Invasive Candida infection: epidemiology, clinical and therapeutic aspects of an evolving disease and the role of rezafungin.

INTRODUCTION: Invasive Candida Infections (ICIs) have undergone a series of significant epidemiological, pathophysiological, and clinical changes during the last decades, with a shift toward non-albicans species, an increase in the rate of exogenous infections and clinical manifestations ranging from candidemia to an array of highly invasive and life-threatening clinical syndromes. The long-acting echinocandin rezafungin exhibits potent in-vitro activity against most wild-type and azole-resistant Candida spp. including C.auris. AREAS COVERED: The following topics regarding candidemia only and ICIs were reviewed and addressed: i) pathogenesis; ii) epidemiology and temporal evolution of Candida species; iii) clinical approach; iv) potential role of the novel long-acting rezafungin in the treatment of ICIs. EXPERT OPINION: Authors' expert opinion focused on considering the potential role of rezafungin in the evolving context of ICIs. Rezafungin, which combines a potent in-vitro activity against Candida species, including azole-resistant strains and C.auris, with a low likelihood of drug-drug interactions and a good safety profile, may revolutionize the treatment of candidemia/ICI. Indeed, it may shorten the length of hospital stays when clinical conditions allow and extend outpatient access to treatment of invasive candidiasis, especially when prolonged treatment duration is expected.

Invasive Candidiasis.

Invasive candidiasis (IC) is the most frequent health care associated invasive fungal infection. It is also associated with high morbidity, mortality, and cost. The most frequent etiologic agent is Candida albicans, but non-albicans species are increasing and associated with reduced antifungal susceptibility and outbreaks. Candida auris is an emerging multidrug-resistant species recently described. IC presents as a spectrum of disease, going from fungemia to deep-seated candidiasis, and to septic shock with multiorgan failure. Diagnosis of IC is challenging. Several biomarkers and molecular methods are available for improving diagnosis. Early initial treatment with echinocandins is the treatment of choice. Step-down therapy when antifungal susceptibility is available is possible. Several new antifungal agents for the treatment of IC are in clinical development.

Clonality of Fluconazole-Nonsusceptible Candida tropicalis in Bloodstream Infections, Taiwan, 2011-2017.

Candida tropicalis is the leading cause of non-C. albicans candidemia in tropical Asia and Latin America. We evaluated isolates from 344 patients with an initial episode of C. tropicalis candidemia. We found that 58 (16.9%) patients were infected by fluconazole-nonsusceptible (FNS) C. tropicalis with cross resistance to itraconazole, voriconazole, and posaconazole; 55.2% (32/58) of patients were azole-naive. Multilocus sequence typing analysis revealed FNS isolates were genetically closely related, but we did not see time- or place-clustering. Among the diploid sequence types (DSTs), we noted DST225, which has been reported from fruit in Taiwan and hospitals in Beijing, China, as well as DST376 and DST505-7, which also were reported from hospitals in Shanghai, China. Our findings suggest cross-boundary expansion of FNS C. tropicalis and highlight the importance of active surveillance of clinical isolates to detect dissemination of this pathogen and explore potential sources in the community.

Invasive Candida auris infections in Kuwait hospitals: epidemiology, antifungal treatment and outcome.

PURPOSE: Candida auris is a recently recognized yeast pathogen, which has attracted worldwide attention due to its multidrug-resistant nature and associated high mortality rates. Its persistence in hospital environment and propensity of nosocomial transmission underscores the need of continuous monitoring to prevent outbreaks. Since the first case of C. auris candidemia in May, 2014, we have identified 17 additional invasive cases, which are described here. METHODS: Identity of 17 isolates originating from proven or possible cases of invasive C. auris infection and identified as Candida haemulonii by Vitek 2 yeast identification system was confirmed by PCR-sequencing of rDNA. Information about risk factors, treatment and outcomes were retrospectively retrieved from case files. Antifungal susceptibility testing was performed by Etest. RESULTS: Thirteen cases of candidemia and 4 cases of other invasive infections were detected in 6 hospitals across Kuwait. Major risk factors included adult patients with cancer, diabetes, gastrointestinal/liver diseases and extended (> 25 days) hospital stay. All isolates were resistant to fluconazole. Additionally, 5 and 4 isolates were also resistant to voriconazole and amphotericin B, respectively. Despite antifungal treatment, 9 of 15 patients died. Most patients (n = 12) were hospitalized in 2 hospitals that are in close proximity, whereas 5 other patients were from 3 hospitals that are situated > 10 km apart. CONCLUSIONS: Occurrence of successive cases of invasive C. auris infections with resulting mortality in nine patients suggests persistence of this multidrug-resistant yeast in major hospitals in Kuwait. Early detection by continuous surveillance and enforcement of infection control measures are recommended.

