How Victoria can drive the coronavirus out

We are rapidly heading towards double figures for new case reports of COVID-19 in Victoria. Everything is pointing that way, even our daily press conferences that have this past week been appropriately cautiously optimistic are now verging on buoyant as we hit the 100s, with the Chief Health Officer bidding farewell to counts in the terrible 300s on his watch.

But the reality is, we don’t know how far we can push the numbers down once we get into double digits. Epidemic curves can have long tails even when they are simple single outbreaks with random transmission in the community. In Victoria, we have multiple outbreaks simultaneously, some workplace-based, some in healthcare or residential care settings, some in the community, and of course, those mystery cases that do not present a clear picture of transmission chain or predictable infection risk.

Can Premier Daniel Andrews and Chief Health Officer Brett Sutton help ease Melbourne off COVID-19 restrictions?Credit:Wayne Taylor

It will be fabulous if we can suppress transmission to a point where it stifles chains of spread enough to shut this down completely, so we can achieve elimination of local transmission once more. To achieve this, we would need to get to low double digits this week, and then hold cases at that level for the remainder of stage 4.

Restrictions that suppress the number of close contacts are ideal for closing down remaining outbreaks, and mopping up other chains of transmission, whether they are being tracked through testing and visible, or not. That is a big ask. Not impossible, and something we should all individually and collectively strive for, but we should also be prepared for plan B.

The alternative reality for Victoria looks a lot like New South Wales, but then that might be true even if we eliminate the virus again now. No state, territory or country can afford to think that they have impermeable borders. We must be prepared to find a way to live with the virus until we both have a vaccine solution, and know we can achieve sufficient uptake levels to guarantee population herd immunity to rid us of this viral threat.

The rapid and aggressive test, isolate and contact-trace approach, possible when numbers are low, can keep an outbreak manageable. NSW has proven this. The identification of possible exposure locations prompts people with symptoms to test. Chasing up close-contacts of close-contacts even before the first round of test results are in, especially if close contacts of a confirmed case already have symptoms, allows contact-tracing to move half a step ahead in the race to stop further spread.

This is what it takes. We must be relentless in our pursuit so that community transmission levels never get to a point again where large outbreaks can be silently seeded in workplaces, and then feed more virus back into the community before discovery – the devastating dynamics of our second wave. DHHS is now starting the hotspot location announcements, something finally possible. Imagine the lists two weeks ago with hundreds of outbreaks in train! But we must also keep our testing of anyone with any symptoms up, no matter how low the daily case count.

Masks are here to stay. Possibly even after a vaccine is rolled out, until we know we have the vaccine uptake required for us to lower our guard. But with the risk of community transmission dropping, it should soon be possible to restrict mandatory masks to more limited settings. The Premier has identified the likelihood of continuing mask-wearing in high-risk workplaces, and public places where we are not able to maintain our 1.5 metre physical distance. This makes sense.

An alert system that triggers changes in public health response according to transmission reports has been suggested as one way ahead. This might be necessary if an outbreak does threaten to break the contact-tracing cordon but generally I think it better if we don’t chop and change. We don’t need to think as we buckle down for the longer haul: wear a mask when around other people, and just be mindful to keep some distance from others if you want to enjoy the great outdoors mask-free. We will have to be prepared for rolling local closures after exposures while investigations and cleaning are carried out, but hopefully widespread restrictions are behind us.

Monitoring and surveillance will be increasingly important, not only to protect our highest risk settings, but to provide early warning system as they monitor for virus activity across suburbs and regional areas. The government is already trialling waste water monitoring, and will soon know if this is a system suitable to our needs.

State borders debates are also heating up with case numbers being held down, or coming down, in the eastern states. In my mind, this is more an issue of state-preparedness than of risk of cases arriving from other states. Impenetrability of international or state borders cannot be guaranteed, therefore all states must have the resources and capability ready to respond. The decision then will be how the economic and broader societal advantages of open borders weigh up against the very small risk of the virus coming in from states with controlled local outbreaks, against the risk the virus will arrive some other way.

How far can we suppress this virus in Victoria in these remaining weeks of stage 4? The community transmission control is in our hands. We are now peddling downhill with the wind behind us… don’t ease off, pedal harder!

Catherine Bennett is chair in epidemiology at Deakin University.

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