
Nearly 40% of Icelanders are using a Covid app, but it hasn’t helped much - jtbayly
https://www.technologyreview.com/2020/05/11/1001541/iceland-rakning-c19-covid-contact-tracing/
======
g_p
I think often the goals of contact tracing apps are misunderstood. The goal
isn't to replace "name and phone number" human contact tracing, but rather to
augment it. Iceland's location based approach seems to emphasise this, albeit
at expense of privacy.

Where contact tracing apps help is for contact events where people are in
relative proximity for sustained periods of time. It seems that prolonged
contact is a major factor in spreading the virus. If you're on a train with
someone for half an hour, you'd not be able to identify them through regular
contact tracing, and they wouldn't be able to be altered. On an aircraft this
can usually be done as the airline cooperates with public health authorities
to identify those sitting near a given individual on the plane etc.

The impersonal but sustained contact situations are the ones apps can really
help with, by raising the number of people able to be alerted to their risk of
exposure. Traditional tracing handles people you know. App-based tracing, if
it gets adopted, can help with the people you don't know but are sitting near,
or otherwise around for a prolonged period.

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dogma1138
Iceland is quite unique, only one real large population center, limited public
transport, tiny venues, multi-generational homes and overall a tiny population
so it doesn’t seem to be the prime candidate for contact tracing apps since
it’s effectively the best case scenario for traditional contact tracing.

~~~
dehrmann
All the interesting places people have been pointing to are islands. Except
South Korea, but it's effectively an island.

~~~
manquer
South Korea is this context similar to an island . While it is peninsula the
only land border is with North Korea and highly guarded , effectively you can
only enter by flying in just like an island.

~~~
Mediterraneo10
Not just flying. South Korea is also connected to Russia, China and Japan by
ferry.

~~~
wigl
Not sure about the Russia and China routes but the Busan-Shimonoseki ferry is
pretty impractical. 13 hrs and about as expensive as a flight. More if you
consider train costs from Shimonoseki.

~~~
9nGQluzmnq3M
Busan-Fukuoka ferries go directly between two huge cities and are priced
competitively, particularly if you get a cabin instead of paying for a hotel.

~~~
wigl
Wow the JR Beetle is super fast! Didn't know about that, my knowledge is
pretty old, thanks!

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reitzensteinm
I'm surprised nobody has mentioned this, but the effectiveness of the app is
equal to the square of the penetration. Both parties need the app.

At 38% penetration only about 15% of contacts with a carrier will be warned.
That is indeed not going to do much.

~~~
this_user
You also have to consider the failure rate of the app. I don't know about the
Icelandic implementation, but most approaches seem to be based on Bluetooth.
There are all kinds of reasons why one might miss a signal sent by device
nearby, including interference on the 2.4 GHz band with things like Wifi.

Furthermore, the user has to actually report their infection, which probably
not everyone is going to do.

If we multiply all of those terms, the end result will be much lower than 15%
even in this scenario. The tracing apps seem more like wishful thinking than
something that is going to provide sufficiently broad and reliable coverage to
have anything more than a marginal impact.

~~~
trfhuhg
The entire premise of the app is that P[transmission] = F(distance, duration).
I think this is a naive assumption and just the two input parameters have
nearly zero predictive power, i.e. the variance of the estimated probability
would make any further analysis useless. I'd also argue that the only case
where it would be useful is tracing a zombie-level virus when there's
willingness to lock down with military a 5 sigma radius around the probable
infection. Otherwise it's just a tool for marketing and spying.

------
seesawtron
Maybe I am just ignorant but the article doesn't list a single reason as to
why the automated tracing app hasn't helped much. There is a quote from a
person who was involved in the tracing op but no comment from him/her either
as to why it hasn't helped much.

This is supposed to be a "technology review". Did the writer bother to ask
"WHY NOT"?

PS: Happy to stand corrected if someone else was able to read between the
lines and find some reasons.

~~~
kjaftaedi
The main reason is that we were able to control the spread of the virus faster
than the need for the app.

At the moment we're going several days at a time with zero new cases.

It makes it a more difficult sell to the general public, when the overall
feeling is that we've 'beaten' this.

I get the feeling most of the general public aren't preparing for future
outbreaks because, like most places, I think everyone wants to rely on the
hope that the worst is over.

~~~
seesawtron
Assuming that your argument is correct that it's a little too late to see the
benefits of tracing in Iceland, the article's negative connotation to use of
the tracing app (or lack thereof) is misleading and discouraging for countries
that are still struggling to contain the virus. I find the overall quality of
online media, even tech blogs like this one that I used to love, seriously
falling being caught up in the age of click bait news cycles.

------
pizza
Something I've been thinking about during lockdown is that, while we are for
the most part staying at home when possible, if you get sick, you only have,
maybe, 4 or 5 contacts to trace, on average. If we release lockdown, the
number of average contacts to trace goes way way up.

~~~
MiroF
I suspect that many of the people getting infected are not observing as strict
of social distancing as you imagine.

e: Why am I getting downvoted? Just conditioned on | getting infected by
covid, means more likely to have had more contacts.

