Coronavirus: New maps show which parts of New Zealand are most at risk if there's a new outbreak

New maps showing which parts of New Zealand are most vulnerable if there is another COVID-19 outbreak could be used to speed up future pandemic responses, experts say. 

Researchers at the University of Canterbury looked at not just age - the biggest factor when it comes to the chance of dying of COVID-19 - but also ethnicity, population density, deprivation, health conditions, smoking rates, linguistic barriers and health service awareness/access to find out what regions would be most at risk in a future outbreak.

To date just 26 people in New Zealand have died of COVID-19, which has killed at least 2.8 million people worldwide - likely hundreds of thousands more. Modelling early last year suggested tens of thousands of Kiwis could potentially die in an uncontrolled outbreak, prompting the Government to enact one of the strictest lockdowns in the world to eliminate it from our shores completely. 

"Vulnerability to COVID-19 depends on a number of factors including older age, disadvantage, background medical conditions and smoking," said Dr Amanda Kvalsvig, an epidemiologist at the University of Otago's Department of Public Health. "These factors tend to occur together, creating a 'syndemic' situation where people experience multiple types of disadvantage, leading to multiple health issues."

Dr Collin Tukuitonga of the University of Auckland's Faculty of Medical and Health Sciences said areas "with high Māori and Pacific populations are among the most vulnerable, including south Auckland and Porirua", because of "known health inequities in care and access across New Zealand, particularly for ethnic minorities and those living in socioeconomically deprived areas".

"Identifying where these areas of high vulnerability are located allows for better targeting of resources."

The new maps combine all the risk factors to show just where the biggest risks are. Light-coloured areas are low-risk, mauve areas at risk due to high numbers of people over-65, lavender for other factors like deprivation and health conditions, and a deep violet for both. 

The risks, weighted towards socioeconomic factors.
The risks, weighted towards socioeconomic factors. Photo credit: Journal of the Royal Society of New Zealand/University of Canterbury

That parts of the country with high density and low incomes such as south Auckland are considered vulnerable won't be a surprise. 

"This is reflective of increased deprivation, negative health behaviours such as smoking, larger Māori populations and lower service awareness in these areas," the study, published Thursday in the Journal of the Royal Society of New Zealand, said.

The risks, weighted towards age factors.
The risks, weighted towards age factors. Photo credit: Journal of the Royal Society of New Zealand/University of Canterbury

But with a relatively young population, it's not amongst the most at-risk according to the University of Canterbury researchers. 

"There were notably few areas of high vulnerability based on [age and socioeconomic factors] in major cities, demonstrating that vulnerability based on this combination of factors may be more influential in rural areas of New Zealand, particularly those with large Māori populations," the study said.

"This is an unexpected pattern compared to common findings that study the overall population and often identify worse health and well-being outcomes in urban settings. Such findings may be due to higher concentrations of younger populations living in socioeconomically deprived areas of cities compared to deprived rural areas."

People living rurally also typically have "less access to healthcare and fewer resources" than those in the cities, "and also attract less attention". 

The risk in the cities.
The risk in the cities. Photo credit: Journal of the Royal Society of New Zealand/University of Canterbury

Outside of the cities, the North Island areas with the biggest overall risks were the western coast of Northland, the East Cape, south and west of Lake Taupo, parts of Manawatu, Taranaki and Wairarapa, Mahia, Kawhia and Coromandel.

In Auckland south and west are moderately at risk, but the study also singled out wealthy Mission Bay and isolated Waiheke Island due to their older populations.

In the South Island, Kahurangi, parts of the West Coast, Southland and Otago and Stewart Island are vulnerable. 

"Interestingly, this offers some support for the actions taken by some local communities who, recognising their vulnerability, implemented protective measures (additional to nationwide lockdown) such as road barriers, to protect their populations," the study said, referring to controversial moves like those taken by former MP Hone Harawira in Northland. 

Dr Kvalsvig said while the maps remain a broad stroke, "this type of approach is a huge advance on looking at health factors one by one".

"An important contribution of the paper is that the methods used to understand and communicate about overlapping risk factors could be used in many other ways: to plan the response to a new pandemic for example, or to map strengths and resources in communities across the country. 

"Area-based information about strengths and risks has enormous value in a public health emergency because it can guide decision-makers to get the right resources immediately to where they’re needed, without waiting for things to go wrong."