Rotorua schools are seeing an "upsurge" of seasonal flu, colds and gastric illness among staff and students - with one principal worried the high level of absences would result in "children in catch-up mode".
This comes as another secondary school has asked junior students to learn remotely this week due to a "significant" number of staff members testing positive for Covid-19.
Westbrook School principal Colin Watkins said the continuity for kids to learn had been "shot in the foot big time" because of the level of winter illnesses circulating in recent weeks.
He compared the number of staff and students absent to when Covid peaked in the school community in Term 1 at the end of March.
At its highest during this time, there were 190 students and about seven staff infected with Covid, he said.
Levels of staff and students testing positive for Covid was currently low, but other sicknesses - including flu, colds and gastric illness - were "taking a massive hit".
At one point there were between 115 to 125 students away which equated to nearly a quarter of the school, he said.
This had dropped since then, with 66 students and five staff absent on Tuesday.
He said when there were a number of teachers or students absent for multiple days it had a significant impact on the continuity of learning.
"It's terrible - we thought we were out of the woods at the end of last term when the numbers of Covid started to drop. The continuity for kids to learn is shot in the foot big time. Kids need to be [at school] every day to pick up learning on an incremental scale," he said.
"It's stalling learning for kids because of the lack of consistency of attendance at school. It's having the same impact that Covid had over the last two years, except it's not Covid."
He believed the country would "pay the price" for the high level of absences and which would result in "children in catch-up mode".
"I can tell you honestly that we are seeing a dip across the school in the performance of students at most year levels because there are not enough kids in the classroom."
"For every day a child is away, they miss out on three days of learning because the consistency has been broken."
Staff absences and difficulty securing relief teachers had also meant some students had to be spread across various classes. Watkins said he had only done this on two separate days when there were no other options.
Other times staff would fill in for each other, he said.
Rotorua's Western Heights High School asked its junior school students to stay home this week after a "significant" number of teachers tested positive for Covid-19 over the weekend.
In a letter emailed to all parents and caregivers, principal James Bracefield asked Year 9 and 10 students to stay home from Tuesday until Friday.
Bracefield said teachers would provide students with work today and on Google Classroom. However, teachers would not be conducting Zoom lessons as they would be working with Year 11, 12 and 13 students, who would continue to attend school for the remainder of the week.
On Tuesday, Bracefield told the Rotorua Daily Post that 15 out of 80 teaching staff were off sick.
"With winter illnesses and the re-emergence of Covid, we have had a contingent of staff out of the school which we can't cover by relief teachers. So we have sent the Year 9 and 10s home to be learning remotely."
Bracefield said it was important senior students were on site to complete assessments before the end of term and praised those who were unwell and taking responsibility to stay home.
Getting students to learn from home was a "last resort" for the principal, who said they always did better when they had a teacher in front of them. It ensured hands-on learning, social interaction and helped instil a sense of belonging in students.
He said the school was seeing a "higher number" of illnesses in general compared with previous years. Masks were not mandatory at school, but strongly encouraged.
He said the school may look to change this in the future if levels of sickness continued to escalate.
Kaharoa School principal Lynden Cook said there was a larger number of staff and students absent compared to previous years - either isolating as a household contact, Covid-19 positive or away with seasonal illness.
The school's three junior classes had been particularly impacted by this.
Cook said to manage the situation there were "a number" of junior students supported with learning from home this week. Caregivers who needed support to be able to work could continue to send their children to school.
John Paul College acting principal Maree Stewart said there had been a "big upsurge" in Covid cases this week and the winter flu had been "taking its toll" over the past fortnight.
This meant an increased number of absences among staff and students, she said.
"There is an upsurge in both of those at John Paul College.
"Staff absences are big. On Friday we had six away with the flu and on top of that we have had four recently with Covid."
She said while the school was fortunate to have a "good team" of relief teachers, sick staff members were under pressure trying to set work from home for their classes.
"Student learning is affected, even though teachers are doing the best they can then they are very unwell."
All students would be rostered home on Friday, the last day of term, to take the pressure off staff, she said.
Rotorua Girls' High School principal Sarah Davis said while absences were "a heck of a lot better" compared to the last term during the Covid outbreak, winter illnesses were still "really tough to manage" right now.
She had noticed that these illnesses were typically lasting longer this term than in previous years, with some teachers and students missing up to two weeks of school.
"There is definitely a really nasty flu that is around - and that is almost the same severity as Covid. We are very sympathetic to the fact some staff are taking the same length of time to get over that than the Covid positive cases."
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