Now we’re opening up, testing and contact tracing really matters29th October 2020
“Quarantine” is when you are a close contact of a case and are asked to self-isolate until it is known whether you have escaped infection. If you are a direct contact of a case, you will stay the 14-day course, being monitored for symptoms even if you test negative initially. You will be tested at day 11, and if negative, may be notified you can stop isolating.
It gets more complicated if you are in quarantine because you are a close contact of someone who is a close contact of a case. Usually you will be asked to self-isolate until tests results for the primary contact are known.
If they test negative at least 48 hours after you were last in close proximity to them, you will be cleared and not have to self-isolate. This is true even if they later test positive as you were not a close contact during their infectious period.
If you are in the same household and have remained in close contact as the primary contact, you will be asked to self-isolate for the full 14 days. If the primary contact becomes a case, your status changes to a contact of a known case. It can get complicated so the department will give you tailored instructions that fit your circumstances, and case managers should be used for each house or cluster so that instructions are consistent and clear.
It is worth revisiting the case timeline to help understand these processes.
Incubation period from exposure to symptoms varies but is five to six days on average. You are infectious for one to two days before you are symptomatic. Let’s assume you get tested as soon as you get symptoms and stay in isolation until you get result, now within 24 hours.
If positive, you will receive your result directly from the health department. They will then work with you to determine how long you have been infectious and who your close contacts were during that time. They will also work out when you might have become infected and connections to other cases or known exposure sites.
In this best-case scenario, this is completed within 48 to 72 hours of your first symptoms. But even then, if you had been at the grocery store a couple of days before your symptoms started when you were already possibly infectious, a notice will go up at the store saying a possible exposure occurred five days earlier. This is the minimum lag, and will be longer if there were any delays in the case getting tested.
The longer you have been out and about with symptoms, the more contacts you will have, and the harder it will be to remember everywhere you have been and who might have been exposed.
The places you went to when infectious might be the site of infection for others who would now be spreading the virus. The double ring of contacts approach now implemented in Victoria should still be able to contain outbreaks, but the job is much larger and harder. More people in your circle are affected by the case investigation and are at risk of infection.
Early containment of clusters is how we stop case numbers creeping up and is the key to preventing further waves. Keeping our distance, our masks on and hygiene up will help each of us avoid infection if the virus is still circulating or is reintroduced, and getting tested and doing this as early as possible is critical in containing risk of wider spread.
If we all do this, it really will take an extraordinary set of circumstances for us to have to face a third wave. Let’s not give the virus that opportunity.
Catherine Bennett is chair in epidemiology at Deakin University.