The battle against fungi: lessons in antifungal stewardship from COVID 19 times

The COVID-19 pandemic has highlighted the detrimental effect of secondary pathogens in patients with a primary viral insult. In addition to superinfections with bacterial pathogens, invasive fungal infections were increasingly reported. The diagnosis of pulmonary fungal infections has always been challenging; however, it became even more problematic in the setting of COVID-19, particularly regarding the interpretation of radiological findings and mycology test results in patients with these infections. Moreover, prolonged hospitalization in ICU, coupled with underlying host factors. such as preexisting immunosuppression, use of immunomodulatory agents, and pulmonary compromise, caused additional vulnerability to fungal infections in this patient population. In addition, the heavy workload, redeployment of untrained staff, and inconsistent supply of gloves, gowns, and masks during the COVID-19 outbreak made it harder for healthcare workers to strictly adhere to preventive measures for infection control. Taken together, these factors favored patient-to-patient spread of fungal infections, such as those caused by Candida auris, or environment-to-patient transmission, including nosocomial aspergillosis. As fungal infections were associated with increased morbidity and mortality, empirical treatment was overly used and abused in COVID-19-infected patients, potentially contributing to increased resistance in fungal pathogens. The aim of this paper was to focus on essential elements of antifungal stewardship in COVID-19 for three fungal infections, COVID-19-associated candidemia (CAC), -pulmonary aspergillosis (CAPA), and -mucormycosis (CAM).

Opportunistic Candida Infections in Critical COVID-19 Patients.

The frequency of opportunistic fungal infections in critically ill patients whose intensive care unit stays are prolonged due to coronavirus disease 2019 (COVID-19) is higher than in the period before COVID-19. We planned this study to improve the management of Candida infections by defining the Candida species, the etiology of infections caused by Candida species, and the antifungal susceptibility of the species. This retrospective study included patients older than 18 hospitalized in the intensive care unit (ICU) with a definitive diagnosis of COVID-19 for seven months (from March 2021 to September 2021). All study data that we recorded in a standard study form were analyzed with TURCOSA (Turcosa Analytics Ltd. Co., Turkey, www.turcosa.com.tr) statistical software. The patients were evaluated in four groups as group 1 (candidemia patients, n = 78), group 2 (candiduria patients, n = 189), group 3 (control patients, n = 57), and group 4 (patients with candidemia in urine cultures taken before Candida was detected in blood culture, n = 42). Candida species were identified using both conventional and VITEK® 2 (BioMérieux, France) methods. The antifungal susceptibility of fungi was determined using the E test method. Of the 5,583 COVID-19 patients followed during the study period, 78 developed candidemia, and 189 developed candiduria. The incidence of candidemia (per 1,000 admissions) was determined to be 1.6. As a result of statistical analysis, we found that Candida albicans was the dominant strain in candidemia and candiduria, and there was no antifungal resistance except for naturally resistant strains. Candida strains grown in blood and urine were the same in 40 of 42 patients. Mortality was 69.2% for group 1, 60.4% for group 2, and 57.8% for group 3. Antifungals were used in 34 (43.5%) patients from group 1, and 95 (50.2%) from group 2. In the candidemia group without antifungal use, mortality was quite high (77.2%). Antifungal use reduced mortality in the group 2 (p < 0.05). Length of ICU stays, comorbidity, broad-spectrum antibiotics, and corticosteroids are independent risk factors for candidemia in critically ill COVID-19 patients. Our study contributes to the knowledge of risk factors for developing COVID-19-related candida infections. The effect of candiduria on the development of candidemia in critically ill COVID-19 patients should be supported by new studies.

Determinants of fluconazole resistance and echinocandin tolerance in C. parapsilosis isolates causing a large clonal candidemia outbreak among COVID-19 patients in a Brazilian ICU.

