The World Health Organization (WHO) has compiled its first-ever list of fungal “priority pathogens”. These are the fungal organisms that pose the greatest risk to human health worldwide.
In all, 19 fungi form the priority pathogens list (FPPL). One of the aims is to help to direct global health efforts to research into methods to tackle fungal pathogens, considering that many of the fungi and the diseases they causes represent unmet research and development areas in relation to public health importance.
Many fungal pathogens represent a major threat to public health and several are becoming increasingly common and resistant to treatment. This is in the context of there being only four classes of antifungal medicines commercially available. More concerningly, there are only a few candidates in the clinical pipeline.
People at greatest risk are those with underlying immune system related conditions, such as people with cancer, HIV/AIDS, organ transplants, chronic respiratory disease, and post-primary tuberculosis infection.
Critical group: Cryptococcus neoformans, Candida auris, Aspergillus fumigatus and Candida albicans.
High group: Nakaseomyces glabrata (Candida glabrata), Histoplasma spp., eumycetoma causative agents, Mucorales, Fusarium spp., Candida tropicalis and Candida parapsilosis.
Medium group: Scedosporium spp., Lomentospora prolificans, Coccidioides spp., Pichia kudriavzeveii (Candida krusei), Cryptococcus gattii, Talaromyces marneffei, Pneumocystis jirovecii and Paracoccidioides spp.
Different criteria were used to group the fungal species, including death rates, incident rates, distribution, preventability and resistance to medication.
It is also worrying that evidence indicates that the incidence and geographic range of fungal diseases are expanding worldwide. This is connected to global warming, coupled with an increase of international travel and trade. Climate change can alter the structure of fungal communities. These changes may favour fungi over other organisms, such as due to the acidification of soils that tends to inhibit certain micro-organisms and favour fungal growth up to certain pH values.
During the COVID-19 pandemic the incidence of invasive fungal infections increased; this included fungi that are becoming resistant to anti-fungal medications and which cause infections like candida oral and vaginal thrush.
It seems that awareness of fungal risks needs to emerge from the shadow of bacterial antimicrobial resistance and receive greater focus and attention from the medical and research community.
While the list is important for overall awareness, it needs to be interpreted and contextualized carefully. This is because some endemic pathogens could be of greater concern in regional or local contexts.
Going forwards, WHO recommends that governments strengthen laboratory capacity and surveillance; increase investments in research, development, and innovation; and enhance public health interventions for prevention and control.
