It turns out scientists around the world are investigating this very question.
It’s likely the coronavirus that causes COVID-19, SARS-CoV-2, started in an animal before jumping to humans. But exactly how it all happened is still a kind of mystery.
That’s what I found out from my friend Michael Letko, a researcher at Washington State University who studies viruses and how they cross different species.
“We don’t have all the details sorted out for this one, but basically, we can assume it starts in one animal and somehow gets to us. That ‘somehow’ is the challenging part,” he said.
When we first learned about SARS-CoV-2, scientists swabbed and tested different animals in the wild and at markets to see if they could track down the virus.
Some of these “virus hunters” looked for the virus in pangolins, a mammal that has horny scales, long snout and sticky tongue for catching bugs.
Meanwhile, other scientists looked at an animal that has transmitted other kinds of coronaviruses: bats.
Bats live in really big groups. Hundreds to thousands of bats can all live together, which can create an environment where viruses can spread.
“There’s so many challenges that the chances of you ever finding a bat that has this exact coronavirus is like finding a needle in the haystack,” Letko said.
While people may not come into contact with bats very often, other animals do.
For instance, when scientists learned about a coronavirus called MERS they traced the virus back to camels. But it was actually bats that first passed the virus to the camels.
When scientists look at connections between different animal species, they can start to learn more about how viruses infect humans. They can start to piece together how the virus spreads. But it isn’t always an easy task.
Letko said sometimes tracking down a virus is about being at the right place at the right time and looking in the right animal. It can take a long time to find answers and sometimes we are left with unknowns.
“It can be super quick or it can be the virus hunt of the century,” Letko said.
While we are still learning about the source of SARS-CoV-2, we do know there are ways to help prevent it from spreading among humans who can get sick from the virus.
When you wear a proper face mask, practice social distancing and wash your hands, you help prevent the virus from spreading to you and those around you.
While we do our part to help prevent the virus from spreading, it’s also great to know that scientists like Letko are helping us learn more about viruses so that we can respond to, and maybe even prevent, future pandemics.
Who knows, maybe one day you will become a scientist who helps us learn more about where viruses come from, too.
Have you ever wondered what’s inside the Ask Dr. Universe e-newsletter? We keep it simple. The weekly question and answer. Click this link to subscribe.