Wairarapa is likely in the grip of its next covid-19 wave, with the region high on the leaderboard for infection rate in New Zealand.
Ministry of Health [MoH] data showed new cases in the region were increasing week on week since mask mandates were removed on September 12.
The ministry confirmed this week that Wairarapa had one of the highest infection rates in the country, with the expectation that case rates would vary regionally over time “as the virus moves through the community”.
Data analyst David Hood, who graphs daily MoH case numbers against population data, said the rate of infection was trending upwards across the board.
However, the lower North Island had seen significant increases, with a steep upwards trend in Wairarapa compared with other regions.
“It’s pretty much from when mask mandates lifted. However, we’re watching how far it goes and how sustained the increase is.
“At the moment it is not really distinguishable from new variants and waning immunity.
“But, we can say, the chances of catching covid when out and about in Wairarapa are higher than what they were a couple of weeks ago.”
Hood’s October 12 data analysis estimated the rate of infectious people per 100 met in Wairarapa was doubling in less than two weeks across multiple age groups.
“For example, 0.18 per 100 is about two people per thousand. So, to explain the risk from that number, if you meet 200 people in a day, what is the chance at least one is covid positive?
“While the chance one person is positive is low, the chance of not meeting anyone covid positive in a day starts to drop.”
He said new cases showed a general community increase rather than a targeted school or rest home outbreak.
“The trend over 2022 was that older people were among the last to fall. The first people were working age, or the 20-29 age group, then schools, then up the age groups.
“The recent infections, however, tend to be older than in that first wave in February.”
Hood said it was likely the spike in Wairarapa was driven by new covid-19 variants, however, without regional genome sequencing data it was impossible to be certain.
The latest Ministry of Health covid report said the BA.5 variant was well and truly surpassing the Omicron strain, accounting for 75 per cent of cases nationally in the two weeks to September 30.
However, it said the latest data showed the BA.4.6 variant had increased sharply to 15 per cent, with the B.2.75 variant not far behind on 10 per cent.
ESR said the latest wastewater genome sequencing report noted two genomes from Wairarapa, “both of which were BA.5”.
“However, due to the low volume of PCR tests available for sequencing in the Wairarapa region, we can’t comment further on this reliably.”
Otago University professor of public health Michael Baker said covid infection numbers had never sat still, reflecting a “dynamic situation”, and New Zealand was now experiencing global trends.
“What we are seeing here is the introduction of new subvariants that can evade some of our immunity.
It’s just natural selection.”
He said globally there had been two “big discrete waves”, with new variants leading the charge.
“The numbers are the product of opposing forces. It could be a mixture of waning immunity from vaccination or infection, new variants, and lightened controls.
“It’s generally very hard to know what’s most important because we’re not measuring most of these factors.”
Baker warned against the illusion that New Zealand was now in post-covid era, saying the big peaks of northern hemisphere infection occurred in summer.
“The excess mortality is around 25 million now globally, and it has been the number on killer for two successive years.”
He said what New Zealand needed was a long-term strategy for when covid became a more predictable and endemic disease.
Baker said on the individual level people needed to think about boosters and anti-virals.
“Think about your exposures in indoor settings. Confined, crowded, and close contact applies to almost all social events that we love.
“N95 masks are very effective. You shouldn’t feel the need to turn into a hermit.”