Labyrinth of Challenges that Surround the Identification of Candida auris and Shedding Light on the Enigma of Its Susceptibility Breakpoints?

In any given case, the identification of a new organism could potentially indicate it as an index case for that specific organism. There is a possibility that infections caused by the same organism may have occurred in the past but were misidentified as other similar species or underreported.[1,2] As a result, the identification methods, suggestive treatment plans, and their outcomes for it are not found. This has been the case for Candida auris for a long time (pyrexia of unknown origin cases, when the diagnosis is not confirmed and antibiotic treatment not working, can be suspected for C. auris infection). Previously, it was often misidentified as another species, sometimes considered colonization or contamination. Several times, due to the lack of feasible identification methods in every place, it was counted as a nonsignificant species.[3,4] In Table 1, we have listed the automated systems that misidentify C. auris as other organisms. This list provides information that C. auris was present previously but was not accurately identified in various automated yeast identification systems.Table 1: Misidentification of Candida auris in various automation systems[ 3 , 4 ]In the past 2–3 years, microbiologists and physicians have become aware that C. auris is an emerging infection. Specifically, it is reported in the critical care and intensive care unit of the hospital. However, none of them knew how to treat it. The guidelines issued by CLSI, EUCAST, and others regarding antimicrobial susceptibility breakpoints for bacterial and fungal organisms do not specify the susceptibility testing range, minimum inhibitory concentration (MIC), or breakpoints of sensitivity/resistance. Based on experience and several studies, C. auris can be treated pharmacodynamically using several antifungal drugs such as amphotericin B and liposomal amphotericin B. Their suggested MIC breakpoints, found in various literatures, are given in Table 2.[5-7]Table 2: Suggestive breakpoints for Candida auris on the base of several studies[ 5-7 ]Several case reports and outbreaks have been reported in the past. Early cases were reported in 2015 in France and Germany among European countries. Later, more cases began to be notified. Among all of Europe, Spain has reported the highest number of C. auris cases.[1] The reason for mentioning this is that cases were present, but due to the lack of resources and correct prompt diagnosis, they were not reported worldwide. Numerous reports are available that isolate C. auris, but they do not discuss the antifungal agents used to treat the infection.[8] Misidentification is a major challenge in low- and middle-income countries like ours, where automation for identification is only available in a few government setups. Many patients are receiving treatment as if for other Candida species. We appreciate the study conducted by Dbeibo et al., where they isolated C. auris in 5.5% (31 of 564) of the cases, along with a 9.7% mortality rate. They also made efforts to differentiate between colonization and infection. Their efforts have become the guidelines for countries where new cases and outbreaks will be reported.[1] Now, in areas where facilities for correct identification are not available, lessons must be taken from this letter. If any other Candida species are found either by conventional methods or automation, as given in Table 1 and the patient does not respond to treatment (as reported by the microbiologist), one should consider the possibility of C. auris misidentification. As no breakpoints or definitive treatments have been published, previous case reports can be followed to treat the patients. As C. auris is resistant to many antifungal drugs such as echinocandins, azoles/triazoles, and polyenes, treatment is required to prevent future outbreaks where the index case is diagnosed.[6] When any specific treatment guidelines are not available, prevention is the best tool to prevent an outbreak. C. auris is a multidrug-resistant organism, but its treatment breakpoints are not established. Majority of it are found in hospitalized patients as hospital-acquired infections.[9] As we know, hand hygiene and infection control practices are the most appropriate steps to prevent the outbreak of C. auris-type, hospital-acquired infection.[10] We hope that everyone will take note and exercise proper vigilance for the identification and treatment of C. auris. It is well-known that empirical treatment has a minor effect on the C. auris outbreak and infection, although along with effective infection control and prevention practice, it can give effective support during the outbreaks. They should take responsibility for reporting the case, along with the given treatment and outcomes, so that the health-care community can benefit from these insights. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.