Patients presenting with severe COVID-19 are predisposed to acquire secondary fungal infections such as COVID-19-associated candidemia (CAC), which are associated with poor clinical outcomes despite antifungal treatment. The extreme burden imposed on clinical facilities during the COVID-19 pandemic has provided a permissive environment for the emergence of clonal outbreaks of multiple Candida species, including C. auris and C. parapsilosis. Here we report the largest clonal CAC outbreak to date caused by fluconazole resistant (FLZR) and echinocandin tolerant (ECT) C. parapsilosis. Sixty C. parapsilosis strains were obtained from 57 patients at a tertiary care hospital in Brazil, 90% of them were FLZR and ECT. Although only 35.8% of FLZR isolates contained an ERG11 mutation, all of them contained the TAC1L518F mutation and significantly overexpressed CDR1. Introduction of TAC1L518F into a susceptible background increased the MIC of fluconazole and voriconazole 8-fold and resulted in significant basal overexpression of CDR1. Additionally, FLZR isolates exclusively harboured E1939G outside of Fks1 hotspot-2, which did not confer echinocandin resistance, but significantly increased ECT. Multilocus microsatellite typing showed that 51/60 (85%) of the FLZR isolates belonged to the same cluster, while the susceptible isolates each represented a distinct lineage. Finally, biofilm production in FLZR isolates was significantly lower than in susceptible counterparts Suggesting that it may not be an outbreak determinant. In summary, we show that TAC1L518F and FKS1E1393G confer FLZR and ECT, respectively, in CAC-associated C. parapsilosis. Our study underscores the importance of antifungal stewardship and effective infection control strategies to mitigate clonal C. parapsilosis outbreaks.

Candida dubliniensis fungemia in a patient with severe COVID-19: A case report.

Candida dubliniensis phenotypically mimics Candida albicans in its microbiological features; thus, its clinical characteristics have yet to be fully elucidated. Here we report the case of a 68-year-old Japanese man who developed C. dubliniensis fungemia during treatment for severe coronavirus disease 2019 (COVID-19). The patient was intubated and received a combination of immunosuppressants, including high-dose methylprednisolone and two doses of tocilizumab, as well as remdesivir, intravenous heparin, and ceftriaxone. A blood culture on admission day 11 revealed Candida species, which was confirmed as C. dubliniensis by mass spectrometry. An additional sequencing analysis of the 26S rDNA and ITS regions confirmed that the organism was 100% identical to the reference strain of C. dubliniensis (ATCC MYA-646). Considering the simultaneous isolation of C. dubliniensis from a sputum sample, the lower respiratory tract could be an entry point for candidemia. Although treatment with micafungin successfully eradicated the C. dubliniensis fungemia, the patient died of COVID-19 progression. In this case, aggressive immunosuppressive therapy could have caused the C. dubliniensis fungemia. Due to insufficient clinical reports on C. dubliniensis infection based on definitive diagnosis, the whole picture of the cryptic organism is still unknown. Further accumulation of clinical and microbiological data of the pathogen is needed to elucidate their clinical significance.

Fungal colonization and infections in patients with COVID-19 in intensive care units: A real-life experience at a tertiary-care hospital.

