Rotorua mayor Steve Chadwick has tested positive for Covid-19.
Chadwick, who was made a companion of the Queen's Service Order in January, says the worst of the illness appears to be over but it hit her "very hard".
"This was not like any flu I have experienced before.
"I am fully vaccinated and boosted and generally fit and healthy. I'm feeling much better now but still not one hundred percent."
Thursday's scheduled council meeting has been moved online and parts of the council building have been deep-cleaned as a result, according to the council.
An unidentified council staff member has been identified by the council as a "likely case" and is awaiting test results.
Speaking to Local Democracy Reporting on Wednesday, Chadwick said she was doing "light duties" and hoped she would be able to get back to full duties at the council on Monday, after testing positive on Thursday.
She said she went to bed early on Wednesday last week which was unusual for her as she was a night owl.
She woke up in the night with a headache and in the morning had "severe muscle aches and deep pains", as well as sore eyes and a congested nose.
"I knew this wasn't only the flu.
"I went straight to the testing centre with a fear that [Covid] might be what it was."
Prime Minister Jacinda Ardern had visited Rotorua on Thursday and Chadwick was due to attend engagements with her, but stayed home due to her illness.
Chadwick said she notified close council staff and friends she had been in contact with that she felt unwell and had got a test. She didn't leave home after she had had her test.
Chadwick learned she was Covid-19 positive on Sunday.
"I'm not a person that panics. I did go 'oh my golly'. It confirmed my worst fear, really.
"It's very real."
She said she no longer had aches, pains or a headache but still felt fatigued, saying the illness "lurks".
"I lie down to read, which I love doing, and I fall asleep, and that's not me. Until that's gone then I know I'm really good, but I have got cabin fever now."
Chadwick, 73, said she kept a "very good diary" and was stringent with the Covid tracer app so she had no trouble remembering where she had been for contact tracing.
"When I watch anti-vaxxers I feel deeply sad about their position.
"The [vaccine] mandate got us to this stage where people like myself who are fully vaxxed and boosted can get through this at home.
"I hate to think of me cluttering up a hospital bed. You need that for the very very vulnerable, and the very very sick. If I got these symptoms being fully vaxxed, I hate to think what it's like if you're not vaccinated. It's quite nutty."
She said she had "no idea" where she might have caught the virus.
"It's serious and it's real and it's in our community, and please take it seriously."
In a statement released by the council on Wednesday afternoon, Chadwick encouraged people to get the booster and remain vigilant with handwashing, mask wearing, social distancing and tracking places visited.
In the statement, council chief executive Geoff Williams said cases within the council organisation were not unexpected and that was why there had been a "precautionary approach" to date.
"The safety of our staff, elected members and the public is a priority and it's also vital for us to continue taking precautions to ensure we are able to continue providing uninterrupted essential services to our community.
"We want to do what we can to minimise the impact of the current Omicron surge on our organisation and the community and will continue to review and monitor the situation and make decisions accordingly."
The statement said a deep clean of potentially-impacted work spaces in the council building had been completed, along with contact tracing.
Some staff were awaiting confirmation on whether they were close contacts or not, and were working from home as a precaution.
Thursday's council meeting will be held over video conferencing and live streamed. The public could attend online by watching the live stream or its recording on the council website or its YouTube channel.
Local Democracy Reporting is Public Interest Journalism funded through NZ On Air