events, and mortality for C. parapsilosis PVE when compared with bacterial PVE.

Conclusion:C. parapsilosis was the commonest etiological agent causing PVE. Predominant mitral valve involvement, higher rates of late-onset presentation, complications, and mortality were key differential characteristics observed.

Highlights: The manuscript throws light on the changing epidemiology, clinical, and microbiological profile of PVE due to Candida sp., which are scarcely studied and reported in low- and middle-income countries like India.

How to cite this article: Ponnambath DK, Gopalakrishnan A, Pillai VV, Kaviyil JE, Raja K. Clinical Profile of Prosthetic Valve Endocarditis due to Candida parapsilosis: An 11-year Retrospective Observational Study from a Quaternary Cardiac Referral Institute in India. Indian J Crit Care Med 2021;25(8):860–865.