PURPOSE: To evaluate the management of patients with COVID-19 in the intensive care units (ICUs) with fungal infection/colonization and to highlight diagnostic problems in these patients. METHODS: We included all patients with a COVID-19 diagnosis who were aged ≥18 years and followed in the ICU for the first 8 months. Patient data were obtained from medical records. We compared the risk factors, laboratory data, and outcomes of patients with fungal infection/colonization. RESULTS: A total of 118 patients (81 men and 37 women) were included. The mean age was 70.3 ± 14.8 (35-94) years. Of the patients, 79 (66.9%) patients were ≥65 years old. Fungal infection/colonization was detected in 39 (33.1%) patients. Fungi were isolated from 34 (28.8%) patients. Ten fungal species were isolated from 51 samples (the most common being Candida albicans). Three patients (2.5%) had proven candidemia. We observed two (1.7%) possible cases of COVID-19-associated pulmonary aspergillosis (CAPA). Eighteen patients (15.3%) underwent antifungal therapy. The risk of fungal infection/colonization increased as the duration of invasive mechanical ventilation increased. The fatality rate was 61.9% and increased with age and the use of mechanical ventilation. The fatality rate was 4.2-times-higher and the use of mechanical ventilation was 35.9-times-higher in the patients aged ≥65 years than in the patients aged <65 years. No relationship was found between fungal colonization/infection, antifungal treatment, and the fatality rate. CONCLUSION: During the pandemic, approximately one-third of the patients in ICUs exhibited fungal infection/colonization. Candida albicans was the most common species of fungal infection as in the pre-pandemic area. Because of the cross-contamination risk, we did not performed diagnostic bronchoscopy and control thorax computed tomography during the ICU stay, and our patients mainly received empirical antifungal therapy.

Rapid Detection of Bacterial and Fungal Pathogens Using the T2MR versus Blood Culture in Patients with Severe COVID-19.

A high rate of bacterial and fungal superinfections was reported in critically ill patients with COVID-19. However, diagnosis can be challenging. The aim of this study is to evaluate the sensitivity and the clinical utility of the point-of-care method T2 magnetic resonance (T2MR) with the gold standard: the blood culture. T2MR can potentially detect five different Candida species and six common bacteria (so-called "ESKAPE" pathogens including Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Acinet`obacter baumanii, Pseudomonas aeruginosa, and Enterococcus faecium). If superinfection was suspected in patients with COVID-19 admitted to the intensive care unit, blood culture and two panels of T2MR were performed. Eighty-five diagnostic bundles were performed in 60 patients in total. T2MR detected an ESKAPE pathogen in 9 out of 85 (10.6%) samples, compared to BC in 3 out of 85 (3.5%). A Candida species was detected in 7 of 85 (8.2%) samples of T2MR compared to 1 out of 85(1.2%) in blood culture. The mean time to positive test result in samples with concordant positive results was 4.5 h with T2MR and 52.5 h with blood culture. The additional use of T2MR enables a highly sensitive and rapid detection of ESKAPE and Candida pathogens. IMPORTANCE Coronavirus disease 2019 (COVID-19) has led to a high number of deaths since the beginning of the pandemic worldwide. One of the reasons is the high number of bacterial and fungal superinfections in patients suffering from critical disease. However, diagnosis is often challenging. In this study we could show that the additional use of the culture-independent method T2MR did not only show a much higher detection rate of bacterial and fungal pathogens but also a significantly shorter time until detection and therapy change compared to the gold standard: the blood culture. The implementation of T2MRin the care of patients with severe course of COVID-19 might lead to an earlier sufficient antimicrobial therapy and as a result lower mortality and less use of broad-spectrum unnecessary therapy reducing the risk of resistance development.

Prevalence, risk factors, treatment and outcome of multidrug resistance Candida auris infections in Coronavirus disease (COVID-19) patients: A systematic review.

BACKGROUND: Candida auris is an emerging multidrug-resistant pathogen in intensive care settings (ICU). During the coronavirus disease 19 (COVID-19) pandemic, ICU admissions were overwhelmed, possibly contributing to the C. auris outbreak in COVID-19 patients. OBJECTIVES: The present systematic review addresses the prevalence, underlying diseases, iatrogenic risk factors, treatment and outcome of C. auris infections in COVID-19 patients. METHODS: MEDLINE, Scopus, Embase, Web of Science and LitCovid databases were systematically searched with appropriate keywords from 1 January 2020 to 31 December 2021. RESULTS: A total of 97 cases of C. auris were identified in COVID-19 patients. The pooled prevalence of C. auris infections (encompassing candidemia and non-candidemia cases) in COVID-19 patients was 14%. The major underlying diseases were diabetes mellitus (42.7%), hypertension (32.9%) and obesity (14.6%), followed by the iatrogenic risk factors such as a central venous catheter (76.8%%), intensive care unit (ICU) stay (75.6%) and broad-spectrum antibiotic usage (74.3%). There were no significant differences in underlying disease and iatrogenic risk factors among C. auris non-candidemia/colonisation and C. auris candidemia cases. The mortality rate of the total cohort is 44.4%, whereas, in C. auris candidemia patients, the mortality was 64.7%. CONCLUSION: This study shows that the prevalence of C. auris infections remains unchanged in the COVID-19 pandemic. Hospital-acquired risk factors may contribute to the clinical illness. Proper infection control practices and hospital surveillance may stop future hospital outbreaks during the pandemic.

