Disease X: A new pandemic in the offing?

disease X What is Disease X? (Image: Sandhya Raghavan)

Apologies at the outset for the scaremongering headline. The doctor who uncovered the Ebola virus disease in 1976 may have just the bad news to begin the year with. Professor Jean-Jacques Muyembe Tamfum from Congo is now predicting a disease in the offing that could be a “threat to humanity” – Disease X. That’s right. A disease so deadly and urgent that it had to be hurriedly named with just a letter? And sci-fi culture tells us that anything nicknamed “X” is bad news.

Ok, enough scaremongering. Let’s get a sense of what it is all about and whether it will dampen our euphoria about COVID vaccines.

What is Disease X?

Disease X is a hypothetical disease. It figures among the top 10 priority diseases listed by the World Health Organisation.

It was recognised in 2018 as a “serious international epidemic could be caused by a pathogen currently unknown to cause human disease.”

According to WHO, “Disease X represents the knowledge that a serious international epidemic could be caused by a pathogen currently unknown to cause human disease.”

Here are some stunning facts about it.

Disease X is a hypothetical disease

This means that there’s no existing disease named Disease X. It is rather, a disease that could come into existence, given the present environmental circumstances.

Pathogen X may cause it

Like the hypothetical disease, the pathogen responsible for Disease X is also hypothetical. It is a pathogen, previously unknown to cause human disease, possessing the potential to cause epidemic or pandemic.

Pathogen X could be any but not limited to viruses, bacteria, fungi, parasites, or prions.

COVID-19 was the first Disease X

The coronavirus took the world by surprise because previously, it was unknown to mankind. Ever since the virus started first infecting people in Wuhan, China, scientists have speculated whether COVID-19 fits the bill for the hypothetical disease. Here’s an excerpt from a January 2020 article in The Telegraph.

For the last two years health authorities around the world have been on high alert for the emergence of disease X – a novel pathogen for which there is no treatment or vaccine.  But could a mysterious pneumonia circulating in central China be the latest candidate?

Anne Gulland, The Telegraph

COVID-19 may not the last

In a recent interview with CNN, Professor Tamfum warned of more diseases to come out of the woodwork in the years to come: “We are now in a world where new pathogens will come out.”

More pandemics may appear with emerging pathogens that may take advantage of the global conditions.

A probable one has already appeared in the Congo

Alarms have gone off recently after doctors diagnosed a woman in the Congo with haemorrhagic fever. She has tested negative for several diseases. Researchers are afraid that she could be patient zero for a new kind of illness, which has 50-90% fatality rate of Ebola.

Emerging pathogens can catch the world off guard as SARS-CoV-2 did. To have foreknowledge about such diseases can help governments and global agencies save lives by deploying countermeasures in time.


  1. Disease X and other unknowns

  2. The Next Pandemic: Prepare for “Disease X”