Growing Threat of Antifungal Resistance

Syllabus: GS2/ Health, GS3/ Science and Technology

Context

• A research on Candida auris demonstrates that resistance to antifungals can arise through gene mutation, gene duplication and compensatory mechanisms in the cell.

What are Fungal Infections?

• Fungal infections are diseases caused by pathogenic fungus that can damage the skin, nails, lungs, blood stream and other organs.
• Dermatophytes are fungi that are common causes of skin, nail and hair infection, while yeasts such as Candida auris can cause severe systemic infection.
• Fungal infections are particularly hazardous in immunocompromised individuals because they can become invasive and life-threatening.

Why is Candida auris a concern?

• Candida auris is a developing multidrug-resistant yeast that causes bloodstream and other invasive infections, notably in health care settings.
• It was first identified in Japan in 2009 and has since been reported in several nations.
• In India, more than 90% of the clinical isolates of C. auris tested were resistant to azole antifungals such as fluconazole, and many were also resistant to polyenes.

Why is Antifungal Resistance Increasing?

• Global Warming: Most fungi cannot normally survive well at the human body temperature, which limits their ability to infect humans.
  • Rising global temperatures favour heat-tolerant fungi that can gradually adapt to warmer conditions.
• Frequent or inappropriate use of antifungal medicines puts selection pressure on fungi, allowing resistant strains to survive and multiply.
• Limited Diagnostic Facilities: Many healthcare facilities lack adequate capacity to identify fungal species and test their drug susceptibility.
  • As a result, infections may be treated with ineffective medicines, allowing resistant fungi to persist.
• Limited Treatment Options: Unlike bacteria, fungi have fewer biological differences from human cells, making it difficult to develop drugs that selectively kill fungi without harming the patient.

The Eagle Effect

• The Eagle effect is the paradoxical phenomenon where some fungi, when exposed to a low concentration of an antifungal, survive or re-grow when exposed to a very high concentration.
• In C. auris, this can occur because high drug concentrations activate compensatory pathways such as increased chitin synthesis.
• Therefore, an increase in the amount of antifungal does not always ensure a larger therapeutic benefit.

What are the challenges? 

• Many healthcare facilities lack adequate fungal diagnostic and identification infrastructure.
• Conventional susceptibility testing may not fully capture unusual resistance mechanisms such as paradoxical growth.
• Advanced genomic testing to identify resistance-associated mutations can be expensive and difficult to deploy routinely.
• Limited availability of effective antifungal classes increases the risk of therapeutic failure.
• Weak surveillance can delay the identification of emerging resistant fungal strains.

Way Ahead

• Strengthen fungal surveillance: Establish integrated national surveillance systems for emerging and drug-resistant fungal pathogens.
• Improve diagnostics: Expand access to fungal culture, antifungal susceptibility testing and genomic methods, particularly in tertiary hospitals.
• One Health approach: Antifungal resistance should be studied across human, animal and environmental ecosystems, particularly in the context of climate change.

Source: TH