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Disease X: The World's Most Mysterious Lethal Disease

There has been an upsurge of new and emerging virus diseases. SARS and MERS form the latest pandemic diseases that were identified in recent years including COVID-19 that has made the World Health Organization (WHO), other national and international health institutions, and scientists, worried of potentially deadly diseases erupting, and killing more people in a shorter time.

The increased emergence of new viruses can be attributed to several factors, among them, the increased rate of human-to-wildlife contact, wild animal trade, consumption of infected bushmeat, and climate change.

The eruption of COVID-19 in late 2019 caught the world unprepared. In its wake, it infected millions of people, and killed close to two million people towards the end of 2020. A scary disease by all accounts, it fades in comparison to unknown diseases that are thought to be more lethal, and fast-spreading.

What is Disease 'X?'

In 2018, the World Health Organization (WHO) set up a priority list under the organization's Research and Development Blueprint to identify diseases which "pose the greatest public health risk due to their epidemic potential and/or whether there is no or insufficient countermeasures." The purpose of the organization prioritizing certain diseases is to ensure "efforts under WHO'S R&D are focused and productive."

The prioritized diseases are:

  • COVID-19
  • Crimean-Congo haemorrhagic fever
  • Ebola virus disease and Marburg virus disease
  • Lassa fever
  • MERS and SARS
  • Nipah and henipaviral diseases
  • Rift Valley fever
  • Zika
  • Disease 'X'

According to WHO, the list isn't complete, and doesn't provide the full picture of the most likely causes that might lead to another epidemic. Instead, "WHO reviews and updates this list as needs arises and methodologies change. Based on the priority diseases, WHO then works to develop R&D roadmaps for each one."

A couple of years after WHO prioritized diseases requiring its foremost attention, a strain of coronavirus family, initially nicknamed, novel coronavirus, emerged from China. The symptoms resembled that of pneumonia before the scientists were able to identify the disease. As a result, COVID-19 fitted the list of Disease 'X' which "represents the knowledge that a serious international epidemic could be caused by a pathogen currently unknown to cause human disease."

However, a more menacing yet-to-be-identified disease which scientists believe is as contagious as COVID-19, and as as lethal as Ebola virus disease with a fatality rate of between 50 and 90 percent is lurking somewhere.

The revelation of a potentially deadly disease infecting and killing more people in a shorter time comes after a woman in Congo exhibiting symptoms of the haemorrhagic fever didn't display any symptoms of the known diseases she's tested for. Is it possible the woman could become patient zero for Disease 'X?' It's still early to know but scientists are of the opinion their is a deadly disease lurking. What it is, when it can occur, or where it'll emerge from is not yet certain. Even so, scientists have a lead which can enable both global and regional health organizations combat it before it spirals out of control.

EcoHealth Alliance notes, "We know which species are most likely to be carrying Disease X. We know the viral families to which Disease 'X' is most likely to belong and, therefore, which known viruses are likely to be similar. Thanks to our hotspots map of global pandemic risks we know the parts of the world where Disease X is most likely to make the jump to people."

Why Are There Increased Cases of New Viruses?

An interesting question to ask is why the world is witnessing a surge in newly identified virus diseases? Why are they becoming so common nowadays?

The first virus disease, Yellow Fever, was discovered in 1901. Since then, scientists have been able to identify only 263 viruses that have the potential of infecting humans, that is, causing illness in people.

According to EcoHealth Alliance, there exists 1.67 million uknown viruses on earth. In essence, it means that scientists "know almost nothing about 99.6% percent of potential pandemic threats." They estimate between 631,000 and 827,000 of the unknown viruses are capable of infecting humans.

Adelaide Sarukhan, a scientific writer for Baralona Institute for Global Health states, "A rough estimate based on a study in bats suggests that at least 320,000 viruses can infect animals, and that all species of vertebrates together could host at least 3 million and a half different viruses. If we put together vertebrates, invertebrates, plants, lichens and algae, this number could rise to over 100 million. And this would be without counting the viruses that infect bacteria (bacteriophages)..."

The increased vulnerability of humans falling prey to emerging viruses is a result of humans "invading ecosystems where many animals (and their viruses) live and with which we did not have previous contact, and we are travelling faster and further," notes Sarukhan. CNN states, "Experts say the rising number of emerging viruses is largely the result of ecological destruction. As the natural habitats disappear, animals like rats, bats, and insects survive where large animals get wiped out. They're able to live alongside humans beings and are frequently suspected of being the vectors that can carry new diseases to humans."

Whether the world is prepared to deal with future emerging threats of this kind to reduce their severity is yet to be seen. If there is anything that COVID-19 has taught us is that virus diseases, or pathogens, in general, can become a global health disaster when the world is unprepared in dealing with them in their initial stage after being identified.

© 2021 Alianess Benny Njuguna