Shutterstock
As the sun shines for longer every day in the northern hemisphere, we can all breathe a sigh of relief – literally.
That’s because as we enter spring we are gradually leaving cold and flu season – the time at which the majority of these viruses are spread.
That doesn’t mean to say that you won’t get a cold in spring or summer (of course you might), only that it is less likely.
And that’s because the common cold, a kind of RNA virus, thrives in colder temperatures, buoyed by the fact that we huddle indoors in closer proximity, with windows less likely to be open and our immune systems naturally less effective.
Pexels
But did you know that our understanding of RNA viruses is relatively new? In fact, the oldest known RNA virus in humans was contracted by a woman in London around 250 years ago.
From this point RNA viruses in humans evolved considerably; now, this type of virus – so called because it is genetically formed of ribonucleic acid – and now, we’re closer to understanding how and why these viruses have evolved in humans over time.
That’s thanks to a new study from an international team of researchers, who reconstructed the RNA virus from the lung tissue of this first known sufferer of the common cold. Her tissue had been preserved in alcohol since her death in the 1700s, using tiny fragments to reconstruct her DNA and the RNA that affected her, as the team explain in their preprint paper, available on bioRxiv:
“Our extraction protocol uniquely enables the dual isolation of DNA and RNA from the same sample, providing a comprehensive view of the molecular history of museum specimens.”
Pexels
By doing this, the researchers were able to diagnose the conditions that caused her death all those years ago.
As well as suffering from the common cold (a now extinct RNA virus known as human rhinovirus A), she had various bacterial infections in her lungs, affecting her ability to respirate through her cold, through the interactions between the conditions:
“Our analyses show that the historical A genome represents an extinct lineage closely related to HRV A19 and suggests a dynamic turnover of A genotypes. Rhinovirus infections are typically limited to the upper respiratory tract but are known to infect the lower respiratory tract and cause severe disease when associated with bacterial co-infections. This clinical scenario is well recognized today but rarely described in 18th-century medical texts.”
This insight is fascinating as it is, but understanding and sequencing the RNA virus that contributed to this woman’s death tells scientists a lot about how human viruses have evolved over time – and how they may continue to evolved into the future.
And understanding is crucial, if we are to prevent and treat these viruses effectively.
If you enjoyed that story, check out what happened when a guy gave ChatGPT $100 to make as money as possible, and it turned out exactly how you would expect.