Ten killer viruses that pose the most "urgent" threat to humanity have been revealed by concerned experts. The World Health Organization has released its annual list of lethal pathogens that research should be fast-tracked for. Ebola and Zika, which both have caused brutal pandemics in the past four years, were named amid fears they could strike again. For the first time ever, 'Disease X' - representing a pathogen currently unknown to scientists - was mentioned by the WHO. The list, published this week, comes amid mounting fears of a global pandemic, with experts concerned about the flu season that rocked the world. Dr. Tedros Adhanom, director general of the WHO, warned earlier this week humanity is 'vulnerable' to an outbreak that could kill millions. Announcing the list of "prioritized diseases", a statement on the WHO's website read: "The order of diseases on this list does not denote any ranking of priority. This is not an exhaustive list, nor does it indicate the most likely causes of the next epidemic." Crimean Congo hemorrhagic fever, which kills 40 per cent of those it strikes and was recently spotted in Uganda, made its way onto the list. Officials are also concerned about Marburg virus, considered to be one of the most deadly pathogens in existence. It also rocked the African nation in November. The other five lethal diseases mentioned on the list of needing urgent action include: Lassa fever, MERS, SARS, Nipah virus and Rift Valley fever.
