It also shows that children under 10 infect fewer people on average and are less likely to become “super-spreaders,” defined as infecting more than five other people.
New Zealand recorded nearly 1,500 cases of Covid-19 between February 26 and May 22 last year, before a nationwide lockdown and several other major measures effectively eliminated the virus.
In the study, Associate Professor Alex James and fellow modeler Te Punaha Matatini used a wealth of case data – mostly collected through contact tracing – to find patterns around how the virus spreads in these important months.
They found that, before moving to alert level 4, more than half of all domestic cases resulted in at least one secondary case.
But age plays a role in how many other people who are infected can pass on the virus.
Modeling shows the effective reproductive rate (R) – the mean number of secondary cases – is estimated at 0.87 for children under 10 years, 1.49 for people between 10 and 65, and 1.51 for those older than 65.
“Although children under 10 years of age are equally likely to infect at least one person, adults tend to infect more people than children under 10 years of age,” the researchers reported.
Cases among adults and the elderly also had a “significant” chance – 6 percent in the 10 to 65 group and 7 percent in the over 65 year group – of being a super-spreader.
During the lockdown, the R rate fell to below one for all of these age groups except for those over the age of 65 – something that may be due to elderly care facilities being over-represented in data from later stages of the epidemic.
In all, the researchers identified 29 super spreaders – 21 of which had symptoms of Covid-19 before the lockdown began.
Of the other eight who had symptoms during lockdown, six were involved in the elderly care group.
The study also highlighted that children under 10 tend to have a lower “secondary attack rate” – a measure that determines the likelihood of infection spreading among a close or vulnerable group of people, such as households.
This is in line with research abroad – such as the finding that “super-spread” events are a major contributor to transmission.
“Our results show that among adults 20 percent of cases are responsible for between 65 percent and 85 percent of transmission,” the researchers said.
“This suggests that interventions targeting super spreaders or super spread events may be very effective in reducing the spread of Covid-19.
“This may include restrictions on collection size, especially in confined environments or crowded spaces.”
While health officials struggled to contain the Auckland cluster in August – which ultimately led to 179 infections and three deaths – scientists helped link the cases by sequencing the genomes of positive samples.
Overall, they were able to generate genomes from about 81 percent of laboratory-confirmed samples – or 145 of 179 cases – and then compare them with available global genome data.
It quickly informed them that the virus behind the outbreak was part of a group – and thus from one introduction into the community.
“Indeed, the timing and duration of the locking action was partly informed based on these data,” said study authors, led by Otago University and ESR virologist Dr Jemma Geoghegan and University of Auckland researcher Dr Jordan Douglas.
“Overall, real-time viral genomics have played an important role in eliminating Covid-19 from New Zealand and since then helping prevent additional regional lockdowns, leading to substantial economic savings.”
However, they say an important tool has been limited by the “biased nature” of global sampling, including the contribution of very little genome sequences from a particular region.
“We therefore recommend that potential sampling biases and gaps in the available genomic data be carefully considered whenever trying to determine the geographic origin of a particular SARS-CoV-2 outbreak,” they said.
“The analysis should consider all available evidence, including that from genomic and epidemiological sources.”
Waitaki was pushed by a powerful force. Steam, coal, hydropower, tectonic forces – the whole region seems to be filled with energy.
From the Argentinian charcoal grill Pablo Tacchini to the crackling, popping coke at Nicol’s Blacksmith; from the steam-powered madness of the retro-futuristic Steampunk movement Ōamaru to the power of the hydro dams lining up and down the intertwined Waitaki River, and the slow grinding power of earth that creates the incredible Waitaki geopark; Waitaki is strength and strength.
However this was an area only a few Kiwis could place on the map.
If flying from the north, you will enter Waitaki about half way between Dunedin (the nearest airport) and Ōamaru (the district’s main city). It’s a route that takes you past some of New Zealand’s long-respected stops – Moeraki’s breezy rocks and legendary seafood restaurant Fleur to start. But take your photos and eat fast, because Waitaki has so much to explore.
Ōamaru is a small town full of character, and character. In the Victorian Precinct, a scene of neoclassical limestone streets built in the 1860s, you’ll find Craftwork, a small building that looks like a Belgian pub. Inside, at the tap or waxing the lyrics to the customer, you might find Michael O’Brien and Lee-Ann Scotti, the owners of this little brewery (forget micro-brewing; it’s nano-sized) and the tasting room. The pair are cunning to the point – she was once a bookbinder, she sewed her own clothes. In a three-piece corduroy suit and mustache, Michael speaks passionately about Belgium and the guild hall and farmhouse brewery, and educates his guests about Wallonian saison, unknown trappist beers, and other specialty and rare drinks. The tasting room makes nano clocks to match their manufacturing capacity, so check before you visit to make sure they’re open.
If the strong ales (and they are very strong) steal your time, make sure you go when the daylight disappears outside, because when the sun starts to set in Ōamaru, the penguins come home. Hundreds of them, en masse, arrive each night from the sea to the Ōamaru Blue Penguin Colony – an old stone quarry, just a five-minute drive from the city.
These are the smallest penguins in the world, but they are mighty. Blue penguins swim up to 50 km each day, hunt and eat as they go, covering miles before coming ashore in rafts of up to 100 birds at a time. Crowds ooh and aah as they sweetly scramble down the slopes of the mines, dodging the common fur seals that get in their way and aiming for their fins when they get too close.
They bring food for their chicks and will immediately regurgitate it for the chicks’ daily food. But for now, they’re packed – they stumble like drunks back home, belly bloated, balance more than a little off-center.
