19 fungal pathogens and groups on the WHO priority list

On 25 October 2022 the World Health Organization published the report WHO fungal priority pathogens list to guide research, development and public health action. It was the first such list in the organisation's history: a catalogue of 19 fungi identified as the greatest threat to public health, arranged in three priority groups — critical, high and medium.

The list is not a ranking by frequency or by mortality. It was produced by multicriteria decision analysis, in which experts scored each pathogen against a set of criteria: mortality, the availability and effectiveness of treatment, drug resistance, access to diagnostics, distribution and gaps in knowledge. A species can therefore rank highly because the tools to deal with it are missing, not because it causes the most cases.

The purpose of the document is organisational. The equivalent bacterial list from 2017 steered research funding towards new antibiotics — the fungal version is meant to do the same for antifungal drugs, diagnostic tests and surveillance systems. Its starting point is the observation that there are only a few classes of antifungal drug, few new molecules, and rising resistance — including in Candida auris, which appeared in hospitals on several continents almost simultaneously.

The number 19 describes the state of knowledge and priorities in 2022, not a fixed property of the world. WHO has said the list will be reviewed periodically, so a later edition may cover different species or move them between groups. When citing it, give the year and the version of the document — otherwise the number takes on a life of its own, detached from the method that produced it.

How to read the three priority levels

WHO divided the 19 entries into four critical, seven high and eight medium priorities. Its multicriteria analysis included mortality, drug resistance, access to diagnosis and treatment, incidence and research gaps. A higher position does not automatically mean more cases in every country.

“Nineteen species” is an imprecise shorthand. Some entries represent a species complex or a broader taxon, so the title now refers to pathogens and groups. The list is a tool for research and public-health priority setting, not a diagnostic atlas or an individual-patient prognosis.