26 Mar 2020

How lockdown, contact tracing may stamp out Covid-19 in NZ

From Checkpoint, 5:24 pm on 26 March 2020

Modelling by New Zealand researchers shows how the country is buying time in the fight against Covid-19.

There is no certainty the four-week lockdown will be enough. Researchers say that left unchecked the virus would infect 89 percent of the population and up to 80,000 people would die.

The good news is with the current strict measures fatalities would drop considerably.

But that scenario requires the restrictions to be in place for some time - so how long?

“The important thing about that modelling is really we did a lot of that work before New Zealand took these very strict measures, so really we were looking at what would happen if we didn’t,” University of Auckland Professor Shaun Hendy told Checkpoint

“But we have taken some very strong controls, and that gives us a pretty good chance at getting on top of things. 

“One thing that’s not in our modelling - and this is something we’ll be working on in the next couple of weeks - is the effect of things like contact tracing and testing. 

“That actually gives us a pretty good chance at reducing the length of time we’ll have to be in that lockdown but we’re going to have to watch those case numbers. 

“Our argument is provided that we’re clearly getting on top of those case numbers, particularly the community transmission - that’ll be a signal as to whether we can relax the current alert level four,” Professor Hendy says. 

Under New Zealand’s current lockdown restrictions, the estimated number of fatalities from Covid-19 would be very low, he says. 

“If we kept this up, in our model we could keep the fatality rate to a very small number,” - less than 100, Professor Hendy said. 

“The big ‘but’ is that we’d have to keep that going for a very long time, essentially until we’ve got a vaccine.

“But because we’ve also go the contact tracing taking place and the testing taking place, and the fact we can quarantine people who have Covid-19, this regime should be more effective than what we’ve modelled.” 

Having contact tracing going at the same time as the lockdown gives New Zealand a chance at stamping it out, and the possibility of relaxing the lockdown, Professor Hendy said. 

“If need be, the tougher strategy we’re embracing now - we can use it into the future to keep deaths low.

“We just have to stop enough people passing it on, and eventually the disease will die out.

Professor Hendy said completely closing New Zealand’s borders to any entry may help, but by and large that is less risky than community transmission. 

“We’re really concerned about the transmission that might be taking place in parts of the country that we’re unaware, because that’s where there’s the potential for the exponential growth that we’re seeing in Italy and the US at the moment.”