With the return to Level 3 ahead of us, we’re all asking what life looks like in Level 3. How will businesses operate? How do we ensure that the results of a rapid reduction in new cases due to Level 4 lockdown are maintained? Last week the Ministry of Health published a report authored by Dr Ayesha Verrall, titled “Rapid Audit of Contact Tracing for Covid-19 in New Zealand”.
She outlined the need for contact tracing, the effectiveness and what an ideal technological solution would look like.
The full report can be found here
Why do we need contact tracing?
In her report Verrall outlines the effectiveness contact tracing can have on the elimination of a virus. She also cites how without contact tracing the Covid-19 virus can expand very quickly as it did in Korea with the Church outbreak. She suggests that New Zealand needs to get to a “new normal’, without an Alert Level 4 lockdown and contact tracing can provide that.
“Rapid case detection and contact tracing, combined with other basic public health measures, has over 90% efficacy against COVID-19 at the population level, making it as effective as many vaccines. This intervention is central to COVID-19 elimination in New Zealand.”
Why do we need a technology solution?
As referenced in her article, the Public Health Units (12 across New Zealand), have been pushed to capacity in the last few months. They are unable to keep up with the contact tracing requirements even though there were only ever 100 new cases per day. The National Close Contact Service, which was established in a matter of weeks, handles most of the contact tracing requirements but is still unable to handle complex larger gatherings.
“The contact tracing system is the final part of a process that begins with someone who is ill with Covid-19, called an index case. The index case becomes ill and infectious, is assessed and tested, isolated and if they test positive their close contacts are traced and quarantined. The contacts of probable cases are also traced and quarantined. Contact tracing is a key preventive measure for Covid-19 and is recommended by the World Health Organization (1).”
What does a technology solution need to include?
- Near instantaneous notification of contacts following case diagnosis
- High levels of uptake will also be required to achieve impact
- Transmission models show Covid-19 outbreaks could be controlled through this system provided tracing is fast enough
- There is also the potential to use QR-codes to ‘check in’ to high traffic settings like public transport or cafes
- The primary way in which smartphone technology could support contact tracing is through Bluetooth detection of close contact between people’s smartphones and, if one is later found to be a case, instantaneously notifying contacts of their exposure and the need to self isolate
- Identify contacts that would be missed by manual methods due to poor recall or anonymous contacts in a crowded venue. The time from case diagnosis to contact isolation could also be reduced
- Needs to be available quickly, piloted and continuously improved
- Potential impact will not be realised unless it is acceptable to a large proportion of the population and enjoys high uptake. Less than a fifth of the Singaporean population downloaded the Tracetogether app in ten days
- An app cannot replace the option to interact with a real person as many contacts will develop illness, have welfare needs, or face issues with accessibility
- Scalable – able to respond to exponential growth in case numbers
- Equitable – high performance across age and ethnicity
- Acceptable – to contacts and PHUs
This report outlines the need for a technology solution to be both acceptable by the users (public), have no inherent bias (technology, socio economic, gender, ethnicity) and support the NCCS and Public Health Units in their contact tracing efforts.