IF you are depressed by the prospect of a winter of lockdown limbo, you might be even more depressed to consider that it could have been avoided altogether.

Not by having a “circuit break” now or a four-tier traffic light system.

Not through harsher penalties for those flouting self-isolation rules.

Not even by just “letting the virus rip” through the population while we “shield the vulnerable” indoors, as was last week advocated by the scientifically dubious “Great Barrington Declaration”.

There was an alternative exemplified in the Asia Pacific: a robust system for testing, tracing and isolating.

What do we actually mean by that?

Firstly, 80 per cent of people who are eligible for a test should be tested. In the UK this is mainly restricted to people displaying possible symptoms, but should also include groups particularly at risk of asymptomatic spread and/or superspreading – for example, students sharing halls of residence and health and care staff.

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It is impossible to know how many people in Scotland who think they might have the new coronavirus infection never bother to get tested.

We know there has been reluctance from some – especially those in low-paid jobs – who are worried they cannot afford to take 14 days off work.

Within hospitals, staff in certain departments – for example cancer units – are regularly tested for Covid regardless of symptoms, but many others are not.

Next, test results should be returned within 24 hours. There is no published data, either for the NHS-run or Lighthouse labs, to indicate what proportion of tests meet this timescale.

However, we know the return of schools and universities in England put Scotland’s Lighthouse lab (which processes tests from all over the UK, not just Scotland) under pressure, causing backlogs for test results.

Home test kits as well as tests from care homes, drive-thru centres, and walk-thru centres also have to be dispatched from all over Scotland to the Lighthouse lab in Glasgow when it might be quicker if they could be processed at local sites.

Delays of up to a week for some care home test results have prompted moves to transfer this responsibility to NHS labs by mid-November, although their overall capacity remains lower.

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Finally, at least 80 per cent of a Covid positive individual’s contacts should be traced within 24 hours of them receiving their test result.

Again, we don’t have this data. All we do know from Public Health Scotland’s reports are that between May 28 (when Test and Protect launched) and October 4 there were 15,901 confirmed cases of Covid in Scotland, and that by October 4 contact tracing had been completed for 82% of these cases.

That doesn’t tell us whether 80% of their contacts were successfully traced, nor how quickly they were tracked down.

However, we do know that for every person testing positive during this time, an average of 4.4 other individuals were contacted by Test & Protect, warned they may have been exposed to the virus, and told to self-isolate.

Which brings me to the final problem: the importance of self-isolating. We are told to self-isolate at home as soon as we develop symptoms, but how many comply with that? We have no idea.

According to the scientific advisory paper drawn up to guide the Scottish Government ahead of imposing the current 16-day restrictions, “claimed compliance with self-isolation and quarantine is low”.

The paper cites a UK-wide survey by King’s College London, carried out between March 2 and April 5, that found just 23.1% of people said they had stayed at home after developing symptoms.

Of course, this was before widespread community testing. It may be that people are more persuaded to self-isolate if they know they have Covid – but we don’t know that.

Unlike New Zealand, the UK borders have never been closed. And yet the checks on holidaymakers returning from quarantine list countries have been patchy at best.

No checks were carried out during the first four weeks of the policy due to an “administrative error” and the subsequent target (if it is even achieved) is to check on just 20% of returnees.

Other countries also provide dedicated 'quarantine hotels’ so that self-isolation is both easier to comply with and more rigorously monitored.

READ MORE: Why a shielding and non-shielding split is doomed to fail

Payments to support people to self-isolate are welcome, but should have been introduced months ago, and summer months should have been dedicated to achieving all of the above.

The fact the numbers of people admitted to hospital are rising as rapidly as they are tells us we failed.

Now we are lost in debates over levels of lockdown, when we should be asking why New Zealand is holding rugby matches in packed stadiums and has had just 25 Covid deaths to date.

It did it through a robust test, trace and isolate system, closed borders, clear public health messaging, and high compliance.

We did not need to end up here, and the public can be rightly angry that we are.