‘Weak positive’ case sent to quarantine

A person who returned a ‘‘weak positive’’ Covid-19 result on Monday and a negative test yesterday was sent to Auckland’s quarantine facility as a precaution.

The person was one of the 85 passengers who travelled on a chartered flight from Christchurch to Auckland on September 11 with a man who later tested positive for Covid-19 – a week after completing his managed isolation at the Crowne Plaza in Christchurch.

Director-general of health Dr Ashley Bloomfield said yesterday that the ‘‘cycle threshold’’ (CT) value of the person’s polymerase chain reaction (PCR) test was high, which suggested an old infection.

The person, who had no symptoms since arriving in New Zealand, had returned negative day 3 and day 12 tests while in managed isolation, Bloomfield said.

The Ministry of Health was investigating the case to confirm it was an historic infection, and whether it was already reported as a case in India.

‘‘Meanwhile, a precautionary approach is being taken and the person has been transferred to the Auckland quarantine facility,’’ Bloomfield said.

The 28 other plane passengers sitting in rows closest to the man who tested positive a week after completing his managed isolation at the Crowne Plaza in Christchurch had been tested.

They had all returned a negative result.

The remaining people on the flight were being contacted and would be tested as appropriate, Bloomfield said.

Test results came through ‘‘from time to time’’ indicating a historical infection, Bloomfield said.

International research showed such people were not infectious and did not pose a risk to others, he said.

The Ministry of Health was developing a protocol and setting up an expert panel to help standardise the way these ‘‘borderline’’ cases were being managed and reported, Bloomfield said.

The panel and protocol will assess individuals returning a weak positive test with a high CT value to determine whether the infection is historical or recent and guide public health measures, especially regarding contact management and any steps required to limit risk to the community, he said.