Disease detectives on virus case
Cruise ship docks and passengers spill out into a city. A celebrity couple is mobbed by fans and dignitaries eager to shake their hands. Well-to-do socialites arrive at a birthday party fresh from a ski trip in Aspen. A man steps off a plane and kisses his wife.
These are some of the bestknown stories of coronavirus infection in Australia so far. In every one of them, as the virus spread, a team of disease detectives was on the case, retracing the patient’s footsteps, zeroing in on who else might have been exposed, joining the dots on Australia’s outbreaks.
The process, known as ‘‘contact tracing’’, is infectious disease control 101, often deployed against illnesses such as measles, meningococcal disease and some sexually transmitted infections.
But in a fast-moving pandemic, it becomes a race against time to protect not just a few people but whole countries. Across Australia, armies of doctors, health officials, academics, medical students, even actual soldiers have been called in to the fight. Experts say this work will largely determine how many lives can be saved in the months ahead without a vaccine or treatment for Covid-19.
To track a virus you can’t see, which jumps person to person in close quarters and can linger on door handles, sinks, sometimes even briefly in the air, you need a particular skill set. Dr James Smith is clinical lead on contact tracing efforts in Queensland. Feeding information back and forth with other states and the national incident room in Canberra, his teams have followed several high-profile patient trails, including those of Hollywood couple Tom Hanks and Rita Wilson, and Home Affairs Minister Peter Dutton. While Smith swears he has no secret ambitions as an amateur sleuth, he admits the job can be aptly described as part doctor, part detective. Most of the work is done over the phone by clinicians and scientists, not private investigators, because the tracers need a good handle on how diseases spread. But mysteries do get solved.
Smith also worked on the world’s previous pandemic, the H1N1 swine flu in 2009, and last year helped the World Health Organisation trace a disastrous measles outbreak in Tonga to a rugby team newly returned from New Zealand. But ‘‘there’s never been anything like [Covid-19] in public health’’ in his lifetime.
Victoria’s deputy chief health officer, Dr Annaliese van Diemen, agrees. Usually, in what she calls ‘‘peacetime’’, she heads a team of just 20 or 30 investigators. Now, their ranks have swelled by as many as 1000 – and could expand further.
Tracers interrogate and analyse, stitching infected threads through weddings and parties and across borders into what, during this pandemic, is becoming one of the most expansive webs of health data the nation has ever built. Meanwhile, epidemiologists and analysts are poring over the numbers, van Diemen says, drilling down into suspected local outbreaks and ‘‘places of interest’’. The names and contact details of almost 10,000 people already feature on Victoria’s Covid-19 spreadsheets and geo-maps.
Once a patient’s test comes up positive in a lab, teams in their state get a ping – and the hunt begins. Close contacts of the new case, such as those they live with, are quickly informed and asked to self-isolate, and the infected person is interviewed in depth. Smith and van Diemen say they’re looking for more than just your basic movements. They will go back over the day-to-day, even minute-by-minute minutiae of your every interaction.
Armed with a list of people with possible exposure, tracers hit the phones again. Expect a call if you’ve had at least 15 minutes of face-to-face contact with a known case or spent at least two hours with them in an enclosed area.
A New South Wales Health spokeswoman likens contact tracing to hacking back the tentacles of the virus, one by one, as they wrap around the world.
‘‘It’s hard work, but it works. We won’t stop.’’ – Nine