In the fight against infectious diseases, scientists are digging into the family trees of viruses to predict which one might cause the next big pandemic, known as Disease X.
A new study involving scientists from the Universities of Edinburgh and Liverpool and Peking University in China has found 70 virus groups that pose the greatest risk, helping us get a step closer to figuring out Disease X.
Why virus families matter
Viruses that carry their genetic code as RNA, like the ones causing the common cold or COVID-19, are responsible for most epidemics or global pandemics.
By studying their family history, we can learn more about how they evolved and how likely they are to cause big outbreaks.
Tracking down Disease X
Researchers at the University of Edinburgh looked at the history of 743 different RNA viruses, including those that affect humans.
Their investigation encompassed all known species capable of infecting humans, aiming to discern patterns between strictly zoonotic viruses – those transmitted from animals to humans but not among humans – and human-transmissible variants.
Through meticulous analysis, the researchers uncovered a striking dichotomy between viruses capable of human transmission and their strictly zoonotic counterparts.
Human-transmissible viruses often diverge from strictly zoonotic viruses, with epidemic potential often emerging when closely related viruses within the same lineage can already spread among humans.
While acknowledging the persistent threat posed by strictly zoonotic viruses and the possibility of entirely novel pathogens, the study underscores a promising avenue for pandemic surveillance.
By prioritising viruses with ancestral ties to existing human pathogens with epidemic potential, researchers aim to streamline the daunting task of identifying Disease X amidst the vast array of RNA viruses.
A call for focus
Professor Mark Woolhouse, Professor of Infectious Disease Epidemiology at the University of Edinburgh, emphasises the significance of ancestry in epidemic dynamics.
He advocates for concentrating efforts on virus lineages with a propensity for human transmission, significantly narrowing the search for Disease X.
He said: “Viruses without the right ancestry don’t seem to cause epidemics. Out of potentially huge numbers of mammal and bird viruses in circulation, we should concentrate on the ones that are related to existing human viruses with epidemic potential. This research narrows the search for the next Disease X enormously.”
As the world remains vigilant against the threat of global pandemics, understanding the evolutionary lineage of viruses emerges as a crucial tool in the arsenal of public health preparedness.
