The Ministry of Health is providing a Covid-19 update after a former Pullman Hotel guest, who has been isolating at home for a week, tested positive.

Director of Public Health Dr Caroline McElnay told media the positive case was asymptomatic and they were acting with an “abundance of caution”.

“People in and around Hamilton should not be alarmed.”

Dr McElnay said there was also one new case in managed isolation to report today, as well as one new case which was being treated as historical.

Earlier today, the ministry said the guest at the managed isolation facility in Hamilton had been isolating at their home since 30 January.

It is the fourth case of a person leaving that hotel and testing positive, with a fifth person also catching the virus from one of the Auckland returnees.

Dr McElnay said this afternoon the individual – who is asymptomatic – has been isolating at home in Hamilton since 30 January and previously returned three negative tests.

The person was in managed isolation from 16 January to 30 January and returned negative tests on 20 and 28 January. A further test on 2 February also came back negative. Another test on 4 February came back positive yesterday afternoon.

She said they were awaiting further test results but that the public health risk was low.

Dr McElnay said there were no exposure events and the only people at this stage who need to get tested are people who are symptomatic. The person who tested positive told the ministry they wore face masks in communal areas of the house and isolated away from the others.

The positive test was picked up on day five outside of managed isolation, as a result of recent measures put in place for guests who have completed their managed isolation at the Pullman Hotel, she said.

Recent Pullman managed isolation guests have been required to self-isolate for five days after two weeks in managed isolation.

“As well as their routine testing on days 0, 3 and 12 while in a facility, there is a requirement for all Pullman managed isolation guests to self-isolate for five days following completion of the 14 days in managed isolation, and to return a negative test at day five.

“Today’s case reinforces the importance of self-isolation and repeat testing strategy that we have adopted around the Pullman Hotel.”

The latest case will form part of the ongoing investigation into the Pullman Hotel and why guests are contracting the virus there. The last guests will leave tomorrow. The investigation into how transmission of the virus is occurring in the Pullman Hotel is inconclusive at this stage.

The person who had tested positive was staying on the same floor of the Pullman Hotel as other people who have tested positive, but the source of their infection is yet to be determined, Dr McElnay said.

The latest case is now being transferred to a quarantine facility. They live with two other people, who are close contacts. Neither is symptomatic and they have both returned negative tests.

Yesterday there was one new case in managed isolation and no community cases.

Epidemiologist Michael Baker said managed isolation facilities need to be investigated systematically after the detection of another Covid-19 case.

Professor Baker said officials need to rethink the number of people being allowed back into the country.