Logan Park High School is set to close until at least this weekend as about 150 close contacts of the pupil who tested positive are tested.

Ministry of Health Director-General Dr Ashley Bloomfield announced there are eight new cases of Covid-19, including one in Invercargill, however there are no new confirmed cases in Dunedin.

The Logan Park High School pupil became symptomatic at the weekend, and attended school on Monday.

When his father's test result came back that day, he contacted his son, who then went home. His father developed symptoms of the virus five days after returning from a trip to Germany.

Dr Bloomfield said the approximately 150 close contacts of the infected pupil would be put into self-isolation for 14 days and tested. The school which was initially closed for 48 hours would now be closed until at least the weekend.

“After discussion and consideration this morning with the Prime Minister’s chief science adviser, the Ministry’s chief science adviser and the local chief officer of health and because this is the first positive case within a school we have decided that in addition to the self-isolation that these close contacts will be tested over the next 24 hours.

“This is a unique situation and is part of our precautionary approach.

Because not all the test results would be back until Friday, it was now advising the school to close from now through to after the weekend.

All close contacts would be required to self-isolate for 14 days, even if test results came back negative, because it was possible they were incubating the virus.

The eight new cases involve one in Christchurch, two in Waikato, four in Auckland and one in Invercargill, Dr Bloomfield said

That brings the total to 20 since the start of the outbreak in New Zealand.

Details for each case will be on the Ministry of Health website, including flight information, once it becomes available.

"We expected more cases, and it's most important that we identify," and contact close contacts to prevent further spread, Bloomfield said.

Ministry of Education's Secretary of Education Iona Holsted said it was following a plan in Dunedin and said there were no immediate plans for widespread closures.

Dr Bloomfield did not comment on a third suspected Dunedin case of coronavirus after two cases were confirmed in the city yesterday.

The third suspected case is from the same family as the two other confirmed cases, a Dunedin man in his 40s and his son, a pupil at Logan Park High School, who was last night confirmed as the 12th confirmed case in New Zealand.

It was announced yesterday the person was experiencing symptoms and was in self-isolation along with their family members. Like other New Zealand cases the positive Dunedin tests were linked to overseas travel, with the father showing symptoms of the virus five days after returning from a trip to Germany. The Southern District Health board said yesterday it was working to track down close contacts of both cases.

Dr Bloomfield said yesterday that closing Logan Park would help prevent more cases.

‘‘The school will not open until cleared to do so by health officials,’’ Director-general of Health Ashley Bloomfield said.

‘‘These steps will help limit the chances of further cases.’’

Close contacts of the student would be traced and put in self-isolation; casual contacts would be given advice about what to do if they became unwell, Dr Bloomfield said.

The school would cleaned before being allowed to reopen.

The lights were still on at Logan Park High School at 8pm yesterday after the announcement a pupil tested positive for Covid-19. Photo: Linda Robertson

It is understood a lecturer from the University of Otago, with possible links to the Logan Park pupil, had last night been advised to self-isolate. Their lectures would continue remotely.

Concerns were also high in Queenstown, where the region’s other case of Covid-19 was confirmed on Friday, with health officials urging anyone who had used shared bathroom facilities at Lakeview Holiday Park to contact them.

News of a possible case at Logan Park sparked an anxious wait for news for parents in the west and north of Dunedin. Logan Park School has about 718 pupils and a catchment area which encompasses North Dunedin, the central city and West Harbour.

Logan Park also has close links with Dunedin North Intermediate and the University of Otago Language Centre.

SDHB chief executive Chris Fleming says parents of pupils who go to other Dunedin schools should feel safe sending them. Photo: ODT files

Southern District Health Board chief executive Chris Fleming said parents with offspring at other schools should feel confident to send their children to school, as the family concerned were in self-isolation.

‘‘In this instance the child has contracted coronavirus through close contact with a parent.’’

Mr Fleming understood contact tracing for the father was well-advanced.

‘The boy being in a school, the contacts are quite a lot wider ... there is a very clear protocol regarding close contacts, and all those close contacts will be required to go into self-isolation.’’

A message from Logan Park to parents said the school had started tracing close contacts of the pupil, and staff would begin contacting those people tomorrow morning.

‘‘They will be asked to go into self-isolation for 14 days from their last contact with the student ... we will make sure the family is well cared for and supported for the rest of their time in isolation.’’

Dr Bloomfield said the man did not begin to show symptoms until five days after he reached Dunedin, so no-one on his flights needed to be traced.

Mr Fleming was confident the SDHB had the capacity to handle an expected rise in the number of Covid-19 tests required in the next few days.

‘‘There are something like 1500 tests available per day across the country and Southern is fortunate enough to have a laboratory which can process results in Southern.’’

Dunedin Mayor Aaron Hawkins said news of Covid-19 cases in Dunedin was worrying, but he urged people to stay calm.

‘‘A range of organisations, including the Dunedin City Council, have been preparing for this situation,’’ he said.

‘‘The response to this announcement is being led by health authorities and the DCC will provide any support it can.’’

People should continue to follow advice from the Ministry of Health and other relevant agencies, Mr Hawkins said.

University of Otago vice-chancellor Harlene Hayne said she believed the Dunedin case was being handled in a ‘‘textbook manner.’’

Logan Park is close to the student quarter and university campus, but the possible Covid-19 case nearby would not interrupt classes, Prof Hayne said.

‘‘OUR university is operating as normal, and I wanted to give you as much reassurance as possible that the university is working hard to keep staff and students safe and healthy while continuing to deliver the best education possible under unprecedented conditions,’’ Prof Hayne said.

Meanwhile, a public alert was put out by the SDHB yesterday for people who may have come into contact with the Danish woman who unknowingly travelled to Queenstown last week with Covid-19.

Officials highlighted three locations — two in Christchurch and Queenstown’s Lakeview Holiday Park — where they knew the woman would have casual contact with others but whom they were unable to trace.

At the park, people who had used shared bathroom facilities from March 11-14 were warned they might have come into contact with the woman.

SDHB medical officer of health Susan Jack said anyone who had was at low risk of contracting Covid-19.

‘‘The case went to one restaurant in Queenstown,’’ Dr Jack said.

‘‘CCTV footage shows that she did not have close contact with any staff or customers; the restaurant has been informed and a deep clean has taken place.’’

Yesterday, several aged-care facilities, including some in Otago and Southland, went into lockdown, banning all but essential visitors to try to prevent an outbreak of Covid-19 in an age group known to be highly vulnerable to the disease.

Mr Fleming said the SDHB was taking part in national discussions about how to care for the elderly, but had not issued any directive about access to aged-care facilities.

— Additional reporting Hamish Maclean.

mike.houlahan@odt.co.nz