Nosocomial and Emerging Fungal Infections

Nosocomial and emerging fungal infections are mycoses tied to the healthcare environment and to organisms that are newly recognised, spreading, or acquiring resistance. They include healthcare-associated invasive infections, aggressive moulds such as the agents of mucormycosis, and emerging multidrug-resistant pathogens such as Candida auris. As medicine sustains ever more vulnerable patients, this overlapping category has grown in importance across the depth-and-distribution scheme.

Definition

Fungal infections that arise in association with healthcare delivery (nosocomial mycoses) and fungal pathogens that are newly recognised, increasing, geographically expanding, or developing drug resistance (emerging mycoses); the two categories overlap because many emerging fungi spread within healthcare settings.

Scope

The topic covers fungal infections acquired in or amplified by the healthcare setting and the broader phenomenon of emerging mycoses — newly described species, expanding geographic ranges, outbreaks, and antifungal resistance — with mucormycosis and Candida auris as illustrative examples. It is a reference overview and does not give individualised diagnostic or treatment advice.

Key concepts

• Healthcare-associated (nosocomial) acquisition
• Emerging and newly recognised fungal pathogens
• Antifungal resistance
• Mucormycosis and angioinvasive moulds
• Candida auris and multidrug resistance
• Outbreaks and environmental sources in healthcare
• Changing epidemiology with expanding at-risk populations

Mechanisms

Two forces drive this category. First, the healthcare environment exposes highly vulnerable patients — through devices, breached barriers, contaminated materials, and immunosuppression — to fungi that can cause invasive disease, and some fungi can persist on surfaces and spread between patients. Second, fungal pathogens themselves change: new species are recognised, known organisms expand their range or cause outbreaks, and resistance to antifungal agents emerges (Benedict, 2017). Mucormycosis exemplifies an aggressive, angioinvasive mould infection seen especially in immunocompromised and metabolically deranged hosts (Cornely, 2019), while Candida auris exemplifies an emerging, often multidrug-resistant yeast that spreads in healthcare settings (Lockhart, 2017). Because these infections are frequently deep and disseminated yet ubiquitous in origin, they cut across the depth-and-distribution framework rather than occupying a single tier.

Clinical relevance

This category is increasingly central to infection prevention and to the care of immunocompromised and critically ill patients, because emerging and resistant fungi can be difficult to detect and to treat and can cause outbreaks. The entry summarises the concepts and microbiology for reference and is not a basis for diagnosing or managing any individual patient.

Epidemiology

The burden of nosocomial and emerging mycoses has risen alongside the growth of immunocompromised and critically ill populations, advances in intensive care, and the spread of antifungal-resistant organisms; reports document new outbreaks, geographic expansion, and the rapid international emergence of Candida auris, set against an already large global burden of serious fungal disease (Benedict, 2017; Bongomin, 2017; Lockhart, 2017).

History

Attention to nosocomial fungal infection grew through the late twentieth century with transplantation and intensive care, and the twenty-first century has been marked by striking examples of emergence — including the near-simultaneous recognition of multidrug-resistant Candida auris on several continents (Lockhart, 2017) and growing concern over mucormycosis and antifungal resistance (Cornely, 2019; Benedict, 2017).

Seminal works

• cornely-2019
• lockhart-2016
• benedict-2017

Frequently asked questions

What is an emerging fungal infection?

It is an infection caused by a fungus that is newly recognised, increasing in frequency, expanding into new regions, causing outbreaks, or developing resistance to antifungal drugs — Candida auris is a prominent recent example.

Why do nosocomial and emerging fungal infections overlap?

Many emerging fungi spread within or are amplified by healthcare settings, where vulnerable patients, invasive devices, and selection pressure from antifungal use bring the two categories together.