With winter fast approaching and New Zealand's borders about to open to all tourists in July, Herald reporter Emma Russell looks at how our country is tracking with non-Covid illnesses.
An outbreak of influenza among university students has sparked a sharp rise in New Zealand's overall rate of flu-like illnesses.
However, one expert says, despite the new cluster, overall cases of winter bugs were still tracking at a lower rate than the five years before our country was hit with the Covid-19 pandemic.
ESR virologist Sue Huang said we are still months way from a seeing a spike of flu-like illnesses and warned New Zealanders to ensure they and their kids were up to date with their vaccinations.
In the week ending May 8, the number of new influenza cases recorded by Environmental Science and Research (ESR) was 50. In comparison, the average number of cases seen that week during the five years before the pandemic struck our shores was 16.
Before May, only eight cases of influenza had been recorded this year.
Huang said this was "remarkable" and "strange" so she investigated further and found of the 50 cases reported, 44 were from Dunedin.
"This is likely because there are a lot of students living in Dunedin. They're living in poor conditions and they are generally more active than the rest of the general public. Viruses are floating a lot in that area," Huang said.
"It's a cluster from a uni student outbreak," Huang said.
She said uni students were far more mobile so likely to have been travelling to Australia and their immune system could be down due to two years of lockdowns and New Zealand's borders being shut.
However, overall rates of flu-like illnesses were still significantly lower than pre-pandemic times.
In the five years between 2015 and 2019, before the Covid-19 pandemic hit New Zealand, the average number of influenza cases we would usually see by this time of year was about 265. This year, ESR has so far recorded 58.
"Usually it's around July and August that we see the flu start to peak," Huang said.
She said we would likely see some influx from our borders opening to all tourists in July but given that many travellers would be coming from the northern hemisphere, which would be in summer, it may not be too severe.
ESR gathered data from six major hospital labs in New Zealand - in Wellington, Waikato, Christchurch, Dunedin and two in Auckland. The cases came from people presenting to hospital and general practices who tested positive for influenza.
New Zealand Principals' Federation (NZPF) president Cherie Taylor-Patel said schools were struggling to find relief staff to cover teachers away with Covid and they were also starting to see kids away with other sicknesses.
"The last two years have been anything but normal. We have spent a lot of time in lockdowns so we haven't really had a normal winter in the last couple of years."
Taylor-Patel, who is also the principal of Flanshaw Road School in Te Atatū South, Auckland, said there was general unwellness which was a backlash from Covid.
"People have been living in quite anxious states for quite a long time and there was a bit of fatigue and stress catching up with people."
She said schools now had a strict "stay home, if sick" policy which helped prevent the spread of colds and other illnesses.
"In classrooms, people are still working hard to social distance and use sanitiser, making sure ventilation is attended to so that all these protection factors were in place as much as they could be."
The Ministry of Health's Flutracking site showed rates of "influenza-like illness" was trending higher than the last two years but still below 2019.
Last year, New Zealand was hit with an RSV outbreak, which is a contagious respiratory virus prevalent in babies and young children.
By July, more than 4000 people had become infected with RSV that year and by August, nine New Zealanders had died after becoming infected with RSV.
ESR public health physician Dr Sarah Jefferies said, at the time, the high prevalence of RSV was likely the result of lower population immunity because of New Zealand's Covid-19 isolation last year, and the increase in movement since then.
There have only been four cases of RSV recorded so far this year.
Meanwhile, ESR records show so far this year 1469 people have had rhinovirus, also known as the common cold.
Immunisation coverage 'way too low'
Vaccinologist and associate professor Helen Petousis-Harris said our vaccination coverage was "way too low" and on some level people hadn't prioritised getting their "other" immunisations because Covid has been an unwelcomed distraction.
But, she said, that was only part of the issue. Government funding to raise awareness about the importance of getting vaccinated had dropped significantly and it had been replaced with the spread of misinformation, Petousis-Harris said.
"If you're not aware, it flies off people's radar. [Raising awareness] isn't just something you can do from time to time, you've got to do it all the time because every year we have a new cohort come along."
Vulnerable communities, such as Māori, are often targeted by groups spreading misinformation and access to immunisation services had also eroded, "you reap what you sow, so as soon as that happens, coverage drops," she said.
Herd immunity depends on the disease, so for highly infectious diseases, like measles or whooping cough, the threshold is closer to 95 per cent vaccine coverage, whereas it's much lower for influenza, about 50 per cent, Petousis-Harris said.
For meningococcal vaccines, which was only available privately, herd immunity was much lower, like 30 per cent, because it doesn't spread as rapidly, Petousis-Harris said.
Only 68.3 per cent of 18-month-olds have been fully immunised, which is the age toddlers should have two measles vaccine doses.
That's out of 15,000 18-month-olds, which means 4755 who are that age haven't been fully vaccinated.
"That is way too low and the problem is it's not just that cohort because you have the kids who turned 5 this year and then the kids that turned five last year or the year before or the year before that, so you know have a lot of individuals without those vaccines," Petousis-Harris said.
Immunisation coverage for toddlers who were aged 54 months (4.5 years) sat at 67 per cent. That's out of 15,768 kids who were that age, which means at least 5203 54-month-olds weren't fully vaccinated.
"We will see these viruses again, influenza is here and we will see measles come in again and we will see reassurance of viruses that have been here all along but because of our behaviour it's been suppressed."