The Landscape of Candidemia During the Coronavirus Disease 2019 (COVID-19) Pandemic.

BACKGROUND: The COVID-19 pandemic has resulted in unprecedented healthcare challenges, and COVID-19 has been linked to secondary infections. Candidemia, a fungal healthcare-associated infection, has been described in patients hospitalized with severe COVID-19. However, studies of candidemia and COVID-19 coinfection have been limited in sample size and geographic scope. We assessed differences in patients with candidemia with and without a COVID-19 diagnosis. METHODS: We conducted a case-level analysis using population-based candidemia surveillance data collected through the Centers for Disease Control and Prevention's Emerging Infections Program during April-August 2020 to compare characteristics of candidemia patients with and without a positive test for COVID-19 in the 30 days before their Candida culture using chi-square or Fisher's exact tests. RESULTS: Of the 251 candidemia patients included, 64 (25.5%) were positive for SARS-CoV-2. Liver disease, solid-organ malignancies, and prior surgeries were each >3 times more common in patients without COVID-19 coinfection, whereas intensive care unit-level care, mechanical ventilation, having a central venous catheter, and receipt of corticosteroids and immunosuppressants were each >1.3 times more common in patients with COVID-19. All-cause in-hospital fatality was 2 times higher among those with COVID-19 (62.5%) than without (32.1%). CONCLUSIONS: One-quarter of candidemia patients had COVID-19. These patients were less likely to have certain underlying conditions and recent surgery commonly associated with candidemia and more likely to have acute risk factors linked to COVID-19 care, including immunosuppressive medications. Given the high mortality, it is important for clinicians to remain vigilant and take proactive measures to prevent candidemia in patients with COVID-19.

Incidence and risk factors for COVID-19 associated candidemia (CAC) in ICU patients.

BACKGROUND: Critically ill COVID-19 patients have a high risk for the development of candidemia due to being exposed to both well-defined classical risk factors and COVID-19-specific risk factors in ICU. OBJECTIVES: In this study, we investigated the incidence of candidemia in critically COVID-19 patients, and the independent risk factors for candidemia. PATIENTS/METHODS: COVID-19 patients hospitalised in ICU during 1-year period (August 2020 to August 2021) were included. Clinical and laboratory characteristics of all COVID-19 patients, applied treatments, and invasive procedures that may predispose to candidemia were recorded. RESULTS: Of 1229 COVID-19 patients, 63 developed candidemia. Candidemia incidence rate was 4.4 episodes per 1000 ICU days. The most common species was Candida albicans (52.3%). Only 37 patients (58.7%) received antifungal therapy. The presence of central venous catheter (OR 4.7, 95% CI 1.8-12.2, p < .005), multifocal candida colonisation (OR 2.7, 95% CI 1.4-5.2, p < .005), a prolonged ICU stay (≥14 days) (OR 1.9, 95% CI 1.08-3-37, p < .05), the absence of chronic lung disease (OR 0.4, 95% CI 0.1-0.9, p < .05) and the absence of corticosteroid use (OR 0.3, 95% CI 0.14-0.52, p < .0001) were significantly associated with candidemia. CONCLUSIONS: Our study filled the knowledge gap in the literature about the impact of COVID-19-associated risk factors for the development of candidemia. The classical risk factors for candidemia had a significant effect on candidemia, and contrary to expectations, corticosteroids had a protective effect against the development of candidemia. The results of these studies showing interesting effects of corticosteroids in critically ill COVID-19 patients should be confirmed by further studies.

