Systemic fungal infections: why speed, diagnosis and stewardship matter
Systemic fungal infections — including aspergillosis, candidiasis, cryptococcosis, mucormycosis and pneumocystis pneumonia — are medical emergencies. When diagnosis or treatment is delayed, mortality rises sharply. This comprehensive review brings together current understanding of how these infections arise, why they are so difficult to diagnose, and what is needed to improve outcomes.
Why fungal infections are often missed
Unlike many bacterial infections, systemic fungal infections can be hard to confirm quickly. Fungal organisms are often present in low numbers, may be released intermittently into the bloodstream, and can be difficult to grow in standard cultures. As a result, no single test is usually sufficient, and clinicians often need a combination of imaging, cultures, antigen tests, molecular tests (PCR), and histopathology.
Because delay can be fatal, antifungal treatment is frequently started on clinical suspicion alone — especially in critically ill or immunocompromised patients. The paper emphasises that this approach is often necessary, but it must be paired with a clear diagnostic strategy.
Antifungal stewardship: knowing when to stop
A central message of the paper is that diagnostic tests are just as important for stopping treatment as for starting it. Antifungal drugs can be toxic, interact with many other medicines, and drive antifungal resistance if used unnecessarily.
The authors stress that:
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Diagnostic results should be actively reviewed
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Antifungal therapy should be stopped or stepped down if infection is not supported by evidence
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This approach protects patients and preserves antifungal effectiveness
Antifungal resistance is a growing threat
Antifungal resistance is no longer rare. The review highlights:
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Azole resistance in Aspergillus, including cryptic species
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Rising resistance in several Candida species
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The global spread of multidrug-resistant Candida auris
Because of this, the authors recommend that all clinically relevant fungal isolates are identified to species level and tested for antifungal susceptibility wherever possible. Making assumptions about drug sensitivity is increasingly unsafe.
Aspergillosis: a broad spectrum of disease
The paper clearly outlines the many forms of aspergillosis, ranging from:
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Allergic disease (such as allergic bronchopulmonary aspergillosis)
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Chronic pulmonary aspergillosis, often in people with underlying lung damage
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Subacute and acute invasive disease, particularly in immunocompromised or critically ill patients
Importantly, the review notes that aspergillosis is not limited to severely immunocompromised people. Chronic and subacute forms often occur in individuals with structural lung disease who are otherwise immunocompetent.
Climate change and emerging fungal risks
One of the most forward-looking sections of the paper addresses how climate change and natural disasters are altering fungal disease patterns. Rising environmental temperatures, flooding, storms and environmental disruption are:
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Increasing exposure to environmental fungi
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Enabling fungi to adapt to higher temperatures
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Contributing to outbreaks after natural disasters and trauma
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Expanding fungal diseases into new geographic regions
The authors argue that fungal infections must be considered part of future public health and healthcare resilience planning.
Key take-home messages
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Systemic fungal infections are time-critical medical emergencies
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Diagnosis usually requires multiple tests, not a single result
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Early antifungal treatment is often necessary — but must be reviewed
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Diagnostics are essential for safe antifungal stewardship
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Antifungal resistance is a real and growing problem
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Climate change is reshaping fungal epidemiology and risk
Free access to the full article
Elsevier has provided free access to the full paper for a limited time (no registration required):
👉 https://authors.elsevier.com/a/1mZqR4qdNoJLH2
🗓️ Available until 28 March 2026
This article is recommended reading for patients wanting a deeper understanding of fungal disease, as well as clinicians, microbiology teams, and healthcare planners.
