- Researchers sequenced a genome from a measles strain from 1912 to help determine the origin of this disease
- Working with the genomes of RNA viruses remains challenging, but could help us understand where Covid-19 came from
- It's difficult to understand how pathogens jump from animals to humans, but genome sequencing can help
There is still a lot to unpack about SARS-CoV-2, the novel coronavirus that emerged in 2019, and now some researchers are looking at the history of existing diseases to help answer their questions.
When an international group of researchers tried to find out when measles first came into existence, they discovered that it could be linked to the emergence of large cities, according to a news release.
Measles strain from 1912 used
The research team traced back measles by sequencing a genome from a measle strain from 1912 and worked backwards to see exactly when measles emerged.
Their research concluded that the virus likely emerged around the 6th century BCE. The team's findings were published in the journal Science.
How could this research answer questions about Covid-19?
Besides the above findings, evolutionary experts from the University of Sydney and University of Melbourne also published an article that suggested that this kind of research could be used to help us understand more about when exactly SARS-CoV-2 and other zoonotic diseases jumped from animals to humans, and when the virus started to spread among humans.
This type of research remains tricky, as obtaining genomic data from RNA viruses such as the measles virus can be a challenge as it degrades rapidly in the environment, according to Professor Simon Ho from the School of Life and Environmental Sciences.
"It's very difficult to pinpoint exactly when and where pathogens such as viruses and bacteria jump into humans. Sometimes these jumps happen and they fizzle out. But sometimes they take hold and spread across the globe,” Professor Ho stated in the news release.
"For any particular pathogen, the timing of the jump must have occurred between two time points: when it split from its nearest known relative and when we look at the pathogen in humans and trace the lineages back to the common ancestor," he said.
What do we know about Covid-19 so far?
Although we know that SARS-CoV-2 is a coronavirus that likely originated from bats, many scientists are still trying to understand exactly when this happened.
Professor Ho states that the SARS-CoV-2 virus’ closest relative is another coronavirus from a horseshoe bat that was discovered about 40 years ago, but that the transmission to humans happened much more recently.
"Had the coronavirus jumped from its animal host to a human much earlier than November or December last year, it probably would have been detected," he said.
According to Professor Ho, the chance of a virus jumping between species will increase with the level of contact, especially where our civilisation is encroaching into the habitat of wild animals more and more, such as at zoos.
But he also states that more work needs to be done if we fully want to understand the role of viruses and the way they are distributed in wildlife.
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