Update on the diagnosis of invasive fungal infection.

The number of patients at risk of suffering invasive fungal infection (IFI) is increasing. Because of its high mortality, new rapid and accurate diagnostic tools are needed. Last advances in invasive candidiasis diagnosis comprise Peptide Nucleic Acid Fluorescent In-Situ Hybridization (PNA-FISH), direct MALDI-TOF or multiplex acid nucleic testing. While all of them rely in positive blood cultures, T2Candida uses PCR coupled with T2Magnetic resonance detection directly in whole blood, allowing detection of 1-3 UFC/mL of Candida in about four hours. Beyond galactomannan (GM), novelties in IFI caused by molds include the international standardization of PCR techniques, with several commercial kits available. A combination of GM and PCR appears to be a good diagnostic strategy for invasive aspergillosis. PCR coupled to electrospray ionization/mass spectrometry and detection of volatile organic compounds in exhaled air by gas chromatography/mass spectrometry are other promising approaches to IFI diagnostic that still need to be validated.

Multidrug-Resistant Candida: Epidemiology, Molecular Mechanisms, and Treatment.

Invasive Candida infections remain an important cause of morbidity and mortality, especially in hospitalized and immunocompromised or critically ill patients. A limited number of antifungal agents from only a few drug classes are available to treat patients with these serious infections. Resistance can be either intrinsic or acquired. Resistance mechanisms are not exchanged between Candida; thus, acquired resistance either emerges in response to an antifungal selection pressure in the individual patient or, more rarely, occur due to horizontal transmission of resistant strains between patients. Although multidrug resistance is uncommon, increasing reports of multidrug resistance to the azoles, echinocandins, and polyenes have occurred in several Candida species, most notably Candida glabrata and more recently Candida auris. Drivers are overall antifungal use, subtherapeutic drug levels at sites of infection/colonization, drug sequestration in the biofilm matrix, and, in the setting of outbreaks, suboptimal infection control. Moreover, recent research suggests that DNA mismatch repair gene mutations may facilitate acquisition of resistance mutations in C. glabrata specifically. Diagnosis of antifungal-resistant Candida infections is critical to the successful management of patients with these infections. Reduction of unnecessary use of antifungals via antifungal stewardship is critical to limit multidrug resistance emergence.

The current treatment landscape: candidiasis.

The epidemiology of Candida species infection has changed over recent decades, influenced by local hospital-related factors, patient predisposing conditions and type of antifungal agents administered. A shift from Candida albicans as the predominant pathogen towards an increasing prevalence of the species Candida glabrata and Candida parapsilosis amongst critically ill patients has been documented. Changes in Candida species distribution may impact treatment recommendations due to differences in susceptibility to antifungal agents among species. Previous exposure to antifungal agents has likely contributed to this shift in species distribution. Another evolving epidemiological factor to consider is the global increase in antifungal resistance to certain antifungal drug types, which has been contributed to by the inappropriate use of these agents. Proposed management strategies to optimize treatment of patients with Candida infection include starting prompt 'early' antifungal therapy, early cessation of inappropriate therapy, using an adequate dose and duration of therapy and de-escalating treatment whenever possible. The implementation of institutional antifungal stewardship programmes has the potential to promote appropriate utilization of antifungal agents and to significantly improve the care of patients with Candida infection. However, a cultural change among healthcare providers and authorities is currently needed to improve antifungal use worldwide.

Epidemiology of candidemia and antifungal susceptibility in invasive Candida species in the Asia-Pacific region.

In the Asia-Pacific region, Candida albicans is the predominant Candida species causing invasive candidiasis/candidemia in Australia, Japan, Korea, Hong Kong, Malaysia, Singapore and Thailand whereas C. tropicalis is the most frequently encountered Candida species in Pakistan and India. Invasive isolates of C. albicans, C. parapsilosis complex and C. tropicalis remain highly susceptible to fluconazole (>90% susceptible). Fluconazole resistance (6.8-15%), isolates with the non-wild-type phenotype for itraconazole susceptibility (3.9-10%) and voriconazole (5-17.8%), and echinocandin resistance (2.1-2.2% in anidulafungin and 2.2% in micafungin) among invasive C. glabrata complex isolates are increasing in prevalence. Moreover, not all isolates of C. tropicalis have been shown to be susceptible to fluconazole (nonsusceptible rate, 5.7-11.6% in China) or voriconazole (nonsusceptible rate, 5.7-9.6% in China).

Invasive Candidiasis.

Invasive candidiasis is a collective term that refers to a group of infectious syndromes caused by a variety of species of Candida, 5 of which cause most cases. Candidemia is the most commonly recognized syndrome associated with invasive candidiasis. Certain conditions may influence the likelihood for one species versus another in a specific clinical scenario, and this can have important implications for selection of antifungal therapy and the duration of treatment. Molecular diagnostic technology plays an ever-increasing role as an adjunct to traditional culture-based diagnostics, offering significant potential toward improvement in patient care.

