The release of the priority list comes as WHO also revealed it has developed a special tool to identify diseases that pose a widespread health risk.
The most recent review took place in February, with experts agreeing the following diseases are the ones that most urgently require researchers' attention: Crimean-Congo haemorrhagic 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 virus. The committee consisted of leaders in virology, bacteriology and infectious diseases.
The organization at first discharged the rundown of organized diseases in December 2015. Each of these outbreaks have been hard to combat.More news: Zidane: Bale is a 'fundamental player' for Real Madrid
During the recent meeting which was held in Geneva, the World Health Organization added Disease X into their Blueprint Disease list as the 9 decease that may cause a worldwide outbreak. They statement said that research and development was underway to be prepared for disease X "as far as possible".
John-Arne Rottingen, chief executive of the Research Council of Norway and a scientific adviser to the World Health Organization committee says that the next big outbreak is going to be something that the scientists have not seen before. The systems would generate "countermeasures" to any of these illnesses as soon as they break out.
The disease could come about a number of ways, including as a result of biological warfare or as the result of the sudden spread of a virus similar to the "Spanish flu" which affected large parts of the world and is thought to have killed at least 40 million people in 1918-1919. The jumps from animals to humans happen as their ecosystems clash and the animals lose their habitats he said. These include Severe Fever with Thrombocytopenia Syndrome (SFTS), emergent non-polio enteroviruses including EV71, D68 and Chikungunya.
Code-named "Disease X", this mystery pathogen hasn't even been discovered yet, but the looming threat of its nearly certain inevitability has secured it a place on the WHO's "most dangerous" list: a catalogue of potential future epidemics for which countermeasures are insufficient - or don't exist at all.