48 | New Scientist | 28 November 2020
Understanding this transmission cycle
could allow scientists to better predict
outbreaks, from studying weather cycles
perhaps, or checking on viral levels in the
bats. It also suggests a possible way to
stop spillover events from happening.
“A postdoc in my lab a few years ago
suggested we set up mango juice stands
for the bats and I remember laughing,”
says Plowright. “But we’ve come to realise
that’s the killer experiment. We’re starting to
build up a nice evidence base that replanting
winter-flowering trees could stop spillover.”
A similar approach is being used to stop
the Nipah virus being passed from bats
to humans in South-East Asia. The virus
causes flu-like symptoms and brain
inflammation and is often fatal, but its
spread can be curtailed by using nets to
prevent bats accessing collection pots for
date palm sap, a popular drink in the region.Pandemic prediction
The ecosystem approach could combat
viral threats identified elsewhere too,
but it requires serious investment to
understand complex ecological scenarios,
viral dynamics and the interplay of wild
and domestic species. “There needs to be a
push to galvanise activities in a coordinated,
globally funded way,” says Barbara Han
at the Cary Institute of Ecosystem Studies
in New York. “In order to do pandemic
prediction or prevention with any level
of accuracy, you have to have a way of
assessing the who, what, where, whenand why of spillover. And ecology is really
critical for getting at all of those areas.”
The research needed to fill the gaps
in knowledge sounds old-fashioned in
an age of genome sequencing. It comprises
basic questions related to things like social
structures and the interactions of animal
groups, their metabolism, lifespan and how
many times a year they have offspring.
“These things might seem a bit removed
from our goal of being able to predict
pandemics, but if you don’t know what
the animals are doing, then you’re not going
to have a chance of being able to make
predictions that are useful,” says Han.
Not everyone agrees. Colin Carlson,
a biologist at Georgetown University in
Washington DC, says the idea that basic
ecological studies can prevent pandemics
is an example of the unhelpful “covidisation”
of research. The risk, he says, is that attention
and funds get diverted away from proven
methods of fighting infections and
protecting public health. Hype over the
importance of viral surveillance means
“you have a bunch of wildlife biologists
essentially at the forefront of global efforts
to prevent the next pandemic”.
A similarly damning argument was
made in an article in Nature in 2018 by
three leading biologists, who argued that
efforts such as PREDICT and the Global
Virome Project were of little practical value
and that “making promises about disease
prevention and control that cannot be
kept will only further undermine trust”.
Money should be spent instead on boostinghealth capacity in developing countries,
to spot the early signs of infection in
people, they argued.
But Jonathan Epstein, a disease ecologist
with the EcoHealth Alliance, a conservation
and public health organisation that was
part of the PREDICT programme, insists
that viral surveillance offers a way to slash
the risk of spillover events – even if it can’t
always stop them. Changing human
behaviour to keep people away from the
sources of zoonotic viruses in the first place
is key, he says, using methods such as tighter
controls on live animal markets.
“You can certainly understand what the
major activities are that promote spillover
and work to reduce the risk there,” he says.
“We have to try to reduce risks but at the
same time be ready to respond when an
outbreak does happen.”
Most of the world got that response
wrong this time around – too slow, too
little and too late. We didn’t heed earlier
warnings. This is a planet of viruses, and
we need to take the fight to them. ❚David Adam is a science writer
based in Hertford, UK. His most
recent book is The Genius Within949
Novel viruses discovered by the
PREDICT surveillance programme
Cost of the Global Virome Project
surveillance programme
$1.2 billion
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