A physician has shed light on “disease X,” a term coined by the World Health Organization (WHO) to describe a potential future global pandemic threat. This hypothetical pathogen is considered to be an unforeseen menace potentially waiting to emerge.

In a TikTok video, NHS doctor Suraj Kukadia elaborated on the concept to his audience of over 300,000 followers. He asked, “Have you ever heard of disease X?” He described it as a WHO term that serves as a metaphorical question mark on the world’s health landscape, representing mysterious infectious diseases that may be lurking nearby.

First introduced in 2018, the designation aims to motivate global efforts toward pandemic preparedness. The idea is that anticipating the emergence of an unknown infectious disease could lead to a swifter and more efficient public health response.

Amesh Adalja, MD, a prominent figure at the Johns Hopkins Center for Health Security, provided further insights on the Johns Hopkins website.

It was thought that planning for the arrival of an unknown infectious disease could mean a quicker, more effective public health response.

Amesh Adalja, MD, a senior scholar at the Johns Hopkins Centre for Health Security, explained more on the John Hopkins website.

The infectious disease physician said: “With disease X, we’re preparing for an unknown unknown. Disease X is a placeholder concept that refers to a pandemic pathogen that has not yet been characterised.

“Its purpose is to encourage proactive thinking about pathogens that could cause a pandemic. It represents a way to push people’s thinking forward so that they’re not wedded to lists of prior pandemic pathogens, like influenza.”

He added that it’s more likely to be a virus and one that can spread easily. “There are definitely characteristics that would be likely – not every pathogen can cause a pandemic,” Dr Adalja said.

“In general, a few things need to be present. One, it’s likely to be spread through respiration, because that’s more efficient for a pathogen.

“People talking, laughing, coughing, sneezing – all of that is very hard for public health to intervene on, as we saw with COVID-19. It’s likely to be a virus, not bacteria or fungus.

“It’s likely to be something that could spill over from an animal species into a human. Or it could be a human pathogen that develops new characteristics or changes its genetics in such a way that makes it more conducive to causing a pandemic.”

Speaking last year, Dr Adalja added that although we are “more prepared” now than we were ahead of the COVID-19 pandemic, we are not “fully prepared”.