Director-General of Health Ashley Bloomfield is asking New Zealanders, and especially young people, to be aware of the different symptoms people infected with the new strains of Covid-19 are experiencing.
Some of those who get the UK or South African strains are getting more aches, pains and fatigue, as opposed to cold symptoms.
At last night's emergency press conference, where it was announced Auckland was going back into lockdown, Dr Bloomfield asked people to be aware.
"We are seeing people with this variant of the virus with symptoms that are not obviously the ones we were seeing earlier in the outbreak and that formed the case definition earlier in the outbreak.
"So rather than the respiratory like a sore throat, runny nose or cough, we are seeing people with muscle aches, typically that fluey feeling, general weakness and fatigue.
Anyone displaying those symptoms should get a test.
"I think particularly for young people who might be putting these symptoms down to something else, they may not be seeking advice about getting a test.
"I'd like to encourage everyone to get a test."
Dr Bloomfield said the 21-year-old who tested positive yesterday did seek a test after feeling unwell.
However, they also went to the gym after visiting their GP.
They have the UK variant.