Candida glabrata--unique features and challenges in the clinical management of invasive infections.

Candida glabrata is a pathogenic yeast with several unique biological features. This article provides an up-to-date review on current data and reasoning aspects of this clinically problematic organism. Haploidy, absence of pseudohyphae, facultative anaerobe growth of C. glabrata, as well as its intrinsically low susceptibility to azole antifungals require specific consideration in diagnosis and treatment approaches. As C. glabrata today represents a sizeable percentage of pathogens in candidaemia, the use of azole antifungals in upfront therapy of invasive yeast infections is discouraged by recent guidelines. While the selection of C. glabrata mutants with impaired susceptibility to echinocandins has been described, analyses of several clinical studies indicate an association of improved outcomes with the use of echinocandins as the primary treatment for invasive yeast infections with potential or documented involvement of C. glabrata.

Proyecto Épico: Formulación de unas recomendaciones educativas con metodología DELPHI para pacientes adultos críticos no neutropénicos y con candidiasis invasiva / Épico project. Development of educational recommendations using the DELPHI technique on invasive candidiasis in non-neutropenic critically ill adult patients

Antecedentes. Aunque en la última década ha mejorado el manejo de la candidiasis invasiva, todavía persisten aspectos controvertidos, en especial por lo que respecta a la estrategia diagnóstica y terapéutica. Objetivos. Identificar los conocimientos clínicos esenciales y formular unas recomendaciones con la obtención de un alto grado de consenso, necesarias en la asistencia de pacientes adultos no neutropénicos en estado crítico con candidiasis invasiva. Métodos. Se preparó una encuesta prospectiva cuyo texto se redactó en español, y se obtuvo un consenso mediante técnica DELPHI (un método de reestructuración de un proceso de comunicación con el que se obtiene un grado de consenso de los especialistas sobre el problema planteado). En primer término, se envió de forma anónima por correo electrónico a 25 especialistas nacionales de diferentes disciplinas médicas, expertos en infecciones fúngicas invasivas, de 5 sociedades científicas nacionales, incluidos intensivistas, anestesistas, microbiólogos, farmacólogos e infectólogos, que respondieron a 47 preguntas preparadas por el grupo de coordinación, tras una revisión exhaustiva de los estudios publicados durante los 5 últimos años. Los objetivos educativos contemplaron 5 categorías: epidemiología, instrumentos diagnósticos, scores, estrategias terapéuticas y de desescalada. Para ser seleccionado, el grado de acuerdo alcanzado entre los expertos del panel en cada uno de los ítems debía superar el 75%. En segundo término, después de extraer las recomendaciones de los ítems seleccionados, se celebró una reunión presencial donde se invitó a participar en una segunda ronda a más de 80 especialistas y se les solicitó la validación de las recomendaciones preseleccionadas. ...(AU)

Background. Although there has been an improved management of invasive candidiasis in the last decade, controversial issues still remain, especially in the diagnostic and therapeutic approaches. Aims. We sought to identify the core clinical knowledge and to achieve high level agreement recommendations required to care for critically ill adult patients with invasive candidiasis. Methods. A prospective Spanish survey reaching consensus by the DELPHI technique was made. It was anonymously conducted by electronic mail in a first term to 25 national multidisciplinary experts in invasive fungal infections from five national scientific societies, including intensivists, anesthesiologists, microbiologists, pharmacologists and infectious diseases specialists, who answered to 47 questions prepared by a coordination group after a strict review of the literature in the last five years. The educational objectives spanned five categories, including epidemiology, diagnostic tools, prediction rules, and treatment and de-escalation approaches. The level of agreement achieved among the panel experts in each item should exceed 75% to be selected. In a second term, after extracting recommendations from the selected items, a face to face meeting was performed where more than 80 specialists in a second round were invited to validate the preselected recommendations. ...(AU)

Invasive candidiasis and the utility of antifungal susceptibility testing in the ICU.

Invasive fungal infections are a major cause of health care-associated morbidity and mortality in the ICU. In particular, Candida spp. are among one of the leading causes of bloodstream infections and sepsis. Advances in antifungal therapy in the last decade have led to many more options in the treatment of fungal infections, yet increasing resistance and clinical failures are common, especially in the management of invasive candidiasis in the ICU. Prompt diagnosis of these infections and appropriate antifungal treatment are imperative for improving survival. Although reliable antifungal susceptibility testing is available to aid in the therapy of fungal infections, testing is not always recommended. This review addresses the epidemiology of Candida infections in the ICU, antifungal resistance, therapy, and the usefulness of antifungal susceptibility testing in the ICU setting.