Alarms Sound for Candida auris
The WHO included the yeast Candida auris in its group of pathogens with critical priority, and since 2009, it has raised alarm owing to the ease with which it grows in hospitals. In that setting, C auris is known for its high transmissibility, its ability to cause outbreaks, and the high mortality rate from disseminated infections.
“It has been a concern for the mycological community because it shows resistance to most antifungals used clinically, mainly azoles, but also for causing epidemic outbreaks,” emphasized Dr. Sánchez Paredes.
Its mode of transmission is not very clear, but it has been documented to be present on the skin and persist in hospital materials and furniture. It causes nosocomial infections in critically ill patients, such as those in intensive care, and those with cancer or who have received a transplant.
Risk factors for its development include renal insufficiency, hospital stays of more than 15 days, mechanical ventilation, central lines, use of parenteral nutrition, and presence of sepsis.
As for other mycoses, there are no precise studies reporting global incidence rates, but the trend indicates an increase in the detection of outbreaks in various countries lately — something that began to be visible during the COVID-19 pandemic.
In Mexico, Dr. Treviño Rangel and colleagues from Nuevo León reported the first case of candidemia caused by this agent. It occurred in May 2020 and involved a 58-year-old woman with a history of severe endometriosis and multiple complications in the gastrointestinal tract. The patient’s condition improved favorably thanks to antifungal therapy with caspofungin and liposomal amphotericin B.
However, 3 months after that episode, the group reported an outbreak of C. auris at the same hospital in 12 critically ill patients co-infected with SARS-CoV-2. All were on mechanical ventilation, had peripherally inserted central catheters and urinary catheters, and had a prolonged hospital stay (20-70 days). The mortality in patients with candidemia in this cohort was 83.3%.
Open Ending
As seen in some science fiction series, fungal infections in the region still have an open ending, and Global Action For Fungal Infections (GAFFI) has estimated that with better diagnostics and treatments, deaths caused by fungi could decrease to less than 750,000 per year worldwide.
But if everything continues as is, some aspects of what is to come may resemble the dystopia depicted in The Last of Us. No zombies, but emerging and reemerging fungi in a chaotic distribution, and resistant to all established treatments.
“The risk factors of patients and their immune status, combined with the behavior of mycoses, bring a complicated scenario. But therapeutic failure resulting from multidrug resistance to antifungals could make it catastrophic,” Dr. Sánchez Paredes summarized.
At the moment, there are only four families of drugs capable of counteracting fungal infections — and as mentioned, some are already scarce in Latin America’s hospital pharmacies.
“Historically, fungal infections have been given less importance than those caused by viruses or bacteria. Even in some developed countries, the true extent of morbidity and mortality they present is unknown. This results in less investment in the development of new antifungal molecules because knowledge is lacking about the incidence and prevalence of these diseases,” Dr. Treviño Rangel pointed out.
He added that the main limitation for the development of new drugs is economic. “Unfortunately, not many pharmaceutical companies are willing to invest in the development of new antifungals, and there are no government programs specifically promoting and supporting research into new therapeutic options against these neglected diseases,” he asserted.
Development of vaccines to prevent fungal infections faces the same barriers. Although, according to Dr. Treviño Rangel, the difficulties are compounded by the great similarity between fungal cells and human cells. This makes it possible for harmful cross-reactivity to occur. In addition, because most severe fungal infections occur in individuals with immunosuppression, a vaccine would need to trigger an adequate immune response despite this issue.
Meanwhile, fungi quietly continue to do what they do best: resist and survive. For millions of years, they have mutated and adapted to new environments. Some theories even blame them for the extinction of dinosaurs and the subsequent rise of mammals. They exist on the edge of life and death, decomposing and creating. There is consensus that at the moment, it does not seem feasible for them to generate a pandemic like the one due to SARS-CoV-2, given their transmission mechanism. But who is willing to rule out that this may not happen in the long or medium term?
Dr. Sánchez Paredes, Dr. Treviño Rangel, Dr. Messina, Dr. Santiso, Dr. Álvarez, and Dr. Segundo Zaragoza have declared no relevant financial conflicts of interest.
This story was translated from Medscape Spanish Edition using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.