Coronavirus: Cluster ‘could easily spread beyond Auckland boundaries’, says data modeling expert

The only group in the country may have its roots in the City of Sails, but the outbreak “could easily spread beyond the borders of Auckland,” explains a leading data modeling expert.

Professor Shaun Hendy de Te Pūnaha Matatini at the University of Auckland: The Center for Complex Networks and Systems contributed to a modeling document delivered to the Ministry of Health this week.

Among the findings was a figure cited by Prime Minister Jacinda Ardern during Monday’s announcement that Auckland and the rest of New Zealand would remain at 2.5 and 2 respectively.

Ardern referred to the newspaper’s finding that there was a one-in-four chance that a Covid-19 case could breach Auckland’s boundaries, and said it informed the government’s decision-making process about this week’s reassessment.

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The modeling paper, released to Stuff on Wednesday, it reported that the possibility of Covid-19 spreading to other regions “will remain as long as there are active cases in the Auckland group combined with near-normal rates of interregional travel.”

Hendy said the evaluation was made based on estimates of the number of detected and undetected cases that may be present in the community.

“Putting those two things together, we can consider the likelihood that we have a case outside of Auckland. If you are in the North Island, it is between 20 and 30 percent. If you’re on the South Island, it’s between 5 and 10 percent, so your chances of finding something outside of Auckland are 1 in 4, ”Hendy explained.

He believed the figure represented a “high probability” that a case would escape from Auckland, with the probability influenced by people’s travel in and out of Auckland: the longer an Aucklander stayed outside the region, the riskier the visit.

“This means that people outside of Auckland should take precautions and not think that this outbreak is something that is confined to Auckland. I think what this shows is that everyone must be cautious across the country.

“There is a tendency to think that it is limited to Auckland, but it could easily extend beyond the Auckland limits. Certainly when we look inside Auckland, [the cluster has] touched all parts of Auckland. It has not been limited to a single suburb, ”Hendy said.

Health Director General Dr. Ashley Bloomfield said the 25 percent figure was “essentially an average across the country, with the difference between the North and South islands.

“About a week ago, outside Auckland [in the North Island], the risk was between 30 and 40 percent, and in the South Island, between 10 and 20 percent, so there was a difference.

“In both cases, it is obviously not zero, and it will continue to decline as the days go by when we do not find cases that have focused outside of Auckland,” Bloomfield said Wednesday.

One of the latest sources of concern centers on the Les Mills gym in Takapuna, where nearly 100 people were classified as close contacts of a Jet Park Hotel health worker who tested positive for the virus.

Since most people develop symptoms four to six days after exposure, the most likely time period for any potential case of Les Mills would show that symptoms would occur from September 13-16.

The model also looked at how well the Auckland cluster had been contained, and although contact tracing “took a while to catch up” in the early stages of the outbreak, once the city went into lockdown alert level 3 , tracking efforts “were quickly ahead of the cluster.”

While it is only “the early days” in terms of level 2.5 restrictions, Hendy said the model showed that it had been an effective step.

“That means maybe we can expect to lower alert levels in the coming weeks,” Hendy said.