Skip to main content

ALERT: KPBS 89.5FM is undergoing scheduled upgrade work which may result in a temporary signal outage. Click here to listen on our radio stream.

LATEST UPDATES: Tracking COVID-19 | Vaccines | Racial Justice

VIDEO: Virus Hunters Seek To Solve The Mystery Of Coronavirus Origins

Photo caption:

Photo by NPR/YouTube

VIDEO: Virus Hunters Seek To Solve The Mystery Of Coronavirus Origins

Scientists have learned a great deal about how the novel coronavirus spreads. But one of the mysteries they're still trying to untangle is where the virus, known as SARS-CoV-2, came from in the first place. Scientific evidence points overwhelmingly to wildlife — and to bats as the most likely origin point.

Bats are critically important for pollinating flowers and dispersing seeds. They catch bugs, the same ones that bite us and eat some of our crops. But bats also harbor some of the toughest known zoonotic diseases — those caused by germs that spread between animals and people.

The rabies virus, the Marburg virus, the Hendra and Nipah viruses all find a natural reservoir in bats, meaning those viruses can live in bats without harming them. The Ebola outbreak in West Africa was traced to a bat colony. The SARS virus originates in bats, along with other coronaviruses. And now, SARS-CoV-2 is linked to bats too. The virus has a 96% genetic similarity to coronavirus samples previously found in bats.

Globally, zoonotic diseases have been on the rise for decades. The CDC estimates that six out of ten infectious diseases in people come from animals. Increased human interactions with animals through land development that destroys habitat, agricultural practices and livestock and wildlife trade have created a perfect storm for emerging diseases to appear throughout the world, pathogens both previously known and completely novel.

There is not enough genetic evidence to know how precisely this particular coronavirus transmitted from animals (likely bats) to humans, and whether an intermediate animal was involved in the chain of transmission. Further genetic testing and evidence is needed to fully know where this coronavirus came from. The work of virus hunting — of tracking an outbreak to its origin point — can take years. The 2003 outbreak of SARS, for instance, took a decade of detective work, sampling the feces, urine, or blood of thousands of horseshoe bats across China until a match was found.

Copyright 2020 NPR. To see more, visit


San Diego News Now podcast branding

San Diego news; when you want it, where you want it. Get local stories on politics, education, health, environment, the border and more. New episodes are ready weekday mornings. Hosted by Anica Colbert and produced by KPBS, San Diego and the Imperial County's NPR and PBS station.

  • Need help keeping up with the news that matters most? Get the day's top news — ranging from local to international — straight to your inbox each weekday morning.

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Curious San Diego banner

Want more KPBS news?
Find us on Twitter and Facebook, or sign up for our newsletters.

To view PDF documents, Download Acrobat Reader.