The Ministry issued a further update on Friday night saying the child and its family had not tested positive for Covid-19.
"Since the initial test, further testing has shown negative COVID-19 test results from the child's family, both from PCR and serology testing. Further COVID-19 tests from the broader community have also returned negative results," it said in a statement.
"Adding to the overall assessment, the child tested positive for rhinovirus – a particularly infectious virus causing cold and flu type symptoms reported in the wider community."
It also revealed 195 test swabs had been collected from a testing centre on Stewart Island.
"The swabs are being processed today and tomorrow and the tests available to date have all returned a negative result."
Yesterday's result came as a family had Covid tests before planning to head overseas. The rest of the family tested negative.
Bloomfield said during the lockdown period last year there were quite a few Covid cases that health teams never knew about.
He said it might have been linked to the Bluff wedding cluster, which was the country's biggest Covid-19 cluster with more than 85 cases.
Stewart Island/Rakiura Community Board chairman Jon Spraggon said he was informed yesterday morning of the existence of the weak positive case.
Southland Mayor Gary Tong said he was contacted at 8am yesterday about the positive result. Everything continued operating as normal while the Ministry of Health followed protocols, he said.
Real Journeys general manager Paul Norris said as soon as staff heard there was a potential case on the island, its Covid response team acted.
The company, which operates the Stewart Island-Bluff ferry, had a few cancellations and it was happy to rebook or refund anyone who had concerns about travelling to the island, he said.
Stewart Island Flights director Bill Moffat said flights to the island had operated as normal.
