"Disease X represents the knowledge that a serious international epidemic could be caused by a pathogen currently unknown to cause human disease," WHO said in a statement late Monday.
‘Besides Disease X, Crimean-Congo hemorrhagic fever (CCHF); Ebola virus disease and Marburg virus disease; Lassa fever; Middle East respiratory syndrome coronavirus (MERS-CoV) and Severe Acute Respiratory Syndrome (SARS); Nipah and henipaviral diseases Rift Valley fever (RVF); and Zika have also been included in the priority diseases list.’
"Disease X" was listed in the 2018 annual review of R&D Blueprint, a list developed by the WHO to identify, prioritise and accelerate research and development for diseases that lack efficacious drugs and/or vaccines, and pose public health risk.
Thus, the new report "explicitly seeks to enable cross-cutting research and development preparedness that is also relevant for an unknown 'Disease X' as far as possible".
Besides Disease X, the seven other potential global disease threats each lacking an effective drug or vaccine includes Crimean-Congo hemorrhagic fever (CCHF); Ebola virus disease and Marburg virus disease; Lassa fever; Middle East Respiratory Syndrome (MERS-CoV)
and Severe Acute Respiratory Syndrome (SARS)
; Nipah and henipaviral diseases Rift Valley fever (RVF); and Zika.
These diseases pose major public health risks and further research and development is needed, including surveillance and diagnostics.
They should be watched carefully and considered again at the next annual review. Efforts in the interim to understand and mitigate them are encouraged, the statement said.
Outside the 2018 Blueprint, the WHO also mentioned dengue, yellow fever, HIV/AIDs, tuberculosis, malaria, influenza causing severe human disease, smallpox, cholera, leishmaniasis, West Nile Virus and plague, saying further research and development is needed to tackle these diseases.