[First Case of COVID-19 Positive Candida auris Fungemia in Turkey]. / Türkiye'de Ilk COVID-19 Pozitif Candida auris Fungemi Olgusu.

Candida auris is a species of fungus that has gained importance in recent years owing to its ability to cause hospital infections and epidemics, resistant to antifungal agents and disinfection processes and frequently misidentified by commercial systems. Hospital outbreaks caused by C.auris have been reported from some countries. It has been determined that C.auris has lower virulence than Candida albicans; however, it is associated with high mortality rates in immunocompromised individuals. An increase in the incidence of invasive fungal infections which can lead to serious complications and death, has been identified in severe coronavirus-2019 (COVID-19) patients or immunocompromised individuals with underlying disease. Studies demonstrated an increase in the frequency of C.auris isolation in COVID-19 patients with candidemia. In this report, the first case of COVID-19 positive C.auris fungemia detected in Turkey was presented. A 71-year-old male patient with a history of myocardial infarction, diabetes mellitus, donation of a single kidney and lobectomy surgery due to lung cancer was hospitalized in the pandemic thoracic surgery service due to the findings consistent with viral pneumonia on thoracic computed tomography. Favipiravir 2 x 600 mg and intravenous dexamethasone 1 x 6 mg therapy was administered. The patient tested positive for SARS-CoV-2 polymerase chain reaction, and severe involvement of the left lung was detected in the following days. Antibiotics were administered, followed by insertion of a right jugular vein catheter and initation of tocilizumab. The patient was transferred to the intensive care unit due to increased respiratory distress. Yeast growth was detected in the patient's hemoculture. The yeast strain could not be identified using API ID 32C (bioMerieux, France) (Sacchromyces kluyveri, Candida sake, unacceptable profile), but was identified as C.auris using the VITEK MALDI TOF MS (bioMerieux, France) (99.9%) system and confirmed by sequencing. The minimum inhibitor concentration values were detected as 3 µg/ml for amphotericin B; > 256 µg/ml for fluconazole; 0.19 µg/ml for voriconazole; 0.19 µg/ml for itraconazole; 0.016 µg/ml for posaconazole; 1 µg/ml for caspofungin and 0.094 µg/ml for anidulafungin by using the antibiotic gradient method. The patient's initial treatment comprised meropenem 3 x 1 g, vancomycin 2 x 1 g, caspofungin 1 x 70 mg, and continued as caspofungine 1 x 50 mg after the loading dose, and vancomycin 1 x 1 g/48 hours from the third day of treatment. The patient died on the ninth day after developing candidemia. The present case is the first case of fungemia caused by C.auris in a COVID-19 positive patient in Turkey, and it emphasizes the need of caution for fungemia due to C.auris in intensive care units in our country which has a high COVID-19 incidence.

COVID-19 and Candida duobushaemulonii superinfection: A case report.

INTRODUCTION: Critically ill COVID-19 patients are at high risk for nosocomial bacterial and fungal infections due to several predisposing factors such as intensive care unit stay, mechanical ventilation, and broad-spectrum antibiotics. Data regarding multidrug resistant (MDR) Candida species in COVID-19 patients is scarce, and nonexistent regarding Candida duobushaemulonii superinfections. CASE DESCRIPTION: A 34-year-old male presented to our institution with acute respiratory distress syndrome (ARDS) due to COVID-19 infection and developed Candida duobushaemulonii fungemia after multiple courses of antibiotics and prolonged mechanical ventilation. He died after recurrent pneumothorax led to respiratory failure and cardiac arrest. DISCUSSION: Bacterial and fungal infections are common complications of viral pneumonia in critically ill patients. Data regarding these infections in COVID-19 patients has been poorly studied with only a few cases reporting secondary infection, mostly without identifying specific pathogens. Prolonged hospital stays, invasive interventions (central venous catheter, mechanical ventilation), and the use of broad-spectrum antibiotics in COVID-19 infections could carry a high risk of bacterial and/or fungal superinfections. CONCLUSION: Strategies to improve outcome in COVID-19 ICU patients should include early recognition of candidemia and appropriate antifungal therapy.

