Coronavirus’s genetic fingerprints are used to rapidly map its spread

SEATTLE — Unprecedented data sharing and breakneck genetic sleuthing are charting the new coronavirus’s travels around the globe.

By cataloging tiny genetic tweaks to the virus, called 2019 novel coronavirus or 2019-nCoV, computational biologist Trevor Bedford at Fred Hutch, a cancer research center in Seattle, and his colleagues show the virus is spreading around Wuhan, China, and kicking off much smaller chains of transmission elsewhere.

That mapping was presented February 13 at the annual meeting of the American Association for the Advancement in Science and is being constantly updated by a wide collaboration of scientists at www.nextstrain.org.  Charting these genetic lineages will help scientists piece together what this virus might be capable of, and whether interventions are helping slow its spread, Bedford said (SN: 1/28/20).

Since the virus’s debut, scientists from around the world have been furiously exchanging data, including genetic details of viruses that have infected people. By February 12, the genetic makeup of over 100 virus samples had been shared by research groups around the world. Comparing those genomes allowed Bedford and colleagues to piece together a viral family tree. “We can chart this out on the map, then, because we know that this genome is connected to this genome by these mutations,” he said. “And we can learn about these transmission links.”

Researchers have found identifying mutations in the virus as it has moved around the globe — and none that suggests the virus is getting more virulent, Bedford said. For a spreading virus, mutations are expected. Viruses typically have “a very error-prone form of replication,” Bedford said. For instance, seasonal flu mutations occur once every 10 days and “we don’t worry about that suddenly becoming extra severe.”

The genetic mapping also suggests the new coronavirus is closely related to a bat coronavirus found in China in 2013. But the two strains would have diverged between 20 and 70 years ago, he said. “We don’t really know where it’s been since then.”