~~~
Reelin
Without any actual data to hand I would also guess that infections would skew
towards people who come into frequent contact with others as part of their
job. If true, it would make taking precautions at, for example, the grocery
store all the more important because those most likely to be infected are also
those who you're most likely to come into contact with in turn.

------
barbegal
This app tracks users’locations using GPS data and according to the article
"allows investigators—with permission—to look at whether those with a positive
diagnosis are potentially spreading the disease"

Without also being able to know the location of people without a positive
diagnosis, the app probably doesn't help that much.

But I don't think this necessarily applies to apps being developed for other
countries where Bluetooth is being used to measure person to person contact
directly.

This article lacks any real insight into what isn't working or why.

~~~
Kephael
Couldn't you DDoS this infrastructure by having beacons masquerade as users
and then have people quarantined because they were marked as near an infected
individual when in reality they were near a rogue beacon that spams generated
identifiers? This certainly can't be constitutional in any Western system of
government.

Even if the identifiers were encrypted with a public key that only the tracer
service had the private key to, couldn't a bad actor register as a bunch of
actual people and then have them show as coming in contact with infected
people?

~~~
visarga
Those beacons would be quickly identified for being motionless, or if they are
carried by a person then it's basically someone lying on the app about being
infected. This could be verified by medical testing before publishing the ids.

~~~
Kephael
Stick it on a bus or a drone, now it's not motionless.

------
cwhiz
Only 33% of Americans would consider using a contract tracing app.

[https://www.axios.com/axios-ipsos-coronavirus-
week-9-contact...](https://www.axios.com/axios-ipsos-coronavirus-
week-9-contact-tracing-bd747eaa-8fa1-4822-89bc-4e214c44a44d.html)

~~~
chrischen
Well, I never opted into Amber Alerts so maybe it can still work by forcing
people to use the Apple/Google built in contact tracing API.

~~~
redis_mlc
I'm under the impression most Amber Alerts are really custody battles.

~~~
chrischen
You also get them for flash foods and other things.

------
jonastryggvi
here is the covid19 info website in iceland, if anyone is interested in how
many tests have been done and other statistics;
[https://www.covid.is/data](https://www.covid.is/data)

~~~
krzyk
Wow, it looks like Iceland recovered from it pretty fast. Only 6 active cases

~~~
dredds
The next issue is whether to count positives who are new arrivals placed into
quarantine of 2 or more weeks. Countries will be reluctant to blemish their
clean virus-free records even though quarantine may be effective and necessary
to have limited allowable travel. Seems we should only count people who test
positive after passing through quarantine if they were first cleared as
negative and released.

------
srmatto
I thought ~60%+ must adopt for it to be effective?

[https://045.medsci.ox.ac.uk/](https://045.medsci.ox.ac.uk/)

------
efitz
Slightly offtopic, but it bothers me that the tech community has remained
silent or supportive for contact tracing technology, when there were massive
outcries for the past several years regarding other kinds of surveillance-
enabling technology like face recognition. In general I would prefer that
contact tracing technology not exist.

~~~
9nGQluzmnq3M
There are ways to implement contact tracing so that unnecessary information is
not shared and so that you are in control of what gets shared and when. This
is not the case for (say) face recognition on a CCTV feed.

