The emergence of antifungal resistance to most classes of antifungal agents (azoles, echinocandins, pyrimidines, and polyenes) is an increasing global public health threat and is exacerbating the already high mortality and morbidity rates seen with fungal infections. Although existing antifungal drugs are still clinically useful, they are often associated with serious toxicities, and significant resource utilization due to long durations of therapy often requiring hospitalization for intravenous administration. Global access to the currently available antifungal agents is also unevenly distributed, as is access to effective and affordable diagnostics. Importantly, both therapies and diagnostic tests are frequently unavailable where disease burden is highest. New antifungal therapies, formulations, and diagnostic tools are therefore urgently needed for the effective prevention and control of fungal infections.
These issues are concerning so the WHO developed a Fungal Priority Pathogen List (FPPL) to inform and identify public health and R&D priorities and gaps globally.
The development of the list followed a multicriteria decision analysis (MCDA) approach. The prioritization process focused on fungal pathogens that can cause acute and subacute invasive and systemic fungal infections for which drug resistance or other treatment and management challenges exist. The pathogens included were ranked, then categorized into three priority groups (critical, high, and medium). The critical group includes Cryptococcus neoformans, Candida auris, Aspergillus fumigatus and Candida albicans. The high group includes Nakaseomyces glabrata (formerly Candida glabrata), Histoplasma spp., eumycetoma causative agents, Mucorales, Fusarium spp., Candida tropicalis and Candida parapsilosis. Finally, pathogens in the medium group are Scedosporium spp., Lomentospora prolificans, Coccidioides spp., Pichia kudriavzeveii (formerly Candida krusei), Cryptococcus gattii, Talaromyces marneffei, Pneumocystis jirovecii and Paracoccidioides spp.
Whilst regional variations and national contexts need to be taken into consideration when implementing the WHO FPPL to inform priority actions, three clear areas for action were identified: (1) strengthening laboratory capacity and surveillance; (2) sustainable investments in research, development, and innovation; and (3) public health interventions.