How good is Australia’s virus contact tracing?

Melbourne would suggest it sucks. Evidence suggests it sucks. Via Crikey:

How many known close contacts of COVID-19 carriers in Victoria and NSW are notified by government tracing teams?

The answer may seem self-evident — all of them — but if the experience of other countries is anything to go by, many close contacts may be falling through the gaps of the tracing system.

In England, a quarter of people referred to National Health Service (NHS) tracers cannot be reached due to a combination of unanswered calls and incorrect contact details. Of referrals who are successfully interviewed, around a third of the close contacts they provide to tracers are also proving impossible to find.

Putting both factors together means tracing teams in England are currently reaching only around half of the close contacts of known coronavirus carriers. Half.

Worryingly, the US makes England’s numbers look good. In New York, as few as 35% of people referred to tracing teams have been willing or able to provide a list of close contacts. Some areas of New York have even resorted to issuing subpoenas to force suspected coronavirus spreaders to cooperate. No wonder White House health adviser Dr Anthony Fauci has admitted US contact tracing is “not going well”.

So is the contact tracing hit-rate any better in Victoria and NSW? It seems an important thing to know — but we don’t.

Australia’s lack of data

Unlike their counterparts in England and the US, neither the Victorian Department of Health and Human Services nor the NSW Ministry of Health publishes performance data about their contact tracing efforts. Both have refused to provide figures to Crikey.

According to Professor Catherine Bennett, chair in epidemiology at Deakin University, Australia’s contact tracing performance is likely to be a lot better than in England and the US. But, she says, “a relatively small percentage” of contacts may still be unreachable.

“We have been nowhere near as overwhelmed by case numbers as the UK, so I think that alone means we have probably had more capacity to be more persistent in our detective work following up cases and contacts,” Bennett tells Crikey.

The maths suggests a small percentage of missed contacts is still a problem. Even if just 3% of close contacts prove to be unreachable — a mere 10th of the contact failure rates in England — that still equates to hundreds of close contacts in Victoria and NSW never being informed of their status. A 10% contact failure rate would put the number of missed close contacts into the thousands.

(Bennett also points out that less than 1% of tests are positive, including close contacts, so missing a few hundred might only mean a couple of them actually have the disease.)

We can only hope Australia is performing better than England and the US, but without seeing official figures it is impossible to know.

Why is contact tracing so tricky?

Bennett says outright non-compliance with contact tracers is rare, but getting useful information from people requires a lot of time and skill.

“I’ve had contact tracing calls with hundreds of people over a variety of [non-COVID] outbreaks, and don’t recall anyone flat-out refusing,” Bennett says. “They always gave a little info at least, but it can take a lot of time to work with them to even get that.”

“The ability of the contact tracers to build rapport, trust and confidence at first contact is really important and why so much effort needs to be put into training — even in this current crisis.”

Perhaps the biggest obstacle for tracers is getting people to answer their phones in an era when few people are willing to field calls from unknown numbers.

The lack of data is the giveaway. If we’re not monitoring how good our tracing methods then that indifference suggests that they are very likely to be poor.

As I have argued many times, Australia is no position to replicate the excellent contract tracing of North Asian nations. We’re too heterogeneous and rambunctious.

Suppression will fail as a result.

David Llewellyn-Smith
Latest posts by David Llewellyn-Smith (see all)

Comments

  1. Ronin8317MEMBER

    Pretty much every person has a smart phone. Both Google and Android will track where you have been pretty accurately, even if they don’t have the COVIDSafe app installed. Mobile phone tower data can tell you who is in the area. Creditcard transaction can tell you who is at a restaurant pretty much, none of this “if you have been in the restaurant please isolate yourself” stupidity. If the government REALLY wants to, they can get a hold of everyone with a mobile phone in the area and time of suspected infection, and test all of them.

    On a side note. Why doesn’t the COVIDSafe app show time and location where COVID-19 infection has occurred, and match it with user location data? It is a very simple feature that would make the app a lot more useful.

      • All institutional hegemony grasp for ultimate power before we find it revolting. Comprehensive surveillance looks to be it’s last grasp, this might piss us off enough to opt out of the network and grab a pitchfork.

    • drsmithyMEMBER

      Pretty much every person has a smart phone. Both Google and Android will track where you have been pretty accurately, even if they don’t have the COVIDSafe app installed. Mobile phone tower data can tell you who is in the area. Creditcard transaction can tell you who is at a restaurant pretty much, none of this “if you have been in the restaurant please isolate yourself” stupidity. If the government REALLY wants to, they can get a hold of everyone with a mobile phone in the area and time of suspected infection, and test all of them.

      That is a very, very risky Pandora’s box to open, especially in today’s world.

    • Forrest GumpMEMBER

      Covid Safe app was developed by a partner of one of the LNP members

      It should at least show a history of infected users locations and data match that to your history of locations and flag any concerns. Its basic data matching

  2. ” This virus is not a living organism. It is a protein molecule (RNA or DNA) covered by a protective layer of lipid (fat), which, when absorbed by the cells of the ocular (eyes), nasal (nose) or buccal mucosa (mouth), changes their genetic code (mutates) and converts into aggressor and multiplier cells.
    * Since the virus is not a living organism, but is a protein molecule, it cannot be killed. It has to decay on its own. The disintegration time depends on the temperature, humidity and type of material where it lies.
    * NO BACTERICIDE OR ANTIBIOTIC WILL WORK because the virus is not a living organism like bacteria; antibodies cannot kill what is not alive.”

  3. contact tracing is only good when they are few cases and when they are all imported
    in an epidemic progresses as much as VIC one contact tracing is useless
    that has nothing to do with our abilities … look at Singapore or Israel … big brother states that still failed with contact tracing

    • No its not, its vital. If your good enough at it and have enough effective testing and NPI’s in place to reduce the r0 thats all you should need. Failure at this stage is due to an unconsidered weakness in your society, so far typically underclasses, the deprived, BAMEt, Elderly etc.

      In the rambunctious West we need lockdowns as we didn’t respond proactively and we didn’t introduce NPI’s like masks and distancing quickly enough. Masks in July is laughable when centuries of study and experience shows masks are the single most effective measure short of change in mobility.

      The Vic outbreak is now well and truly under control, has been for nearly a week, and thats with poor compliance. If compliance was better we’d get out quicker, simples.

Leave a reply

You must be logged in to post a comment. Log in now