ANALYSIS: When Prime Minister Jacinda Ardern announces the new alert levels at 3pm on Friday, it will be astonishing if level 4 is not extended across the country.

In our newly acquired lingo around Covid-19, there is often talk of cases ‘downstream’ or ‘upstream’ of the initial case in the community. Upstream refers to cases closer to the source of the infection – sometimes called the index or primary case – while ‘downstream’ refers to people that may have been in contact with infectious cases we know about and have or could subsequently get infected.

The very good news on Thursday was that the ‘upstream’ was shorter than expected. It now appears that the person arrived in New Zealand on August 7 and tested positive on August 9. This is much better than another possible scenario, whereby the case was brought in by someone on a mercy flight out of Australia who arrived July 30 or earlier.

That would have meant the virus had been lurking out in the community, undetected for quite some time. The fact it appears not to have done so, is good news.

The bad news is that the potential downstream cases in this instance could still be plentiful. Some people spread the virus easily, others don’t. Most of the infected are young and have been to university, pubs, schools, the casino, church, a mall ... and KFC. These are places where the virus can be easily spread around.

To reduce the alert level outside of Auckland on Friday – given Delta’s virulence – health officials would have to be confident they had contract-traced every single person who had come into contact with an infectious person, and then be satisfied those people hadn’t passed it on. A Cabinet which has been pretty consistently conservative and cautious on these issues would then have to agree with that assessment.

Given all that and the fact that the infectious cycle is 14 days, it seems highly unlikely that there will be any alert level changes on Friday.

As with every lockdown there are both strong and messy aspects to the response. This time around the biggest messiness seems to have been around people getting home within 48 hours.

The thousands of people stuck in Queenstown, for instance, have been given an extra 24 hours to come home, on the grounds that there are simply not enough flights out. They have until when the lockdown could theoretically end to get home. The Government was simply mugged by reality here, transportation can't just be magicked up.

And that brings us to the initial three-day countrywide lockdown. If it is extended – which has seemed pretty apparent since Thursday – it would have been better to simply announce an extension.

The initial period of seven days in Auckland/Coromandel and three days elsewhere appears to be calibrated on the possibility that transmission outside Auckland/Coromandel could be quickly ruled out. Clearly that hasn’t been the case.

The issue here is that, because most people want to do the right thing: they think carefully about where they want to spend lockdown. The difference between three and seven or 14 days or more is not trivial. While the Prime Minister said on Thursday that she had indicated that it was a possibility – which she sort of did – most people aren't in fact political tea-leaf readers and clarity would have been better.

You don’t want to be too critical here because it's a no-win situation. On the one hand the Government erring towards shorter lockdowns is positive. But on the other hand, surely it is better to signpost a longer timeframe, which you can then shorten. Either way people could be irked.

And while the news on Thursday was more positive, there was another darker cloud. It now looks most likely that the case somehow jumped out of managed isolation and quarantine (MIQ). In this instance a human failing in the system somewhere is almost more comforting than the opposite.

A few hours before this new community case was announced on Tuesday the Ministry of Health revealed another case where there was transfer within an MIQ facility because two people open doors simultaneously for a few seconds.

If there was a mistake of either process or practices within MIQ the Government can be held to account and the problem be sorted. If it is something far more random – such as two people opening doors at the same time – it means that even if we succeed in suppressing or even eliminating Covid-19 after this outbreak, it will be a constant companion at the border.

Only last week the Government announced its plan to reintegrate with the world. That will be a very hard ask politically if further lockdowns are the price we will collectively pay, which we probably will, because we are committed to eliminating the virus.