You will immediately understand how they feel. From the old quarry, it is only a few minutes’ drive to Cucina, an Argentinian restaurant located in the Category 1 building, 1871 on Tees St. The building has been home to women’s hats, AMPs, tailors and office space. Now, on the grill, Pablo Tacchini burns old steaks according to the traditions of his native country. Pablo and his wife, Yanina, moved to Ōamaru in 2008. Eight years later (and now with three children), they run the Cucina and Tees St Cafe around the corner. Here, the food reflects Pablo and Yanina’s heritage and culture, and a little bit of Kiwi ingenuity too.
On the party menu on a winter’s night there are pork and apple empanadas, grilled cauliflower and labneh. There’s homemade chorizo sausage and ribs branded with a charred line and topped off with ashes from the fire. For dessert, hot oiled churros, and fire-roasted marshmallows. Get the food out, eat slowly, enjoy the feast. As we left, the city clock rang at 10. Cucina speakers rung music into the dark streets as we returned home, fat and unbalanced like little blue penguins.
How to revive the city
Few people have heard of Duntroon, a half hour drive from Ōamaru. This small town may sound like a ghost town in the Scottish Highlands or a revolutionary American outpost, but in Waitaki, it’s a city of being reborn.
In Duntroon (population: approx. 114), smoke and fire are part of what revives the city. Here you’ll find Nicol’s Blacksmith, a smithy who was named after Duntroon’s last blacksmith, Nicol Muirden. Muirden retired in the 1960s, and the workshop was empty for many years. But thanks to some enterprising local farmers, the building was saved and restored, and the business revived.
International visitors have never been a major part of this 130-year-old blacksmith trade. It’s the Kiwi who wants to bang and hammer in the hot coals of the hammer. Nicol’s offers a course for visitors – for just $ 90 for a half day of training, a volunteer blacksmith will guide you through the bellows, heating your metal, banging it into shape. The smell, heat, instrument light, and the sound of hammering were intoxicating. It’s tough and rewarding work, and within an hour or two the visitor can have his own poker hammered, twisted and twisted, a memento of a job well done.
70 million years in the making
New Zealand… rocks !!! that’s the old joke of Flight of the Conchords.
Around here, rocking is serious business. Duntroon is surrounded by the Waitaki geopark, an area of geological and scientific interest covering 7,200 square kilometers where visitors can drive from site to site (mostly on private land, but visible from the road) on their way through Waitaki.
This park is a series of geological sites that are phenomenally named. Earthquake limestone cliffs, alien form Elephant Rocks and the picturesque Whale Valley are all a must-stop along the Vanished World Trail – a heritage trail that takes you through 75 million years of history – from fossil remains of fantastic creatures to extinct volcanoes and limestone cliffs that collapsed.
Geologists think a little differently than the rest of us. As the garden educator, geologist Sasha Morriss, shows us, she calls the Southern Alps “new” (they started appearing about five million years ago). He showed us around the Elephant Rocks and explained how limestone is just compressed fossils – just layer upon layer of giant pounding penguins and shark-toothed dolphins and other prehistoric animals (think of that fact when you gaze in awe at the limestone Ōamaru Architecture).
As he guides us through Whale Valley, we learn that where we stand was once a solid ocean floor, eroded by water and wind over millennia to become what we see today – even though what we see varies. Where some people saw elephants, I saw giant boots, persimmons and a honeycomb, which seemed to fall from the sky. We stand on rocks the size of buildings and depict sea creatures swimming above our heads. With a little imagination, that’s wonderful.
The area’s appeal doesn’t end there – around the corner, historic Māori rock art; at Duntroon, the remains of a large toothed dolphin with jaws that can easily grab your head. Waitaki is eyeing Unesco’s geopark status, aiming to become the first of its kind in New Zealand.
From pebbles to grapes
The Waitaki River begins at Lake Benmore and is the natural boundary that separates Otago and Canterbury. It is in this river of complex and ever-changing braids that we turn.
Jet boat driver Ron picked us up outside Duntroon. We took a braided line, and walked down the river, towards the Waitaki hydro station. In freezing and dangerous conditions, 1,200 people built this dam. Ron describes the work that went in, and points out the endangered species that nest on these isthmus, which is always on the move. She just relaxed until we were comfortable, then wagged her finger in the air to prepare us for the 360-degree turn that had our heads spinning like a dash hula girl. The water was six degrees, and the splash from the river water we received made the face numb.
How to fix it? Straight from the gravel to the grapes. A river trip can be tailored to suit your needs, so why not choose a vineyard as a starting point for your trip?
Waitaki has one of New Zealand’s longest growing seasons, and the limestone layers that run across the region give its grapes a special character. With cool air from Ōamaru acting as the valley’s natural air conditioning unit, with cool nights balancing the warm days, this is the place to enjoy pinot gris, pinot noir, and chardonnay, when you ignore the native vines.
River-T Estate prides itself on not only storing their own wine, but also the world’s largest collection of Waitaki wines. The reason is that many producers in this area are very small, this is the only shop in the country where they are found. You don’t get more local boutiques or more than that.
Enjoy a tasting paddle from a warm chair in the sun overlooking the vines. And grab a bottle to go, because you won’t find this, or the incredible Waitaki treasure, anywhere in the country.
Soak your bones in the fresh mountain water in hot tubs in Omarama. This private outdoor bath overlooks panoramic views including Benmore Peak. hottubsomarama.co.nz
Visit Duntroon’s The Center of the Lost World to see the remains of a 25 million year old toothed dolphin, and obtain real-life excavation equipment. vanishedworld.co.nz
Stay at Duntroon’s Black Cabin, which is suitable for two people. Here, every detail is thoughtful, with stylish black fixtures, smart storage features, and everything you need for warm, cozy nights and healthy breakfasts. blackcabin.nz
For more New Zealand travel ideas and inspiration, visit newzealand.com