One in five Candida auris bloodstream infections spread to other organs

Candidozyma auris — the yeast formerly named Candida auris — is one of the clearest examples of why the World Health Organization decided fungi needed their own threat list. It is an emerging, often multidrug-resistant organism associated with hospital outbreaks worldwide, able to colonise both patients and healthcare environments, and since its identification in Japan in 2009 it has been reported on every continent except Antarctica [s1].

What has been poorly characterised is what happens after it enters the bloodstream. A new study in Emerging Infectious Diseases sets out to describe that — the pattern of metastatic infection, who is at risk, and what it costs.

The cohort

Researchers conducted a retrospective study at Hospital Universitari i Politècnic La Fe, a 900-bed tertiary institution in Valencia, Spain, covering May 2016 to December 2024 [s1]. The hospital's experience with the organism is itself a case study: C. auris was first detected there in May 2016 during an outbreak and has remained endemic since, affecting both intensive care and non-ICU patients [s1].

Over that period the team identified 108 adult patients with C. auris candidemia and reviewed their records for evidence that the infection had seeded a distant, anatomically separate site [s1].

One in five spread

Of the 108 patients, 24 — 22.2 percent — experienced metastatic infections [s1]. Endocarditis, infection of the heart's inner lining, was the most frequent, at 7.4 percent, followed by osteoarticular infection, meningitis and hepatosplenic infection at 3.7 percent each [s1].

That rate sits within, but toward the lower-middle of, the range reported for candidemia generally. Depending on the underlying conditions and the screening protocols used, between 4 and 50 percent of candidemia cases develop metastatic involvement, and the few prior C. auris cohorts that examined the question reported secondary organ involvement in 7.7 to 27 percent — usually without specifying the spectrum of complications, their predictors or their outcomes [s1]. This study's contribution is to supply exactly those details.

What raised the risk, and what it cost

In a multivariable Fine–Gray regression, one factor stood out: having a cardiac device or prosthetic valve was independently associated with metastatic infection, with a subdistribution hazard ratio of 2.89 (95% CI 1.21–6.91), although the association was attenuated in a sensitivity analysis restricted to patients who had undergone echocardiography [s1].

Persistent candidemia — the organism recovered from a blood culture on or after day five — carried a higher but non-significant risk in a day-5 landmark analysis (subdistribution hazard ratio 2.67, 95% CI 0.86–8.32) [s1].

The consequence was measured in deaths. Metastatic infection was associated with increased mortality in time-dependent analyses at 60 days (adjusted hazard ratio 2.21, 95% CI 1.04–4.67) and at 90 days (adjusted hazard ratio 2.26, 95% CI 1.09–4.67) [s1]. In plain terms, when the infection spread, the risk of dying roughly doubled.

Why it matters

Invasive candidiasis is already a serious bloodstream threat, accounting for between 15 and 30 percent of infections in intensive care units, with mortality of 30 to 60 percent in most series [s1]. C. auris adds drug resistance and a tendency to spread within hospitals to that baseline.

The study's practical conclusion is narrow and actionable: its findings support echocardiography in patients with intracardiac devices, because that is the group in which the dangerous complication — endocarditis — concentrated [s1]. It is the kind of specific, low-cost recommendation that an emerging-pathogen series can produce when it tracks outcomes rather than just counting cases.

WHO published its first fungal priority pathogens list in 2022, ranking fungal threats into critical, high and medium categories primarily by their public health impact and the risk of emerging antifungal resistance [s2]. This cohort is a reminder of why that framing matters: the burden is not only in the bloodstream infection itself, but in where it travels afterwards.

What the study cannot tell you

This is a single-centre, retrospective study at a hospital where C. auris is endemic, which limits how far the 22 percent figure generalises to settings with different patient mixes or screening habits [s1]. The device association weakened when restricted to echocardiographed patients, hinting at detection effects, and the confidence intervals are wide. It describes a pattern and its outcomes; it does not establish that any single intervention would change them.

What to watch

Whether routine echocardiography in device-carrying patients with C. auris candidemia catches endocarditis earlier, and whether larger multicentre cohorts confirm the doubling of mortality seen here [s1].

This article is informational and is not medical advice.