Behind the scenes at the World Health Organization, epidemiologists track a list of the most important infectious diseases to keep tabs on. The list is of utmost importance — particularly in an age where a global pandemic has already occurred. This is why in November, the WHO recruited 300 scientists to help identify the most infectious pathogens to update the list, which previously had not been revised since 2018.
Although the WHO's revised list has yet to be published, it is expected sometime in the first quarter of 2023. Right now, the organization's list of the current most infectious pathogens acts as a blueprint for it and other health organizations to prioritize research and development and public health actions. Here are nine of the most infectious diseases the WHO has identified to date:
- Nipah virus
- Crimean-Congo hemorrhagic fever
- Lassa fever
- Rift Valley fever
- Zika
- Ebola and Marburg
- Middle East respiratory syndrome (MERS) and severe acute respiratory syndrome (SARS)
- COVID-19
- Disease X (any unknown pathogen that could cause a future outbreak)
According to NPR, "The WHO says it does not rank diseases in any order of potential threat, but it acknowledges the possibility that an as-yet-unknown disease could cause a serious pandemic."
Of the list of top pathogens, the WHO notes, "This is not an exhaustive list, nor does it indicate the most likely causes of the next epidemic. WHO reviews and updates this list as needs arise, and methodologies change. Based on the priority diseases, WHO then works to develop R&D roadmaps for each one."