The Economist 04Apr2020

70 Science & technology The EconomistApril 4th 2020

2 are less likely than adults to present the

symptoms of covid-19, and rarely suffer se-

vere disease. It remains unclear, though, to

what degree they are being infected “silent-

ly”, and are thus able to pass the infection

on to others around them while apparently

remaining healthy themselves. Antibody

tests will reveal a fuller picture.

Antibody tests will no doubt also be in

demand from members of the public want-

ing to know their immune status—for their

peace of mind if nothing else. This might

be cause for conflict. Even when they are

cleared for general use it will take time for

manufacturers to ramp up the production

of tests, and those working in health care

and one or two other important areas, like

teaching, policing and delivering groceries

to stores and markets, will surely be at the

head of the queue to be tested. It is there-

fore hardly surprising that unvalidated

kits, purportedly for domestic use, are al-

ready being offered for sale by unscrupu-

lous online suppliers. Britain’s medical

regulator, for one, has had to take down

several fraudulent websites and is warning

people not to use any home-testing kits

they find being sold online.

Even when more kits do become avail-

able (and with due acknowledgment to the

different putative uses of different sorts of

test) the next goal for most countries after

protecting crucial members of the work-

force will be population-level surveillance.

This will, as a by-product, provide infor-

mation to individual members of the pub-

lic. But its primary purpose will be to track

how the epidemic is progressing.

One of the most important elements of

this analysis will be determining the rate of

silent infection—with all the implications

that brings for herd immunity. Comparing

recent test data from the Netherlands and

Iceland hints at the gap in current knowl-

edge of just how much silent infection

there may be. Both countries use genetic

testing for the virus, but the Netherlands

only tests those with severe symptoms of

covid-19, whereas Iceland has been testing

widely, even people without symptoms.

Unsurprisingly, but crucially, the Icelandic

approach has revealed far more infections

in younger people than the Dutch one (see

chart). Moreover, according to Kari Ste-

fansson, who is leading the Icelandic pro-

ject, 50% of those who have tested positive

reported no symptoms.

Silence is not golden

Mass testing will be laborious. It will mean

taking regular blood samples from mil-

lions of people, even though the actual

analysis will be done by robots in central-

ised high-throughput laboratories. To save

effort, such projects might piggyback on a

country’s blood-transfusion services, for

donated blood is already subject to rigor-

ous screening for pathogens.

German scientists have announced

plans to start, this month, a reasonably

large-scale surveillance project. It will

monitor blood samples taken regularly

from 100,000 participants. Those proving

immune may be given a certificate exempt-

ing them from restrictions on working or

travelling. If nothing else, that would cer-

tainly be an incentive to sign up. 7

Test early, test often

Confirmed covid-19 cases*, % by age group

Sources: RIVM; Covid.is *To March 31st 2020

25

20

15

10

5

0

9080706050403020100

Netherlands

tests only serious cases

Iceland

tests widely

Age group

A

s countries across the rich world

placed themselves under restriction

over the course of March, journalists there

turned to the question on everyone’s lips:

“will the coronavirus break the internet?”

For them, the answer in the main is “no”.

Most broadband networks are built for

peak evening usage, when lots of people

settle in for a session of hdstreaming.

Even widespread, daylong videoconfe-

rencing and online gaming do not come

close to that level of data consumption.

The internet, as one infrastructure pro-

vider puts it, was “built for this”.

Such sangfroid does not, however, ap-

ply if your internet connection is mobile.

And in the poorer parts of the planet that is

generally the case. Indeed, most of the 4bn

or so people who use the internet today do

so via mobile connections rather than

land-lines. As countries such as India,

South Africa and those in South-East Asia

start staying at home they are turning to

their phones for entertainment, for com-

munication and for work. With little fixed-

line capacity to fall back on, the load on lo-

cal mobile networks is immense.

A mobile-data connection runs as a ra-

dio signal from a phone to the local base-

station. Thence it links up, via optical fibre

or a microwave connection, with the net-

work’s core, which is connected to the wid-

er internet. If too many people try to con-

nect simultaneously to the same base

station, that station will be overwhelmed,

causing calls to drop, data-transfer speeds

to slow and tempers to rise.

Even some rich countries are suffering

in this regard. According to James Barford

of Enders Analysis, a British research firm,

Telefonica Spain has seen a 30% surge in

data traffic and Telecom Italia reports a 10%

rise. Download speeds in Italy have also de-

clined, according to OpenSignal, a net-

work-analytics firm.

Elsewhere, things are worse still. Some

networks have seen internet use rise by as

much as 80% says Bhaskar Gotri of Nokia,

which makes networking equipment and

helps operators manage their systems. Mo-

bile networks are constantly being upgrad-

ed, and have assumptions of double-digit

growth baked into them. But those as-

sumptions are for growth over the course

of months or years, not days.

So far, network operators have proved

equal to the task. But things could deterio-

rate. Routine maintenance will suffer as

engineers go off sick or are forced to self-

isolate. There will be less capacity for

emergency maintenance. Far-off base sta-

tions will become harder to reach. And on

top of all this, demands on networks will

probably rise. More people will discover

video chatting. As television broadcasters

struggle to provide fresh entertainment,

people will turn to streaming in ever great-

er numbers. All of these things will add to

congestion. The longer that stay-at-home

orders remain in place, the more likely it is

that some networks will fall over.

Mobile operators and regulators are not

standing around waiting for such failures,

though. In several countries, including

Spain, mobile operators have asked users

to reduce their data consumption. Others

are trying novel ideas. Kenya has fast-

tracked Google’s Loon project, which will

provide 4gsignals from high-altitude bal-

loons. In India, where data consumption is

up 30% and speeds down 20%, operators

are contemplating joining forces, to ease

each other’s peaks. European and other

regulators have asked the big streaming

services—Netflix, Amazon, YouTube—to

reduce the quality of their videos, in a bid

to free up capacity. America has granted its

networks additional radio spectrum on a

temporary basis, and several other coun-

tries are in the process of doing the same.

Around a third of the planet’s inhabit-

ants are now stuck at home. That is bad

enough—for morale, for businesses and for

countries’ economies. For those people to

lose in addition what is, for many of them,

their only connection to the wider world

just makes it worse. 7

Can mobile networks handle becoming

stay-at-home networks?

Overloaded telecoms

Breaking the net