Opinion: Key considerations for tracing COVID-19 with geospatial data

Countries around the world are working to operationalize test-trace-isolate-support chains and lower COVID-19 transmission. Such operations require tracing individuals who have been in meaningful contact with confirmed or presumptive coronavirus carriers and moving them quickly to supported isolation.

Traditionally, this detective work was done using a low-tech, labor-intensive army of tracers who call or visit people who have had contact with confirmed carriers. Contacts are tested, isolated, and supported, before the cycle is repeated.

Data and case management can be done with a pen and paper, spreadsheets, or case management applications such as Dimagi’s CommCare contact-tracing app. Evidently, this method helps disrupt transmission only when the data is processed and acted on quickly to get people to supported isolation so they stop spreading the virus.

The hard-to-resist appeal of proximity-tracking applications

In the last few months, a number of governments announced the creation of smartphone applications that aim to complement the traditional tracing process. Using geolocation and spatial movement data, these applications aim to identify whether someone has been in the proximity of a person with the virus — also known as “proximity tracing” — hence potentially finding asymptomatic individuals who might have otherwise been missed by traditional contact tracing.

The idea that these applications could lead to faster tracing — and targeting a whole new population that we simply wouldn’t have been able to trace otherwise — is appealing. Who among us can make a list of all the people who were at the grocery store we visited last Monday? In countries such as South Korea and Singapore, these applications have been part of a test-trace-isolate-support process that many credit with curbing disease transmission.

Despite the hype, for many low- and middle-income countries, these geospatial applications may not be worth the investment. Policymakers should carefully assess whether such applications are worth the investment.

Complement — but never replace — a broader public health effort

At the risk of stating the obvious, digital tracing applications will only have the intended impact if accurate, rapid-results testing is already widely available to the public at no cost at the time of launch. If these essential conditions are not met, applications will be ineffective. If they are ineffective, the public will, in all likelihood, lose faith in or never adopt them.

Digital tracing applications also require the physical tracing infrastructure to be operational and interoperable with apps. Digital tracing will only break transmission if people can isolate while awaiting testing and results — whether at home or, ideally, in a dedicated facility — with safety net systems such as sick-leave benefits or minimum cash transfers. As such, digital applications can perhaps complement, but not replace, a public health strategy.

These applications also require a widespread use, a condition unlikely to be met in many LMICs.

To be considered effective, these applications need to be downloaded and actively used by more than half of the population. Yet to date, no contact-tracing application has been reported to reach this target. In Iceland, only 40% of the population has downloaded the country’s contract-tracing app.

Anything that prevents widespread use — lower smartphone penetration, poor literacy rates, connectivity issues, or a lack of trust between the general public and the government — will reduce the overall effectiveness. It is easy to see how the most vulnerable will be largely left out.

Collect lifesaving data while protecting privacy?

These applications track where users are all the time. That is understandably concerning for many citizens, who will wonder about who has access to the data, how others will be using it, or what they might do with it after the crisis ends. As such, any government that wishes to increase downloads and use must take data privacy extremely seriously right from the design stage.

While most existing apps are able to prevent the identification of end users — for instance, by regularly modifying the signal transmitted by phones — additional precautions are recommended. One possibility is to follow the lead of Singapore, Israel, and the Czech Republic, which made their code open source, hence allowing experts to assess privacy. Additional steps include placing limits on how long the data ­— even anonymized data — will be stored and committing to shutting the tools down when the pandemic is over.

Publishing frequently asked questions or similar information in the application itself, setting up an oversight committee and a hotline for people to ask questions and report concerns, and sharing information in the media can help facilitate higher levels of transparency, trust, and, in turn, use.

Encouraging adoption with public-goods messaging and behavioral insights

For a rollout to be successful, people need to be willing to report their exposure without worry of stigma, losing their job, or other potential repercussions. When it comes to digital tracing, these worries are layered on top of the skepticism around data privacy. As such, mandating the installation of the applications would probably undermine people’s willingness to use them and to report their test results or symptoms.

Instead, good communication and encouragement strategies will rely on positive messaging and behavioral insights about cues to action. Individuals need to see the value in engaging with an app, in addition to feeling safe when doing so. Participating should make the public feel that they are protecting their family, community, and the broader public good.

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