Coronavirus: Expert doesn't trust Kiwis to stay inside if lockdown rules relaxed

Although it looks like we're successfully flattening the curve, don't expect the lockdown to be lifted early - or even on time.

That's the message from David Murdoch, infectious diseases specialist at the University of Otago, as new figures show New Zealand so far is avoiding the kind of exponential growth in COVID-19 cases seen overseas.

We've now got more than 1000 confirmed cases of the virus, but the growth in numbers has been steady despite a rapid increase in testing. Forty-five percent of cases have to date have clear links to international travel and 36 percent are contacts of known cases. 

Cases of confirmed community transmission are just 1 percent, while the remaining 18 percent are still under investigation.

"Cautious optimism I think is probably what we have at the moment... waiting to see whether we see a true trend. Great to see the fact the numbers are staying steady each day," Dr Murdoch told The AM Show on Monday.

"It's important to remember if we have uncontained transmission in the community, we'd expect to see increases every day - which we're not seeing. This is good news so far."

New Zealand has been on a pandemic alert level 4 lockdown for one-and-a-half weeks. As the virus can take up to 14 days to show symptoms, it's hoped soon the daily number of cases will start to drop - meaning the lockdown and social distancing measures are working. 

Without a vaccine or proven treatment for the disease, they're all we have right now to kill it off. Even if the number of cases starts to drop, Dr Murdoch says we shouldn't expect the lockdown - initially set for four weeks - to be loosened until it's absolutely clear the virus has been defeated. 

There is growing evidence the virus can be transmitted by people showing no symptoms, who might not even be aware they're infected. 

"I think as a country we've done well, but I'm not sure I trust us to keep going once [the rules are] relaxed... I think we'd have to have a very, very good reason to relax them early... If we start to see things go the way we hope it does and cases drop off, the risk is complacency. We really have to keep it going longer than we think.

"I think everyone should be prepared for a longer period of shutdown, whatever that is. We need to be prepared for it. It would be wonderful if it wasn't, but the chances are pretty high."

Government modelling had suggested without the lockdown, we'd have 4000 cases by now. For comparison, the US had 4000 cases just three weeks ago, with 87 deaths. They've now had 321,000 confirmed cases and more than 9000 deaths. New Zealand has had a single death so far. 

Just two-and-a-half months ago, the entire world only had the number of cases New Zealand has now.