~~~
smsm42
I'm sure there are ways. But can you ensure this specific app, recommended (or
mandated) by your government, puts you in control and doesn't try to sneak a
quick one past you? What would be the incentive for your government to ensure
that instead of making the population much more observable and thus governable
under the guise of taking care of your health? It's literally doing work
against government interests, and the governments aren't usually very good at
that. Same with major companies which just happen to be also major
accumulators of stockpiles of tracking and surveillance information about you.
Maybe this one they'd lay down their instincts and truly will roll out a
perfectly privacy-preserving solution. But could you trust them to do that?

~~~
9nGQluzmnq3M
As an example, the one used in Singapore is open source and implements a
public standard (bluetrace.io), so you don't even need to trust them, you can
check it yourself. And before you ask, yes, people have decompiled the app to
verify this.

------
blickentwapft
The more successful the battle against coronavirus, the less effective such an
app would appear.

------
avsteele
This paper * suggested, under some pessimistic assumptions, that it would
require "near-universal app usage and near perfect compliance" This is due to
the large fraction of spread from asymptomatic/presymptomatic carriers.

My review of the paper __is that their assumptions are overly optimistic and
that contact tracing will be largely ineffective even at universal adoption.

* [https://science.sciencemag.org/content/368/6491/eabb6936/tab...](https://science.sciencemag.org/content/368/6491/eabb6936/tab-pdf)

__[https://twitter.com/adamvsteele/status/1259661260406349824?s...](https://twitter.com/adamvsteele/status/1259661260406349824?s=20)

------
duxup
I wonder how much it would.

There's a chance that a chance encounter would result in an infection. But
then how many data points of low probability events are useful?

------
crushthecurve
Contact tracing (of the human-powered kind) is obviously hugely important in
reducing the scale of outbreaks in the early stages.

However digital contact tracing has a fatal flaw: Bluetooth cannot be used to
reliably estimate proximity in dynamic, real-world scenarios as objects
(especially human bodies) absorb huge amounts of the signal.

In many scenarios this can make two people sitting next to each other look
like they're 10-20 metres away compared to line-of-sight equivalents (just by
having a phone in a pocket, handbag, or even next to a head taking a call).
You can easily see this using, for instance, Apple's Bluetooth Explorer tool
as part of Xcode developer tools [1] (or any of the bluetooth signal strength
tools in the Play / App Stores).

You don't have to rely on DIY tests from the internet though. While they're
extremely static tests, the Singapore TraceTogether team did some field
studies highlighting the significant variability across hardware [2]. Their
tests ended in a plea for factory calibration data from hardware
manufacturers.

The Singapore team has talked about false positives in depth as a major issue
(one was someone in a different apartment, because bluetooth goes through
walls), which is why they set a hard, low RSSI value to reduce false positives
- this means a lot of true positives will be missed too.

The key Australian dev revealing significant issues in Australia's COVIDSafe
app also acknowledged the major limitations of BLE. [3]

The problem of course is you have a situation where you cannot determine if a
contact is epidemiologically interesting, because accuracy in real-world
situations is really down to the 20-30 metres of Bluetooth range, even over
longer time-frames.

This means you either have a huge caseload for human tracers to sort the
signal from the noise (and this relies on the memory of all participants) or
you have some kind of automated system (such as amber alerts that the NHS
talks about) and the challenge there is that no-one knows if they're really
interesting epidemiologically, as no-one can tell where each party was in the
context.

A recent series of talks by bluetooth experts is extremely informative.

In one, an expert discusses all the significant sources of error which creates
the huge variability you can see in DIY tests at home. [4]

There are other great talks in that video, but Jen Watson - who leads a team
at MIT engaged in advanced signal processing - delivers a good brief talk of
the issues, hoping to use statistical analysis - using detection theory of
fluctuating signals to estimate interesting contacts. [5]

The takeaway from all this though is that it's a hard problem, and in Watson's
talk she quickly moves on to thinking about additional future capabilities
(such as features in upcoming Bluetooth standards) that might help improve the
resolution.

This does leave us with a large _current_ problem though. Tracking apps have
been thoroughly oversold with little evidence of usefulness, and in the case
of the UK and Australia government authorities have refused to publish the
algorithms they are using to determine proximity from an RSSI value and a
phone model.

There is nothing sensitive about this apart from the fact it may reveal the
system is not useful for the stated purposes.

[1]
[https://twitter.com/crushthecurve_/status/125911361479693926...](https://twitter.com/crushthecurve_/status/1259113614796939266)

[2] [https://github.com/opentrace-community/opentrace-
calibration...](https://github.com/opentrace-community/opentrace-
calibration/blob/master/Trial%20Methodologies.md)

[3]
[https://twitter.com/jim_mussared/status/1255498092239036417](https://twitter.com/jim_mussared/status/1255498092239036417)

[4] [https://youtu.be/KgKbllhgESc?t=2991](https://youtu.be/KgKbllhgESc?t=2991)

[5] [https://youtu.be/KgKbllhgESc?t=3175](https://youtu.be/KgKbllhgESc?t=3175)

~~~
cozzyd
If there's a GPS signal then it may be possible to use the differential phase
satellite between two phones to get relative position down to a meter or so
(kind of like a super crappy rtk taking advantage of the pps stabilițy). Not
sure the gps devices on phones expose enough information for this.
Differential rssi of cell/wifi networks is another indicator but probably not
very accurate.

------
tucosan
Does anyone know more about the actual implementation of the app? Is it using
Google/Apple Contact Tracing APIs already?

------
user_50123890
This reassures the hypothesis that you probably won't catch the virus from a
brief contact in a grocery store or similar if you keep your distance.

Infections happen within families, and spread from one family to another by
friends/coworkers. The infected people should be easily able to list all
exposed out by name.

An exception is of course mass indoors public events that are forbidden now.
This is where a contact tracing app would probably prove to be the most
useful.

~~~
Retric
Incidental contact is unlikely to matter in most cases. However, multiple
people at different tables where infected at a restaurant from a single
customer. So, it doesn’t take that much.

~~~
eloff
Or on public transport. New York's subway system was probably it's Achilles
heel during this outbreak.

~~~
dehrmann
Except Staten Island had the second most cases per capita. Lots of the obvious
NYC theories have holes where you look at places affected.

~~~
jmull
People who live or work on Staten Island used mta services, including subways,
heavily.

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justinclift
[https://archive.vn/g7Pp1](https://archive.vn/g7Pp1)

