Contact-tracing: How it works
Rapid and effective contact-tracing is a key pillar of keeping us safe, by ring-fencing cases and their contacts before they might infect others.
Capacity has come a long way since midMarch, when the system could trace 10 active cases a day and the 12 regional public health units had different IT systems that couldn’t talk to each other.
Now it’s all been integrated and workload can be shared, National Investigation and Tracing Centre lead analyst Claudia Rees says.
That has enabled surge capacity to trace hundreds of cases a day, as well as the ability to look across multiples systems for someone’s contact details.
When a person’s laboratory result comes back positive, the national centre and the relevant PHU are notified.
Officials then make contact to give advice and do a risk assessment before a proper investigation — which can be a series of interviews to determine movements, and close and casual contacts.
Identified close contacts are told to isolate and get tested, and are then given daily follow-ups to check their health or welfare needs, any symptoms, or if they’re isolating properly.
It is helpful if the case has been using the Covid Tracer App,
which has seen a surge in uptake during the current outbreak.
The national centre can generate a code for the case to put into the app.
“They do that while we’re on the phone to them and all of their contact locations will populate the National Contact Tracing Solution [system],” Rees says.
“That makes it a lot faster to get a full pathway of where the case has been. I then look through those and decide which ones are maybe a bit more high risk, or ones I want to send out a push notification for.”
High-risk ones might be indoor events where people are packed closely together and have been singing or exercising.
Rees can then create an “exposure event”.
“Everyone will get a notification on their app who scanned in at the same time as the case.”
Rees also has an overview dashboard of the day’s work tasks.
“You can see the cases opened recently we are actioning, the total close contacts and how many are awaiting contact, and other parts like any symptomatic close contacts or any who are essential workers.
“It just gives us that really good overview, maybe where some risks are or where immediate attention needs to go to, and also where we might need more people.”
Tracers’ work has been well above the gold standard recently; from August 28 to September 3, 94 per cent (80 is the target) of close contacts were in isolation within 48 hours
of a positive test result.