46 | New Scientist | 28 November 2020air travel means that few outbreaks can
be contained as local problems. A virus
can now travel across the world in less than
a day, giving medics and scientists little time
to react – hence the call for better surveillance
to act as an early-warning system.
“We absolutely need to understand
what viruses are circulating in animals,”
says Tracey Goldstein, a specialist in viral
surveillance at the University of California,
Davis. “We need to understand more about
the hosts and their behaviour and when they
might be shedding the viruses.”
At its most ambitious, such a surveillance
scheme would sample and sequence the
genomes of the viruses that live within all
wild and domestic animals that humans
could encounter. That’s a lot of animals, but
an even larger number of viruses. Nobody
knows for sure how many viruses such an
effort would need to find and analyse, but it
is probably more than 500,000. That is likely
to cost a few billion dollars and entail a
decade of trudging around caves, jungles
and forests looking for species and taking
samples of their urine, saliva and droppings.
Such a scheme was proposed in 2016.
The Global Virome Project is marketed as
“the beginning of the end of the pandemic
era”. Although it can boast some high-profile
supporters – former UK prime minister
David Cameron backed the idea in
June – it is yet to raise the necessary funds.
This project isn’t the only attempt at global
surveillance, and it isn’t the only initiative
to illustrate the scale of the undertaking.
A US government-funded programme called
PREDICT was launched in 2009 to provide
an early warning of pandemics, prompted
by the 2005 bird flu outbreak. PREDICT was
cancelled by the Trump administration
earlier this year (although it has since been
given a six-month reprieve to assist with the
covid-19 pandemic). Spending $207 million
in 60 countries and taking 164,000 samples
from wildlife, livestock and humans, it
discovered 949 novel viruses. In other words,
PREDICT only scratched the surface of an
estimated 10,000 potentially zoonotic
viruses in wild mammals. It found just one SAKC
HA
I^ LALIT/AP/SHUTTE
RSTO
CK“ Fate and biology combine to put the virus
in the wrong place at the wrong time”
1.6 million
Estimated number of undiscovered
viruses in birds and mammalsthat was possibly linked to deaths in
humans – the Bas-Congo virus – and it didn’t
spot the coronavirus that causes covid-19.
“We targeted the animals that we thought
had the highest potential to carry the most
viruses that could spill over,” says Goldstein,
one of the leaders of PREDICT. “That’s not
completely comprehensive, but you have to
start somewhere. And we targeted primarily
RNA viruses. Those are the ones that are less
stable and those are the ones that have
caused most of the pandemics in the past.”
Finding a virus in an animal is just the
start. The next step is to assess the potential
pandemic risk by seeing if it can infectResearchers in Thailand
don protective equipment
to catch bats in a hunt
for coronaviruses