Characteristics of candidemia in COVID-19 patients; increased incidence, earlier occurrence and higher mortality rates compared to non-COVID-19 patients.

Severe COVID-19 patients in ICU are at high risk for candidemia due to exposure to multiple risk factors for candidemia. We aimed to compare the incidence of candidemia in ICU patients with and without COVID-19, and to investigate epidemiologic and clinical characteristics of candidemia patients and risk factors for mortality in candidemia patients. This retrospective study was conducted in patients followed in the ICUs of Ankara City Hospital for 2 years, divided into pre-pandemic and pandemic periods. The incidence (event per 1000 patient-days) and epidemiology of candidemia, clinical and laboratory characteristics of patients were compared in COVID-19 and non-COVID-19 groups. Candidemia incidence was higher in the COVID-19 group (2.16, 95% CI 1.77-2.60) than the non-COVID-19 group (1.06, 95% CI 0.89-0.125) (p < .001). A total of 236 candidemia episodes (105 in COVID-19 patients and 131 in non-COVID-19 patients) were detected during the study periods. COVID-19 cases had a higher rate of corticosteroid use (63.8% vs. 9.9%, p < .001). Epidemiology of candidemia and antifungal susceptibility were similar. Candidemia developed 2 weeks earlier in COVID-19 groups and resulted in higher mortality (92.5% vs. 79.4%, p .005). One-third of candidemia patients died before receiving any antifungal treatment, and this rate was higher in the COVID-19 group. In multivariate logistic regression analysis, corticosteroid use, presence of sepsis and age older than 65 years were independent risk factors for mortality in candidemia patients. Candidemia with high mortality is a more serious problem for COVID-19 patients due to its increased incidence, earlier occurrence and a higher rate of mortality.

Role of tocilizumab for concomitant systemic fungal infection in severe COVID-19 patient: Case report.

RATIONALE: Bacterial and fungal infections in Coronavirus Disease-19 (COVID-19) patients have been inadequately investigated and reported thus far. The safety profile of tocilizumab (TCZ) administration in candidemia patient still debatable. PATIENT CONCERNS: A 54 year-old woman presenting with weakness on the left side of her body was diagnosed with COVID-19. After 7 days of admission, her condition worsened and developed respiratory distress and was having respiratory distress despite standard treatment. DIAGNOSES: Acute respiratory distress syndrome (ARDS) in COVID 19 was diagnoses based on real time-PCR swab, deterioration of PaO2/FiO2 and increased of acute phase reactants. INTERVENTIONS: Anti Interleukin-6 (IL-6) was considered to tackle her inflammatory condition. Prior to TCZ administration, blood culture was performed and the result came with Candida tropicalis in the absence of bacterial growth. OUTCOMES: No major complications associated with intravenous antifungal or TCZ occurred. After 40 days of hospitalization, the patient's clinical condition improved and was finally discharged. LESSONS: This case underscores the safety profile of giving TCZ in candidemia as a secondary infection in severe COVID-19 patient.

Successful management of the first reported case in Austria of COVID-19 with ARDS.

We report the successful management of a patient with severe respiratory failure due to COVID-19 admitted to an intensive care unit complicated by secondary catheter-related infection of Candida glabrata. We are discussing some of the clinical challenges and the pitfalls in molecular diagnosis of SARS-CoV-2, including the fact that a positive PCR result may not always reflect infectiousness.