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.”
