The novel coronavirus has sickened over 80,000 people worldwide and killed at least 2,700, across 35 countries, leading one expert to say that it fits the criteria for “Disease X,” a designated placeholder on the World Health Organization’s (WHO) list of illnesses that have potential to reach international epidemic levels.

AUSTRIA, CROATIA CONFIRM FIRST CORONAVIRUS CASES

“Disease X is a term that was coined by WHO,” Marion Koopmans, a member of WHO’s emergency committee, and head of viroscience at Erasmus University Medical Center in Rotterdam, told Fox News. “After the Ebola crisis in West Africa, they did an in-depth evaluation on what went wrong, and the so-called R&D blueprint for emerging disease was developed.”

“Disease X” was added to WHO’s “Prioritizing diseases for research and development in emergency contexts” list of illnesses that includes Crimean-Congo hemorrhagic fever (CCHF), Ebola and Marburg virus disease, Lassa Fever, MERS, SARS, Nipah and henipaviral diseases, Rift Valley fever and Zika.

“There is a number of diseases on that list that we know, but also ‘Disease X,'” she told Fox News. “That is meant to alert the world to think about how to prepare for these diseases.”

IRAN'S CORONAVIRUS TASK FORCE HEAD CONTRACTS ILLNESS AS COUNTRY'S DEATH TOLL HITS 15

Under its definition, the health agency noted that “Disease X represents the knowledge that a serious international epidemic could be caused by a pathogen currently unknown to cause human disease, and so the R&D Blueprint explicitly seeks to enable cross-cutting R&D preparedness that is also relevant for an unknown ‘Disease X’ as far as possible.”

COVID-19, as it’s been named by WHO, “fits the Disease X category,” Koopmans wrote in the journal Cell last week.

According to Koopmans, it’s the first time a disease fits the criteria for “Disease X” since the blueprint was created in 2016.

Koopmans said the blueprint helps the agency think ahead to what possible threats may be looming so that it can better prepare to handle a widespread pandemic or outbreak. It also helps the agency prepare for funding needs and ways to fast-track vaccine development.

And while the agency declined to label the COVID-19 outbreak a pandemic on Monday, Koopmans said that it has little relevance as to whether it would qualify as “Disease X.”

“Pandemic simply means there is global widespread circulation,” she said. “The blueprint diseases can also be a disease with regional major impact.”

SIGN UP FOR THE FOX HEALTH NEWSLETTER

The outbreak has seen a number of unprecedented shutdowns and quarantines across the globe, with China first cutting off Wuhan, the virus epicenter, in an effort to stop the spread. Elsewhere, those returning from coronavirus-hit regions have been under 14-day quarantine periods while airlines have suspended routes to the disease hotspots.

WHO chief Tedros Adhanom Ghebreyesus said the past few weeks have demonstrated “just how quickly a new virus can spread around the world and cause widespread fear and disruption.”

Still, as new countries report cases of coronavirus, experts caution that not every case may stem from China.

CLICK HERE TO GET THE FOX NEWS APP

“Many different countries around the world may be sources of COVID-19 infections,” Mark Woolhouse, a professor of infectious disease epidemiology at the University of Edinburgh, told The Associated Press. “This makes it much harder for any one country to detect and contain.”