Total lockdown and Henrik Ibsen

Today's announcement of additional postcodes returning to stage 3 restrictions and a total lockdown for 3,000 people in public housing could be encouraging:

Statement From The Premier

It implies that governments are following public health advice to ensure the hospitals do not get overwhelmed.

There is still no recognition that the need for this retreat indicates that the current level of opening up is already unsustainable. But perhaps it indicates that if and when that does become clear, the resulting shutdown will be clearly aimed at Eradication.

Even with successful Eradication (at least a month with no new cases) it can be expected that occasional sporadic outbreaks would occur (both from quarantine failures and the very long tail of asymptomatic or pre-clinical carriers). The point is that sporadic outbreaks can be contained by the sort of local measures successfully undertaken relatively easily in regional Northern Tasmania and now being taken with greater difficulty in suburban Melbourne. The resources available for testing, contact tracing and isolation can contain an outbreak that really is just local, sporadic and occasional.

But with any level of underlying "community transmission" there is simply no way to avoid the statistical certainty that some of the regular inevitable clusters resulting from that will become outbreaks, some of which will again become epidemics.

According to the current testing results we now have an unacceptable level of community transmission from untraced sources whose contacts are unknown and cannot be isolated. That level is higher than when Australia abruptly went into stage 3 physical distancing. We are now restoring the same level of "stay at home" orders in 12 postcodes that we had more widely in March, plus a total lockdown for 3,000 people (enforced by 500 police, 1 for every two or three households!).

It may well be feasible to contain the current epidemic wave without the wider response that was needed in March, because:

• We are able to do far more testing now and can be more confident that the level of community transmission is not already dramatically higher than we are aware of.
• The surge capacity of the hopsitals has been greatly increased.
• We know that if containment fails we can revert to stage 3 restrictions and expect them to work rapidly enough to avoid the increased surge capacity being overwhelmed.

Obviously it is better to impose these restrictions locally than nationally if that can work, just as it is better to isolate large numbers of "contacts" than to shutdown the whole society.

But the main reason for confidence that these local shutdowns could work is the genomic evidence that they originate from a single common cause. The virus strains of many current cases were not known in Victoria prior to the shutdown and so can reasonably be assumed to have arisen from failures of quarantine of incoming travellers rather than from underlying
"community transmission".

If that was not the case, it would be illogical to attempt just shutting down local areas, except as a way of preparing for a wider shutdown. The underlying community transmission could not reasonably be assumed to be sufficiently localised for that to work.