All Dunedin school children tested for coronavirus have returned negative tests.

Forsyth Barr Stadium turned into a temporary testing station on Wednesday for 150 children who possibly came into close contact with a high school student who tested positive for coronavirus.

Health professionals wore protective equipment as they swabbed each child's nostrils and throat.

LAWRENCE SMITH/Stuff Ministry of Health Director General Ashley Bloomfield provides an update on New Zealand's coronavirus cases and plans to mitigate its spread.

Director-general of health Dr Ashley Bloomfield confirmed all 150 results had come back negative, which indicated the Dunedin cases were linked to overseas travel, rather than a possible community link.



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"This is reassuring for the local community and for our broader public health response."

HAMISH MCNEILLY/STUFF Logan Park High School in Dunedin is in the middle of a coronavirus scare.

The school could reopen next week after being cleaned.

Secretary of Education Iona Holsted acknowledged the support that the school and school community showed each other over the past couple of days while waiting for the test results.

"All 150 close contacts will remain in self-isolation for a period of 14 days. Over that time, as a further precaution, they will be watched carefully for symptoms in case they develop," Bloomfield said.

HAMISH MCNEILLY/Stuff The 12th positive coronavirus case (one of 20 now confirmed in New Zealand) involves a student at Logan Park High School in Dunedin.

The letter sent to families of the 150 noted the request had come from Prime Minister Jacinda Ardern, chief science advisor Juliet Gerrard, and director-general of health Dr Ashley Bloomfield.

"The reason for the Ministry of Health wanting to do this test is to see if community spread of coronavirus is occurring or if we are still in the situation where the virus is only being imported from other countries around the world," the letter said.

The Dunedin student who tested positive caught the virus from his father who had returned from Germany.

Hamish McNeilly/Stuff A coronavirus warning at the entrance to Dunedin Hospital.

The father, who is aged in his 40s, developed symptoms five days after his return to New Zealand.

A third family member, who was showing signs of coronavirus earlier in the week, has not been confirmed as having the virus.

No other Dunedin schools closed.

Henry Cooke/Stuff Prime Minister Jacinda Ardern is confident New Zealand has the capacity to test more coronavirus samples.

Education Minister Chris Hipkins urged the students: "Obviously you can go outside, go for a walk ... but avoid contact with other people."

He recommended following the advice given by the Ministry of Health regarding self-isolation.

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